Patent Publication Number: US-2005128892-A1

Title: Apparatus and method for controlling the disc loading/ejecting operation in an optical disc drive

Description:
BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      The present invention relates to optical disc drives, and more particularly, to an apparatus and a method for controlling the disc loading/ejecting operation in an optical disc drive.  
      2. Description of the Related Art  
      With the developments of information technology and the widespread utilization of multimedia contents, the demanding for data storage solutions with high capacities and low costs raises day by day. Among all the data storage solutions, the optical discs are becoming more and more important for backing up data and exchanging information due to many advantages that the optical storage media have that includes a high data capacity, portability, and a long lifetime for preserving information. Currently, the optical disc drives are widely used such in desktop computers, laptop computers, DVD players, and some instruments or electronic products with built-in microprocessors.  
      Generally speaking, an optical disc drive loads or ejects an optical disc by utilizing a disc loading mechanism of the optical disc drive. After loading the optical disc into the optical disc drive, the optical disc is fixed to a turntable of a spindle motor for further data access. Besides the conventional tray loading mechanism, the slot loading mechanism is getting more and more popular for its convenience. It is quite handy for users to just insert a disc slightly into the loading/ejecting slot, and then the slot loading mechanism of the optical disc drive takes over the following loading process. Moreover, while loading or ejecting a disc with the slot loading mechanism, the slot loading mechanism can hold the disc firmly throughout all the loading or ejecting process. Thus it makes the slot loading mechanism especially suitable for using in a moving or vibrating environment such as car-use CD audio players and databases for GPS navigators.  
      Please refer to  FIG. 1 .  FIG. 1  is a top view for illustrating the relation between various elements in an optical disc drive with slot loading mechanism of the prior art after a disc has been loaded. A prior art optical disc drive  100  has a loading/ejecting slot  102 , a first sensor  112  disposed at a first sensing position for detecting if a disc passing the first sensing position, and a second sensor  114  disposed at a second sensing position for detecting if a disc passing the second sensing position. There are also two round contours in  FIG. 1  for showing the positions of two regular sizes of the loaded optical disc: one is for a larger disc with 12 cm diameter  120 , and the other is for a smaller disc with 8 cm diameter  130 . The first sensor  112  is designed to trigger the loading operation and to help to decide if a loaded disc is a 12 cm disc. Thus a distance R 1  between the center of the turntable and the first sensing position for deposing the first sensor  112  is larger than the radius of the 8 cm disc  130  and smaller than the radius of the 12 cm disc  120 . Furthermore, after a disc is loaded into the disc drive, the disc is fixed on a turntable  108  of the spindle motor. A logical element (Not Shown) manages the status of the loading/ejecting operation according to the outputs of the first and the second sensors and controls a motor (Not Shown) to drive a roller  104  via a gear set  106  to load or eject the optical disc. The roller  104  is used to convey optical discs into or out of the disc drive according to the rotating direction of the roller. The position of the roller  104  is set to overlap with the covering range of both the 8 cm disc  130  and the 12 cm disc  120  to ensure that the roller  104  can convey those tow kinds of discs with different radiuses as specified in the specification.  
      Moreover, some components are not described in detail for the sake of not to unnecessarily obscure the description of the present invention. As shown in  FIG. 1 , whether a user is inserting a 12 cm disc  120  or a 8 cm disc  130 , the second sensing position in a prior art would be designed within the covering range of the 8 cm disc  130  so that the output of the second sensor  114  could provide a reference to determine if there is an optical disc inside the optical disc drive or not. Meanwhile, combining the output of he first sensor  112 , the size of a loaded optical disc can also be determined. For example, while the loaded disc is a 12 cm disc  120 , both sensors  112  and  114  can sense the disc. And when the loaded disc is an  8  cm disc  130 , only the second sensors  114  senses the disc.  
      The sensors as mentioned above can be electronic switches that includes leaf springs or rods with a HIGH level and a LOW level logical states for indicating whether a disc has been detected. And in the preferred embodiment, the above mentioned sensors are optical sensors that each has an emitter and a receiver to emit and receive a light beam, respectively. For example, when a disc is passing an optical sensor, the light beam from the emitter is blocked by the disc and the sensor has an out put at the LOW level. On the other hand, when the sensor is not blocked by the disc, the sensor has an out put at the HIGH level. Of course the output levels of a sensor can be easily redesigned to have a HIGH level output when the sensor is blocked, and to have a LOW level output when the sensor is not blocked. Furthermore, the logical element for managing the loading and ejecting operations can be a hard-wired logic circuitry or a microprocessor executing a firmware. And in some embodiments, the logical element can even share the same PCB with the first and the second sensor.  
      Now refer to  FIG. 2A .  FIG. 2A  is a top view for illustrating the optical disc drive with slot loading mechanism of the prior art when a disc has just been inserted into the loading/ejecting slot  102 . While a  12  cm disc  120  or an  8  cm disc  130  has been inserted into the loading/ejecting slot  102 , the logical element (Not Shown) recognizes that the disc should be loaded into the disc drive if the disc blocks the first sensor  112 . Then the logical element gives instructions to drive the roller  104  for conveying the disc into the drive and fixed the disc on the turntable. To allow users being able to insert a 12 cm disc from every angle, the first sensor  112  is usually disposed near the loading/ejecting slot  102  and around the center of the optical disc drive  100 . More specifically, the first sensor  112  is usually disposed on the virtual line between the center of the turntable and the center of the loading/ejecting slot  102 .  
      The position of the first sensor  112  of the prior art is disposed close to the roller  104  as shown in  FIG. 2A . This arrangement allows the first sensor  112  being blocked by the disc after the disc has been ejected whether a 12 cm disc  120  or an 8 cm disc  130  is used. Such that once the disc has been removed by the user after ejection, the first sensor  112  can be prepared for the next loading operation by simply determining if the status of the first sensor  112  has been changed from block to unblock after the eject operation. However, users have to insert the disc into a deeper position to block the first sensor  112  and trigger the loading operation according to prior art design. Please refer to  FIG. 2B .  FIG. 2B  is a top view for illustrating the optical disc drive with slot loading mechanism of the prior art when an  8  cm disc has been inserted into the loading/ejecting slot  102  sidelong. Furthermore, when an  8  cm disc  130  has been inserted into the loading/ejecting slot  102  but not through the middle of the loading/ejecting slot  102 , the 8 cm disc  130  could have touched the roller  104  without initiate the loading operation. This raises lots of inconvenience to users for using an optical disc drive with slot loading mechanism.  
      Please refer to  FIG. 3A .  FIG. 3A  is a top view for illustrating the optical disc drive with slot loading mechanism of the prior art when an  8 cm disc  130  or a 12 cm disc  120  has been ejected from the optical disc drive. As shown in the diagram, the second sensor  114  can be used to decide when to stop the roller  104  during the ejecting operation. When the logical element receives commands to eject a disc inside the optical disc drive, the logical element gives instructions to drive the roller  104  for conveying the disc out of the drive  100  until the second sensor  114  no longer being blocked by the disc. Since the second sensor  114  can also help to determine if there is a disc inside the optical disc drive  100  or not, the distance R 2  between the center of the turntable and the second position for deposing the second sensor  114  should be less than the radius of an 8 cm disc. Concerning the layout of mechanical and electronic components, the second position is usually at a side of the virtual line between the centers of the turntable and the loading/ejecting slot  102 . Moreover, for users to handle the disc after ejecting operation, a distance D between the second sensor  114  and the loading/ejecting slot should be less than the diameter of an 8 cm disc  130 . And a distance L between the second sensing position and the first sensing position should be less the radius of an 8 cm disc  130  to ensure that the first sensor  112  can be blocked when the ejecting operation has just done.  
      Please refer to  FIG. 3B .  FIG. 3B  is a time diagram illustrating the output of the first sensor  112  in an optical disc drive with slot loading mechanism of the prior art after an ejecting operation is performed. At the time point A, the second sensor  114  has just been unblocked (for example, a HIGH level output, not shown in  FIG. 3B ) and the ejecting operation has just been done. Thus the roller  104  stops to convey the disc, and the disc blocks the first sensor  112  (for example, a LOW level output) at this time no matter an 8 cm disc  130  or a 12 cm disc  120  being ejected. Then users remove the disc from the disc, the first sensor  112  will become unblocked and output a HIGH level logical state. After that, if users further want to insert a disc into the optical drive again at time point B, a disc can be inserted into the loading/ejecting slot. When the logical element finds that the output from the first sensor  112  has changed from a HIGH level to a LOW level, which it also means that the first sensor  112  is blocked by the disc again, the logical element can initiate a loading operation to convey the inserted disc into the drive.  
      Please refer to  FIG. 4 .  FIG. 4  is a flow chart illustrating the method for controlling the disc loading operation in an optical disc drive with slot loading mechanism of the prior. Presume that there is no disc inside the optical disc drive  100  at beginning according to the flow chart. In step  402 , when the first sensor  112  output a HIGH level logical state (sensor unblocked) and the second sensor  114  HIGH level logical state (sensor unblocked), it indicates that there are no discs inside the optical disc drive  100  for the logical element. Then in the step  404 , the logical element monitors if the logical state of the first sensor  112 . Once the first sensor  112  outputs a LOW level logical state (sensor blocked), the progress moves into step  406  and the logical element gives instructions to drive the roller  104  to perform a loading operation. After the loading operation is done, the progress moves into step  408  and the output of the second sensor  114  should be at LOW level logical state (sensor blocked). Following, in the step  410 , the logical element monitors if an ejection command is received. If an ejection command is received, the progress proceeds to step  412  and the logical element gives instructions to drive the roller  104  to perform an ejecting operation until the second sensor  114  outputs a HIGH level logical state (sensor unblocked). After user removes the disc, the progress goes back to step  402 .  
      Therefore, apparatus and method for controlling the disc loading/ejecting operation in an optical disc drive as mentioned above requires users to insert a disc deeper into the loading/ejecting slot to trigger the loading operation. Besides, when an 8 cm disc has been inserted into the loading/ejecting slot  102  without through the middle of the loading/ejecting slot, the 8 cm disc  130  could have touched the roller  104  without starting the loading operation. This raises lots of inconvenience to users for using an optical disc drive with slot loading mechanism.  
     SUMMARY OF THE INVENTION  
      Accordingly, it is an object of the present invention to provide an apparatus for controlling the disc loading/ejecting operation in an optical disc drive that has a turntable and is able to access a larger disc with radius A and a smaller disc with radius B. The apparatus comprises a loading/ejecting slot, a roller for conveying an optical disc into or out of the optical disc drive, a first sensor being disposed at a first sensing position having a distance R 1  between the center of the turntable and the first sensing position and B≦R 1 ≦A, a second sensor being disposed at a second sensing position having a distance R 2  between the center of the turntable and the second sensing position and R 2 ≦B, a distance L between the second sensing position and the first sensing position and B≦L≦A, and a distance D between the second sensing position and the loading/ejecting slot and D≦ 2 B, and a logical element for managing the loading/ejecting operation according to the outputs of the first and the second sensors and controlling a motor to drive a roller to load or eject the optical disc.  
      Furthermore, in one embodiment of the present invention, the distance L is approximately equal to B. And the larger disc with radius A is a 12 cm disc and  2 A is 12 cm, and the smaller disc with radius B is an 8 cm disc and  2 B is 8 cm. The first sensor and the second sensor are optical sensors and output a HIGH level or LOW level logical states to indicate if a disc has been detected. The first sensing position is on the virtual line between the turntable and the center of the loading/ejecting slot. The second sensing position is at a side of the virtual line between the turntable and the center of the loading/ejecting slot.  
      In one embodiment of the present invention, the logical element is a hard-wired logic circuitry or a microprocessor executing a firmware. And the logical element can share the same PCB with the first sensor and the second sensor.  
      It is another object of the present invention to provide a method for controlling the disc loading/ejecting operation in an optical disc drive by utilizing a logical element for managing the loading/ejecting operation according to the outputs of a first and a second sensors and controlling a motor to drive a roller to load or eject the optical disc. The method comprising steps to perform an ejecting operation until the second sensor outputs a first logical state, and to hold to wait for the first sensor having output transition from a second logical state to first logical state.  
      In one embodiment of the present invention, the first logical state is a HIGH level logical state and the second logical state is a LOW level logical state. The first sensor and the second sensor are optical sensors and output a HIGH level or LOW level logical states to indicate if a disc has been detected. 
    
    
     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 top view for illustrating the relation between various elements in an optical disc drive with slot loading mechanism of the prior art after a disc has been loaded.  
       FIG. 2A  is a top view for illustrating the optical disc drive with slot loading mechanism of the prior art when a disc has just been inserted into the loading/ejecting slot.  
       FIG. 2B  is a top view for illustrating the optical disc drive with slot loading mechanism of the prior art when an 8 cm disc has been inserted into the loading/ejecting slot sidelong.  
       FIG. 3A  is a top view for illustrating the optical disc drive with slot loading mechanism of the prior art when an 8 cm disc or a 12 cm disc has been ejected from the optical disc drive.  
       FIG. 3B  is a time diagram illustrating the output of the first sensor in an optical disc drive with slot loading mechanism of the prior art after an ejecting operation is performed.  
       FIG. 4  is a flow chart illustrating the method for controlling the disc loading operation in an optical disc drive with slot loading mechanism of the prior.  
       FIG. 5  is a top view for illustrating the relation between various elements in an optical disc drive according to the present invention.  
       FIG. 6  is a top view for illustrating the optical disc drive according to the present invention when a disc has just been inserted into the loading/ejecting slot.  
       FIG. 7A  is a top view for illustrating the optical disc drive according to the present invention when an  8 cm disc or a 12 cm disc has been ejected from the optical disc drive.  
       FIG. 7B  is a time diagram illustrating the output of the first sensor in an optical disc drive according to the present invention after an ejecting operation is performed.  
       FIG. 8  is a flow chart illustrating the method for controlling the disc loading operation in an optical disc drive according to the present invention. 
    
    
     DESCRIPTION OF THE EMBODIMENTS  
      Please refer to  FIG. 5 .  FIG. 5  is a top view for illustrating the relation between various elements in an optical disc drive according to the present invention. Some components are not explained in detail for the sake of not to unnecessarily obscure the description of the present invention. For controlling the slot loading mechanism, an optical disc drive  500  according to the present invention has a loading/ejecting slot  502 , a first sensor  512  disposed at a first sensing position for detecting if a disc passing the first sensing position, and a second sensor  514  disposed at a second sensing position for detecting if a disc passing the second sensing position. In  FIG. 5 , there are also two round contours for showing the positions of two regular sizes of the loaded optical disc: one is for a 12 cm disc  520 , and the other is for an 8 cm disc  530 . The first sensor  512  is designed to trigger the loading operation and to help to decide if a loaded disc is a 12 cm disc. Thus a distance R 1  between the center of the turntable and the first sensing position for deposing the first sensor  512  is larger than the radius of the 8 cm disc  530  and smaller than the radius of the radius of the 12 cm disc  520 .  
      After a disc is loaded into the disc drive, the disc is fixed on a turntable  508  of the spindle motor. A logical element (Not Shown) manages the status of the loading/ejecting operation according to the outputs of the first and the second sensors and controls a motor (Not Shown) to drive a roller  504  via a gear set  506  to load or eject the optical disc. The roller  504  is used to convey optical discs into or out of the disc drive according to the rotating direction of the roller  504 . In the preferred embodiment according to the present invention, the sensors are optical sensors that each has an emitter and a receiver to emit and receive a light beam, respectively. For example, when a disc is passing an optical sensor, the light beam from the emitter is blocked by the disc and the sensor has an out put at the LOW level. On the other hand, when the sensor is not blocked by the disc, the sensor has an out put at the HIGH level. Furthermore, the logical element for managing the loading and ejecting operations can be a hard-wired logic circuitry or a microprocessor executing a firmware. And in some embodiments, the logical element can even share the same PCB with the first and the second sensor. As shown in  FIG. 5 , the first position for deposing the first sensor  512  according to the present invention has been moved toward the loading/ejecting slot  502  than it was in the prior art as shown in  FIG. 1 . However, the actions after a disc being loaded into the disc drive  500  are similar to the prior art shown in  FIG. 1 .  
      Now refer to  FIG. 6 .  FIG. 6  is a top view for illustrating the optical disc drive according to the present invention when a disc has just been inserted into the loading/ejecting slot  502 . According to the present invention, the first position for disposing the first sensor  512  has been moved outward while comparing it to the sensor  112  in the prior art. More specifically, the distance between the first sensor  512  and the loading/ejecting slot  502  according to the present invention is not longer than the distance the first sensor  512  and the roller  504 . While a 12 cm disc  520  or a 8 cm disc  530  has been inserted into the loading/ejecting slot  502 , the logical element (Not Shown) recognizes that the disc should be loaded into the disc drive if the disc blocks the first sensor  512 . Even the 8 cm disc  530  being inserted via the aside of the loading/ejecting slot  502 , the first sensor  512  according to the present invention can sense the disc and initiate the loading operation effectively. Then the logical element gives instructions to drive the roller  504  for conveying the disc into the drive and fixed the disc on the turntable.  
      Now refer to  FIG. 7A .  FIG. 7A  is a top view for illustrating the optical disc drive according to the present invention when an  8 cm disc  530  or a 12 cm disc  520  has been ejected from the optical disc drive. As shown in the diagram, the second sensor  514  can be used to decide when to stop the roller  504  during the ejecting operation. When the logical element receives commands to eject a disc inside the optical disc drive, the logical element gives instructions to drive the roller  504  for conveying the disc out of the drive  500  until the second sensor  514  no longer being blocked by the disc. Since the second sensor  514  can also help to determine if there is a disc inside the optical disc drive  500  or not, the distance R 2  between the center of the turntable  508  and the second position for deposing the second sensor  514  should be less than the radius of an 8 cm disc. Moreover, for users to handle the disc after ejecting operation, a distance D between the second sensor  514  and the loading/ejecting slot  502  should be less than the diameter of an 8 cm disc  530 . And a distance L between the second sensing position and the first sensing position is no less than the radius of an 8 cm disc  530  and no more than the radius of a 12 cm disc  520 , preferably approximately equal to the radius of an 8 cm disc  530 , since the first sensor  512  has been moved outward according to the present invention.  
      Please refer to  FIG. 7B .  FIG. 7B  is a time diagram illustrating the output of the first sensor  512  in an optical disc drive according to the present invention after an ejecting operation is performed. At the time point A, the second sensor  514  has just been unblocked (for example, a HIGH level output, not shown in  FIG. 7B ) and the ejecting operation has just been done. If a 12 cm disc  520  is used, the disc blocks the first sensor  512  (for example, a LOW level output) at this time as mentioned in prior art. However, owing to the first sensor  512  being moved forward according to the present invention, an 8 cm disc  530  nay not be able to block the first sensor  512  (for example, a HIGH level output) as shown in the figure for the central hole of the 8 cm disc  530  may just reach the first sensing position. Then users remove the disc from the disc, the first sensor  512  will become unblocked and output a HIGH level logical state. This results in the first sensor  512  being blocked first (at time point C) and then unblocked (at time point D) during users removing the disc if a  8 cm disc is used. By using the method for controlling the disc loading/ejecting operation of the prior art with the sensors according to the present invention in the optical disc drive, the logical element will take the LOW level output of the first sensor  512  at time point C as a signal to prepare for next loading operation if an 8 cm disc  530  is used. Thus it will mistakenly initiate a loading operation before time point B when an 8 cm disc is actually being removed.  
      Please refer to  FIG. 8 .  FIG. 8  is a flow chart illustrating the method for controlling the disc loading operation in an optical disc drive  500  according to the present invention. Presume that there is no disc inside the optical disc drive  500  at beginning according to the flow chart. In step  802 , when the first sensor  512  output a HIGH level logical state (sensor unblocked) and the second sensor  514  HIGH level logical state (sensor unblocked), it indicates that there are no discs inside the optical disc drive  500  for the logical element. Then in the step  804 , the logical element monitors if the logical state of the first sensor  512 . Once first sensor  512  outputs a LOW level logical state (sensor blocked), the progress moves into step  806  and the logical element gives instructions to drive the roller  504  to perform a loading operation. After the loading operation is done, the progress moves into step  808  and the output of the second sensor  514  should be at LOW level logical state (sensor blocked). Following, in the step  810 , the logical element monitors if an ejection command is received. If an ejection command is received, the progress moves to step  812  and the logical element gives instructions to drive the roller  504  to perform a ejecting operation until the second sensor  514  outputs a HIGH level logical state (sensor unblocked).  
      Next, the progress goes to step  814  after the second sensor  514  outputs a HIGH level logical state in step  812 . To avoid the problem mentioned above that the logical element may take the LOW level output of the first sensor  512  at time point C in  FIG. 7B  as a signal to initiate a loading operation if an 8 cm disc  530  is actually being removed, the logical element holds to wait for this transition of the first sensor in step  814 . The first sensor  512  will experience a transition from a LOW level output to a HIGH level output no matter what kind of disc is used. If no, the logical element continues to monitor the first sensor  512 . If the transition of the output is sensed by the logical element, the disc can be thought as being removed by users and the ejecting process is completed. Now the progress can return to step  802  for next insertion of discs  
      While the present invention has been particularly shown and described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes in form and detail may be without departing from the spirit and scope of the present invention.