Abstract:
The invention works in an environment where an optical disc, such as a CD, is inserted into an optical disc player. The disc typically has a label that is affixed to an upper surface of the disc. If the label is loose, for instance if a portion of the disc becomes raised toward the grill, the CD will become stuck since the raised label will not exit the opening in the grill. This obstructs the disc rollers and causes the motor to not be able to push the disc out of the player. The present invention senses this event and invokes an ejection routine to allow the raised label portion to be rotated to a position where it will not obstruct the slit in the grill or the roller.

Description:
NOTICE OF MATERIAL SUBJECT TO COPYRIGHT PROTECTION  
       [0001]     All of the material in this patent document is subject to copyright protection under the copyright laws of the United States and of other countries. Portions of the material in this patent document are also subject to protection under the maskwork registration laws of the United States and of other countries. The owner of the copyright and maskwork rights has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the United States Patent and Trademark Office file or records, but otherwise reserves all copyright and maskwork rights whatsoever.  
       BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     The present invention relates generally to optical disc players.  
         [0004]     2. Background of the Invention  
         [0005]     Optical disc players have become one of the most popular mechanisms by which a user is able to listen to music, watch movies, or otherwise use data that can be encoded onto a spiral track on the disc and operated by the optical disc player. Optical disc players in automobiles, for instance, or other situations where CD players are installed and are able to receive discs become problematic when the player malfunctions and cannot eject the disc.  
         [0006]     In particular, players like those common in automobiles have a grill with an opening on the face of the grill and rollers inside the player used in conjunction with motors and braking mechanisms to smoothly guide the disc into the player so it can be used. When the user wants to eject the disc, the same type of mechanism reverses the process where rollers, motors, and brakes smoothly push the disc partially out of an opening in the grill, to where the user can grasp the disc with their hand and remove it.  
         [0007]     With the advent of CD burners and music encoded in a computer readable form, such as mp3s, it has become common for users to arrange their own customized music or video selections on an optical disc and to label the optical disc so that it is easy to determine the content of any particular disc. The most common form of labeling is using a paper having an adhesive on one side “a sticker”, so that it can be affixed to the disc and then the user can write on the label to easily identify its content. Such labels suffer the disadvantage that over time the adhesive wears out and the label can start coming loose at the edges. Moreover the label adds an additional, albeit small, height to the disc that is relevant in a sensitive optical disc holder or carriage. In many carriages, many optical discs are stacked on top of one another in the carriage and if each CD includes an additional label, there is a noticeable upward adjustment in the position of the carriage relative to the opening where the disc is ejected.  
         [0008]     In either case, current CD labeling causes a problem. For instance, if the label becomes unstuck at an edge and that edge happens to be aligned with the rollers inside the player (or the opening in the grill), the label can move above the opening in the grill, which stops the roller from ejecting the disc. In such a case, the player must be returned for service where a technician must take the player apart and remove the disc. This situation however is problematic because the user must take their car in for service each time and this problem is becoming increasingly common.  
       SUMMARY OF THE INVENTION  
       [0009]     The invention works in an environment where an optical disc, such as a CD, is inserted into an optical disc player. The disc typically has a label that is affixed to an upper surface of the disc, although the present invention will operate on any disc, labeled or unlabeled. If the label is loose, for instance if a portion of the disc becomes raised toward the grill, the CD will become stuck since the raised label will not exit the opening in the grill. This obstructs the disc rollers and causes the motor to not be able to push the disc out of the player. The present invention senses this event and determines that the CD has not been ejected properly. When this happens, the player performs an ejection routine to allow the unstuck label to move to a position where it will not obstruct the slit in the grill or the roller.  
         [0010]     In one embodiment, the user inserts a disc into an optical disc player. A loader function is activated, which uses a sensor near the opening of the player to sense that the disc has been inserted, and causes a motor to turn a roller. The roller pulls the disc into the player. When the user attempts to eject the disc, the loader function is activated again. In a multiple disc CD changer, a tray holding the CDs is put into a position of alignment with the opening through a vertical movement. The loader function then activates the motor again which turns the roller in the opposite direction and attempts to push the disc out of the opening in the player.  
         [0011]     The sensor, which detects the physical presence of the disc, is used to determine that the loader has not been successful (i.e., the disc is still present in the player). When this occurs an ejection routine is invoked. The ejection routine comprises reactivating the motor with a motor controller to cause the roller to pull the disc back into the player. The disc reaches its final position when it is positioned in alignment with a spindle motor or a stepper motor so the disc can be rotated. The player status is then returned to Play, rotating the disc approximately 90 degrees. The system then tries to eject the disc again and repeats the process. Typically the disc will safely be ejected after the disc has been turned between 90 and 270 degrees. One skilled in the art will understand that other degrees of rotation will suffice so long as the raised portion of the sticker is directed substantially away from the roller. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0012]     The invention will be more fully understood by reference to the following drawings, which are for illustrative purposes only:  
         [0013]      FIG. 1  is a block diagram of an optical medium with a loose label.  
         [0014]      FIG. 2  is a block diagram of a typical throttle player with a disc inserted with a loose label.  
         [0015]      FIG. 3  is a block diagram of an ejection mechanism according to an embodiment of the present invention  
         [0016]      FIG. 4  is a flowchart of an ejection routine according to an embodiment of the present invention.  
         [0017]      FIG. 5  is a block diagram of an ejection mechanism that uses an ejection routine according to an embodiment of the present invention.  
         [0018]      FIG. 6  is a flowchart of an ejection routine according to an embodiment of the present invention.  
         [0019]      FIG. 7  is a block diagram of an optical disc player with an ejection mechanism according to an embodiment of the present invention.  
         [0020]      FIG. 8  is a flowchart showing the operation of an optical disc player with an ejection mechanism according to an embodiment of the present invention.  
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0021]     The present invention operates in an environment where an optical disc, such as a CD, is inserted into an optical disc player, such as a single-disc player or a multi-disc changer. If the label on the disc becomes loose, for instance if a portion of the label becomes raised where the adhesive becomes weak, the scenario shown in  FIG. 1  occurs.  FIG. 1  is an example of an optical medium that includes a label that has loosened. In medium  200  the spiral track is behind side  210  so it is not visible. Medium  200  has a label  220 , for instance a sticker, which is common in labeling discs. Portion  230  of optical medium  200  represents the area where label  220  has become loose and raised, either through carelessness of the user who applied the label  220 , through deterioration of the adhesive over time, or for any other reason.  
         [0022]     Optical medium  200  may become stuck in certain scenarios, since the raised label may not exit the opening in the grill of the player if the disc aligns in certain configurations.  FIG. 2  shows an example where such a scenario may occur. In  FIG. 2 , optical medium  320  is inserted into the player through slit  310  in grill  300 . Roller  340  is designed, in part, to assist in ejecting medium  320 . Label  330  on medium  320  has become loose. As is shown in  FIG. 2 , label  330  is no longer in alignment with slit  310  even though medium  320  is still aligned with slit  310 . Upon a command to perform ejection, roller  340  spins in a clockwise direction. If this happens, label  330  will be pushed against grill  300  and not through slit  310 . The force of roller  340  is not sufficient to overcome the force of the label  330  pushing against the grill  300 . As such, the medium  320  will become stuck using a prior art ejection mechanism. Only the removal of grill  300  will allow a technician to remove medium  320 , which is time consuming and expensive.  
         [0023]      FIG. 3  is a diagram showing an ejection mechanism according to an embodiment of the present invention. Spindle  400  is used to spin medium  410  using motor controller  420  to operate spindle motor  425 , also interchangeably called a stepper motor. Motor controller  420  also controls roller  435  using motor  430 . A sensor  450  is used in conjunction with motor controller  420  and motor  430 . When the medium  410  is in use, spindle  400  rotates medium  410  at the appropriate speed. When the medium  410  is intended to be ejected, motor controller  420  rotates roller  430  so that medium  410  slides out of the player via a loader mechanism.  
         [0024]     In some scenarios, the ejection of the medium  410  is not successful. For instance, sensor  450  may be used to recognize that the ejection attempt has been unsuccessful and the disc is physically still present inside the player. Sensor  430  is typically located near the slit in the grill, in close proximity to medium  410  and senses the physical presence of the medium  410  near the sensor  450 . If the medium  410  is successfully ejected the sensor  450  is able to determine that it is no longer physically present in the drive. When the ejection attempt is not successful, the sensor  450  shows that the medium  410  is still present and hence, the medium  410  was not properly pushed out of the player.  
         [0025]     When sensor  450  determines that an ejection did not succeed, routine  460  is invoked to attempt a successful ejection of the medium  410 . Routine  460  can be hardware, software, firmware, or a combination of all three. Routine  460  typically operates in conjunction with a computing device known to those skilled in the art to carry out instructions to the player. In one embodiment of the present invention, routine  460  operates as shown in  FIG. 4 .  
         [0026]      FIG. 4  is a flowchart showing the operation of an ejection routine according to an embodiment of the present invention. At block  600  an attempt is made to eject the disc. At block  610  a loader is activated to carry out the attempted ejection of the disc. At block  620  it is determined if the ejection is complete. If so, the process ends. Otherwise at block  630  the number of ejection attempts is incremented. At block  640  it is determined if the number of ejection attempts exceeds a threshold number of times to try to eject the disc. This number, for instance, may be set to 5 ejection attempts. If so, the process is complete. Otherwise, the disc is loaded again at block  650 . At block  660  the spindle is rotated and the process repeats at block  610 .  
         [0027]      FIG. 5  is a block diagram showing an ejection mechanism that uses an ejection routine according to an embodiment of the present invention. Spindle  500  spins medium  510  using motor controller  520  to operate spindle motor  525 . Motor controller  520  also controls roller  535  using motor  530 . A sensor  550  is used in conjunction with motor controller  520  and motor  530 . When the medium  510  is in use, spindle  500  rotates medium  510  at the appropriate speed and in the appropriate direction. When the medium  510  is intended to be ejected, motor controller  520  rotates roller  530  in a first direction  531  so that medium  510  slides out of the player via a loader mechanism in the direction of arrow  532 .  
         [0028]     Sensor  550  determines whether the medium  510  is still present in the player because if it is, the medium  510  remains in close proximity to sensor  550  and the sensor  550  determines its physical presence. If medium  510  is still present near sensor  550 , computing unit  560  is invoked to initiate an ejection routine according to an embodiment of the present invention. First, motor controller  520  reverses motor  530  so that roller  535  turns in direction  570 . Roller  535  turning in direction  570  causes medium  510  to move in the direction of arrow  571 . Medium  510  is returned to a position of alignment over spindle  500 . Instructions  580  in computing unit  560  are executed. This causes status controller  581  to return the player status to PLAY and the disc is rotated 90 degrees on spindle  500 . Counter  582  is incremented and motor controller  520  again attempts to move the disc in the direction of arrow  532 . This process repeats until the disc is ejected successfully or the counter  582  determines the number of ejection attempts exceeds a threshold and the disc must be removed by another method.  
         [0029]      FIG. 6  is a flowchart showing the operation of an ejection routine according to another embodiment of the present invention. At block  700  an attempt is made to eject the disc. At block  710  a loader is activated to carry out the attempted ejection of the disc. At block  720  it is determined if the ejection is complete. If so, the process ends. Otherwise at block  740  a motor controller is used to reverse a motor that controls the roller. This has the effect of pushing the disc back into the player. At block  750 , it is determined if the disc is back in alignment with the spindle. If not, the process repeats until the disc is re-loaded into the player.  
         [0030]     At block  760  the status of the player is returned to PLAY. At block  770  the disc is rotated 90 degrees. At block  780  a counter is incremented. At block  790  it is determined if the number of ejection attempts exceeds a threshold number of times to try to eject the disc. If so, the process is complete. Otherwise, the process repeats at block  710 .  
         [0031]     Once the disc has been returned to the player to a position of alignment with the spindle motor, the ejection routine is invoked.  FIG. 7  is a block diagram showing the components used in an ejection routine according to an embodiment of the present invention. The player motor used to spin the disc is called a stepper motor or a spindle motor  800  whose angle of rotation is controlled with a series of pulses  810 . An ejection mechanism  815  is used having at least a microprocessor  820 , or other comparable computing apparatus, having software or firmware instructions  830  for controlling the pulses  810  needed to cause the disc  840  to spin over various angles of rotation (e.g., 90 degrees).  
         [0032]     In operation, a servo circuit (spindle motor controller)  850  is implemented where the software or firmware  830  sends a command to the servo circuit  850 , which sends pulses  810  to the spindle motor  800 . The spindle motor  800  begins to rotate (and hence the disc  840  rotates) and at the same time a laser pickup  860  feeds back a first absolute address  870 , which is embedded in a spiral track  890  of the disc  840 , to the servo circuit  850 . As the disc  840  rotates, the laser  860  continues feeding back absolute addresses, for instance second absolute address  880 , and the pulses  810  for the particular spindle motor  800  are generated until the disc  840  is rotated the appropriate amount.  
         [0033]      FIG. 8  is a flowchart showing the operation of an ejection routine for an optical disc player according to another embodiment of the present invention. First, it is determined at block  900  if the disc has been re-positioned in alignment with the stepper (spindle) motor. Thus, the disc was not previously ejected successfully and has been returned to its operating position. At block  905 , instructions are received from a computing unit that tells the system how to pulse the stepper motor. At block  910 , the instructions are sent to a servo circuit. At block  915 , a pulse is sent from the servo circuit to the stepper motor. At block  920  a laser is used to read an absolute address from the disc. The absolute address is embedded in the spiral track of the disc along with the other data used to create the music and/or video. At block  925 , it is determined if the disc has rotated enough. The system compares the current absolute address to the address indicating the disc has rotated far enough (for example, ninety degrees). If not, the process repeats at block  905 . Otherwise, the process is complete.  
         [0034]     Although the description above contains many specificities, these should not be construed as limiting the scope of the invention but as merely providing illustrations of some of the presently preferred embodiments of this invention. Thus the scope of this invention should be determined by the appended claims and their legal equivalents.