Abstract:
A CD changing method (and drive for carrying out said method) enables information stored on an information-containing CD to be transferred to a blank space-containing CD in order to duplicate the information on said information-containing CD without a human having to be in attendance in order to manually remove the information-carrying CD from a CD transport tray and then replace said information-containing CD with a blank space-containing CD.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     In the operation of a compact disk drive (“drive”), a printed circuit board receives commands from the drive&#39;s controller which, in turn, is managed by an operating program. The printed circuit board translates those commands into voltage fluctuations that move a read (or write) head across a surface region of a compact disk (“CD”), e.g., across its bottom surface. The printed circuit board also tells the drive when to read from, and when to write to, the disk. These operations are carried out by several different kinds of CD drives and disks. For example, CD-Recordable (“CD-R”) drives can write data to a recordable compact disk containing portions that have permanently inscribed data (which can not be written upon or deleted) and portions that can accept writing (but which can not thereafter be changed or deleted). Drives for so-called rewriteable CD-ROMs (“CD-RW”) are characterized by the fact that they are capable of receiving writing upon (and erasing writing from) virtually the entire working surfaces of the CD-RW. Write-once, read-many (WORM) CDs also find various uses. DVD digital video disk (or digital versatile disk) drives are used with respect to video and/or audio generating information and useable data. 
     Various technologies are used to read from, and/or write to, appropriate compact disk types. For example, one such technology uses phase changes in a material out of which the media portion of such a disk is made. These phase changes enable a user to write, change, and erase data. This technology is frequently employed to write on and read from CD-RWs and DVDs. It does this by focusing a laser beam on a layer of media material (often made of silver, indium, antimony and tellurium) which has a polycrystalline chemical structure. The laser writes on the media material by selectively heating certain crystals to such an extent that they are changed into a non-crystalline or amorphous phase material. Those areas comprised of amorphous phase material reflect less light than the surrounding crystalline areas. Thus, when a weaker laser beam (used only to read data from such disks) strikes the non-crystalline area, the beam is scattered and not picked up by a light-sensitive diode in the drive&#39;s read head. With their lower reflectance, these areas become analogous to pits; representing ls. Areas that are not heated constitute more reflective lands, representing  0 s. When a read laser beam strikes the lands it is reflected directly to a diode, creating an electrical current that is sent to a computer. A computer interprets the pattern of electrical pulses, decompresses the data they represent, and sends the data to the software. In order to erase data or to change a pit back to a land, a process called “annealing” is employed. It involves the use of a lower-energy laser beam to heat pitted areas to about 400F degrees. This degree of heating is below the phase change medians melting point, but it still is powerful enough to loosen the media material enough that it naturally recrystallizes to its original crystalline state. 
     The writing capabilities provided by such technologies has intensified the need for copying or duplicating compact disks. This copying or duplicating is usually carried out in one of two general ways. The first general way is decidedly “manual” in nature. It involves manually loading and unloading compact disks from the drive&#39;s CD disk transport tray. In order to perform these operations, the tray is moved laterally from a fully closed position (such that a CD on the tray is inside the drive) to a fully open position (such that a CD on the tray is outside the drive). In the tray&#39;s fully opened position, a compact disk is exposed for manual removal from, or placement upon, the CD transport tray. A mechanical transmission provides the lateral motion of the CD transport tray as it travels back and forth between its fully open position and its fully closed position. In the tray&#39;s fully closed position, data stored on a CD can be read by the drive&#39;s read head—or a blank portion of a CD can be written upon through use of a writing technology such as the focused laser beam/phase change media material technology described above. 
     A very commonly used CD duplicating operation is one wherein a data-carrying, first CD is manually placed on a transport tray and loaded into the drive. After the data on said first CD has been read and stored, the tray is again moved to its full outward position. The data-carrying, first CD is then manually removed from the tray. The user then manually loads a second, blank space-containing CD on the CD transport tray. Upon the user&#39;s command, the blank CD is then transported (on the tray) into the drive. Thereafter, the data taken from the first CD (and stored in a hard drive) is written upon the second CD. Thus, the information contained on the first CD is duplicated by copying it on the second CD. 
     The primary problem with this method of duplicating the first CD is that the user must be physically present in order to manually exchange the first, data-carrying, CD for the second, blank CD after the information on the first CD has been read and stored. Since the user does not always know how long the reading of the first CD may take, a great deal of time can be wasted in simply awaiting completion of these reading and storing processes. This represents a particularly irksome problem when a user wishes to duplicate a disk in an “overnight” copying situation because the manual exchange of the two CDs will often be needed somewhere in the middle of the night when the user is not in attendance. 
     Such potential waste of a user&#39;s valuable time by simply having to wait around for a copying and storing operation to be finished has been met by providing drives with two CD transport tray systems. Thus, a first, data-carrying CD is simply placed in a first CD transport tray and a second, blank, CD is placed in a second CD transport tray. Both trays are then loaded into the drive so that the data on the first CD can be duplicated on the second CD. Given this capability, the user can load the two tray drives with the appropriate disks before leaving for the day and have the duplication process automatically completed when the user arrives next morning. 
     2. Statement of the Problem 
     These two transport tray drive systems address the human attendance problem associated with loading and unloading data carrying CDs and blank CDs into CD drives having only one CD transport tray. The problem is solved by duplicating the mechanical elements of the CD transport tray drive and the read/write heads associated with them—and by greatly increasing the complexity of the motherboard and controller components of the drive in order to properly coordinate not only physical movement of the trays, but the reading, storing and writing activities of the drive. These factors all contribute to a very significant increase in the cost of those drives that do employ two CD transport trays. 
     SUMMARY OF THE INVENTION 
     The present invention provides a method and apparatus for exchanging the positions of two CDs in a CD drive without having a human being taking part in the exchange process. Such a capability has several useful applications. For example, it can be used for copying information stored on a first CD on to a second CD without a human being having to unload the first CD from the drive and load the second CD into the drive—or without having to use a drive equipped with two separate disk transport trays. In one particularly preferred operational circumstance associated with this invention, two compact disks are stacked on a single CD disk transport tray, the tray (and the two CDs stacked on it) is inserted in a drive, the disks are separated within the drive, data is read from a first disk and stored in a hard drive, the first disk is transported out of the drive, the second disk is lowered, the first CD is inserted back into the drive such that the former positions of two CDs in the drive are exchanged, the data stored in the hard drive is written on the second disk and both CDs are transported out of the drive. 
     Another operating circumstance where this invention could be put to good use is one wherein a drive is loaded by placing two blank CD&#39;s on its transport tray so that the user can insert them and then write to both CDs (assuming the data to be written to the CDs is already on the computer&#39;s hard drive). Still another operating circumstance where this invention could be employed is one wherein two CDs that each already have data on them are loaded on a tray and inserted into a drive. Under these circumstances, the user could access data on either CD. This capability would, for example, be useful in the operating circumstance where the CD drive was at a remote location from the user. It also should be noted that this invention could be used in CD-ROM drives as well (read only—no write functionality). Moreover, by using the methods and apparatus of this invention in a CD server, the capacity of the server would be immediately doubled without needing to double the number of CD-ROMs in the server. In effect, the server would be a network server with many CD-ROM drives installed—all with data CDs in each drive—and thereby giving users of the network access to many more CDs. 
     One particularly preferred embodiment of this invention involves copying information from a data-carrying CD to a blank CD. Hence, this application will be used as a representative example of the CD position exchange concept of this invention. Such a CD exchange operation would comprise: (1) placing a first CD, having information on its underside, upon a CD transport tray (having an opening which permits the underside of the first CD to be in optical (“opto”) and/or electromagnetic communication with an electromagnetic communication device contained in a CD drive); (2) stacking upon said first CD, a second CD having blank regions on its underside for receiving opto/electromagnetic communication from the opto/electromagnetic communication device in a CD drive; (3) inserting the CD transport tray (and hence the first and second CDs stacked upon it), into the CD drive; (4) separating the second CD from the first CD in the drive and holding the second CD in an upper position; (5) reading information from the underside of the first CD and storing said information on the device&#39;s (e.g., on a personal computer&#39;s) hard drive; (6) withdrawing the CD transport tray (and the first CD which rests upon it), out of the CD drive; (7) dropping the second CD to a lower position so that the first CD can occupy the upper position formerly occupied by the second CD; (8) placing the second CD on the CD tray in a position formerly occupied by the first CD when the tray is reinserted; (9) writing information read from the bottom of the first CD and stored in the CD drive on a blank region of the bottom surface of the second CD and (10) removing the two CDs from the transport tray. In one particularly preferred embodiment of this invention, after the information stored in the CD drive is copied on the second CD, the first CD is dropped on to the second CD in a stacked relationship so that the CD transport tray, and the second and first CDs resting upon it, are simultaneously transported out of the CD drive and then removed from said tray. 
     Aside from the known electrical and mechanical components used in such drive devices to control and move a single CD transport tray, the apparatus for exchanging the positions of the two CDs according to the teachings of this invention further comprise, a disk-separator, a top disk holder and a top disk lowering mechanism. More detailed descriptions (and drawings) of these devices (as well as their working relationship with the CD transport tray) will be given in subsequent parts of this patent disclosure. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIGS. 1A to  1 E depict the CD exchange method of this patent disclosure. 
     FIGS. 2A and 2B depict a preferred method for separating two stacked CDs from each other. 
     FIG. 3 is a plan view of the CD changing device depicted in FIG.  2 B. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     FIGS. 1A to  1 E sequentially depict how the positions of two compact disks can be interchanged using a single CD transport tray and drive system  10 . The CD types can vary. For example, they can be CD-Rs, CD-RWs, WORMs, DVDs or suitable combinations thereof such as, for example a CD-ROM that is “read from” and a CD-RW that is “written to”. Be the CD types as they may, FIG. 1A depicts a top CD (“CD(T)”) in a position above a bottom CD (“CD(B)”) which rests on a CD transport tray  12 . Direction arrow  13  indicates that CD(T) is to be placed (e.g., manually) in a stacked relationship upon CD(B) while the two CDs are outside of a CD drive  14  into which the two CDs are to be loaded. The bi-directional arrow  16  shown in FIG. 1A suggests that the CD transport tray  12  can be laterally inserted into, and withdrawn from, the CD drive  14  by changing the operating direction of a CD tray transmission (see FIGS.  2 B and  3 ). 
     The CD&#39;s stacked relationship allows them, and the CD tray  12  upon which they rest, to be simultaneously loaded into the CD drive  14 . FIG. 2A shows CD(T) and CD(B) in such a stacked relationship as the CD tray  12  begins to enter CD drive  14 . The CD tray  12  comes to rest in either a fully extended position (such as that depicted in FIG. 1A) or a fully inserted position (such as that depicted in FIGS.  1 B). This tray/disk insertion and exit into and out of the drive  14  is made via a slot or opening  18  in the front surface  20  of the drive  14  (see FIG.  1 B). The CD tray  12  depicted in FIG. 1A is shown provided with an opening  22  that extends over a large part of the tray&#39;s surface area. Consequently, when the CD tray  12  is fully inserted into the CD drive  14 , the opening  22  permits opto/electromagnetic communication device(s)  24 A,  24 B, etc. (e.g., laser beam reading and/or writing devices) to receive energy from (and transmit energy to) the underside of CD(B) as it rests upon the CD transport tray  12 . Thus, such a electromagnetic communication device can, via opening  22 , “read” data from (and/or “write” data to), the underside of a CD, e.g., CD(B), resting on the tray  12 . For the purposes of this patent disclosure, such operations will be collectively referred to as “read/write” operation(s). 
     The direction arrow  26  shown leading from FIGS. 1A to  1 B suggests a transition from an initial state of this CD changing method wherein the two CDs are first positioned in a stacked relationship (such as that shown in FIG. 2A) and then moved to a succeeding relationship wherein the two CDs are physically separated from each other (e.g., in the manner shown in FIGS.  1 B and  2 B). Thus, getting to the relationship depicted in FIG. 1B involves both driving the CD transport tray  12  in an inward direction  16 (i) to an operating position in the drive  14  where information on the CD, e.g., on the bottom  28  of CD(B), can be read by an opto/electromagnetic communication device  24 A,  24 B, etc. and holding CD(T) in an elevated position above CD(B). The physical separation of CD(T) from CD(B) (such that the two CDs are no longer in their previous stacked relationship) is suggested by the upwardly directed arrows  13 ′ in FIG.  1 B. Thus, the separated relationship of the two CDs shown in FIG. 2B is comparable to the separated relationship shown in FIG.  1 B. 
     Again, the CD exchanging method of this patent disclosure can be used in circumstances where both CDs are blank, or where both CDs contain data, but for purposes of illustration an example wherein one CD contains information and the other CD is blank will be used. In this example, after information on a first, data-carrying CD(B) has been read and stored, the CD changing operation would then proceed to its next sequential step. This is suggested by the direction arrow  30  leading from FIG. 1B to FIG.  1 C. In FIG. 1C, the CD tray  12  is shown laterally transported out of the CD drive  14  in direction  16 (o) to its full outwardly extended position (i.e., such that it extends out of the housing of the drive  14  far enough that any CD on the tray  12  is fully exposed for manual handling). CD(T), however, remains positioned in the drive  14  in the same elevated position  32  it occupied in FIG.  1 B. It remains so positioned through use of a CD holding device hereinafter more fully described in the verbal descriptions associated with FIG.  2 B. 
     The next step in the operating sequence of this patent disclosure is to transfer CD(B) to the elevated position  32  formerly occupied by CD(T) (again, see FIG. 1B) and to transfer CD(T) to the position on the tray  12  formerly occupied by CD(B). Again, this is the step that, under the manual CD changing operations of the prior art, requires the user to be in attendance when the first CD is transported (on tray  12 ) out of the drive  14  so that said first CD can be exchanged for a blank, second CD. Returning to the CD changing concept of the present invention, we next note that in order to make room for the incoming CD(B), CD(T) must fall from its elevated position  32  to either an intermediate position depicted in FIG. 1C by elevation line  34 , or it may fall onto a portion of the top surface  36  of CD tray  12  and thereafter be driven into a CD-shaped depression  38  in the CD transport tray  12 . Either mode of lowering CD(T) is generally depicted in FIG. 1C by downwardly directed arrow  40  leading from the bottom surface  42  of phantom CD(T) depicted in FIG.  1 C. As can be seen in FIG. 2B, a CD holding ledge system, preferably formed by a CD separation device  44  (e.g., comprised of elements  44 A and  44 B), can be moved laterally and thereby allowing CD(T) to generally drop downward in the manner suggested by arrow  40  in FIG.  1 C. 
     The transition from FIG. 1C to FIG. 1D suggested by arrow  46  results in the CD transport tray  12  again being driven in an inward direction  16 ( i ) to its fully inserted or loaded position in the drive  14 . In being so driven, CD(B) is forced (e.g., through the CD separating action of the CD separator device  44  shown in FIG. 2B) into the upper position  32  formerly occupied by CD(T). CD(T) is lowered into the position formerly occupied by CD(B). That is to say that CD (T) eventually is placed in the CD-shaped depression  38  in the tray  12 . To facilitate the placement of the CDs in the CD-shaped depression  38  in tray  12 , the CD-shaped depression has a diameter slightly larger than the diameter of the CDs that temporarily reside in it. 
     Thus, the positions of CD(T) and CD(B) are exchanged and CD(T) is now in a position such that a opto/electromagnetic communication device  24 B (e.g., a laser writing device) can write upon blank regions of CD(T)&#39;s bottom surface  42 . For example, it can be written upon by use of a laser beam that, in the manner previously described, causes a media material on the bottom surface  42  of CD(T) to undergo a phase change from a material having a light-reflecting crystalline structure to an amorphous phase that does not reflect a “reader” laser beam as well. Be the writing technology as it may, the data that was read from the underside  28  of CD(B), and stored in a hard drive, is then written on the underside  42  of CD(T). This results in the data stored on the underside  28  of CD(B) being duplicated on the underside  42  of CD(T). 
     CD(T) can be removed from the drive  14  in any one of several ways. For example, it can be carried out of the drive  14  on the transport drive tray  12  while CD(B) remains in its upper position  32 . After CD(T) is lifted from the transport drive tray  12 , said tray  12  can be sent back into the drive  14  in order to retrieve CD(B). CD(B) can then drop onto the transport tray  12  and be removed. In a particularly preferred embodiment of this invention, however, after the information stored in the hard drive has been written on CD (T), CD (B) is lowered (e.g., by dropping it) into a stacked relationship with CD (T). Thus, both CDs can be simultaneously removed from the drive  14  on the transport tray  12 . This lowering of CD(B) to rest upon CD(T) is depicted in FIG. 1D by downwardly directed arrow  40 . Thus, CD (B) is again in a stacked relationship with CD(T) (albeit in exchanged positions) and, as such, is ready to be removed from the CD drive  14  via the slot  18  in its front face  20 . Consequently, direction arrow  48  suggests a transition from FIG. 1D to FIG. 1E wherein the CD tray  12  is shown being moved in an outward direction  16 ( 0 ) to such an extent that the two CDs are transported completely out of the drive device  14  when the tray  12  reaches its full outwardly extended position. In this position, both CD(B) and CD(T) can be raised in the upward direction depicted by arrows  50  and  52  in FIG.  1 E. Thus, CD(B) can be separated (e.g., manually) from CD(T) and CD(T) can be separated (e.g., manually) from the CD shaped depression  38  in the CD transport tray  12  and thereby complete the overall CD copying operation. 
     FIG. 2A is a front, cross section view of a CD drive  14  having certain features needed to carry out the CD changing operation depicted in FIGS. 1A to I-E. The drive  14  has a housing  54  which physically positions and protects the drive&#39;s internal components. In FIG. 2A, CD(B) is shown resting upon the top surface  36 A of the depression  38  of CD tray  12 . The bottom surface  42  of CD(T), in turn, rests upon the top surface  56  of CD (B). The top surface  36 A of the depression  38  is preferably far enough below the top surface  36  of the tray  12  that the entire thickness of CD(B) and at least a portion of the thickness of CD(T) lie in the depth  39  of the depression  38  in the tray  12 . Thus, depression  38  serves to hold both CD(B) and CD(T) in a fixed location on the CD transport tray  12 . In other words, in a preferred embodiment of this invention, a portion of the thickness of CD(T) may project above the top surface  36  of the tray  12 . 
     FIG. 2B shows that, as the two stacked disks, CD(T) and CD(B) are carried (on tray  12 ) into the drive  14 , portions of the separator-encountering edges of the CDs (i.e., leading edge regions  58 A and  58 B of CD(B) and leading edge regions  60 A and  60 B of CD(T) shown in FIG. 3) encounter CD separator device(s). In FIG. 2B such a separator device is shown as being comprised of two components  44 A and  44 B. These CD separator devices  44 A and  44 B are vertically positioned at an elevation  62  such that the separator devices  44 A and  44 B make physical contact with the edges of the stacked CDs at their interface  64  (see FIG. 2A) and thereby separates them. That is to say that a leading edge (e.g.,  65 A and/or  65 B as seen in FIG. 3) of the separator device is positioned at a vertical elevation  62  such that the separator device encounters the two stacked CDs at the elevation where the bottom surface  42  of CD(T) rests on the top surface  56  of CD(B) and thereby separates the two CDs by wedging them apart. The depression  38  in tray  12  can be provided with a beveled region  66  (shown in FIG. 3) to facilitate the CD/separator encounter at the interface  64  of the two stacked CDs. 
     FIG. 2B also illustrates how CD(T) can be held above CD(B) by use of two wedge-shaped separators  44 A and  44 B. Again, CD(T) could be held by a separate and distinct CD holder, but in a particularly preferred embodiment of this invention the top surface of the wedge-shaped separators  44 A and  44 B also serve as a support or holder for CD(T). In such an arrangement, the bottom surface  42  of CD(T) is shown resting on a top region of the separator wedges  44 A and  44 B at an elevation level or position  32  that also is depicted in FIGS. 1B to  1 D. 
     Next, it should be noted that the directional arrows  68  and  70  respectively associated with wedges  44 A and  44 B in FIG. 2B depict a mechanical capability for laterally moving each of these two wedge-shaped separators  42 A and  42 B away from CD(T). Thus, if wedge  44 A moves laterally far enough to the left in the manner suggested by arrow  68 , and wedge  44 B moves laterally far enough to the right in the manner suggested by arrow  70 , CD(T) will be free to fall downward in direction  40  under the force of gravity. To this end, a left support member  72  and a right support member  74  are shown respectively attached to the left and right sides of the drive housing  54 . These support members  72  and  74  are each provided with an opening  76  (or  78 ) for receiving its associated separator device ( 44 A or  44 B). Thus, separator device  44 A can be driven (by drive means not shown) in a left lateral direction  68  in opening  76 , while separator device  44 B can be driven in a right lateral direction  70  in opening  78 , and thereby allowing CD(T) to drop downward. 
     FIG. 2B also depicts how CD(T) could fall to a intermediate level or position  34  rather than falling onto the tray  12 . This intermediate position  34  (see also FIGS. 1C and 1D) can be produced and (employed) by the presence (and action) of two CD holder ledges  80 A and  80 B that serve to hold CD(T) at such an intermediate level or position  34 . When CD(B) is in this intermediate level or position  34 , the elevated level or position  32  formerly occupied by CD(T) is free to receive and hold CD(B) as it is loaded into the drive  14  on the transport tray  12 . The two CD holder ledges  80 A and  80 B also are respectively provided with lateral drive devices (not shown) that move ledge  80 A to the left and ledge  80 B to the right in the manner depicted by direction arrows  75  and  77  in order to lower CD (T) onto the tray  12 . Preferably, this lowering is done by the force of gravity. 
     FIG. 2B illustrates how the ends  82  and  84  of tray  12  can each be slidably mounted on their respective vertical supports  72  and  74 . In order to produce such a slidable mounting, each of the vertical supports  72  and  74  is shown respectively provided with a channel  86  (or  88 ) in which a downwardly projecting channel follower  90  (or  92 ) of the tray  12  are free to slide. Thus the vertical supports  72  and  74  are fixed and the tray  12  is free to move laterally with respect to them in the manner generally depicted by FIGS. 1A to  1 D. The transport tray  12  can be moved into or out of the device  14  by a transmission having a motor driven pinion gear  94  whose gear teeth engage a rack  96  that forms a part of the tray  12 . Thus, as the pinion gear  94  rotates in one direction, the rack  96  (and the tray  12  to which the rack  96  is attached) is driven in one lateral direction (e.g., in direction  16 (i) of FIG.  1 B). Conversely, when the pinion gear  94  is rotated in the opposite direction, the rack  96  is driven in the opposite lateral direction (e.g., in direction  16 (o) of FIG.  1 C). FIG. 2B also shows how a opto/electromagnetic communication device  24 A can be positioned to transmit energy through the opening  22  in the tray  12  and on to the bottom surface of a CD such as CD(B) residing in the depression  38  in said tray. A spindle  98  driven by a motor (not shown) is shown engaged with a center hole  100  of CD(B) (e.g., in a compression fit of the type well known to this art) and thereby providing a means for rotating a CD (e.g., CD(B)) attached to said spindle. 
     FIG. 3 is a top plan view of the CD drive  14  shown in FIG.  2 A. It shows the slidable, disk transport tray  12  on which the two compact disks (CD(T) and CD(B)) can be placed for loading and unloading the CDs in to and out of the drive  14 . CD(T) is shown residing above CD(B) in the manner shown in FIG.  2 B. FIG. 3 also shows the tray  12  (and CD(B) which rests on it) in a fully extended position such as that shown in FIG.  1 C). Thus, the tray  12  and CD(B) shown in FIG. 3 depict the situation where CD (B) is about to be exchanged with CD(T). To this end, the disk transport tray  12  and CD(B) are driven (by the action of the rack  96  and pinion  94  transmission previously described), in the direction of arrow  16 (o) to the tray&#39;s fully extended position. Again, such lateral movement is made possible by the fact that the left channel follower  90  depicted in FIG. 2B is free to slide in left channel  86  and right channel follower  92  is free to slide in right channel  88 . In the fully extended position of the tray  12  depicted in FIG. 3, CD(B) is clear of the drive housing  54  so that the compact disk(s) carried by the disk transport tray  12  can be easily manually loaded and unloaded to and from the tray  12 . 
     Finally, those skilled in this art will appreciate that various changes in this invention may be made without departing from its spirit and scope. Hence, the invention is limited only by the claims given below.