Patent Application
20050246728
In recent years, the use of optical discs, such as CDs and DVDs, for storing information has become prevalent. Due to the number of optical discs that a person may own, it is becoming increasingly important to properly label and identify such discs. In the past, this could be achieved by applying an adhesive label to the non-data side of the disc. However, the use of an adhesive label requires one to maintain an inventory of such labels and to complete the tedious process of applying the label to the disc, and the label might delaminate from the disc over time. Alternatively, a permanent marker could be used to hand-write information on the surface of the disc, but this typically provides a non-professional appearance.
One potential alternative to adhesive labels is the actual printing or otherwise forming a visual image on the non-data side of the disc. Unfortunately, existing actuators used to move the laser or other printing device cannot consistently and accurately position the printing device with respect to the non-data side of the disc. This causes visible line artifacts in the resulting printed image or label.
Disc interaction system 10 is configured to interact with both side 14 and side 16 of disc 12. In one particular embodiment, disc interaction system 10 is specifically configured to form a visual image, such as a label, upon side 16. Disc interaction system 10 generally includes disc drive actuator 30, disc interaction device 32, sensor 33, coarse actuator 34, fine actuator 36, controller 38 and memory 40. Disc drive actuator 30 comprises an actuator configured to rotatably drive disc 12 about an axis 42 which extends perpendicular to side 14 of disc 12. In one particular embodiment, actuator 30 comprises a motor in communication with controller 38.
Interaction device 32 comprises a device configured to interact with sides 14 and 16 of disc 12. In one particular embodiment, disc interaction device 32 is configured to write data to side 14 and to also form visual images, such as labels, upon side 16 of disc 12. In the particular embodiment illustrated, disc interaction device 32 includes laser generating mechanism 43 and focusing device 44. Laser generating mechanism 43 comprises a device configured to generate a laser. Focusing device 44 includes one or more lenses and is configured to focus or direct the generated laser upon either side 14 or side 16 of disc 12. In one embodiment, mechanism 43 is configured to generate laser beams having at least two different energy levels to either write data to side 14 or form visual images upon side 16. In other embodiments, depending upon the configuration of disc 12, similar energy levels may be applied for writing data to side 14 or forming visual images upon side 16. Although disc interaction device 32 is illustrated and described as comprising a single laser generating mechanism 43 and focusing system 44 to perform both the writing of data to side 14 and the forming of visual images upon side 16, in other embodiments, disc interaction device 32 may alternatively utilize more than one laser generating mechanism 43 and/or more than one focusing system 44 to perform such functions. In still other embodiments, mechanism 43 and system 44 may be employed to only write data to side 14 while other non-laser visual image-forming devices, such as a printhead or image-activating heater, may be employed to form a visual image upon side 16.
Sensor 33 generally comprises a device coupled to disc interaction device 32 and configured to detect the positioning of disc interaction device 32. In particular, sensor 33 is configured to generate electrical signals which are transmitted to controller 38 and which represent the positioning of disc interaction device 32 as disc interaction device 32 is moved by actuators 34 and 36 relative to data side 14 of disc 12. In the embodiment shown, sensor 33 receives and reads laser beams reflecting from data side 14. In the particular embodiment shown, sensor 33 is specifically configured to receive or sense the laser beams generated by mechanism 43, focused by system 44 upon side 14 and reflected off of side 14. As will be described in greater detail hereafter, reflector laser beams vary as disc interaction device 32 is moved across data side 14, enabling sensor 33 to precisely determine the position of disc interaction device 32 relative to side 14 of disc 12. In other embodiments, sensor 33 may be configured to sense other characteristics of data side 14, also enabling controller 38 to determine the position of the disc interaction device 32 relative to data side 14.
Actuator 34 comprises a mechanism configured to move disc interaction device 32 across disc 12. Actuator 34 moves through distinct identifiable states. The movement of actuator 34 between each state results in disc interaction device 32 being moved across disc 12. Due to manufacturing and control variations, the actual distance moved by disc interaction device 32 as actuator 34 moves between the states varies.
In one embodiment shown in
Worm gear 52 is coupled to output shaft 60 of stepper motor 50 and is in engagement with sleeve 54. For purposes of this disclosure, the term “coupled” shall mean the joining of two members directly or indirectly to one another. Such joining may be stationary in nature or movable in nature. Such joining may be achieved with the two members or the two members and any additional intermediate members being integrally formed as a single unitary body with one another or with the two members or the two members and any additional intermediate member being attached to one another. Such joining may be permanent in nature or alternatively may be removable or releasable in nature.
Sleeve 54 is in meshing engagement with worm gear 52 and is coupled to carriage 56. Carriage 56 supports disc interaction device 32 and fine actuator 36. Carriage 56 is movably supported relative to disc 12 by guide 58. Guide 58 comprises one or more rails slidably supporting carriage 56. Although carriage 56 is illustrated as being movably supported by a guide 58 comprising two rails, carriage 56 may alternatively be guided across disc 12 by other support structures.
In operation, movement of stepper motor 50 through each step rotatably drives worm gear 52. Rotation of worm gear 52 drives sleeve 54 and carriage 56 along guide 58 back and forth across disc 12. In one embodiment, movement of stepper motor 50 through a single step may result in carriage 56 and disc interaction device 32 being moved across several adjacent segments of track 18. The precise positioning of device 32 relative to a particular segment of track 18 is achieved with fine actuator 36.
Fine actuator 36 comprises an actuation mechanism supported by carriage 56 and configured to further move disc interaction device 32 across disc 12 relative to carriage 56. In the particular embodiment illustrated, fine actuator 36 is configured to move disc interaction device 32 in finer increments or distances as compared to actuator 34. In the example shown, fine actuator 36 includes a voice coil 62, which upon being energized, interacts with a magnet to move disc interaction device 32 in direction indicated by arrows 64 relative to carriage 56. In other embodiments, actuator 36 may have other configurations. Actuators 34 and 36 cooperate to move disc interaction device 32 relative to disc 12 such that disc interaction device 32 is aligned with track 18.
Controller 38 generally comprises a processor configured to generate control signals for directing the operation of actuators 30, 34 and 36 as well as directing the operation of disc interaction device 32. For purposes of this disclosure, the term “processor” shall mean a conventionally known or future developed processing unit that executes sequences of instructions contained in a memory. Execution of the sequences of instructions causes the processing unit to perform steps such as generating control signals. The instructions may be loaded in a random access memory (RAM) for execution by the processing unit from a read only memory (ROM), a mass storage device, or some other persistent storage. In other embodiments, hard wired circuitry may be used in place of or in combination with software instructions to implement the functions described. Controller 38 is not limited to any specific combination of hardware circuitry and software, nor to any particular source for the instructions executed by the processing unit. As will be described in greater detail hereafter, controller 38 generates control signals which enable system 10 to detect actual distances traversed by disc interaction device 32 across side 14 which occur as actuator 34 moves between distinct states. Controller 38 further utilizes such detected actual distances to accurately and precisely control movement of disc interaction device 32 on side 16 of disc 12.
Memory 40 comprises one or more structures configured to store or contain distance data obtained during movement of device 32 across side 14 of disc 12. In one embodiment, memory stores such information in the form of one or more look-up tables. In particular embodiments, memory 40 may additionally contain instructions for use by controller 38. Memory 40 may include one or more of programmable read-only memory, non-erasable read-only memory or random access memory. Memory 40 may comprise digital memory in the form of hardwired circuitry or may comprise fixed or portable memory such as optical memory (e.g., CDs, DVDs), magnetically encodable memory (e.g., tape, floppy disk), or other forms.
As indicated by step 76, disc interaction device 32 is then positioned adjacent to label side 16 of disc 12. Movement of disc interaction device 32 adjacent label side 16 is controlled based upon the values sensed by sensor 33. As indicated by step 78, disc interaction device 32 is used to form one or more images upon label side 16 of disc 12.
As indicated by step 86, the distance through which disc interaction device 32 moves is detected using data side 14 of disc 12. As indicated by step 88, disc interaction device 32 is then positioned adjacent label side 16 of disc 12. Actuator 34 is once again moved from the first state to the second state to move the disc interaction device 32 adjacent the label side of the disc. As indicated by step 90, the movement of the disc interaction device adjacent the label side of the disc is adjusted based upon the detected distance from the data side of the disc. As indicated by step 92, disc interaction device 32 is utilized to form an image upon the label side 16 of disc 12.
When reading data from or writing data to data side 14 of disc 12, disc interaction device 32 can be precisely positioned relative to a particular desired segment of track 18 as a result of controller 38 continuously obtaining positional feedback from data side 14 of disc 12. In one embodiment, controller 38 receives sensed additional feedback provided by track 18. For example, in one embodiment, track 18 comprises a groove with at least one sidewall having a sinusoidal radial displacement (called wobble). See, for example, U.S. Pat. No. 6,538,966 (Hanks), the full disclosure of which is hereby incorporated by reference. The wobble may be frequency modulated to encode address information. Alternatively, track 18 may comprise a groove having notches in one or more sidewalls which are used for index marks or sector addresses. See, for example, U.S. Pat. No. 5,923,401 (Inui et al.) and U.S. Pat. No. 5,852,599 (Fuji), the full disclosures of which are hereby incorporated by reference. In other embodiments, positional feedback may be obtained by controller 38 by controlling disc interaction device 32 to count track segment crossings. Positioning device 32 at a desired portion of segment of track 18 on the data side generally involves causing actuator 34 to move device 32 in larger increments a distance expected to correspond to the number of track segments to be crossed, identifying the resulting current track segments over which device 32 is located and causing fine actuator 36 to move system 44 in relatively smaller increments from the current segment of track 18 to the desired segment of track 18. Because the reflected laser beams vary depending upon whether the laser beam is reflected from track 18 or a landing between adjacent segments of track 18, disc interaction device 32 is able to count a number of track crossings made by disc interaction device 32 as disc interaction device 32 is moved across data side 14 of disc 12. Using a known distance between adjacent segments of track 18 and the number of segment crossings, controller 38 may calculate an exact position of disc interaction device 32 along data side 14 of disc 12. Because disc interaction device 32 (or another sensing device) receives position information from track 18 whether by sensing notches, whether by sensing wobble or whether by counting tracks, controller 38 is able to specifically identify the location of disc interaction device 32 and to generate control signals to correct for any inconsistent movement of disc interaction device 32 along data side 14.
However, label side 16 of disc 12 does not include tracks or track data which enable controller 38 to constantly receive real time position feedback from side 16. Therefore, controller 38 utilizes positional feedback from side 14 to generate control signals that direct the operation of actuators 34 and 36 to precisely position disc interaction device 32 adjacent side 16.
FIGS. 1, 4A-4C illustrate movement of actuator 34 through three distinct states along data side 14 of disc 12. In the particular example described, stepper motor 50 is moved through a first step, a second step and a third step in
Each of
Although not shown, controller 38 continues to generate control signals which cause stepper motor 50 to move through steps which results in disc interaction device 32 being further moved along data side 14 of disc 12. For each step that stepper motor 50 is moved through, controller 38 generates control signals which cause disc interaction device 32 to detect the actual distance traversed by device 32 across data side 14 by counting track crossings upon data side 14. The detected actual distances moved by disc interaction device 32 for each associated step of motor 50 are stored by controller 38 in memory 40.
In one particular embodiment, controller 38 stores such information in a look-up table of steps and their associated distances D1 through DN, where N represents the total number of steps required for disc interaction device 32 to be moved entirely across disc 12. An example of such a look-up table is:
In another embodiment, controller 38 generates control signals which cause information to be stored in a look-up table of steps and their associated total distances TD1, TD2, TD3 . . . TDN from a known initial starting location such as L0, wherein N equals the total number of steps required to move disc interaction device 32 across disc 12. An example of such a look-up table is:
In still another embodiment, controller 38 stores information in a look-up table of steps 1-N and their associated off-set distances OD1, OD2, OD3 . . . ODN, wherein N is the total number of steps required to move disc interaction device 32 across disc 12 and wherein each off-set distance is the distance between the expected per step distance and the actual distance D moved by interaction device 32 during a particular step. An example of such a look-up table is:
In still another embodiment, controller 38 stores information in memory 40 in a look-up table of steps 1-N and their associated off-set total distances OTD1 . . . OTDN, wherein N equals the total number of steps required to move device 32 across disc 12 and wherein each off-set total distance is the difference between the expected total distance moved by device 32 for a particular step from an initial point along disc 12 and the actual total distance moved by device 32 along disc 14 after completion of a particular step. An example of such a look-up table is:
In lieu of storing actual total distances moved by device 32 from an initial point along disc 12, controller 38 may alternatively store actual locations of device 32 after completion of an associated stop.
In particular embodiments, the actual distance D moved by device 32 during each step may repeat or exhibit a pattern. For example, stepper motor 50 may be configured to move through 18 steps to complete the full revolution of output shaft 60. The actual distances moved by device 32 for steps 19-36 may be substantially identical to the actual distances moved by device 32 during steps 1-18, respectively. In such applications, controller 38 may alternatively store information in a look-up table with values as described above, but wherein N equals the total number of steps required by motor 50 to complete one full revolution or the total number of steps through which motor 50 must move before a pattern of actual distances and their associated steps begins repeating. In such applications, controller 38 may alternatively determine and store one or more formulas for calculating one or more of actual distances D, total distances TD, locations L, offset distances OD or offset total distances OTD based upon a variable representing a completed or to be completed step. Controller 38 accesses and uses the information stored in memory 40 to control movement of device 32 on label side 16 of disc 12.
Once distance information (D, TD, L, OD, OTD) has been obtained during movement of disc interaction device 32 across data side 14 of disc 12, disc 12 is flipped or reversed such that disc interaction device 32 faces label side 16. Moving of disc 12 may occur before or after data has been written to data side 14. In one embodiment, an individual may be prompted to manually remove disc 12, to flip disc 12 and to reinsert disc 12. In still other embodiments, mechanisms may be provided for flipping disc 12 to position interaction device 32 opposite label side 16 of disc 12.
Once the location of device 32 has been initialized, controller 38 generates control signals which cause stepper motor 50 to be moved through its consecutive steps. Each step through which motor 50 moves causes disc interaction device 44 to radially move across more than one radial row of labellable positions on label side 16 of disc 12. Controller 38 further generates the control signals for actuating fine actuator 36 to move device 32 a fraction of the per-step distance achieved by motor 50 to precisely position disc interaction device with respect to label side 16 of disc 12. For each step through which motor 50 moves, controller 38 consults the associated stored distance information (D, TD, L, OD, OTD) and generates control signals to further control the movement of fine actuator 36 to compensate or adjust for any error caused by disc interaction device 32 moving an actual distance different than an expected nominal distance during any particular step of motor 50.
In the particular example shown, disc interaction device 32 alters label side 16 of disc 12 to produce a visual image upon side 14, such as a label. In one embodiment, laser and lens assembly 44 direct a laser beam upon surface 16 which causes portions of surface 16 or underlying portions of surface 16 to have different light absorption characteristics or color thus forming the visual image. Because system 10 precisely and accurately positions interaction device 32 with respect to label side 16 of disk 12, improved higher quality images or labels are formed upon label side 16 of disc 12.
The exact method by which controller 38 calculates a compensation value may vary depending upon the type of distance information obtained from movement of disc interaction device 32 along data side 14 as well as any other known differences between data side 14 and label side 16. For example, in lieu of obtaining distance D3 from memory 40, controller 38 may alternatively obtain an offset distance OD3 while moving stepper motor 50 through step 3. As noted above, the offset distance OD3 is the difference between an actual distance moved by disc interaction device 32 as a result of stepper motor 50 moving through the third step and the nominal per step distance. When using the offset distance OD3, controller 38 adjusts its control and movement of actuator 36 by subtracting offset distance OD3 from the previously calculated incremental distance X. In particular, the offset distance OD3 subtracted from the incremental distance (+X) results in the compensation distance (−C), wherein controller 38 generates control signals to move device 32 by the compensation distance C in the negative direction (i.e., to the left as seen in
Overall, system 10 enables precise and accurate control of movement of disc interaction device 32 along side 16 of disc 12 by using actual distance data obtained from movement of disc interaction device 32 along side 14. In those applications in which disc interaction device 32 interacts with side 16 to form an image, such as a label, upon side 16, system 10 produces sharper images having a higher resolution. In other embodiments, disc interaction device 32 may be alternatively used to interact with side 16 of disc 12 for other purposes.
Although the present invention has been described with reference to example embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention. Those skilled in the art will appreciate that certain of these advantages can be obtained separately through reconfiguring the foregoing structure without departing from the spirit and scope of the present invention. Because the technology of the present invention is relatively complex, not all changes in the technology are foreseeable. The present invention described with reference to the example embodiments and set forth in the following claims is manifestly intended to be as broad as possible. For example, unless specifically otherwise noted, the claims reciting a single particular element also encompass a plurality of such particular elements.
