Patent Application
20070097819
Recent advancements have made it possible to employ lasers in optical disc drives to perform the functions of reading data from and writing data to optical discs as well as writing labels or other information on a label surface of optical discs. In one typical scenario, to write data to a disc, the disc is placed in the disc drive and the write function is performed. Thereafter, the disc is removed from the drive, flipped over, and placed back into the drive to write a label to the label surface of the disc. However, in this scenario, the data and labeling operations are performed sequentially, with one beginning after the other one ends. The disc is not completed until both operations are finished.
The invention can be understood with reference to the following drawings. The components in the drawings are not necessarily to scale. Also, in the drawings, like reference numerals designate corresponding parts throughout the several views.
The optical disc drives described herein include various components as depicted in the various figures that illustrate the various concepts according to various embodiments of the present invention. However, it is also understood that the optical disc drives may include other components not shown that are not particularly pertinent to the concepts described herein.
With reference to
The optical pick up unit 103, rails 106, the motor 113, and screw shaft 116 make up one example of a positioning assembly 126 that is employed to position the laser 109 so that a laser beam generated by the laser 109 may be directed toward a specific location on a first side of the optical disc site 123. Alternatively, assemblies other than a screw shaft/rail assembly may be employed to position the laser 109 as can be appreciated. The positioning assembly 126 is advantageously configured to position the laser beam generated by the laser 109 with a degree of accuracy and stability to facilitate reading data from and writing data to an optical disc disposed in the optical disc site 123.
The optical disc drive 100 also includes a disc drive controller 133 that generates appropriate electronic signals to drive the motor 113, the spindle motor 119, and the various components in the optical pick up unit 103. Such components may comprise, for example, the laser 109, and one or more sensors (not shown) as can be appreciated. In this respect, the disc drive controller 133 orchestrates the operation of the optical disc drive 100 in both reading data from and writing data to one side of an optical disc disposed in the optical disc site 123, and in writing a label to a label side of an optical disc placed within the optical disc site 123.
Next, with reference to
An actuator 166 is coupled to the arm 143. In one embodiment, the actuator 166 is coupled to the arm 143 at a midpoint between the ends of the arm 143, however it is understood that the actuator 166 may be coupled at any point along the arm 143 that results in the desired motion as will be described. The actuator 166 may comprise, for example, a solenoid, a voice coil motor, or other type of actuator as can be appreciated.
The optical disc drive 100a also includes an elastic member 169 that is also coupled to the arm 143. The elastic member 169 is also coupled to a frame structure 173 or other rigid structure of the optical disc drive 100a. The elastic member 169 opposes the movement of the actuator 166. In this respect, in one embodiment, the elastic member 169 exerts a force in a direction that is; aligned with a longitudinal axis that defines the direction of motion of the actuator 166. Alternatively, the elastic member 169 may be oriented such that a component of the force generated opposes the actuator 166 along the longitudinal axis of the actuator 166. The elastic member 169 may comprise, for example, a spring, an elastic material such as rubber, or other type of elastic structure as can be appreciated.
Thus, in one embodiment, where a solenoid is employed as the actuator 166, a steel core of the solenoid is coupled to the arm 143. The elastic member 169 may be a spring as described above. The solenoid includes a coil that causes a magnetic force to be exerted onto the steel core by generating a magnetic field as can be appreciated. When a current is generated in the coil, the resulting magnetic field pulls the steel core toward the center of the solenoid. The pulling force is opposed by the spring or other elastic member 169. For a given solenoid current, the arm 143 settles at an equilibrium point where the force in the spring or other elastic member 169 equals the force on the solenoid core generated by the magnetic force from the solenoid. As the current in the solenoid coil is increased, the equilibrium point moves toward the solenoid itself.
The use of a solenoid, voice coil motor or other similar device as the actuator 166 provides a distinct advantage in that the movement of the laser 153 is accomplished at reduced cost. Specifically, solenoids and voice coil motors, for example, are relatively low cost items as compared with other devices that provide higher precision of movement.
The disc drive controller 133 includes an output interface with a digital-to-analog converter that is coupled to an input of an analog amplifier 176. The output of the analog amplifier 176 is coupled to the input of the actuator 166.
Together the arm 143, actuator 166, and the elastic member 169 comprise a positioning assembly 179 that is employed to position the laser beam 159 generated by the laser 153 and directed toward the side of the optical disc site 123 by the reflector 163 along a path 193 as will be discussed subsequently in greater detail. The positioning assembly 179 can position the laser beam 159 independent of the positioning of the laser beam generated by the laser 109 by the positioning assembly 126. The disc drive controller 133 is operatively coupled to the positioning assembly 179 and the positioning assembly 126 to direct the positioning of each.
According to one embodiment, the laser 109 is a “data side” laser, and the laser 153 is a “label side” laser. A data side laser is defined herein as a laser that is employed to read or write data to a data region or data surface of an optical disc disposed in the optical disc site 123. A label side laser is defined herein as a laser employed to write a label to a label region or a label surface of an optical disc disposed in the optical disc site 123.
Next, the operation of the optical disc drive 100a is described with reference to both
The positioning assembly 179 positions the second laser beam 159 at a point between an inner diameter 183 and an outer diameter 186 of the optical disc site 123. In this respect, the optical disc site 123 defines a write area 189 between the inner diameter 183 and the outer diameter 186 to which either a label or data may be written to, or data read from an optical disc that occupies the optical disc site 123. The positioning assembly 179 positions the second laser beam 159 by virtue of a displacement of the actuator 166. Specifically, in the embodiment shown in
The pivotal movement of the arm 143 positions the second laser beam 159 along a path 193 that traces an arc (an arcuate path), for example, on the optical disc site 123. Thus, the displacement of the actuator 166 causes the pivotal movement of the arm 143 about the pivot point 146, thereby positioning the second laser beam 159 along the path 193. Because the arm 143 positions the laser beam 159 along the path 193 tracing the arc from the inner diameter 183 to the outer diameter 186, the label writing function of the optical disc 100a is adjusted to account for displacement of the laser beam 159 along the arc (path 193) rather than a straight line path as for the laser 109 that is moved along the rails 106.
The movement of the actuator 166 is caused by the application of a signal, such as a current, generated by the amplifier 176 based upon a signal from the disc drive controller 133. Specifically, to move the laser beam 159 to a predefined location along the path 193, the disc drive controller 133 generates a digital value that falls within a range that corresponds to the inner diameter 183 and the outer diameter 186. This value is converted by the interface described above into an analog value that is applied to the amplifier 176. In response, the amplifier generates a current that is in turn applied to the actuator 166, thereby causing the actuator 166 to be displaced in proportion to the magnitude of the current. The elastic member 169 opposes the movement of the actuator 166 in positioning the arm 143 toward the inner diameter 183.
Therefore, the displacement of the actuator 166, and thus the position of the second laser beam 159, is controlled by the magnitude of the current applied to the actuator 166. In this manner, the position of the laser beam 159 may be controlled to facilitate writing a label to the second side of an optical disc disposed in the optical disc site 123. Because the positioning assembly 179 is entirely independent of the positioning assembly 126, the positioning of the laser beam 159 is accomplished independent of the positioning of the laser beam generated by the laser 109 (
In addition, while the actuator 166 is shown as providing a linear motion that is coupled to the arm 143, alternatively, the actuator 166 may be attached to the pivot point 146 and may generate a rotational force that is applied to the arm 143. Such a rotational force would result in the pivotal motion of the arm 143. Alternatively, other types of actuators 166 may be employed.
The spring 169 may also be of a type that is placed around the pivot point 146 and opposes the pivotal motion of the arm 143 in the direction of the inner diameter 183. Alternatively, the spring 169 may be embodied in some other configuration that generates a force that opposes the force generated by the actuator 166.
Referring next to
The optical disc drive 100b also includes rails 206. The laser head 203 is configured to slide along the rails 206. To this extent, the rails 206 and appropriate portions of the laser head 203 comprise guiding structure that facilitates the linear movement of the laser head 203. Such guiding structure may include slots or tunnels or other similar features that are compatible with the rails 206 that facilitate the movement of the laser head 203 along the rails 206. Both the elastic member 169 and the actuator 166 are coupled to the laser head 203 and cause the laser head 203 to move in a linear manner such that the laser 153 may be positioned anywhere from the inner diameter 183 to the outer diameter 186 of the optical disc site 133. The laser head 203, rails 206, elastic member 169, and the actuator 166 make up positioning assembly 209 that is employed to position the laser 153, and the laser beam generated thereby, along linear pathway. The disc drive controller 133 is operatively coupled to the positioning assembly 209 in order to direct the positioning of the second laser beam generated by the laser 153 in the laser head 203.
While two rails 206 are shown, it is understood that more or fewer than two rails may be employed. Also, where like numerals are employed to identify various structures in the optical disc drive 100b depicted in
With reference to
Referring then to
Stored in the memory 236 and executable by the processor 233 are a number of components including, for example, an operating system 243, and a drive control system 246. The operating system 243 controls the allocation and usage of hardware resources such as the memory, processing time, and peripheral devices in the disc drive controller 133. In this manner, the operating system 243 serves as the foundation on which applications depend as is generally known by those with ordinary skill in the art.
The drive control system 246 controls the various functions of the optical disc drive 100. A portion of the drive control system 246 comprises a laser position calibration routine 249. In addition, it is understood that other portions of the drive control system 246 exist that are not described herein in detail. The laser position calibration routine 249 is executed to calibrate the positioning of the laser beam 159 (
The components stored in the memory 236 may be executable by the processor 233. In this respect, the term “executable” means a program file that is in a form that can ultimately be run by the processor 233. Examples of executable programs may be, for example, a compiled program that can be translated into machine code in a format that can be loaded into a random access portion of the memory 236 and run by the processor 233, etc. An executable program may be stored in any portion or component of the memory 236 including, for example, random access memory, read-only memory, a hard drive, compact disk (CD), floppy disk, or other memory components.
The memory 236 is defined herein as both volatile and nonvolatile memory and data storage components. Volatile components are those that do not retain data values upon loss of power. Nonvolatile components are those that retain data upon a loss of power. Thus, the memory 236 may comprise, for example, random access memory (RAM), read-only memory (ROM), hard disk drives, floppy disks accessed via an associated floppy disk drive, compact discs accessed via a compact disc drive, magnetic tapes accessed via an appropriate tape drive, and/or other memory components, or a combination of any two or more of these memory components. In addition, the RAM may comprise, for example, static random access memory (SRAM), dynamic random access memory (DRAM), or magnetic random access memory (MRAM) and other such devices. The ROM may comprise, for example, a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), or other like memory device.
In addition, the processor 233 may represent multiple processors and the memory 236 may represent multiple memories that operate in parallel. In such a case, the local interface 239 may be an appropriate network that facilitates communication between any two of the multiple processors, between any processor and any one of the memories, or between any two of the memories etc. The processor 233 may be of electrical, optical, or molecular construction, or of some other construction as can be appreciated by those with ordinary skill in the art.
Referring next to
The laser position calibration routine 249 begins with box 253 in which an attempt is made to locate a calibration position along the movement of the second laser beam 159. In some embodiments, this calibration position may be considered a second calibration position where the first calibration postion is the rest position when a zero current is applied to the actuator 166. The laser position calibration routine 249 advantageously calibrates the positioning of the laser beam 159 based upon inputs received at two or more separate positions within the range of motion of the laser beam 159.
One or more of the calibration positions may be specified based on the location of reflective materials strategically placed either on an optical disc disposed in the optical disc site 123, or upon a given structure to which the laser 159 is directed when an optical disc is not disposed in the optical disc site. The reflective materials may include reflective structures such as mirrors that are configured to reflect of at least a portion of the laser beam 159. For example, one calibration point may be a point of transition between high reflectivity and low reflectivity of the edge of the outer ring media inner diameter (ID) on an optical disc placed in the optical disc site 123. Another calibration point may be, for example, the transition point from low reflectivity to high reflectivity corresponding to the edge of the write area 189.
The sensor 155 may be located on the arm 143 (
In box 256, assuming that the laser beam 159 is directed at the desired calibration position, then the laser position calibration routine 249 proceeds to box 258. Otherwise, the laser position calibration routine 249 proceeds to box 263. In box 263 the position of the laser beam 159 is adjusted to determine if the calibration position can be located. Thereafter, the laser position calibration routine 249 reverts back to box 256.
In box 258, the laser position calibration routine 249 determines whether the last calibration position has been located such that information relative to at least two such calibration positions is known. For example, if the rest position is taken as one of the two calibration positions, then only one other calibration positions need be located. On the other hand, if the rest position is not employed as one of the calibration positions, then at least two calibration positions within the range of motion of the laser beam 159 are located. When each of the calibration positions is located, the current or voltage applied to the actuator 166 is stored in order to calculate the gain therefrom. If in box 258, the desired number of calibration positions has been located from which the gain of the system may be calculated, then the laser position calibration routine 249 proceeds to box 259. Otherwise, the laser position calibration routine 249 reverts back to box 253 to locate the next calibration position.
When the laser position calibration routine 249 has progressed to box 259, then the gain of the actuator 166 is calculated. In this respect, the gain is calculated based upon the difference in the current or voltage applied to the actuator 166 in moving the arm 143 or laser head 203 from the rest position (or other initial calibration position) to a second calibration position. Since the distance between the two calibration positions is known, the gain may be calculated as a function of the voltage or current per unit length. In one embodiment, the analog voltage or current applied to the actuator 166 is generated by D/A converter that converts a digital position signal (digital value) into a corresponding analog voltage or current. Thus, analog voltage or current applied to the actuator 166 falls within a range that corresponds to the range of motion of the actuator 166. Since the gain varies over time, in box 266, the laser position calibration routine 249 calculates the range of digital values that corresponds to the total range of analog voltage or current that is applied to the actuator 166 to accomplish the full range of motion of the laser beam 159 given the calculated gain. Then, in box 269, these values are stored in the disc drive controller 133 for use in the laser position control. Then, the laser position calibration routine 249 ends as shown. In this manner, the laser position calibration routine 249 accounts for changes in the operation and gain of the respective positioning assemblies 179 or 209.
In order to ensure that the positioning of the arm 143 or laser head 203 is accurate over time, the laser position calibration routine 249 may be executed periodically at specific time intervals. Alternatively, the laser position calibration routine 249 may be performed before the writing of a label to each optical disc disposed in the optical disc site 123. As an alternative, the laser position calibration routine 249 may be executed according to some other schedule or scheme.
Although the laser position calibration routine 249 is described as being embodied in software or code executed by general purpose hardware as discussed above, as an alternative the same may also be embodied in dedicated hardware or a combination of software/general purpose hardware and dedicated hardware. If embodied in dedicated hardware, the laser position calibration routine 249 can be implemented as a circuit or state machine that employs any one of or a combination of a number of technologies. These technologies may include, but are not limited to, discrete logic circuits having logic gates for implementing various logic functions upon an application of one or more data signals, application specific integrated circuits having appropriate logic gates, programmable gate arrays (PGA), field programmable gate arrays (FPGA), or other components, etc. Such technologies are generally well known by those skilled in the art and, consequently, are not described in detail herein.
The flow chart of
Although the flow chart of
Also, where the laser position calibration routine 249 comprises software or code, it can be embodied in any computer-readable medium for use by or in connection with an instruction execution system such as, for example, a processor in a computer system or other system. In this sense, the logic may comprise, for example, statements including instructions and declarations that can be fetched from the computer-readable medium and executed by the instruction execution system. In the context of the present invention, a “computer-readable medium” can be any medium that can contain, store, or maintain the laser position calibration routine 249 for use by or in connection with the instruction execution system. The computer readable medium can comprise any one of many physical media such as, for example, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor media. More specific examples of a suitable computer-readable medium would include, but are not limited to, magnetic tapes, magnetic floppy diskettes, magnetic hard drives, or compact discs. Also, the computer-readable medium may be a random access memory (RAM) including, for example, static random access memory (SRAM) and dynamic random access memory (DRAM), or magnetic random access memory (MRAM). In addition, the computer-readable medium may be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), or other type of memory device.
In addition, with reference to
The positioning of the second laser beam is performed independent of the positioning of the first laser beam. In addition, the example method may further comprise the step of writing a label on the second side of the optical disc using the second laser beam. A user may insert the optical disc into the optical disc drive and then perform steps of positioning the first laser beam, positioning the second laser beam, and writing a label without removing the optical disc from the optical disc drive. Thereafter, the optical disc may be removed from the optical disc drive after performing all of the steps of positioning the first laser beam, positioning the second laser beam, and writing a label have been completed.
A user may advantageously employ the optical disc drive 100 to both read data from/write data to an optical disc while at the same time writing a label to an opposite side of the optical disc without having to remove the optical disc from the disc drive to flip it over to facilitate separate functions of reading/writing and writing a label using a single laser. In addition, the present invention facilitates simultaneous performance of the steps of reading data from/writing data to the optical disc and writing a label to the optical disc.
Although the invention is shown and described with respect to certain embodiments, it is obvious that equivalents and modifications will occur to others skilled in the art upon the reading and understanding of the specification. The present invention includes all such equivalents and modifications, and is limited only by the scope of the claims.
