Patent Publication Number: US-2005131575-A1

Title: Optical data-storage apparatus employing optical media with three-dimensional data pattern

Description:
FIELD OF THE INVENTION  
      The present invention relates generally to the field of optical data-storage apparatuses, and more particularly to an optical data-storage apparatus employing optical data-storage media having a three-dimensional data pattern for processing information in multitasking and in parallel.  
     BACKGROUND OF THE INVENTION  
      It is well known that a conventional computer system is nowadays generally equipped with a hard-disk drive, a removable-disk drive, a CD (compact-disc) drive, a floppy-disk drive, and/or a tape-backup drive for storing information. These drives basically utilize storage media such as magnetic disks, Bernoulli disks, optical/magneto-optical discs, and magnetic tapes, respectively. Among these media, magnetic tapes and even newly developed optical tapes are for use only in tertiary storage because information is stored thereon by a sequential access method and thus cannot be accessed at a speed acceptable by current computer practice.  
      The coexistence of hard-disk, CD, floppy-disk, backup, and other removable drives in computer signifies the fact that no single drive can simultaneously serve as secondary and tertiary storage. However, their combinations do not yield satisfactory overall performance because these conventional drives use different platforms and storage media in construction. Nor, can their combinations result in a user-friendly feature, because the conventional practice requires a purchased software program to go through a tedious software installation process through which all program files are decompressedly copied from an original software CD or floppy disks to a hard-disk drive wherefrom the software program is then executed.  
      In an attempt to resolve the disadvantages mentioned above and to allow software programs to be launched directly from their original discs just as the plug-and-plan feature of a SEGA- or Nintendo-type game system, Applicant has disclosed an information processing apparatus (called master drive hereinafter) to replace all of these conventional hard-disk, CD, floppy-disk, backup, and other removable drive, as detailed in U.S. Pat. No. 5,748,575. The master drive is in a single-platform construction utilizing optical discs as storage media so as to most-efficiently obtain all necessary functions and features of secondary and tertiary storage.  
      Among the conventional storage media between magnetic disks and optical discs, Applicant has suggested only the optical-disc media suitable for achieving the plug-and-play feature of software programs in conjunction with the master drive. Magnetic disks, due to lack of durability and storage density, are by no means suitable media for achieving the plug-and-play feature of software, that is one of the basic characteristics needed to form the master drive of my prior invention.  
      Conventional optical storage basically utilizes either optical discs or optical tapes as storage media. Comparably inferior to magnetic tapes, optical tapes are only suitable for applications in tertiary storage and will not be applicable for use in the master drive of my prior patent. Thus, among the conventional optical storage, only optical-disc media can be utilized in conjunction with secondary and tertiary storage. The optical disc medium is essentially a relative “flat” or two-dimensional plate having circular tracks made in a continuous spiral or many spirals from the inside to the outside of an optical disc. With respect to the so-called DVDs (digital video or versatile discs), information is stored on two layers (U.S. Pat. No.  4,682,321) or multiple surfaces (U.S. Pat. No. 5,487,060) at different depths so as to greatly increase data density. Even though, these types of discs and their data surfaces are still generally in flat or two-dimension form.  
      Relatively recently, Applicant has discovered that the master drive utilizing the conventional optical-disc media may have an oversized plane that would prevent it from being integrated with a space-limited host for some particular applications. There appears no immediate solution for the concern if several turntables have to be generally aligned horizontally with each other. Furthermore, in such a master drive, each turntable is designed for mounting a disc thereon and the total number of discs will be fixed in accordance with the total number of the turntables. Thus, it is impossible to increase the total number of mountable discs. In other words, the optical-disc-based master drive may lack of flexibility in accommodating original software discs more than the turntables provided therein, even though some software discs contain much less data than others and each of them has to equally occupy a turntable.  
      Another Applicant&#39;s concern is how to raise the data transfer rate (or data throughput) of conventional optical data storage to a level comparable to that of a hard-disk drive utilizing magnetic-disk media. An earliest CD-ROM drive used in conjunction with a computer system has a characteristic of doublespin or the so-called 2×, equivalent to a data throughput of 0.3 MBps. The latest CD-ROM drives have advanced to 32× or a data throughput of 4.8 MBps. On the other hand, the newest CD-R (rewritable or recordable) drives remain to be 8× at best yet cost about a 10-fold higher than a typical 32× CD-ROM. To achieve a data throughput of 16.6 MBps that is nowadays typical in any hard-disk drives, a CD-ROM drive has to evolve into at least 100× that will minimally rotate from 55,000 rpm at start-up to 22,000 rpm at the outside edge of an 120 mm-disc. This range of rotation speed reaches about an order of magnitude greater than a typical hard-disk drive, which will invoke technology far beyond our current knowledge and technological capability, especially, in view of the fact that the latest CD-R drives remain to be mostly in 2×.  
      With respect to CD-R drives, the most serious obstacle hindering their advance in speed is that the parameter of time is often essential for a material to transform between different states of phases or for a polymeric carry medium in a magneto-optical disc to be softened enough upon being exposed to an intense laser beam to allow embedded magnetically-sensitive, metallic crystals to undergo re-aligning movements. Thus, there is a strong need to conceive a new form of high-density optical-storage media and a new type of optical storage utilizing such a high-density optical-storage media different from the conventional optical-disc media used in current CD and/or CD-R drives so as to achieve a data throughput at a minimal level of a hard-disk drive.  
      With the concerns just mentioned hereinabove, Applicant now establishes the need, the incentive, and the application for developing a new form of optical-storage media and a new type of optical storage utilizing the new form of optical-storage media to achieve a throughput speed at least comparable to any current hard-disk drives.  
     SUMMARY OF THE INVENTION  
      A first primary preferred embodiment of the present invention is to improve the conventional optical information reproduction system by providing an optical data-storage medium with a base structure adapted to supply a peripheral surface, preferably in cylindrical form, with a medium adhered thereon, forming a three-dimensional data surface responsive to a light beam for providing optical signals corresponding to a plurality of data. The three-dimensional data surface having an imaginary straight center line is preferably selected from the group consisting of at least one helix, at least one ring, at least one circular track, at least one three-dimensional coil, at least one three-dimensional spiral, and their combinations. Preferably, the medium is responsive to an intense light beam to undergo changes between different states of phases or orientations for rewritably storing data thereon. The peripheral surface may contain at least one additional medium disposed with the medium to form a plurality of data surfaces at different depths each for storing a plurality of data thereon. Most preferably, the plurality of data are arranged in a pattern comprising a predetermined plurality of helixes alternately disposed, so as to process information in parallel manner. The helixes may be used for storing different formats of information, such as digital data information and digital audio information.  
      A second primary preferred embodiment of the present invention is to improve the convention optical information reproduction system by providing an optical data-storage cartridge comprising a housing, a plurality of data-storage media rotatably mounted in the housing, each of the optical data-storage media having (1) a base structure adapted to supply a peripheral surface and an axial line of rotation and (2) a medium adhered on the peripheral surface, forming a data surface responsive to a light beam for providing optical signals corresponding to a plurality of data stored thereon, and at least one opening disposed on the housing adapted to allow the peripheral surfaces to be accessed outside the housing in a direction generally parallel to the axial lines. The second primary preferred embodiment protects the optical data-storage media of the invention and facilitates removability.  
      A third primary preferred embodiment of the present invention is to improve the convention optical information reproduction system by providing an optical data-storage apparatus comprising mounting means rotatable about an axial line, for mounting thereon an optical data-storage medium of the invention, means for rotating the mounting means about the axial line, and an optical unit having an optical head means capable of providing a light beam and a driving means for moving the optical head means in a direction generally parallel to the axial line, so as to interface with the optical data-storage medium. Specifically, the optical head means is adapted to allow the light beam to be directed to and reflected from the optical data-storage medium in directions generally perpendicular to the axial line. Preferably, the optical head means further comprises means for sequentially focusing the light beam selectively between a predetermined plurality of distances, so as to access a respectively predetermined plurality of data surfaces on the optical data-storage medium. The optical head means may be adapted to shape the light beam into a narrow-lined light beam with predetermined dimensions to cover a predetermined plurality of data bits adjacently aligned with each other in a direction generally parallel to the axial line. The optical unit may further comprise additional optical head means each discretely spaced apart from and substantially aligned with the optical head means in a direction generally parallel to the axial line. Provided therewith is means for processing a predetermined plurality of data bits each associated with a predetermined one of the optical head means and the additional optical head means in parallel manner. Most preferably, the mounting means is adapted to removably mount thereon a plurality of optical data-storage media of the invention. The optical data-storage apparatus may further comprise a second mounting means rotatable about a second axial line for mounting a second optical data-storage medium, wherein the second axial line is generally parallel to the axial line. The optical unit further comprises a second driving for moving the optical head means in a direction substantially traverse to the axial line and the second axial line, so as to allow the optical head means to selectively access the optical data-storage medium and the second optical data-storage medium. Further provided is a second optical unit having a separate driving means and at least one separate optical head means, so as to allow the optical unit and the second optical unit to perform multitasking. The optical data-storage apparatus may further comprise another mounting means rotatable about another axial line for mounting a conventional optical disc medium having a two-dimensional surface for storing information thereon.  
      A fourth primary preferred embodiment of the present invention is to improve the convention optical information reproduction system by providing an optical data-storage apparatus comprising a plurality of optical data-storage media each adapted to have a data surface for storing a plurality of data arranged in a three-dimensional pattern having an imaginary straight center line, a plurality of mounting means each rotatable about an axial line for mounting thereon one of the optical data-storage media in such a manner as to allow the imaginary straight center lines each to coincide with a respective one of the axial lines, means for rotating the plurality of mounting means each about a respective one of the axial lines, and an optical unit comprising a plurality of optical head means and a driving means for simultaneously moving the plurality of optical head means in a travelling direction generally parallel to at least one of the axial lines. Specifically, each of the plurality of optical head means is adapted to provide a light beam directed to and reflected from a respective one of the data surfaces in a direction generally perpendicular to a respective one of the axial lines. Preferably, one of the optical head means comprises means for sequentially focusing a light beam selectively between a predetermined plurality of distances, so as to access a respectively predetermined plurality of data surfaces on one of the optical data-storage media. One of the optical head means may be adapted to shape a light beam into a narrow-lined light beam with predetermined dimensions to cover a predetermined plurality of data bits adjacently aligned with one another in a direction generally parallel to one of the axial line. Preferably, the plurality of optical head means are aligned with each other in a direction generally parallel to a predetermined one of the axial lines, so as to allow a selected plurality of the optical head means to access a respectively predetermined one of the optical data-storage media. Most preferably, the optical data-storage apparatus further comprises means for processing a predetermined plurality of data bits each associated with a predetermined one of the plurality of optical head means in parallel manner. Specifically, the means for processing is provided selectively for combining the predetermined plurality of data bits retrieved by the plurality of optical head means in a predetermined sequence, and for separating data in accordance with the predetermined sequence to a form of the predetermined plurality of data bits to be sent through respective optical head means for storing onto respective optical data-storage media. At least one of the mounting means each is adapted to removably mount thereon at least one of the optical data-storage media of the present invention. Preferably, the plurality of optical head means are arranged in such a manner as to allow at least one of the plurality of optical head means to be positioned at each one of the plurality of optical data-storage media. The optical data-storage apparatus may further comprise an additional optical unit having at least one optical head means, a first driving means, and a second driving means provided for moving the at least one optical head means respectively in a first direction generally parallel to and in a second direction substantially traverse to at least two of the axial lines, so as to allow the second optical unit to selectively access at least two of the optical data-storage media. The optical data-storage apparatus may further comprise a turntable rotatable about a turntable axial line for mounting a conventional optical disc having a two-dimension surface for storing information thereon. Preferably, the turntable and the head unit are arranged in such a manner as to allow one of the plurality of optical head means to travel in a radial direction of a disc surface of the optical disc medium.  
      An optical data-storage medium of the present invention allows information to be stored in high density, to be accessed in high speed, and to be processed in multitasking and in parallel, not achievable by any conventional optical disc drives.  
    
    
     DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a perspective view of optical data-storage media each having at least one peripheral surface that is relatively symmetrical in shape along a respective imaginary straight center line in accordance with a first primary preferred embodiment of the present invention.  
       FIGS. 2A and 2B  are cross-sectional views of optical data-storage media  100  and  10  along the lines  2 A- 2 A and  2 B- 2 B respectively shown in  FIG. 1 .  
       FIG. 3  is an enlarged view showing a pattern of data tracks arranged in a single helix of the present invention.  
       FIG. 4  is a perspective view of an optical data-storage cartridge in accordance with a second primary preferred embodiment of the present invention.  
       FIG. 5  is a perspective view of an optical data-storage apparatus in accordance with a third primary preferred embodiment of the present invention.  
       FIG. 6  is an enlarged view showing a pattern of data tracks arranged in eight alternate helixes of the present invention.  
       FIG. 7  is a perspective view of an optical data-storage apparatus with parallel processing capability of the present invention.  
       FIG. 8  is a perspective view of an optical data-storage apparatus with multitasking capability of the present invention.  
       FIG. 9  is a block diagram illustrating a parallel processing for the optical data-storage apparatus shown in  FIG. 7  of the present invention.  
       FIG. 10  is a perspective top view of an optical data-storage apparatus having parallel-processing, multitasking, and removable functions capable of serving as a master drive, in accordance with a four primary preferred embodiment of the present invention.  
       FIG. 11  is a perspective top view of an optical data-storage apparatus capable of processing information stored on the optical data-storage media of the present invention and a conventional optical disc. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
      Referring now to  FIGS. 1-3 , the first primary preferred embodiment of the present invention will be described in detail hereinbelow.  
       FIG. 1  is a perspective view of optical data-storage media  100 ,  110 ,  120 , and  130 . Optical data-storage media  100 ,  120 , and  130  each comprises a respective base structure  101 ,  121 , or  131 . The base structures each is adapted to supply a peripheral surface in three-dimensional form such as a hollow (preferred) or solid cylinder or truncated cone, and to have mounting means  103 ,  113 ,  123 , or  133  engageable for mounting onto an optical data-storage apparatus to be detailed in  FIGS. 5, 7 , or  10  of the present invention. Preferably, the base structure and the engagement means are one piece plastic component made of a material such as polycarbonate, polyacrylic resin, or other polymers through precision blow molding or other processing versus injection molding used in the making of conventional compact discs.  
      Optical data-storage medium  110  currently mounted on a common shaft  115  includes four shorter elongated-length optical data-storage media  110   a - 110   d  with separated base structures each in cylindrical form with a diameter of 30 mm identical to optical data-storage media  100  and  130 , but 40 mm in length versus 120 mm of the other three optical data-storage media  100 ,  120 , and  130 . Each of the base structures has one peripheral surface that is relatively symmetrical in shape along a respective one of imaginary straight center line  102 ,  112 ,  122 , or  132 . In accordance with the first primary preferred embodiment of the present invention, the mounting means each is adapted to have an axial line of rotation coaxial with a respective one of imaginary straight center lines  102 ,  112 ,  122 , and  132 . Each of the peripheral surfaces contains at least one data surface capable of storing a plurality of data arranged in a three-dimensional pattern or circular boundary lines with centers moving along a respective one of imaginary straight center lines  102 ,  112 ,  122 , or  132 . More specifically, optical data-storage media  100  and  110  are in cylindrical form, while optical data-storage medium  120  is in truncated conical form. As depicted in optical data-storage medium  130 , it is possible that a base structure is adapted in such a manner as to have a peripheral surface  134  substantially in helical shape (i.e., with two helical outer boundary lines) for storing a plurality of data arranged in helical form. It is also possible that the peripheral surface comprises boundary lines of segments of circles, although less preferred.  
      With respect to optical data-storage medium  100 , its peripheral surface  104  has a length of 120 mm, yet a surface area about 121% of a single side of an 120-mm optical disc. In other words, the optical data-storage medium of the present invention with a length slightly less than a typical pen can have a storage capacity of about 787 megabytes (MB) if made in a single data-surface (or data-layer) format as used in conventional CD-ROM. This allows a new type of optical data-storage apparatus of the present invention to be constructed in a narrower and compact size as compared with convention optical-disc storage that has to be in dimensions of at least 120 mm×120 mm.  
      Each of peripheral surfaces  114   a - 114   d  on respective optical data-storage media  110   a - 110   d  has a length of 40 mm and a storage capacity of 197 MB if made in the single data-surface format, which is sufficient for holding most of software programs. It is also possible that common shaft  115  is mounted with optical data-storage media (or original software optical media) with various lengths so as to achieve different combinations. In accordance with the present invention, thus for the first time, several original software optical media with peripheral surfaces substantially symmetrical in shape can be mounted on a common shaft, so as to be readily accessed by an optical unit having at least one optical head (or pickup). Many software developers produce software discs with contents less than a full capacity (650 MB) of a typical 120-mm optical disc. Without the first primary preferred embodiment of the present invention, these unfilled software discs each has to occupy a turntable.  
      Shown in  FIGS. 2A and 2B  are cross-sectional views of optical data-storage media  100  and  110  along the lines  2 A- 2 A and  2 B- 2 B respectively depicted in  FIG. 1 .  FIG. 2A  is a single data-surface structure, in which base structure  101  (i.e., a hollow cylinder) is coated with a data medium forming a single data surface (or data layer)  210 , which may be an evaporated aluminum film having a thickness of 0.1 to 0.2 m, for serving as read-only-memory medium or storage. Data surface  210  is overcoated with a transparent, protective layer  220  with a thickness of about 0.2 to 0.8 mm. When exposed to a light beam, the data surface is responsive to provide optical signals corresponding to a plurality of data stored thereon.  
      For serving as rewritable storage, data surface  210  may be a magneto-optical medium comprising magnetically-sensitive, metallic crystals (such as barium ferrite) whose orientations are re-alignable only when exposed to an intense laser beam and magnetic impulse, thus being erasable/rewritable. The data surface of the crystals may have a thickness of 2 to 80 nm, which may be formed by vacuum deposition through sputtering processes known in the art. Data surface  210  may comprise other alternative rewritable media or films such as Ge—, Te—, and Sb-containing compounds known in the art, capable of undergoing reversible phase changes when exposed to an intense light beam.  
       FIG. 2B  shows that optical data-storage medium  110  is in a multiple data-surface structure suitable for applications on digital-versatile drums (DVDs) or high-density optical-storage media, wherein base structure  111  is coated with different data media forming a first layer  260 , a transparent layer  270 , a second layer  280 , and then a transparent layer  290 , thus establishing four data surfaces  261 ,  271 ,  281 , and  291  for storing four layers of data thereon. Transparent layers  270  and  290  are made of an identical material with a thickness preferably ranging from 100 to 300 μm and an index of refraction different from first and second layers  260  and  280 , so as to obtain some reflection at data surfaces  261 ,  271 ,  281 , and  291 .  
       FIG. 3  shows an enlarged top side view of data tracks  300  on a single data surface made currently of an evaporated aluminum film. As detailed in an exaggerated circular view  305 , data tracks  300  each comprises a plurality of pits  310  with a width of 0.4 to 0.5 μm and a depth of 0.1 μm and a plurality of flats  311 . The distance between adjacent tracks (or the so-called track pitch) is held constant at 1.6 μm for a CD-comparable format, versus 0.74 μm for a DVD-comparable format. These tracks are in fact arranged in a continuous helix with centers falling onto an imaginary straight center line  301 , so that when rotated about imaginary straight center line  301 , all data can be readily accessed by an optical head (to be shown in  FIG. 5 ) travelling in a single direction parallel to imaginary straight center line  301  and in close proximity to the data surface. To the contrary, in a conventional optical CD drive, an optical head moves in a radial direction relative to a disc or disk, that is in a direction generally perpendicular to an axial line of rotation of a turntable.  
      In addition to data track  300  shown in  FIG. 3 , it may be possible to comprise another data tracks on the same data surface so as to allow an optical data-storage medium to store information in different formats such as a digital data format and a digital audio format needed for running multimedia applications. Pits and flats are mostly preferably arranged in helical form; nonetheless, they can be in ring form, circular-track form, three-dimensional coil form, three-dimensional spiral form, and their combinations with centers generally falling on or along the imaginary straight center line.  
       FIG. 4  is a perspective view of an optical data-storage cartridge  400  in accordance with a second primary preferred embodiment of the present invention. Optical data-storage cartridge  400  comprises a housing  410  with a narrow opening currently covered by a cover  412 , and an optical data-storage medium  420  contained within housing  410 . Cover  412  is biased slidably between a normally closed position (current position as shown in  FIG. 4 ) and an opened position (to be shown in  FIG. 5 ). Optical data-storage medium  420  basically includes a single-piece structure  421  with mounting means  422  (only a front one is depicted) extended out of housing  410 , so as to be externally engageable and rotatable about an imaginary straight center line  424 . Coated on the peripheral surface of structure  421  is an optical medium forming a data surface  423  responsive to a laser light beam for providing optical signals corresponding to a plurality of data bits stored thereon. The peripheral surface and data surface  423  of structure  421  are adapted to allow the plurality of data bits to be arranged in a three-dimensional pattern such as a ring, circular track, helix, coil, spiral, or their combinations with centers substantially falling onto imaginary straight center line  424 .  
      In accordance with the second primary preferred embodiment of the present invention, the opening covered by cover  412  is arranged in such a manner as to allow data surface  423  to be accessed in a direction generally parallel to its axial direction of rotation, that is imaginary straight center line  424  as shown in  FIG. 4 . To the contrary, the opening of a disc or disk cartridge is designed to allow a disc or disk surface to be accessed in a radial direction of the disk or disk surface, that is in a direction perpendicular to the axial direction of rotation. Thus, the conventional disk or disc cartridge design is not applicable for use in the optical data-storage cartridge of the present invention.  
      While  FIG. 4  shows a single optical data-storage medium, it is preferred that an optical data-storage cartridge will comprise a plurality of the optical data-storage media similarly disposed therein to protect the optical data-storage media and to facilitate removability.  
      Referring now to  FIGS. 5-9 , the third primary preferred embodiment will be described in detail hereinbelow.  
       FIG. 5  is a perspective view of an optical data-storage apparatus  500 , currently loaded with optical data-storage cartridge  400  of  FIG. 4 . Optical data-storage apparatus  500  has a housing  510  forming into an inner space with dimensions just enough for accommodating optical data-storage cartridge  400  therein, when a front openable door  511  is currently opened. As entering the space, cover  412  on optical data-storage cartridge  400  is forced downward by a member  520  so as to render an opening  521  opened and data surface  423  accessible by optical data-storage apparatus  500 . The rear mounting means of optical data-storage cartridge  400  is eventually engaged with a mounting means (not shown) connected to a rotating motor  530 . Situated on front openable door  511  is a mounting means  512  rotatable about an axis  513  that will establish engagement with mounting means  422  so as to coincide with and to be rotatable about imaginary straight center line  424  when front openable door  511  is closed and locked.  
      Further comprised in optical data-storage apparatus  500  is an optical unit that basically includes an optical head  550 , a driving motor  551 , a screw shaft  552 , and a sliding rail  553 . Driving motor  551  is provided for moving optical head  550  to a predetermined position along the direction of screw shaft  552  and sliding rail  553 , which is generally parallel to imaginary straight center line  424 , i.e., the axial direction of rotation of data surface  423 . Optical head  550  basically comprises a semiconductor laser diode, a lens system (including an objective or focus lens), a collimator, a quarter-wavelength (λ/4) plate polarizing beam-splitting prisms, photosensors, a focusing mechanism, and control circuitry, as known in the art and needed no additional illustration. Nonetheless, in accordance with the present invention, a laser beam emitted from the laser diode is through the objective lens directed to and reflected from the data surface in a direction generally perpendicular to imaginary straight center line  424 , that is the common axial line of mounting means  422  and  512  and data surface  423 .  
      To the contrary, in a conventional optical disc drive, an optical head is designed to travel in a radial direction of the disc surface, that is perpendicular to the axial direction of rotation of the disc and its turntable. Another key difference lies in the fact that a laser light beam of an optical CD drive is directed to and reflected from a disc surface in a direction parallel to the axial direction of rotation of the disc and the turntable. Thus, the design of the conventional optical disc drives is not applicable for use in the optical data-storage apparatus of the present invention.  
      Optical head  550  can be in a design capable of accessing data stored on various data surfaces arranged at different depths such as optical data-storage medium  110  shown in  FIG. 2B  of the present invention. For this purpose, optical head  550  will comprise means for focusing a laser light beam sequentially onto a predetermined plurality of distances, i.e., onto each one of the data surfaces, so as to allow the laser light beam to be directed to and a data signal to be reflected from a preselected one of the data surfaces one at a time in a sequential manner. Specifically, optical head  550  may comprise, for example, an electrically-adjustable numerical aperture ring assembly, means for adjusting the distance between an objective lens and a selected data surface, and control circuitry for controlling a focus point onto a predetermined one of the data surfaces. Thus, at a preselected data track, optical head  550  can adjust focusing points for interfacing with all data stored on different data surfaces  261 ,  271 ,  281 , and  291  shown in  FIG. 2B .  
      Optical head  550  can further be in a design capable of simultaneously reading a predetermined plurality of data bits at a time if data are arranged in a pattern comprising several helixes alternately disposed, as shown in  FIG. 6  in accordance with the another preferred embodiment of the present invention. Optical data-storage medium  600  has a single data surface with eight helixes  601 - 608  alternately disposed, which have centers generally falling onto an imaginary straight center line  610 . More specifically, helixes  601 - 608  each has a plurality of data tracks, wherein adjacent tracks each is associated with a different one of the helixes, so that data tracks  651  - 658  respectively correspond to helixes  601 - 608 . Repeatedly, Next eight data tracks  659 - 666  are in the alternate pattern of helixes  601 - 608 . To read eight bits or one byte of data one bit from each data track of a respective helix as depicted in an exaggerated view  630 , optical head  550  will comprise at least one lens for collecting a light beam from an optical laser and for shaping the light beam into a narrow-lined light beam  670  then is directed in perpendicular to data tracks  651 - 658 . Narrow-lined light beam  670  has an elongated length along or parallel to the axial direction of rotation of optical data-storage medium  600 , and has dimensions just enough to cover eight data bits, each from a respective one of eight data tracks (i.e.,  651 - 658  as currently depicted in  FIG. 6 ). More specifically, the eight data bits are generally aligned with one another in a direction parallel to imaginary straight center line  610 , that is the axial direction of rotation of the optical data-storage medium  600  and its data surface. The rotating speed of optical data-storage medium  600  and the traveling speed of narrow-lined light beam  670  are coordinated in such a manner as to advance narrow-lined light beam  670  to interface with next eight data tracks  659 - 666 , after one revolution of rotation. Such an arrangement is unobtainable by any conventional compact discs, because a conventional optical CD drive has to constantly change speeds of rotation when positioned at different tracks. Thus, the combination of a particular optical data-storage medium ( FIG. 6 ) and optical data-storage apparatus  500  ( FIG. 5 ) allows a plurality of data to be simultaneously retrieved in parallel manner. More specifically, parallel data processing is proceeded in a form of one byte (i.e., 8 bits) at a time in the current embodiment of the present invention versus the serial data processing (i.e., one bit at a time) of the conventional optical disc apparatus.  
      An alternative parallel-processing optical data-storage apparatus of the present invention is shown in  FIG. 7 . Optical data-storage apparatus  700  comprises eight optical heads  750   a - 750   h  equally spaced apart and aligned in a direction parallel to an imaginary straight center line  724  and jointly movable by a same driving motor  751 , so as to simultaneously position at eight data tracks with centers falling onto imaginary straight center line  724 , that is also the axial line of a rotating motor  730 . This configuration allows optical data-storage apparatus  700  not only to proceed with parallel processing but to reduce track access time to ⅛ of  FIG. 5 . With respect to parallel processing, more specifically, optical data-storage apparatus  700  allows eight data bits to be processed at a time in parallel manner, wherein each one of the eight data bits is associated with a predetermined one of optical heads  750   a - h.  With a speed of rotation comparable with a 32× CD-ROM drive, optical data-storage apparatus  700  can achieve a throughput of 23 MBps for a 30-mm diameter of optical data-storage medium  723 , which exceeds 16.6 MBps of a high-performance hard-disk drive. In fact, the throughput should be higher than 23 MBps based on today&#39;s technology because the present invention utilizes the constant angular velocity (CAV) method for the rotation of the medium and an one-dimensional method for the travelling of the optical head. Most importantly, the present embodiment improves throughput through parallel processing instead of raising the speed of rotation. This is particularly advantageous to advance the speed of data writing, because the present embodiment can now afford an adequate length of time to a material for undergoing necessary transformation between different states of phases or to a polymeric carry medium for undergoing necessary softness upon exposed to an intense laser beam so as to allow embedded magnetically-sensitive, metallic crystals to proceed with re-aligning movements.  
      A multitasking optical data-storage apparatus is shown in  FIG. 8 . Optical data-storage apparatus  800  comprises two members  820   a  and  820   b  for respectively opening covers  812   a  and  812   b  so as to render a data surface accessible by optical heads  850   a  and  850   b  respectively through narrow openings  821   a  and  821   b  on both sides. Optical heads  850   a  and  850   b  are movable by separate driving motors  851   a  and  851   b  (not depicted) so as to independently position at predetermined track positions along separate screw shafts  852   a  and  852   b , respectively. This configuration renders optical data-storage apparatus  800  capable of independently moving and controlling two optical heads to process two software programs or one complex, multimedia program, i.e., multitasking.  
      Referring now to  FIG. 9 , another parallel processing for a data format and optical data-storage apparatus  700  of the present invention will be described in detail hereinbelow.  
       FIG. 9  is a block diagram of a control system of the parallel processing of  FIG. 7  of the present invention to be used in conjunction with a data pattern comprising eight helixes  950   a - 950   h  (each comprising a plurality of data tracks) separately arranged in such a manner that optical heads  750   a - 750   h  each is positioned at a respective one of the eight helixes. More specifically, a plurality of data constituting a software program are evenly distributed in a predetermined plurality of helixes (i.e., eight currently) discretely disposed at a respective plurality of predetermined positions (i.e., eight currently), so as to allow a predetermined plurality of data bits (i.e., eight currently) to be processed at a time, i.e. in parallel manner.  
      Optical heads  750   a - 750   h  are jointly and commonly moved by driving motor  751  and only need to travel the length of a helix, about 15 mm in this preferred embodiment, which is about ¼ of an optical head needed to travel in a conventional 120-mm CD. Optical head controls  910   a - 910   h  are provided to independently control optical heads  750   a - 750   h  for focusing (which includes changing focus points of a light beam onto a predetermined plurality of data surfaces arranged at a respectively predetermined plurality of depths as needed for accessing information stored in a DVD-comparable format) and tracking. Optical data-storage medium  950  is rotated by rotating motor  730  in a high-speed constant angular velocity (CAV) method; in contrast, a conventional optical-disc drive is inherently slow in performance because it needs to constantly change and adjust rotating speeds to achieve a constant linear velocity for its optical head. Driving motor  751  and rotating motor  730  are controlled by a system control unit  920 , which accepts control signals from a host computer  909  through a wide-bus interface  908 .  
      System control unit  920  basically comprises a ROM (read only memory)  921 , a microprocessor (MPU)  922 , and a SRAM (static random-access memory). Stored in ROM  921  are instructions needed for enabling MPU  922  to coordinate the operations of a conversion unit  930 , a CD decoder unit  940 , a CD encoder unit  945 , and for interfacing with host computer  909  through wide-bus interface  908 . MPU  922  is provided for executing of the instructions stored in ROM  921  in accordance with signals received from host computer  909 . SRAM  923  is afforded for serving as a buffer. Each of helixes  950   a - 950   h  can be an individual optical cylinder having a plurality of data tracks in one or several helixes, corresponding to a software optical disc. Thus, SRAM  923  further serves as primary storage for storing basic information such as the read-only or erasable/rewritable nature of data information and directory-structure information or path tables contained in helixes  950   a - 950   h , allowing optical data-storage apparatus  700  to instantly determine the very helixes or the optical data-storage medium with which a new task is to be executed. In brief, use of the SRAM eliminates the need to refresh the contents of the information/instructions many times a second; thus, the information/instructions can be retained through power of a battery.  
      Each set of eight data signals retrieved at a time by optical heads  750   a - 750   h , which correspond to eight channels, are processed by a conversion unit  930  so as to be combined together in a predetermined sequence. Conversion unit  930  basically comprises a ROM  931  stored therein instructions for use in data combination when reading and in data separation when writing, a MPU  932  for executing the combination and the separation, and a RAM (random-access memory)  933  for serving as a buffer needed in data combination and separation processes. Each of helixes  950   a - 950   h  can be an individual optical cylinder having a plurality of data tracks in one or several separate helixes, corresponding to a software optical disc.  
      The combined data are sent to a CD decoder unit  940  which may comprise a CIRC (Cross Interleaved Reed-Solomon Code) decoder, a CD-ROM decoder, and a RAM in order for the combined data to be deinterleaved, demodulated, and decoded for error-correction process, restoring the original sequence of data symbols, and finally converting the 14-bit word back to the original 8-bit data symbols. The processed data controlled under system control unit  920  are sent to an audio-processing unit  960  or through wide-bus interface  908  to host computer  909 . Audio-processing unit  960  comprises a digital-to-analog converter for sound reproducing and an analog-to-digital converter for digitizing analog signals to be stored.  
      In the process of data writing, audio information is first processed by the analog-to-digital converter of audio-processing unit  960 . The digitized audio information is then processed by a CD encoder unit  945  so as to be transformed into an EFM (eight-to-fourteen modulation) format suitable for CD storage. The CD-formatted information is further separated by conversion unit  930  into eight channels or sets of information each transmitted to a respective one of optical heads  750   a - 750   h  through optical head controls  910   a - 910   h  so as to store the separated data onto respective helixes  950   a - 950   h  simultaneously. Similarly, any information received from host computer  909  through wide-bus interface  908  can be processed in parallel manner so as to store information at an eight-fold speed of the serial data processing of the conventional optical-disc drive.  
      Optical data-storage apparatus  700  along with the parallel processing shown in  FIG. 9  will improve the speed of data processing by an order of magnitude, in view of the fact that the conventional optical-disc drive has to constantly change and adjust rotating speeds to arrive at a constant linear velocity in order for its optical head to preform data reading or writing.  
      The fourth primary preferred embodiment of the present invention is illustrated in  FIG. 10 , in which optical data-storage apparatus  1000  is made to have complete functions of serving as secondary and tertiary storage, and most importantly to process information in parallel processing and in multitasking. The construction of optical data-storage apparatus  1000  is based on a single-platform structure, i.e., a single type of data-storage media and data access mechanisms controlled within single system circuitry. To the contrary, any one of conventional computer systems achieves second and tertiary storage by means of combining a hard-disk drive, a floppy-disk drive, a CD drive, and/or a removable drive separately built and controlled, which can process information neither in true multitasking nor parallel processing.  
      Comprised in a housing  1005  (with its top cover removed) of optical data-storage apparatus  1000  are four compartments for storing one stationary optical data-storage medium  1001  rotatable about ann axial line  1006 , and three removable optical data-storage media  1002 - 1004  (with respective openable front doors  1042 - 1044  currently opened) respectively rotatable about axial lines  1006 - 1008 . Situated on the inner panels of front doors  1042 - 1044  are three engagement means  1050  for removably mounting respective optical data-storage media  1002 - 1003  thereon in a manner coinciding with axial lines  1006 - 1008 . Optical data-storage medium  1003  in fact contains optical data-storage media  1031 - 1034  each having a plurality of data tracks arranged in a single helix, so that data tracks of a helix are discretely disposed from data tracks of other helixes. Such a discrete helix of data tracks can be representative of an original software optical medium. For examples, optical data-storage media  1031 - 1032  are respectively future software products of Microsoft Windows®99, Microsoft® Office 99, WordPerfect® Suite 10, and Lotus® SmartSuite 99, each of which can be effectively processed by a single optical head through the conventional serial processing. User created files and other off-line archives are stored on optical data-storage medium  1002  which is removable and transportable to other computer systems also made in accordance with the present invention. Optical data-storage medium  1004  can be an audio drum of future products for playing digital music.  
      Optical data-storage apparatus  1000  has two optical units  1010  and  1020  independently movable by driving means  1019  and  1029  in directions generally parallel to axial lines  1006 - 1009 . Situated on optical unit  1010  are eight optical heads  1011 - 1018  jointly movable by the common driving means  1019 . Optical heads  1011 - 1018  are arranged in such a manner that each two of them are proximate to a respective one of optical data-storage media  1001 - 1004 , so as to position at two different optical tracks on the same optical data-storage media  1001 ,  1002 , and  1004 . This at least allows optical heads  1011  and  1015  to access stationary optical data-storage medium  1001  two data bits at a time, that is the parallel processing mentioned hereinabove. Optical unit  1020  includes four optical heads positioned underneath a selected two of optical data-storage media  1001 - 1004 . The four optical heads are disposed in such a manner as to render axial lines  1006  and  1007  each accessible by two of the four optical heads. In addition to driving means  1029 , optical unit  1020  further comprises a second driving means  1028  for traversing the four optical heads to axial lines  1007  and  1009 , as well as axial lines  1008  and  1009 . Thus, optical data-storage apparatus  1000  can perform true multitasking through optical units  1010  and  1020 .  
      In accordance with the features described hereinabove, optical data-storage apparatus  1000  of  FIG. 10  is a master drive aiming to replace any conventional hard-disk drive, CD drive, and removable-disk drive typically equipped in a conventional computer system. This configuration allows several smaller original software program media to be loaded on a common rotating shaft which is not achievable in any conventional practice including my prior invention (U.S. Pat. No. 5,748,575). It further allows a user to launch software programs directly therefrom without going through a tedious software installation process, thus providing a type of copyright protection to software developers.  
       FIG. 11  is a perspective top view of an optical data-storage apparatus  1110  capable of interfacing with the optical data-storage media of the present invention and a conventional optical disc medium. With a top cover removed, optical data-storage apparatus  1100  includes optical data-storage apparatus  1000  of  FIG. 10  situated on the top and a conventional optical-disc drive situated under the bottom. The conventional optical-disc drive as known in the art comprises a turntable for mounting an optical disc medium rotatable about a turntable axis and a CD optical head means moveable in a radial direction of a disc surface of the optical disc medium. As known, the optical head means is adapted to allow a laser light beam to be directed to and reflected from the disc surface in a direction generally parallel to the turntable axis. In a preferred embodiment, the turntable (not shown in  FIG. 11 ) and optical unit  1020  (shown in  FIG. 10 ) are arranged in such a manner as to allow an optical disc with data surface facing up to be accessed by an additional optical head disposed on optical unit  1020  ( FIG. 10 ). The combination allows a user to access information stored on both types of optical-storage media.  
      While preferred embodiments of the present invention have been shown and described herein, it will be understood that such embodiments are provided by way of example only. Numerous variations, changes, modification, and substitutions will occur to those skilled in the art without departing from the invention herein. Accordingly, it is intended that the invention be limited only by the spirit and scope of the appended claims.