DE3908150A1 - OPTICAL OR MAGNETO-OPTICAL DATA SYSTEM - Google Patents

Abstract

A read/write storage system for reading/writing data to and from a flexible optical or magneto-optical media (disc or tape eg helically scanned by rotating drum) includes an optical read/write head and a fine movement stabilizer 64 positioned proximate the flexible media for stabilizing the flexible media in a desired position so that the optical head providing focussed light need not be moved substantially toward or away from the media in order to maintain the light focussed on the media. A record disc may be additionally stabilised by Bernouilli plate 66 as part of cartridge (12) (eg Fig 1) or attached to drive 10. Magnetic head (170) below the media and plate (166) may provide stabilisation (Fig 11); coupler (164) surrounding lens (156) may also be shaped for stabilisation. Geometrics of stabilizer (64) and magnetic head (170) are detailed W.r.t. (Figs 5 and 12). The magneto-optical assembly of (Fig 13) includes U-shaped magnetic element (180) and the optical head on the same side of the disc. Alternative head assemblies are detailed (Figs 7, 8, 9). Optical information storage systems are disclosed (eg. Fig 1) including spicule member (28) guiding cartridge (12) and motor (34) for moving arm (30) (with the head assembly). <IMAGE>

Description

The invention relates to the field of optical Information storage systems.

The current focus in the development of Infor mationsspeicherunssystemen lies in the ability to store more and more information in a computer storage system from Save table size ("desk-top size"). This table Storage systems that use magnetically recorded hard or Contains permanent data carriers, such as those on the Winchester Plat drive or storage enclosure system used carriers, currently have the capacity to store up to to 20 megabytes of magnetically recorded information nen. The problem with such storage systems is that there is a need to use the hard or duration data to leave the carrier permanently inserted in the computer. Since the The disk is not easily removable User on any part of the hard disk that for information storage at the time of Use remains. As a result, they are magnetically recorded nete hard disk information storage systems not as a potential solution to increasing informa view storage capacity.

The so-called. Floppy disk storage ("Floppy disc storage"), whereby flexible disks, each with a diameter of entwe 13.335 cm or 8.89 cm and ver are used, provide an easily removable storage device dium. However, the problem lies with such storage systems stemen that the current storage capacity of magne table recorded on a single floppy disk memory Information used in such a system not yet a level like the hard disk drives is enough, i.e. a single floppy disk can only hold about 1-2 megabytes of magnetically recorded information to save.

Information storage systems through optical Devices accessible have a greatly increased Attention because of their potential ability to we to store significantly more data, i.e. of the order of magnitude tion of 400-800 megabytes than it is with either magne hard data carriers recorded on the table or with a diskette tens storage systems is possible. One reason for the significantly increased storage capacity of optical Storage systems is that the diameter of a used to write or read information focused light beam typically only 1 µm. As a result, the density is that of one data Information stored in a slower manner is much larger than that Density of a typical magnetic recording. Additionally can nen the data carriers used in such optical systems ger have a shape that of a so-called diskette memory is similar, i.e. it can be an easy one act removable data carrier. Unfortunately, however, are white Any major problems in progress that affect the development and the commercial acceptance of such optical systems hinder or impair, namely the relative slow speed with which information is compared to magnetic storage storage systems that are currently in use gen size restrictions of so-called desktop computers and the Ability to write-erase and rewrite one Information on a single piece of data carrier.

Let us first consider the current size restrictions to be viewed as. The so-called. Desktop computers are with an on number of modular components, in particular information storage components including components, which can be inserted into the housing of the computer in order to to a certain extent a tailor-made training ("tailor-made tailor-made training ") to adapt to a special Need to offer. Since such components of any size from a larger number the American National Standards Institute has with With regard to such components, certain external standard dimensions Solutions provided, which are generally as full-height and Half-height norm are called. Since the half-height norm is available as a appears to be the most desirable for such modular components, there is a need for an optical information store to develop a safety system that complies with the half-height standard fits is. The half-height standard for modular components is as follows: Height 4.1275 cm, width 14.605 cm and depth 20.32 cm. The Pro problem with current optical storage systems is there rin that current constructions and techniques are components that when assembled, easily request this Exceed size norm. It has been shown that only a few ge of the currently available systems an optical head Kit that is just one component of an optical memory systems, which of such a size standard is adapted.

In the following, the relative slowness is considered, with the one information with current optical informa tion systems compared to magnetic storage systems men can be retrieved. The primary factor that on the problem of the slow access of current op table storage systems is the weight of the op table head kit. It is evident that the bigger the weight of a device for reading from or to The more difficult it is to write on an optical disk The ger and consequently the slower the alignment of a sol chen device with respect to precise locations on a rotate the plate is to be executed.

Current optical storage systems include such as it for video disc or compact disc devices (CD-Ge councils) that are of the "read-only" type and those that are used as optical storage systems (WORM- Systems), i.e. "write-once / read-several-times", be be drawn. Currently there is the possibility of one and write from an optical disk and several Times to read, primarily by those for a use in sol disk available on some systems, although it is clear that the present invention is not limited to Media that currently exist is limited.

Current compact disc systems use an optical disc rotated a central axis. A laser beam is aimed at the Surface of the plate with the help of a lens or an object tivs, a reflective mirror or beam splitter and a projection lens. The laser beam is determined by the information stored on the optical disk mation modulates, whereupon the modulated light through a Light sensor or receiver is detected. Output signals from the light receiver are fed to a processor in order to To deliver information and tracking signals. The source of the laser beam, the lens (objective), the mirror, the projection lens and the receiver become together referred to as an optical head kit. This kit is typically radially across the rotating plate moved away to the In formation to gain access.

Since the data to be read from an optical disk or to the the information to be written in close, close together of the lying traces contained are mechanisms for a rough as well as a fine radial movement is provided. So far it has not been possible, and not even as a been viewed desirable, rough and fine movements in to combine within one mechanism. The mechanism for gross radial movement include either one Swivel arm or a radially directed rail that supports the optical head kit radially across many tracks because. The mechanism for the fine radial movement is working tet generally so that the projection lens entwe the along a radial axis, what the lens to a Brings movement between a few adjacent tracks, or along an axis generally perpendicular to the plate, which offers the projection lens the possibility of dyna mix the laser beam onto the face of the plate during focus of the operation is moved. Such a mechanism Men for a fine movement are available in stores optical head kits manufactured by Olympus Corp. of Lake Success, N.Y. (TAOHS-Series) or by Pentax Teknologies of Broomfield, Col. (VU-108-02 Series) ben will find. An example of such a thing optical head kit is also the US-PS 40 92 529 (Aiha ra et al). The level of these mechanisms for Fine movement also contributes to the problem of size limitation kung at. It is also on the WORM optical storage system stem, which is published by W.L. Rosch under "WORM's for Mass Storage "in PC Magazine, Vol.6, No. 12 (23.6.1987), pages 135-148.

Since the fine motion mechanism is typically a Moving the projection lens using re relatively massive electromagnets is the mass of the optical head kit such that its movement arduous and therefore relatively slow. In an effort Solving the problem of access time is an endeavor gen to downsize the optical head kit, reports been. Since the fine movement mechanism is still a white The essential component is, however, the mass and the Size based on such mechanisms. At for example, by Y. Fukui et al in "New servo method with eccentricity correction circuit "in Optical Enginee ring, Vol. 26, No. 11 (November 1987), pp. 1140-1145, discloses an optical head kit that is a combination of an anamorphic prism, a convex line se and a roof-shaped prism in the endeavor, Data and tracking information signals from a single one Determine light beam. Such a combination seems to result in fewer optical components; the The mass and size of the fine movement mechanism remain however received.

The writing of information on a disk with ge current optical systems will typically by "burning in" the information into the disk enough. Available data carriers in which such burned information easily erased and then re-burned can be written have not yet been developed has been wrapped.

A hybrid design of the optical and magnetic information storage systems, so-called magneto-optical information storage systems, should have the ability not only to satisfy the desire for increased storage capacity, but also with regard to the need to delete optical information and rewrite new optical information, fulfill. It has been estimated that the theoretical upper limit of the storage capacity of such systems can be as high as 300 megabytes / 2.54 cm ^{2 of} the volume. In practice, however, a capacity of approximately 400-800 megabytes can be expected on a floppy disk (13.335 cm).

In magneto-optical memory, data is stored on a thin Foil of a magnetic material with yet to be written recorded or deleted from the properties. In a similar way to magnetic recording the information is stored as a bit sequence, where the magnetic field of the film at a given point ent neither an upward north pole (a digital 1) nor an egg has a downward north pole (a digital 0). At ei On an empty plate, all of their magnetic poles show the downward towards the North Pole. The disadvantage with magneto-optical data carriers it is fond that the magnetic field, i.e. the coercive field, around a magnetic domain (magnetic area) of the downward North Pole to the upward North Pole quickly tip, fluctuates to a large extent with temperature. at Room temperature is the coercive force that is necessary to achieve a North Pole overturning, so high that an over licher magnet is too weak. Falls at approximately 150 ° C the coercive force required to overturn a domain drops to near zero, and a bit can be made using known magnetic recording techniques who recorded the.

Optical techniques are used in the magneto-optical system Application to selected spots (spots or points) on the disk, which is close to a relatively large electric magnet passes through to heat. That way one can Point on the data carrier, causing the to Writing in an information bit required Koerzi tive field is reduced and the magnet as a function of its own North Pole orientation so the desired bit can record with. When the laser beam is turned off the point that has just been heated cools down on the data carrier starting, bringing the aligned North Pole to the desired one Orientation is "frozen". To one that way To delete recorded information, the operation le can only be reversed, i.e. the point on the data carrier ger is heated by the laser beam and the north pole off direction of the magnet designed so that the north poles at Da bear a downward orientation.

As it is undesirable to have any contact with the data to have relatively large electromagnets ver turns. However, such magnets are relatively slow what changing their own polar alignment according to the supplied electrical signal concerns, and therefore who the poles on the data carrier by modulating, e.g. on and Turning off the laser, while aligning the magnet field remains relatively constant.

The reading out of such a on a magneto-optical plat te recorded information is solely through optical Components accomplished. A low energy ray of light energy is focused on the data carrier. That reflected Light comes from either above or below the Da read the carrier. Because of the than the Kerr magneto-optic Effect and phenomena known as the Faraday effect is reflected from the data carrier or received through it The second light has a slightly different polarization compared to the light focused on the data carrier. The change in polarization is a function of the North Pole orientation at this point is either in or directed counterclockwise. For a more graphi cal interpretation of the magnetoopti described above This process is based on Robert P. Freese's "Optical disks become erasable "in IEEE-Spectrum, February 1988, pages 41-45, referenced.

The problem with such magneto-optical information storage security systems lies in the ability to store information to overwrite without two passes over the same Point to have to run on the disk. So far the primary method of overwriting information in ai a magneto-optical system in a two-step process send process. First was above the disk one Run performed to find all information in a pre-set given trace. Following was another Run through the same points to get the ge desired information to be recorded. Since during a magne tooptical recording of the laser with a high switching frequency is switched on and off during the data carrier continuously via an electromagnet with a moving relatively constant magnetic field was the process in two steps the primary method to ensure that there is no unwanted information on the disk remains after the overwrite process is complete.

Efforts to solve this problem have consisted of the Use of two optical heads and associated elec solenoids, which are in a lead-lag manner to each other were arranged so that the leading head in the same Delete pass in which information is recorded can. Another attempt at the problem of the two Solving passages consisted of the suggestion to work next to each other of the lying rays of light, which on adjacent tracks fo have been kissed to use. Another suggestion To solve this problem, the laser energy was constant hold while the magnetic field is modulated. This the latter suggestion was made by H. Kobori et al in "New magneto-optic head with a built-in generator for a bias magnetic field "in Applied Optics, Vol. 27, No. 4 (February 15, 1988), pages 698-702 rejected. The one for this Ab The reason given was that to avoid high data bits to achieve speeds, the generator for the magnet field (the magnetic head) in close proximity to the data carrier must be arranged. Hence, it's not just with difficulty getting a two-sided plate too use, but also the removability of the plate maintain.

Accordingly, there is still a need for a magneto optical storage system capable of storing a previously stored information in just a single pass overwrite without the problems related to size and access times that are common to other optical storage systems men can be found.

According to a first aspect of the present invention tion becomes an optical read-write storage system for the Le sending and / or writing data from or to a a flexible optical or magneto-optical data carrier which comprises: an optical read-write head, the focused light on the flexible data carrier sends and reflects light from this flexible data carrier receives, as well as one assigned to the optical read head nete or associated with this and for flexible data fine stabilizers arranged immediately adjacent to the carrier device that stores the flexible data carrier in a ge desired position stabilized so that the optical reading head essentially no movement towards the disk or run away from this in order to keep the light on the data keep carrier in focused state.

According to a second aspect of the present invention tion becomes an optical read-write storage system for the Le sending and writing of data from and to a flexible optical or magneto-optical data carrier created that comprises: an optical read-write head that is focused Light transmits to the flexible data carrier as well as from the flexible data carrier collected light detected, and ei ne assigned to the optical read head or with this ver bound and immediately adjacent to the flexible data carrier bart arranged fine stabilizer, which the flexible disk stabi in a desired position lized so that the optical read head essentially kei ne movement towards or away from the data carrier must lead to the light on the disk in focused To keep state.

In accordance with another aspect of the Invention is an information read-write memory system stem for reading and / or writing data from a or on a flexible magneto-optical data carrier comprising: a magnetic recorder direction with one in the immediate vicinity of the data carrier arranged recording head, the information on records on the disk at a point known as the area of the data carrier is determined on which a Information recorded at any given time is, and an optical read-write device that wäh rend of reading and writing focused light on the Data carrier emits light reflected from the data carrier to read the information receives as well as continuously focused light on the disk to heat the said point, while the magnetic record recording device.

Embodiments of optical information storage systems according to the invention are capable of either an optical disk with speeds that Ma gnet storage systems are comparable to information read or write to this data carrier, they have a lightweight optical head kit and them can be gefer in such dimensions without difficulty which correspond to the half-height norm.

From the exemplary embodiments described below it can be seen that an optical or magneto-optical Information storage system can be created that the need for a dynamic focusing mechanism mus eliminated by using a flexible optical disk is precisely stabilized during the read-write processes, this stabilization on a primary and a secondary level, both a hanging or a hän Low storage of the data carrier on a by the Ber Noulli principle include air bearings generated.

The invention will be described with reference to the drawings hand of exemplary embodiments explained. It demonstrate:

Fig. 1 is a perspective view of an optical informa tion storage system according to the invention;

Fig. 2 is a schematic representation of the storage system;

Fig. 3 is an oblique view of part of the system shown in Fig. 1 is;

FIG. 4 shows the section along the line 4-4 in FIG. 3; FIG.

Fig. 5 is an enlarged view of part of the coupling piece of Fig. 3;

FIG. 6 is a schematic representation of the optical components shown in FIG. 3; FIG.

Fig. 7 is a schematic side view of is provided in Figure 6 the optical components in a abgewandel th embodiment.

Figure 8 is a plan view of the modified optical components shown in Figure 6 in a further embodiment..;

FIG. 9 shows a side view of a further modified embodiment of the optical components from FIG. 6; FIG.

FIG. 10 shows a perspective illustration of part of the magneto-optical information system in an embodiment modified from FIG. 1;

Figure 11 is a section along the line 11-11 in FIG. 10.;

Fig. 12 is an enlarged view of a portion of the coupling piece and magnetic head shown in Fig. 10;

Fig. 13 is an oblique view of a modified Ausfüh approximate form of the magneto-optical system.

Fig. 1 shows a the principles of the present invention constructed in accordance with information storage system 10. A cartridge 12 is partially inserted into a disk drive or disk storage housing 14 so that the ver sliding cover 16 has started to move sideways. When this sideways movement is complete, an opening 18 shown in FIGS. 2-4 is exposed so that a flexible data carrier plate or disk 20 can be acted upon.

In the plate 20 is a central hub 22 for a handle with a drive spindle 24 , when the cartridge 12 is fully inserted into the housing 14 , to rotate the plate 20. The lower cover 26 of the Ge housing 14 is shown partially cut away to expose an attachment or holding part 28 which is used to guide the cassette 12 during its insertion and the arm 30 during access to the plate 20 . Although this is not shown in full detail in FIG. 1, a head assembly 32 is arranged at the free or distal end of the arm 30. A linear drive motor 34 is used to move the arm 30 in the holding part 28 , so that the head assembly 32 is moved radially over the surface of the plate 20 . Although various types of linear drive motors are available for use with the subject invention, it is preferred that the selected linear drive motor be able to provide both coarse and fine movement of arm 30 to both track to look for the head kit 32 as well as to follow this trail. The range of motion of the arm 30 extends from the retracted position shown in FIG. 1 to such an extended position that the free end of the arm 30 abuts against a stop 36.

The details of the construction of the cassette 12 , in particular its one-piece Bernoulli surface, and its onset and engagement by various Plat tenantriebsbauteile are explained in detail in the following documents: US-PS's No. 47 69 733, 47 40 851 , 47 43 989, 46 58 318, in U.S. Pat. Ser.-No. 8 54 342 "Disc-Drive Motor Mount" (McCurtrey et al), filed April 21, 1986, in US Pat. Ser no. 8 54 333 "Disk To Spindle Engaging Device" (Jones et al), filed April 21, 1986 and in GB Pat. No. 21 90 232. The content of these patents and applications is hereby made the subject matter of the present invention. The content of US Pat. Ser.-No. 9 47 632, "Disc Cartidge" (Bauck et al), filed on December 20, 1986, which refers to US Pat. No. 4,658,318 (patented on April 1, 1986), made the subject of the disclosure of the present invention. Since these applications are primarily concerned with magnetically recorded information storage systems, the data carriers (the applications disclosed the use of double disk drives in a single cassette) and the facilities for reading and writing from or on the recording medium are different. On the other hand, the structure used in these applications can be made substantially identical to that which can be incorporated into a memory system according to the present invention. It is believed that a single disk memory can be used for the dual disk memory used in these applications.

A disk drive and spei available on the market cassette for magnetic recording from Informa options that can be modified to be an opti cal or magneto-optical information storage system stem in accordance with the present invention is offered by IOMEGA Corp. of Roy, Utah (USA) provided and distributed Beta 20 system. It should be clear be that the circuit design and programming that used in the Beta 20 system to get through a magnetically recorded information generated Ana Converting log signals into a digital signal is a modifi Make decoration necessary, so that the optically recorded information generated analog signals also in a digital signal can be converted. The technolo gie for converting such optically generated analogs signals in digital signals is known.

Fig. 2 shows an optical information storage system schematically. A disk drive motor 40 causes the disk 20 to rotate. This rotation is triggered by a suitable activation signal from the processor 42 . When the disk 20 rotates, the processor 42 provides an activation signal to the linear drive motor 34 so that radial movement of the optical head assembly 32 over the surface of the disk 20 is caused. The head assembly 32 illuminates a limited area on the disk 20 with a beam of light in a manner to be described in response to a further activation signal from the processor 42 . Information stored on the disk 20 modulates the light reflected away from the surface of the disk 20 , which light is received by the head assembly 32 and converted into an electrical signal which is fed to the processor 42. Various methods are known to accomplish this operation, but the invention is not limited to the use of any particular method. Likewise, the present invention is not limited to the use of any particular method of storing information on disk 20 . The processor 42 causes the disk 20 to rotate, the head assembly 32 is moved radially over the disk 20 with the aid of the linear drive motor 34 and a desired information is written onto the surface of the disk 20 by the head assembly 32 .

If the system is a magneto-optical system, like in the preferred embodiment, then the conversion development of an electrical signal of the reflected light bewerkstel by a differential detection arrangement ligt. It should be noted that a magneto optical disk at a point where information has been written, either reflected or through the plate transmitted light a slightly different Liche polarization compared to that focused on the plate th light will have. The change in polarization depends on the North Pole orientation at this Point either clockwise or counterclockwise. By guiding the reflected light through a beam splitter, detecting each of the split light rays and comparing the detected light rays, it is possible to determine whether the reflected light is in its Polari sation modified is what the presence of a digita len, indicates 1 stored on disk. Since this species a detection arrangement with respect to another magneto optical device by M. Mansipur et al in "Signal and noise in magneto-optical readout "in Journal of Applied Physics, Vol. 53, No. 6 (June 1982), pp. 4485-4493 be has been written, will not go into further detail here received.

Figs. 3-9 relate to an optical information system. Referring to FIG. 3, the cassette is completely inserted is 12, and the arm 30 has been extended so that the optical head kit 32 has moved radially over the surface of the plate 20. The head assembly 32 includes a laser diode 44 with conductors 46 which, of course, are electrically connected to the processor 42 for operation in any of several known ways. The laser diode 44 serves as a light source for the optical head assembly 32 . The term "light" used here is intended to include both visible and invisible light or, more precisely, electromagnetic radiation. In particular, the term "light" means that light with a wavelength in the range of 200-2000 nm is used.

As shown in FIGS. 3, 4 and 6, the light emitted by the laser diode 44 is passed through an aperture plate 48 which serves to limit or collimate the diameter of the beam to a desired dimension, this dimension in the preferred embodiment form is equal to the smallest permissible beam diameter in the optical system. The light transmitted through the diaphragm plate 48 is further collimated by an objective 50 and fed to a polarization beam splitter 52 , where it is reflected in the direction of the plate 20. The light reflected by the polarization beam splitter 52 is then passed through a λ / 4 plate 54 which, as is known, acts to change the plane of polarization of the light. After the reflection, the plane of polarization of the light guided through the λ / 4 plate 54 will be delayed or shifted by 90 ° and to the extent that it will pass through the mirror surface contained in the beam splitter 52 and will not be reflected back to the diode 44.

Light emerging through the λ / 4 plate 54 towards the plate 20 is first guided through the lens 56 , whereupon the light is focused on the surface of the plate 20 . In contrast to previous Ge optical memory systems 56 is not mounted in such a manner the lens to be moved with respect to the arm 30, but rather is fixed in the arm 30th Light reflected away from the surface of the plate 20 is then collimated by a lens 56 and passed through the λ / 4 plate 54 . Since, as has already been said, the plane of polarization of the light has now changed by 90 °, it will pass through the beam splitter 52 and focus on the receiver 60 through the lens 58. Lenses 56 and 58 can be gradient index lenses.

Although various different types can be used for the receiver 60 , the receiver used by Sony Corp. manufactured and sold model IT338 used. Such a receiver is used to record, ie differentiate, both data and tracking information. The receiver 60 in turn generates electrical cal signals which are characteristic of the detected data and Nachführinforma functions. These signals are then transmitted to processor 42 via conductor 62. As a result, the signals from the receiver 60 not only serve to provide access to information, but they also enable the processor to evaluate the tracking information and to feed the appropriate signals to the linear drive motor 34 to the arm 30 in a in such a manner that the optical head assembly 32 can be positioned radially above the desired track on the disk 20 and follow it. As shown in FIG. 4, the lens 56 is held firmly in the connecting or coupling piece 64 , which in turn is firmly supported in the arm 30.

Although not shown, it should be understood that an opaque cover can be placed over the optical head assembly 32 to prevent leakage and also protect the head assembly 32 from the environment as well as from dust.

The lens 56 can be held stationary in the arm 30 due to the elimination of the need to dynamically focus light from the diode 44. The need to perform dynamic focusing has been eliminated as a result of the degree or extent of stabilization offered to plate 20 and the ability to predict the distance between plate 20 and lens 56 during operation . This stabilization and predictability arises from two sources, namely the plate 66 provided in the cassette 12 in the preferred embodiment and the coupling piece 64 . The plate 66 provides a primary stabilization, while the coupling piece 64 brings about a secondary stabilization of the data carrier. The surface of the plate 66 which faces the data carrier plate 20 is a Bernoulli surface which serves to create and maintain an air bearing between the data carrier plate 20 and the plate 66. The structural features that enable the creation of this air bearing the Bernoulli surface as a result are known and will not be repeated here. However, the application of this phenomenon to optical information storage systems to eliminate the need for dynamic focusing of light on the data carrier is not known.

Although in the preferred embodiment the plate 66 forms part of the cassette 12 , it is within the scope of the invention to physically attach the plate 66 to the disk storage housing 14. In this alternative embodiment, the cartridge 12 is constructed so that it is possible to assign the plate 66 when the disk 20 is fully inserted into the cassette 12 near this disk 20 to assign.

While the media disk 20 is primarily stabilized by the air bearing created by the disk 66 , it should be remembered that the optical head assembly 32 accesses the disk 20 through the opening 18. This opening 18 is also present in the plate 66 . In the area of this opening 18 , the data carrier disk 20 is not stabilized. Accordingly, the coupling piece 64 serves to provide a local secondary stabilization in the area surrounding the lens 56 by creating and maintaining an air bearing through which that part of the data carrier plate 20 which passes just below the coupling piece 64 in a very close to this close and predictable positional relationship is maintained. Although the details of the construction located in the coupling piece 64 to produce an air bearing are described in US Pat. No. 4,414,592 (Losee et al), the content of which is hereby made the subject of the disclosure of the invention the application of this phenomenon to optical information storage systems to eliminate the need for dynamically focusing light on the disk is not known.

Referring to FIG. 5, the surface of the coupling piece 64 generates an air bearing between this coupling piece and the Datenträ carrier plate 20, and holds this air bearing upright. In the preferred embodiment, the distance A between the coupling piece and the data carrier plate is approximately 5-10 μm ± 0.5 μm. There are a number of alternative designs and constructions for a coupling piece that are able to achieve the required stabilization of the data carrier. In one of these constructions, the positional relationship between the coupling piece 64 and the plate 20 is achieved in that a substantially planar surface 70 surrounding the lens 56 (not shown) and a number of increasingly steeper ones are attached to the surface 70 subsequent patches are used. It should be noted that in Fig. 5 these surface pieces are not readily distinguishable and in this respect a certain degree of exaggeration of the curved surface pieces is necessary. In the preferred embodiment, the surface piece 72 is a curved surface with a radius of curvature of about 500 mm, the surface piece 74 is also a curved surface with a radius of curvature of about 270 mm, while the surface piece 76 has a generally straight, conical surface is at an angle of approximately 45 ° to surface 70 . It should also be noted that the special radii of curvature selected for the surface pieces 72 and 74 can be changed as a function of the properties selected for the data carrier, such as toughness, hardness and rigidity, and the presence and characteristics of lubrication. The radius of curvature of the lens 56 (not shown in FIG. 5) and the distance with which it protrudes from the surface 70 are also dependent on the properties of the selected data carrier medium. In the preferred embodiment, the radius of curvature of lens 56 is approximately 50 mm, with it protruding from surface 70 approximately 0.02 mm.

It should be particularly noted that the construction of the coupling piece 64 can be used to stabilize either rotating flexible disks, such as the data carrier disk 20 , or tape-shaped optical data carriers. For the construction it is only necessary to generate and maintain an air bearing between the optical head accommodated in the coupling piece 64 and the data carrier, the data carrier either being rotated, moved linearly past the coupling piece 64 or scanned in a spiral form by a rotating drum, what are geometries known in the magnetic data recording art. Furthermore, it may not be absolutely necessary to design the plate 66 for Bernoulli stabilization of a rotating plate. In fact, such stabilization is not required for tape-shaped data carriers. In this respect, the invention is applicable to both flexible optical cal disks and tapes.

FIG. 7 shows a modified embodiment of the optical head assembly shown in FIG. Light passing through the lens 50 is fed to a prism 80 which is a combination of an anamorphic correction and polarization beam splitter prism. In order to reduce the size of the optical head assembly, it was found that some degree of anamorphic correction to the light emitted by diode 44 (not shown) was necessary. The shape of the prism 80 is chosen so that the first optical axis is perpendicular to the last optical axis. For the gradient index lens 56 of FIG. 6, an objective lens 82 was used here. It has been shown that the objective lens provides better wavefront image aberration correction compared to the gradient index lens. To reflect the light towards lens 58 , a polarization beam splitter coating 84 is provided. The light then has a plane of polarization which has been delayed or shifted by the λ / 4 plate 54.

Fig. 8 shows a plan view of a further alternati ve embodiment of the optical head assembly shown in FIG. In a manner similar to the kit of FIG. 7, an objective lens 82 is provided in order to focus light onto the data carrier system 20 (not shown in FIG. 8). A prism 86 is provided so that the lens 58 and lens 50 can now be placed very close together, further reducing the height of the optical head assembly. A polarization beamsplitter coating 88 is also provided to reflect light towards lens 58 . A mirror surface 90 is used to bend the beam path in order to totally reflect light either from the prism 86 to the objective lens 82 or from the objective lens 82 to the prism 86 .

FIG. 9 shows a further modified embodiment of the optical head assembly shown in FIG . There are circumstances or conditions during which it may be desirable to bring about a focusing effect. For this purpose, the laser diode 44 is fixedly mounted on a device 92 designed in the manner of a switching magnet. The objective 50 and the beam splitter 52 are, however, held on a plunger 94 by supports 96 . The device 92 is designed so that the distance between tween the lens 50 and the diode 44 can be changed by choosing a suitable signal on the conductor 97 from the processor 42 can be changed. Such a signal can be supplied by the processor in that it decides from the signal supplied by the receiver 60 on the need for a focusing of the light. Methods for making such decisions are currently known with respect to dynamically focused optical systems. Light emitted by the beam splitter 52 is then reflected by a prism, which has a mirrored surface 98 , through the λ / 4 plate 54 and the lens 56 onto the surface of the data carrier disk 20.

Figs. 10-13 relate to magneto optical storage systems according to the invention. In the following description, components relevant to the magneto-optical aspect of the invention are denoted by reference numbers increased by 100. As shown in FIG. 10, the cassette 112 has been fully inserted and the arm 130 has been extended so that the magneto-optical head assembly 132 has moved radially over the surface of the disk 120 . As can be seen, the arm 130 is divided into an upper arm half 130 A and a lower arm half 130 B , the data carrier disk 120 running between these halves. The magnetoopti cal head kit 132 is also divided between the arm halves 130 A and 130 B to carry the optical and magnetic parts of the head kit.

It should first of the optical part of the kit, which is supported by the Armhälfte 130 A and a laser diode 144 comprises ladders 146, are considered. Although not shown, it will be understood that the conductors 146 are electrically connected to a processor 42 (see FIG. 2) for operation in any of several known ways. The laser diode 144 serves as a light source, with the term "light" having meanings previously discussed.

According to Fig. 10 and 11, out of the laser diode 144 emitted light is passed through the lens 150 and collimated. Then this light is passed through the polarization beam splitter 152 , whereupon it reaches the prism 154 and plate 120 is reflected by a mirror surface 155 in the direction of the data carrier. The lens 150 can be a gradient index lens. The light reflected from the prism 154 is then passed through the lens 156 , which focuses the light onto the surface of the data carrier disk 120. In contrast to previous magneto-optical storage systems, the lens 156 is not mounted such that it is movable with respect to the arm 130. Rather, the lens is stationary with respect to the arm 130. Light reflected from the surface of the data carrier plate 120 is then in turn collimated by the lens 156 , guided through the prism 154 and reflected by the mirror surface contained in the beam splitter 152. Since the light is reflected away from the surface of the data carrier disk 120 , detection of the Kerr effect is dependent. The light reflected from the data carrier and referred to as the "reading beam" has two possible orientations of its plane of polarization, which depends on the orientation of the magnetic moment at the point of reflection on the data carrier medium. Each of these orientations of the reflected light has its plane of polarization rotated a few degrees with respect to the plane of polarization of the illuminating beam. The read beam is limited up by the objective lens 156 again kol and reflected by the prism 154 return to the beam splitter 152nd In the preferred embodiment, the beam splitter 152 is a "leaky or scattering" polarization beam splitter that reflects not only the polarization component of the laser beam generated by the rotating effect of the disk, but also some of the larger polarization component of the light , which is in the original plane of the illuminating beam, reflected. Accordingly, the portion of the reading beam reflected by the beam splitter 152 is an essentially constant fraction of the total intensity of the reading beam incident on the beam splitter 152 , but the rotational difference between the two possible polarization orientations is exaggerated. The reading beam then passes through the λ / 2 plate 157 to the beam splitter 158 , which is a polarization beam splitter which splits the light into two beam components which are focused on receivers 160 A and 160 B by lenses 159 A and 159 B, respectively. The lenses 156 , 159 A and 159 B can be gradient dex lenses. The λ / 2 plate 157 serves as a rotary member to the planes of polarization of the read beam to hernd to rotate Annae 45 °, wherein the intensities of the thus set to an agent reflected and transmitted, emerging from the beam splitter 158 beams are equal.

Different types can be used for the receivers 160 A and 160 B , but a receiver that is preferably used is that of Sony Corp. manufactured and sold model IT338. Such a receiver is used to record or differentiate between data and tracking information. The receivers 160 A and 160 B in turn generate electrical signals which are characteristic of the acquired data and tracking information, these signals then being transmitted to the processor 42 via the conductors 162 . As previously mentioned, the signals from each of the receivers are compared in processor 42 to determine if there is any difference between the signals. The difference between the two signals is an indication of the or identification of the magnetic range polarity and, to that extent, of the logical state stored on the data carrier disk 120 at the point of reflection. For example, a positive difference is an indication of a digital 1 stored at the point, while a negative difference is an indication of a digital 0 stored at the point.

The signals from the receivers are not only used to supply accessed information, but also enable the processor 42 to evaluate the tracking information and to provide the appropriate, appropriate signals to the linear drive motor 34 to the arm 130 so that the magneto-optic head assembly 132 can be positioned radially over a desired track on the disk 120 and follow it. The lens 156 is fixedly mounted in the connecting or bearing piece 164, which is in turn held firmly in the Armhälfte 130 A.

A magnetic head 170 is in the lower arm half 130 B BEFE Stigt. By moving a data carrier between the magnetic head 170 and the lens 156 , information can be magnetically recorded on the disk 120 at the points heated by the light focused by the lens 156.

The lens 156 and magnetic head 170 can be fixedly mounted in the arm 130 due to the elimination of the need to dynamically focus the light emitted by the diode 144. The need to dynamically focus this light has been eliminated as a result of the amount of stabilization imparted to the disk 120 and the predictability of the distance between the disk 120 and lens 156 during operation. This stabilization and predictability arises from two sources, namely the disk 166 provided in the cartridge 112 in the preferred embodiment and the magnetic head 170 . The plate 166 provides primary stabilization, while the magnetic head 170 allows secondary stabilization of the data carrier medium to be achieved. The surface of the disk 166 that faces the data carrier disk 120 is a Bernoulli surface which is used to create an air bearing between the data carrier disk 120 and the disk 160 and to maintain it upright. The design features that result from the generation of this air bearing by the Bernoulli surface are known and will not be repeated here. However, it is not known to apply this phenomenon to magneto-optic information storage systems to eliminate the need for dynamic focusing of light on the data carrier disk.

Although the plate 166 is shown in the preferred embodiment as an integral part of the cartridge 112, in an alternative embodiment the plate 166 may be attached to body Lich on the disk storage or disk drive housing. In this alternative construction, the cassette 112 is modified in a suitable manner so that the disk 166 can be placed on the data carrier disk 120 first. Accordingly, when the cartridge 112 is fully inserted into the disk drive housing, the operation of the Bernoulli surface of the disk 166 with respect to the generation of the primary stabilization of the disk 120 is essentially identical to the process already described above.

Although not shown in the drawings, an opaque cover can of course be provided over the magneto-optic head assembly 132 to block stray light and also to protect the magneto-optic head assembly 132 from the environment as well as from dust.

Although the disk 120 has been stabilized by the air bearing created by the Plat te 166 , it should be understood that the magneto-optic head assembly 132 through the opening 118 provided in the disk 166 , as well as through the opening 18 of the previous Ausfüh approximately examples to the plate 120 can take access. In the area within the opening 118 , the plate 120 is not stabilized. Accordingly, the magnetic head 170 is used to bring about a local secondary stabilization in which the lens 156 surround the area by creating and maintaining an air bearing that that part of the data carrier disk 120 that goes over the magnetic head 170 , in a near and, as will be described, holds predictable positional relationship to this. Although the details of the construction contained in the magnetic head 170 to form the air bearing have been described in US Pat to eliminate dynamic focusing of light on the disk, not known.

Referring to Figure 12, the surface of the coupler or magnetic head 170 creates an air bearing between the magnetic head 170 and the disk 120 , and this surface maintains the air bearing. In the preferred embodiment, the distance between the magnetic head and the data carrier plat is approximately 5-10 µm ± 0.5 µm. There are a number of alternative designs and constructions for coupling pieces that are able to provide the required stabilization of the data carrier. In one of these constructions, this positional relationship between the magnetic head 170 and the disk 120 is achieved in that the Ma gnetkopf 170 with a substantially flat surface that surrounds the lens 156 , and with a series of increasingly steeper surface pieces that adjoin the surface 171 then is provided. It should be noted that in Fig. 12 these patches cannot readily be distinguished and a certain degree of exaggeration of the curved-shaped patches is necessary. In the preferred embodiment, the patch 172 is a curved surface formed with a radius of curvature of 500 mm, the patch 174 is also curved, with a radius of curvature of 270 mm, while the patch 176 is a generally flat surface that is with the Surface 171 forms an angle of 45 °. Although not shown in Fig. 12, a similar means for secondary stabilization can be provided for the optical head assembly. In particular, stabilization around lens 156 is achieved by forming a similar set of curved surface pieces for connecting or bearing piece 164 surrounding lens 156. It is therefore within the scope of the invention to provide such stabilization on one or both parts, ie the magnetic head 170 and the connecting piece 164 , respectively.

In particular, it should be noted that the construction of magnetic head 170 and connector 164 can be used to stabilize either rotating, flexible disks, such as disk 120 , or tape-like formations of magneto-optical data carriers. This construction only needs an air bearing between the magnetic head or the connector and the data carrier, which is subject to rotation, which moves linearly past the magnetic head or can be scanned in a spiral shape by a rotating drum, in geometrical arrangements as they are in the technology of magnetic recording are known, create and maintain. Furthermore, it may not be absolutely necessary to provide the plate 166 for Bernoulli stabilization of a rotating plate, since such stabilization is actually not necessary for a tape-shaped data carrier. Therefore, the present invention is applicable to both magneto-optical disks and tapes.

Since the surface of the disk 120 is stabilized at a relatively fixed distance from the magnetic head 170 , it is possible for the first time to operate a magneto-optical storage system so that the magneto-optical head continuously focuses light on the surface of the disk 120 . Accordingly, information is stored on the disk 120 by changing the orientation of the magnetic field of the magnetic recording element of the magnetic head 170. Since the magnetic head 170 is of a size which is used for magneti cal recording of information on floppy disks (so. Floppy disks), the problem of relatively slow switching of the magnetic field orientation, which is present in previous devices, can be eliminated.

Fig. 13 shows a modified embodiment of the ma gneto-optical head kit. Instead of dividing the arm 130 into upper and lower halves, it may be desirable to arrange the magnetic recording head 170 and the optical head on the same side of the data carrier disk 120. Since the purpose is to be magnetically aufzeich in the same place, the magnetic head 170 with a U-shaped Magnetele element 180 has been provided. It should be understood that the magnet element 180 is an electromagnet to which a magnetic field is imparted in accordance with an electrical signal on the conductors 182. Directed to the surface of the As tenträgerplatte 120 to focusing light is between the legs 184 A and 184 B of the magnetic element 180 therethrough. The height of the magnetic head 170 is to be considered, that is, because the magnetic head will be slightly further from the disk 120 , this distance must be taken into account when selecting the lens 156.

In the following, the magneto-optical information storage system during write and read processes is entered. During a write process, information to be written on the flexible data carrier is organized by the processor 42 for subsequent storage on the disk 120 . Assuming that processor 42 has determined from the signals received from receivers 160 A and 160 B that the magneto-optical head assembly is positioned over a desired track on disk 120 , processor 42 activates laser diode 144 generating signal. When the laser diode 144 is activated, information to be written onto the disk 120 is stored in a known manner by changing the orientation of the magnetic field of the magnetic head 170. Since the plate 120 is heated at the point at which the light from the laser diode 144 is focused, the poles located on the data carrier within this heated area will assume the alignment of the magnetic field generated by the head 170. This reorientation of the poles on disk 120 continues until processor 42 has written all of the information to be stored. It should be understood that during this write operation, of course, the disk 120 revolves around the hub 22 and the linear drive motor 34 operates the arm 30 in such a way that the magneto-optic head assembly 132 is moved radially across the disk 120 , as shown in FIG Responding to signals from processor 42 occurs.

During the reading process, light from the laser diode 144 is focused onto the surface of the plate 120 . Indeed, it is preferred that the energy associated with the reading light be such that any heating of the plate 120 by the light is minimal. Light reflected from the surface of disk 120 passes through the magneto-optic head in the manner previously described and results in a series of electrical signals that are generated and fed to processor 42. The processor 42 determines the difference between the signals from the receivers 160 A and 160 B and uses this result to decide whether a logical 1 or logical 0 stored on the disk 120 is present. If the processor 42 decides on a difference in these signals from the receivers 160 A and 160 B , a logical 1 is basically present on the data carrier medium. If there is no difference between the signals, there is a logical 0 on the data carrier.

Although the invention with reference to special embodiments from WUR described and shown in the drawings, it is clear that the skilled person modifications and Abänderun conditions are given to the hand without leaving the framework of the Grundge of the invention. For example, in a modified embodiment (not shown), the linear drive motor 34 can be replaced by a rotating drive motor. Here, the device will move across the surface of the disk 20 in a manner that is similar to the movement of the tonearm of a conventional turntable. Accordingly, in this embodiment, the arm 30 and the recognition or holding member 28 would not have the configurations shown in Fig. 1, but should be suitably modified to provide an accurate positioning and movement of the head kit 32 via the surface of the data carrier plate 20 away to enable.

Claims (16)

1. Optical read-write storage system for reading and / or writing data from or onto a flexible optical or magneto-optical data carrier, characterized - by an optical read / write head ( 32 , 132 ) which focuses light on the flexible data carrier ( 20 , 120 ) emits and receives reflected light from this flexible data carrier, and - By one of the optical read / write head associated with or connected to the flexible Datenträ ger immediately adjacent arranged fine stabilization device ( 64 , 164 ), which stabilizes the flexible data carrier ( 20 , 120 ) in a desired position, so that the optical Reading head ( 32 , 132 ) essentially does not have to move towards the data carrier or away from it in order to keep the light on the data carrier in fo kussed state. 2. Optical read-write storage system for reading and / or writing data from or onto a flexible optical or magneto-optical data carrier, characterized

• - by an optical read / write head ( 32 , 132 ) which transmits focused light onto the flexible data carrier ( 20 , 120 ) and detects light collected by the flexible data carrier, and
• - by a fine stabilization device (64 , 164 ) which is assigned to the optical read head or is connected to it and is arranged immediately adjacent to the flexible data carrier, which stabilizes the flexible data carrier ( 20 , 120 ) in a desired position so that the optical read head ( 32 , 132 ) essentially does not have to move towards or away from the disk in order to keep the light on the disk in the focused state.

3. Storage system according to claim 1 or 2, characterized by one of the flexible data carrier ( 20 , 120 ) immediately adjacent arranged coarse stabilizing device ( 66 , 166 ), which roughly stabilizes the data carrier during reading and writing of data and an access to the has flexible data carrier forming opening ( 18 , 118 ). 4. Optical read-write storage system for reading and writing data from or to a flexible data carrier

• - by a coarse stabilizing device ( 66 , 166 ) which is arranged near the flexible data carrier ( 20 , 120 ) and roughly stabilizes the data carrier during the reading and writing of data and an opening ( 18 , 18, 118 ),
• - by a light source ( 44 , 144 ) which supplies a type of light suitable for reading and writing information on the flexible data carrier,
• - by a polarization beam splitter (52 , 152 ) arranged to receive the light from the light source,
• - By a motion device connected to the beam splitter ( 34 , 92 ) which positions the beam splitter over the flexible data carrier ( 20 , 120 ) so that the light from the light source is reflected on the flexible data carrier,
• - by an optical phase shift device ( 54 , 154 ) which is arranged near the beam splitter and converts the polarization of the light as it passes through this device,
• - Through a lens arrangement ( 56 , 156 ) which is located near the phase shift device and focuses the light passing through the phase shift device onto the flexible data carrier on the flexible data carrier and collects light reflected from the data carrier and feeds it to the phase shifting device,
• - By a receiving device (60 , 160 A , 160 B ) which is arranged near the beam splitter and which receives the reflected light and generates an information signal in response to this reception, and
• - By a fine stabilizer ( 64 , 164 ), which is connected to the beam splitter and initially arranged the flexible data carrier and stabilizes the flexible data carrier in a desired position, so that the lens ( 56 , 156 ) essentially not to the data carrier must be moved towards or away from this in order to keep the light on the disk in the focused state.

5. Apparatus for reading and / or writing optically detectable data from or to a data carrier contained in a cassette, the cassette being provided with an opening through which the flexible data carrier can be accessed, characterized

• - By a cassette ( 12 , 112 ) with the opening ( 18 , 118 ) located therein in a predetermined position receiving and positioning device ( 28 , 36 ),
• - by an optical system ( 50 , 52 , 54 , 56 , 150 , 152 , 154 , 156 ) with an arrangement by which a light beam is to be brought to a focus at a predetermined plane when the cassette ( 12 , 112 ) is in the receiving device ( 28 , 36 ) is inserted, the light beam passes through the opening ( 18 , 118 ) of the cassette and the predetermined plane lies within the boundaries of the cassette,
• - By a flexible data carrier ( 20 , 120 ) about a substantially perpendicular axis to its plane dre existing device ( 22 , 40 ) and
• - By a Bernoulli effect causing Einrich device ( 64 , 66 , 164 , 166 , 170 ), which locally deflects the flexible data carrier in the area of the opening, so that the deflected part of the data carrier is essentially in a stable, coincident positional relationship reaches the predetermined plane and the light beam on the data carrier without the need for focus adjustment while the data carrier rotates, is to be kept focused.

6. Apparatus according to claim 5, characterized in that the device causing the Bernoulli effect has a coupling piece ( 64 , 164 ) with a the cassette when the cassette ( 12 , 112 ) is inserted into the receiving device in accordance with the opening ( 18 , 118 ) comprises arranged surface, wherein the surface of the coupling piece encloses the beam path of the light beam through the coupling piece. 7. Apparatus according to claim 5, characterized in that the device causing the Bernoulli effect is a coupling piece ( 170 ) with a surface which is arranged so that it with the opening ( 118 ) when inserted into the receiving device cassette (112 ) is aligned, wherein the coupling piece is arranged on the opposite side of the flexible data carrier ( 120 ) to the optical system. 8. Apparatus according to claim 7, characterized in that the coupling piece ( 170 ) magnetic devices ( 180 , 184 A , 184 B ) which are suitable for reading and / or writing of ma gnetooptischen data, comprises. 9. Apparatus according to claim 5, characterized in that the device causing the Bernoulli effect has a first coupling piece ( 164 ) with a surface which is aligned with the opening ( 118 ) when the cassette (112 ) is inserted into the receiving device, and a second Coupling piece ( 170 ) with a surface which is aligned with the opening when the cassette is inserted into the receiving device, the first and second coupling pieces being arranged on opposite sides of the predetermined focal plane of the light beam. 10. Device according to one of claims 5 to 9, characterized in that the receiving device is assigned a coarse stabilization of the rotating data carrier ( 20 , 120 ) causing Bernoulli plate ( 66 , 166 ), the Bernoulli effect causing Device ( 64 , 164 ) produces a fine stabilization of part of the data carrier when a surface of the data carrier crosses the opening ( 18 , 118 ). 11. Device for reading and / or writing optically detectable data from or onto a flexible data carrier tape, characterized

• - by a read-write arrangement which comprises an optical system which brings a light beam to a focus on a predetermined plane,
• - By means of a device transporting the tape along a path traversing the read-write arrangement and
• - By a Bernoulli effect causing Einrich device that locally deflects the flexible tape in the vicinity of the read-write arrangement in order to bring the deflected part of the data carrier into a substantially sta bile, coincident relationship with the predetermined plane, so that the light beam on the tape can be maintained in a focused state without the need for focus adjustment while the tape moves past the read-write assembly.

12. The device according to claim 11, characterized in that the device causing the Bernoulli effect Coupling piece with a surface that is in the area of the Read-write arrangement is located and over which the tape at running its way through the read-write arrangement. 13. Device according to one of claims 6 to 11, characterized in that each existing coupling piece ( 64 , 164 , 170 ) has an interface at which the outer surface of the coupling piece extends away from the predetermined plane. 14. The device according to claim 13, characterized in that the boundary surface comprises a number of surface pieces (72 , 74 , 76 , 172 , 174 , 176 ) with different radius of curvature or different inclination. 15. Information read-write storage system for reading and / or writing data from or to a flexible magneto-optical data carrier, characterized

• - By a magnetic recording device with a in the immediate vicinity of the data carrier ( 120 ) arranged recording head ( 170 ), which records information on the data carrier at a point which is determined as the area of the data carrier at wel chem information about any given Time is recorded, and
• - Through an optical read-write device ( 150 , 155 , 156 ), which emits focused light onto the data carrier during reading and writing, receives light reflected from the data carrier for reading the information and continuously focused light on the data carrier to heat the point while the magnetic recording device ( 170 ) is recording.