CA1078513A - Actuator mechanism for disk storage apparatus - Google Patents
Actuator mechanism for disk storage apparatusInfo
- Publication number
- CA1078513A CA1078513A CA255,203A CA255203A CA1078513A CA 1078513 A CA1078513 A CA 1078513A CA 255203 A CA255203 A CA 255203A CA 1078513 A CA1078513 A CA 1078513A
- Authority
- CA
- Canada
- Prior art keywords
- coil
- actuator mechanism
- substrate
- disk
- actuator
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
- G11B5/48—Disposition or mounting of heads or head supports relative to record carriers ; arrangements of heads, e.g. for scanning the record carrier to increase the relative speed
- G11B5/54—Disposition or mounting of heads or head supports relative to record carriers ; arrangements of heads, e.g. for scanning the record carrier to increase the relative speed with provision for moving the head into or out of its operative position or across tracks
- G11B5/55—Track change, selection or acquisition by displacement of the head
- G11B5/5521—Track change, selection or acquisition by displacement of the head across disk tracks
Abstract
ACTUATOR MECHANISM FOR DISK STORAGE APPARATUS
ABSTRACT
The invention relates to an actuator mechanism suitable for positioning a recording head over the surface of a recording disk. The actuator consists of a planar coil etched from a copper laminated board. The board is pivoted at one end and carries a recording head supported on an extended arm. Magnets produce a flux perpendicular to the plane of the laminate so that current through the coil produces limited motion of the board about its pivot. The actuator mechanism is located in relation to the disk so that the limited motion of the board moves the head over the disk from one transducing position to another. The mechanism is included in a closed loop servo system which derives position information from servo tracks on the disk and enables track access and track following operations to be conducted.
ABSTRACT
The invention relates to an actuator mechanism suitable for positioning a recording head over the surface of a recording disk. The actuator consists of a planar coil etched from a copper laminated board. The board is pivoted at one end and carries a recording head supported on an extended arm. Magnets produce a flux perpendicular to the plane of the laminate so that current through the coil produces limited motion of the board about its pivot. The actuator mechanism is located in relation to the disk so that the limited motion of the board moves the head over the disk from one transducing position to another. The mechanism is included in a closed loop servo system which derives position information from servo tracks on the disk and enables track access and track following operations to be conducted.
Description
~ 78S'~3 1 The invention relates to an actu~tor mechanism for disk storage apparatus and is a modification of the trans-ducer arm assembly disclosed in our U.K. patent specifica-tion No. 1,342,495, published January 3, 1974.
According to the present invention an actuator mech-anism for disk storage apparatus comprises a planar con-ductive coil on an insulating lamina substrate pivoted to permit movement in the plane of the substrate, a recording and playback head assembly mounted on the ~ubstrate, a magnetic assembly positioned with respect to the substrate so that current through the coil causes movement of the substrate about the pivot, and a control circuit for con-trolling the magnitude and direction of current supplied to the coil.
In order that the invention may be fully understood a preferred embodiment thereof will now be described with reference to the accompanying drawings.
In the drawings:
Figure 1 shows the actuator mechanism subject of this invention; and Figure 2 shows schematically the actuator mechanism forming part of a disk storage apparatus.
The actuator mechanism shown in Figure 1 consists of an approximately triangular-shaped insulating lamina sub-strate 1 on each side of which is provided a planar con-ductive coil 2. The coil on the underside is identical to the coil visible in the figure and the two are connected in series by a plated-through hole 3 at the inner extrem-eties of the coils. Both coils are produced using con-ventional printed circuit techniques. The substrate 1 i9mounted for oscillatory motion about a pivot 5 situated in the vicinity o~ the apex of the triangular ~i . . .
1 -shaped substrate. In the preferred embodiment the two portions oE each coil 2 on either side o the pivot 3 extended substantially parallel to lines drawn through the pivot.
Two C-shaped magnetic structures 6 are supported on each side of the lamina substrate so as to produce flux per-pendicular to the plane of the substrate. Each C-shaped structure 6 consists of a magnet 7 with two laterally extending pole pieces 8 and 9 the pole-faces of which define a narrow magnetic gap 10. The structures 6 are positioned so that the portions of the coils along the sides of the substrate adjacent the pivot are situated symmetric-ally in the gaps of the structures. The shape of the pole~
faces is such that practically the whole of the portions of the windings are situated in the magnetic gaps. A head support arm 11 is also mounted on the pivot 5 with its longitudinal àxis parallel to the axis of symmetry of the substrate 1 but extending in the opposite direction. A
magnetic record and playback head 12 is supported at the free end of the arm 11.
In operation, current passed in one direction through `~ the series connected coils 2 produces rotational motion of ` the substrate 1 and thus head 12 in one direction about the pivot 5. Reversal of the current produces motion in the opposite direction. Drive current to the coils is supplied ~- to one of the terminals 4 and returned through the other via solder connected connecting wires (not shown). Movement of the head over a limited arc of travel can therefore be controlled by energisation of the coils 2 with currents of appropriate magnitude and direction.
:~.
.
~71~5~3 1 In practice this may be achieved by including the actua~or in a servo controlled loop supplied with information con-cerning the actual position of the head 12. Such systems are well known in the art and will not be described in this specification.
Figure 2 shows schematically the actua~or described with reference to Figure l forming part of a disk storage apparatus. Members in Figure 2 corresponding to members in Figure l have been given the same reference numerals.
The storage medium used in the present invention is a magnetic disk 13 supported by a central magnetisable hub 14.
The disk is contained within a cartridge 15 of plastics material. In use, the cartridge 15 is located in a main frame (not shown) of the storage apparatus with the disk 13 rotatable supported on a spindle 16 of a drive motor 17 permanently maintained in the main frame. The magnetic chuck 18 carried by the motor spindle 16 cooperates with the hub 14 to lock the disk accurately in place. The cartridge can either be fixed or can be interchangeable with other cartridges. Details of how the cartridge is supported have no bearing on the present invention and are not included in this specification.
The actuator mechanism shown in figure l is also permanently mounted in the main apparatus. The position of the actuator within ~he frame is such that the head 12 projects into an elongated slot 19 in one wall of a cartridge located in the frame to contact the surface of the enclosed disk. The slot è~.tends in a radial direction with respect to the disk and energisation Oe the actuator moves the head su~stantiall~ radially across the disk surface to access concentric data tracks on the disk surface. The direction of movement of the head ~`
: UK974007 a~
`::
. .
8~3 1 relative to the disk is not apparent from the drawiny in figure 2 which is a schematic representation of the apparatus. When a selected track has been reached the head is maintained in a track following mode by control of the energisation of the actuator drive current in a known manner.
The actuator subject of the present invention is of extremely low inertia and is capable of relatively high performance with low drive current. Various modifications to the preferred embodiment of the actuator structure des-cribed above are possible. For example the substrate can be made of a multi-layer laminate with printed circuit coils provided between each layer of the laminate as well as on the two outside surfaces. Clearly, the operation of the actuator can be improved in this way by increasing the number of turns of the composite coil supported by the substrate in the magnetic gap of the two magnetic struc-tures. In practice a trade-off has to be reached between the number of layers and the resulting increased mass of the substrate. Eddy current damping of the actuator movement can also be provided by including an aluminium layer in the multi-layer laminate.
'~
According to the present invention an actuator mech-anism for disk storage apparatus comprises a planar con-ductive coil on an insulating lamina substrate pivoted to permit movement in the plane of the substrate, a recording and playback head assembly mounted on the ~ubstrate, a magnetic assembly positioned with respect to the substrate so that current through the coil causes movement of the substrate about the pivot, and a control circuit for con-trolling the magnitude and direction of current supplied to the coil.
In order that the invention may be fully understood a preferred embodiment thereof will now be described with reference to the accompanying drawings.
In the drawings:
Figure 1 shows the actuator mechanism subject of this invention; and Figure 2 shows schematically the actuator mechanism forming part of a disk storage apparatus.
The actuator mechanism shown in Figure 1 consists of an approximately triangular-shaped insulating lamina sub-strate 1 on each side of which is provided a planar con-ductive coil 2. The coil on the underside is identical to the coil visible in the figure and the two are connected in series by a plated-through hole 3 at the inner extrem-eties of the coils. Both coils are produced using con-ventional printed circuit techniques. The substrate 1 i9mounted for oscillatory motion about a pivot 5 situated in the vicinity o~ the apex of the triangular ~i . . .
1 -shaped substrate. In the preferred embodiment the two portions oE each coil 2 on either side o the pivot 3 extended substantially parallel to lines drawn through the pivot.
Two C-shaped magnetic structures 6 are supported on each side of the lamina substrate so as to produce flux per-pendicular to the plane of the substrate. Each C-shaped structure 6 consists of a magnet 7 with two laterally extending pole pieces 8 and 9 the pole-faces of which define a narrow magnetic gap 10. The structures 6 are positioned so that the portions of the coils along the sides of the substrate adjacent the pivot are situated symmetric-ally in the gaps of the structures. The shape of the pole~
faces is such that practically the whole of the portions of the windings are situated in the magnetic gaps. A head support arm 11 is also mounted on the pivot 5 with its longitudinal àxis parallel to the axis of symmetry of the substrate 1 but extending in the opposite direction. A
magnetic record and playback head 12 is supported at the free end of the arm 11.
In operation, current passed in one direction through `~ the series connected coils 2 produces rotational motion of ` the substrate 1 and thus head 12 in one direction about the pivot 5. Reversal of the current produces motion in the opposite direction. Drive current to the coils is supplied ~- to one of the terminals 4 and returned through the other via solder connected connecting wires (not shown). Movement of the head over a limited arc of travel can therefore be controlled by energisation of the coils 2 with currents of appropriate magnitude and direction.
:~.
.
~71~5~3 1 In practice this may be achieved by including the actua~or in a servo controlled loop supplied with information con-cerning the actual position of the head 12. Such systems are well known in the art and will not be described in this specification.
Figure 2 shows schematically the actua~or described with reference to Figure l forming part of a disk storage apparatus. Members in Figure 2 corresponding to members in Figure l have been given the same reference numerals.
The storage medium used in the present invention is a magnetic disk 13 supported by a central magnetisable hub 14.
The disk is contained within a cartridge 15 of plastics material. In use, the cartridge 15 is located in a main frame (not shown) of the storage apparatus with the disk 13 rotatable supported on a spindle 16 of a drive motor 17 permanently maintained in the main frame. The magnetic chuck 18 carried by the motor spindle 16 cooperates with the hub 14 to lock the disk accurately in place. The cartridge can either be fixed or can be interchangeable with other cartridges. Details of how the cartridge is supported have no bearing on the present invention and are not included in this specification.
The actuator mechanism shown in figure l is also permanently mounted in the main apparatus. The position of the actuator within ~he frame is such that the head 12 projects into an elongated slot 19 in one wall of a cartridge located in the frame to contact the surface of the enclosed disk. The slot è~.tends in a radial direction with respect to the disk and energisation Oe the actuator moves the head su~stantiall~ radially across the disk surface to access concentric data tracks on the disk surface. The direction of movement of the head ~`
: UK974007 a~
`::
. .
8~3 1 relative to the disk is not apparent from the drawiny in figure 2 which is a schematic representation of the apparatus. When a selected track has been reached the head is maintained in a track following mode by control of the energisation of the actuator drive current in a known manner.
The actuator subject of the present invention is of extremely low inertia and is capable of relatively high performance with low drive current. Various modifications to the preferred embodiment of the actuator structure des-cribed above are possible. For example the substrate can be made of a multi-layer laminate with printed circuit coils provided between each layer of the laminate as well as on the two outside surfaces. Clearly, the operation of the actuator can be improved in this way by increasing the number of turns of the composite coil supported by the substrate in the magnetic gap of the two magnetic struc-tures. In practice a trade-off has to be reached between the number of layers and the resulting increased mass of the substrate. Eddy current damping of the actuator movement can also be provided by including an aluminium layer in the multi-layer laminate.
'~
Claims (9)
1. An actuator mechanism for disk storage apparatus comprising a planar conductive coil on an insulating lamina substrate mounted on a pivot means to permit movement in the plane of the substrate, a recording and playback head assembly mounted on said pivot means for movement with the substrate, a magnetic assembly positioned with respect to the substrate so that current through the coil causes movement of the substrate about the pivot means, and a control circuit for controlling the magnitude and direction of current supplied to the coil.
2. An actuator mechanism as claimed in claim 1, in which the magnetic assembly consists of at least one gen-erally C-shaped magnetic structure having facing pole pieces at the open ends thereof, the structure or structures being positioned so that portions of the coil are located in the gaps between the poles.
3. An actuator mechanism as claimed in claim 1, in which the magnetic assembly consists of two generally C-shaped magnetic structures each having facing pole pieces at the open ends thereof, the structures being positioned one on each side of the substrate with portions of the coil located in the gaps between the poles.
4. An actuator mechanism as claimed in claim 2 or claim 3, in which the portions of the coil between the pole pieces extend substantially parallel to a line or lines drawn through the pivot.
5. An actuator mechanism as claimed in claim 1, in which the planar conductive coil is electrically connected to a further planar conductive coil on the opposite surface of the substrate so that current supplied to the coil is supplied to the further coil, the construction and arrangement being such that current through the coil causes movement of the substrate in the same direction.
6. An actuator mechanism as claimed in claim 5, in which the shape of one planar coil is identical to the shape of the other planar coil and is connected in series there-with by means of a plated-through hole through the sub-strate.
7. An actuator mechanism as claimed in claim 1, claim 2 or claim 5 in which the or each coil is disposed to one side of the pivot means and is symmetrically about a line drawn through said pivot means.
8. An actuator mechanism as claimed in claim 1, claim 2 or claim 5 in which the recording and playback head assembly consists of an arm extending from said pivot means with the recording and playback head mounted at the free end thereof.
9. An actuator mechanism as claimed in claim 1, claim 2 or claim 5 in which the substrate is a multi-layer lami-nate having incorporated therein an aluminium layer of sufficient thickness to produce eddy current damping of actuator movement.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB26267/75A GB1516678A (en) | 1975-06-20 | 1975-06-20 | Transducer support and actuator for disc recording and/or reproducing apparatus |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1078513A true CA1078513A (en) | 1980-05-27 |
Family
ID=10240970
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA255,203A Expired CA1078513A (en) | 1975-06-20 | 1976-06-18 | Actuator mechanism for disk storage apparatus |
Country Status (20)
| Country | Link |
|---|---|
| JP (1) | JPS522713A (en) |
| AT (1) | AT360255B (en) |
| BE (1) | BE841412R (en) |
| BG (1) | BG24822A3 (en) |
| BR (1) | BR7603931A (en) |
| CA (1) | CA1078513A (en) |
| CH (1) | CH600476A5 (en) |
| DD (1) | DD125991A5 (en) |
| DE (1) | DE2623572A1 (en) |
| DK (1) | DK274476A (en) |
| ES (1) | ES448217A1 (en) |
| FI (1) | FI761760A (en) |
| FR (1) | FR2315141A2 (en) |
| GB (1) | GB1516678A (en) |
| IT (1) | IT1066869B (en) |
| NL (1) | NL7606383A (en) |
| NO (1) | NO762139L (en) |
| RO (1) | RO72000B1 (en) |
| SE (1) | SE413708B (en) |
| SU (1) | SU641886A3 (en) |
Families Citing this family (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5320908A (en) * | 1976-08-11 | 1978-02-25 | Nec Corp | Magnetic head driving device |
| GB1528539A (en) * | 1976-12-20 | 1978-10-11 | Ibm | Electromagnetic actuator |
| DE2723140C2 (en) * | 1977-05-23 | 1986-06-12 | Basf Ag, 6700 Ludwigshafen | Device for positioning objects |
| US4331990A (en) * | 1979-10-18 | 1982-05-25 | Burroughs Corporation | Flat coil linear actuator for multiple transducer arms |
| JPS56170537U (en) * | 1980-05-16 | 1981-12-16 | ||
| GB2180413B (en) * | 1982-07-27 | 1987-09-23 | Papst Motoren Gmbh & Co Kg | Drive motor unit for signal-processing devices especially information-storage disk devices |
| GB2197456A (en) * | 1986-11-11 | 1988-05-18 | Coal Ind | Dampers |
| GB2307769B (en) * | 1995-11-30 | 1998-07-08 | Samsung Electronics Co Ltd | Data storage device |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR1165161A (en) * | 1956-11-30 | 1958-10-20 | Electric measuring instrument | |
| DE1190510B (en) * | 1964-07-11 | 1965-04-08 | Grundig Max | Device for magnetic recording or reproduction of high-frequency signals |
| US3416535A (en) * | 1967-07-25 | 1968-12-17 | Ibm | Selection apparatus |
-
1975
- 1975-06-20 GB GB26267/75A patent/GB1516678A/en not_active Expired
-
1976
- 1976-04-12 IT IT22181/76A patent/IT1066869B/en active
- 1976-04-29 FR FR7613469A patent/FR2315141A2/en active Granted
- 1976-04-30 CH CH543876A patent/CH600476A5/xx not_active IP Right Cessation
- 1976-05-03 BE BE166689A patent/BE841412R/en active
- 1976-05-19 SE SE7605691A patent/SE413708B/en unknown
- 1976-05-26 DE DE19762623572 patent/DE2623572A1/en active Pending
- 1976-05-26 ES ES448217A patent/ES448217A1/en not_active Expired
- 1976-05-27 JP JP51060688A patent/JPS522713A/en active Pending
- 1976-05-28 AT AT392876A patent/AT360255B/en not_active IP Right Cessation
- 1976-06-14 NL NL7606383A patent/NL7606383A/en not_active Application Discontinuation
- 1976-06-17 FI FI761760A patent/FI761760A/fi not_active Application Discontinuation
- 1976-06-17 SU SU762372533A patent/SU641886A3/en active
- 1976-06-18 BR BR7603931A patent/BR7603931A/en unknown
- 1976-06-18 BG BG7600033523A patent/BG24822A3/en unknown
- 1976-06-18 NO NO762139A patent/NO762139L/no unknown
- 1976-06-18 CA CA255,203A patent/CA1078513A/en not_active Expired
- 1976-06-18 DK DK274476A patent/DK274476A/en unknown
- 1976-06-18 DD DD193449A patent/DD125991A5/xx unknown
- 1976-08-11 RO RO86433A patent/RO72000B1/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| FR2315141B2 (en) | 1979-07-20 |
| DK274476A (en) | 1976-12-21 |
| AU1510776A (en) | 1978-01-05 |
| DD125991A5 (en) | 1977-06-08 |
| SE7605691L (en) | 1976-12-21 |
| RO72000B1 (en) | 1984-05-30 |
| ATA392876A (en) | 1980-05-15 |
| CH600476A5 (en) | 1978-06-15 |
| FR2315141A2 (en) | 1977-01-14 |
| BR7603931A (en) | 1977-04-05 |
| NL7606383A (en) | 1976-12-22 |
| AT360255B (en) | 1980-12-29 |
| ES448217A1 (en) | 1977-07-01 |
| NO762139L (en) | 1976-12-21 |
| BG24822A3 (en) | 1978-05-12 |
| SU641886A3 (en) | 1979-01-05 |
| SE413708B (en) | 1980-06-16 |
| BE841412R (en) | 1976-09-01 |
| DE2623572A1 (en) | 1976-12-23 |
| GB1516678A (en) | 1978-07-05 |
| FI761760A (en) | 1976-12-21 |
| IT1066869B (en) | 1985-03-12 |
| RO72000A2 (en) | 1984-04-12 |
| JPS522713A (en) | 1977-01-10 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |