WO2001063602A1 - Optischer abtastkopf zum lesen von auf einem aufzeichnungsträger gespeicherten daten - Google Patents
Optischer abtastkopf zum lesen von auf einem aufzeichnungsträger gespeicherten daten Download PDFInfo
- Publication number
- WO2001063602A1 WO2001063602A1 PCT/DE2001/000649 DE0100649W WO0163602A1 WO 2001063602 A1 WO2001063602 A1 WO 2001063602A1 DE 0100649 W DE0100649 W DE 0100649W WO 0163602 A1 WO0163602 A1 WO 0163602A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- scanning head
- optical scanning
- point
- actuating
- center
- Prior art date
Links
Classifications
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
- G11B7/08—Disposition or mounting of heads or light sources relatively to record carriers
- G11B7/09—Disposition or mounting of heads or light sources relatively to record carriers with provision for moving the light beam or focus plane for the purpose of maintaining alignment of the light beam relative to the record carrier during transducing operation, e.g. to compensate for surface irregularities of the latter or for track following
- G11B7/0925—Electromechanical actuators for lens positioning
- G11B7/0935—Details of the moving parts
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
- G11B7/08—Disposition or mounting of heads or light sources relatively to record carriers
- G11B7/09—Disposition or mounting of heads or light sources relatively to record carriers with provision for moving the light beam or focus plane for the purpose of maintaining alignment of the light beam relative to the record carrier during transducing operation, e.g. to compensate for surface irregularities of the latter or for track following
- G11B7/0946—Disposition or mounting of heads or light sources relatively to record carriers with provision for moving the light beam or focus plane for the purpose of maintaining alignment of the light beam relative to the record carrier during transducing operation, e.g. to compensate for surface irregularities of the latter or for track following specially adapted for operation during external perturbations not related to the carrier or servo beam, e.g. vibration
Definitions
- Optical scanning head for reading data stored on a recording medium
- the present invention relates to an optical scanning head for reading data stored on a rotating recording medium, in particular an optical scanning head, in which the position can be stabilized against rotational movements.
- An optical scanning head is guided along a data track in order to read data stored on a rotating recording medium.
- the scanning head consists of a lens and an objective support device and is slidably supported by a holding device.
- a light beam is directed from the scanning head via the lens onto the rotating recording medium for recording the information applied, the data tracks applied to the recording medium being scanned. It is included to avoid reading errors It is particularly important that the light beam is guided along the data tracks and focused on the record carrier.
- the housing particularly installed in a motor vehicle, e.g. of a compact disc drive is exposed to various vibrations. If the player is shaken by vibrations, inertial forces act on the scanning head. Here, changes in position of the laser beam with respect to the data track occur. Specially designed electronics receive information for tracking the position of the laser beam.
- the lens system of the scanning head is movable by three of its degrees of freedom. This is a horizontal translation, a vertical translation and a vertical rotation, which are identified in FIG. 1 by the arrows. Changes in position of the laser beam due to translational movements of the scanning head are usually corrected by means of electromagnetic actuators.
- Document DE 196 42 343 A1 describes a method for regulating the focusing of a light beam directed for reading data onto a rotating recording medium of a scanning device on the recording medium and guiding the light beam along the data tracks of the recording medium by a control loop.
- a control loop Only the translatory movements of the scanning device are controlled. The rotational movement cannot be influenced here.
- a low acceleration level is sufficient to disturb the readability of the device.
- the position error of the light beam is caused by unintentional rotary movements of the optics, which make it impossible for the position control electronics to follow the data track.
- FIG. 2 illustrates a side view of an optical scanning device 1 without adjustment of the two positions during operation.
- the scanning head 1 has a lens 4 and an objective carrier device 5, the actuating elements 3 in the form of coil windings 3 each being attached to the end faces of the objective carrier device 5.
- the entire scanning device is located in a constant magnetic field 11 which e.g. is generated by means of permanent magnets.
- the entire scanning head can be slidably held by a holding device ⁇ shown in FIG. 1.
- a light beam 7 is focused via the objective 4 onto a recording medium 2 for reading the data stored on the recording medium 2.
- the position of the center of gravity of the optical scanning head is identified by the circle 8.
- the position of the point of application of a resulting total actuating force 13 of all existing actuating elements 3 is identified by point 9.
- Both the circle 8 and the point 9 represent, of course, an infinitisimal point of attack, their different representations only serve a better understanding.
- the data reader is a compact disc player that is installed in a motor vehicle, it is exposed to certain acceleration and vibration processes. E.g. accelerates the motor vehicle in the direction indicated by the large arrow in FIG. 2 (to the right in the sheet plane), the housing of the CD player is likewise subject to this acceleration in the same direction.
- the compact disc 2, the scanning head 1 and its lens 4 experience changes in position relative to one another due to inertial forces 12.
- the inertial force 12 of the scanning head 1 is symbolized by the force vector 12. It is directed in the opposite direction to the acceleration and acts on the center of mass 8 of the scanning head 1.
- the corresponding actuating elements 3 are attached to the scanning head 1 with respect to the magnetic field direction 11 such that a position control of the scanning head with respect to the compact disc 2 in the translational direction is possible by means of a current flow through the coil windings 3 of certain strength and direction.
- the problem on which the present invention is based is therefore generally to stabilize the position of the scanning head with respect to these undesirable rotational movements.
- optical scanning head according to the invention with the features of claim 1 and the corresponding method according to claim 8 have the advantage over the prior art that undesired rotational movements of an optical scanning head, caused by translatory correction movements of adjusting elements, are prevented.
- the optical scanning head is provided for reading data stored on a rotating record carrier, has a lens and a lens support device and can be slidably held by at least one holding device.
- An application of the invention allows the vibration sensitivity of optical data readers to be reduced. This eliminates a weak point in many of the scanning heads on the market and increases the range of possible types for vibration-relevant applications.
- the at least one control element of the optical scanning head is designed as an electromagnetic actuator, in particular as a coil winding, which can be attached to the optical scanning head in a magnetic field.
- the size of the actuating force of the corresponding actuating element can be varied in a constant magnetic field by changing the strength of the current flow through the coil winding.
- the direction of the corresponding actuating force can be regulated by an appropriate arrangement of the actuating elements, the direction of the current flow or the direction of the magnetic field.
- the position of the point of application of the total actuating force is either by changing the geometry of the Magnetic field or changeable by a displacement of at least one control element and displaceable in the direction of the center of mass of the optical scanning head.
- an additional mass element is attached to the optical scanning head for shifting the center of gravity of the same. This measure allows the position of the center of gravity to be displaced in the direction of the force application point of the adjusting element.
- the optical scanning head is partially adjustable from the force field of the at least one actuating element for shifting the position of the point of attack of the total actuating force.
- the zero position of the optical scanning head is thus shifted, and this is also possible during operation.
- the size and direction of the offset depend on the nature of the scanning head and the actuating elements and must be determined experimentally.
- the recording medium is designed, for example, as a compact disc (CD), digital video disc (DVD), mini disc (MD) or as a magneto-optical disc (MOD). All of these record carriers work on the same principle, in which a light beam for reading the on the data recorded on the recording medium is focused on the recording medium, the recording medium rotating over the scanning head.
- the invention can increase the resistance to vibrations in all such recording media.
- the comparison of the two positions of the center of mass of the optical scanning head and the point of application of the resulting total actuating force is determined by means of resonance measurements of excited vibration states.
- the positions of the two points can be shifted relative to one another until a resonance measurement shows that the two positions match.
- 1 is a perspective view of a conventional scanning head; 2 shows a side view of a scanning head without adjustment during operation;
- FIG. 3 shows a side view of a scanning head without alignment with rotational movement
- FIG. 4 shows a side view of a scanning head with adjustment in operation according to a first exemplary embodiment of the present invention
- FIG. 5 shows a side view of a scanning head with adjustment during operation according to a second exemplary embodiment of the present invention
- FIG. 6 shows a side view of a scanning head with adjustment during operation according to a third exemplary embodiment of the present invention
- FIG. 7 shows a side view of a scanning head with adjustment during operation according to a fourth exemplary embodiment of the present invention.
- Fig. 8 is a diagram showing the difference of a scanning pot with and without adjustment.
- FIG. 4 illustrates a side view of an optical scanning device 1 with adjustment of the two positions in operation according to a first exemplary embodiment of the present invention.
- the scanning head 1 has a lens 4 and an objective carrier device 5, the actuating elements 3 in the form of coil windings 3 each being attached to the end faces of the objective carrier device 5.
- the entire scanning device is located in a constant magnetic field 11 which e.g. is generated by means of permanent magnets.
- the entire scanning head can be slidably held by a holding device 6 shown in FIG. 1.
- a light beam 7 is focused via the objective 4 onto a recording medium 2 for reading the data stored on the recording medium 2.
- the position of the center of gravity of the optical scanning head is identified by the circle 8.
- the position of the point of application of a resulting total actuating force 13 of all existing actuating elements 3 is determined by point 9. features.
- Both the circle 8 and the point 9 represent, of course, an infinitisimal point of attack, their different representations only serve a better understanding.
- the data reader is a compact disc player that is installed in a motor vehicle, it is exposed to certain acceleration and vibration processes. E.g. accelerates the motor vehicle in the direction indicated by the large arrow in FIG. 2 (to the right in the sheet plane), the housing of the CD player is likewise subject to this acceleration in the same direction.
- the compact disc 2, the scanning head 1 and its objective 4 experience changes in position relative to one another due to inertial forces 12.
- the inertial force 12 of the scanning head 1 is symbolized by the force vector 12. It is directed in the opposite direction to the acceleration and acts on the center of mass 8 of the scanning head 1.
- the corresponding actuating elements 3 are attached to the scanning head 1 with respect to the magnetic field direction 11 such that a position control of the scanning head with respect to the compact disc 2 in the translational direction is possible by means of a current flow through the coil windings 3 of certain strength and direction. Only one translatory reset direction is shown in the figures, but of course the principle can be applied to any translatory movement and can be carried out in three dimensions.
- the position of the center of gravity 8 of the optical scanning head 1 is determined by measurement. Then the position of the point of application 9 of the resulting total actuating force 13 is also determined by measurement, which results from the sum of the individual actuating forces of the actuating elements 3, which make a contribution to the restoring movement in the direction of the acceleration.
- the two positions 8, 9 are compared, it being determined, for example, by means of resonance measurements of excited vibration states, whether and to what extent further compensation is necessary or an adjustment has already been made.
- FIG. 5 shows a second exemplary embodiment of the present invention for an alignment of the two layers 8, 9, the geometry of the scanning head 1 being an arrangement which allows coil windings 3 in which the adjusting elements 3 are arranged in the upper region of the scanning head 1 are.
- the force application point 9 of the resulting total actuating force shifts in comparison to the arrangement from FIG. 2 in the direction of the center of mass 8 and can thus be superimposed on it.
- FIG. 6 illustrates a side view of a third exemplary embodiment of the present invention, in which coil windings 3 are also attached to the end faces of the scanning head 1 in a constant magnetic field 11.
- the geometry of the magnetic field 11 is changed in comparison to the arrangement from FIG. 2 such that only the upper region of the coil windings 3 are in the force field of the magnetic field 11.
- This also Grip point 9 of the total actuating force 13 compared to the arrangement of FIG. 2 shifted in the direction of the center of gravity 8 and compared with this with a suitable change in the geometry of the magnetic field 11.
- FIG. 1 A fourth embodiment of the present invention is described in FIG.
- the mechanical zero position of the scanning head 1 with its lens 4 is shifted during operation, so that the point of application of the actuator forces 9 in turn coincides with the center of gravity 8 of the scanning head 1.
- optical scanning head 1 is partially moved out of the force field of the adjusting elements 3, the size of the offset and its direction depending both on the nature of the optical scanning head 1 and on the nature of the adjusting elements 3 used and must be determined experimentally.
- the resistance of the optical scanning system to shocks or accelerations can be increased by the invention and position errors of the light beam due to translational accelerations can be avoided.
- 8 illustrates a diagram which has the maximum acceleration as a function of the vibration or disturbance frequency, at which no operational disturbances occur yet. It is clearly evident that at certain frequencies, an acceleration which is more than three times as high may occur in the case of a comparison of the two positions in comparison to an arrangement without such a comparison, without a data reading interruption occurring.
- the record carrier 2 can also be used as the record carrier 2
- DVD Digital video disc
- MD mini disc
- MOD magneto-optical disc
Landscapes
- Moving Of Heads (AREA)
- Optical Head (AREA)
- Optical Recording Or Reproduction (AREA)
Abstract
Description
Claims
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP01913695A EP1264306A1 (de) | 2000-02-24 | 2001-02-20 | Optischer abtastkopf zum lesen von auf einem aufzeichnungsträger gespeicherten daten |
HU0204545A HUP0204545A2 (en) | 2000-02-24 | 2001-02-20 | Optical scanning head for reading data stored on a medium |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE10008548.2 | 2000-02-24 | ||
DE10008548A DE10008548A1 (de) | 2000-02-24 | 2000-02-24 | Optischer Abtastkopf zum Lesen von auf einem Aufzeichnungsträger gespeicherten Daten |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2001063602A1 true WO2001063602A1 (de) | 2001-08-30 |
Family
ID=7632175
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/DE2001/000649 WO2001063602A1 (de) | 2000-02-24 | 2001-02-20 | Optischer abtastkopf zum lesen von auf einem aufzeichnungsträger gespeicherten daten |
Country Status (4)
Country | Link |
---|---|
EP (1) | EP1264306A1 (de) |
DE (1) | DE10008548A1 (de) |
HU (1) | HUP0204545A2 (de) |
WO (1) | WO2001063602A1 (de) |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5136558A (en) * | 1989-06-20 | 1992-08-04 | Applied Magnetics Corporation | Two axis electromagnetic actuator |
US5165088A (en) * | 1989-05-09 | 1992-11-17 | Pioneer Electronic Corporation | Optical pickup with bilateral and vertical symmetry |
EP0536484A1 (de) * | 1991-10-08 | 1993-04-14 | Pioneer Electronic Corporation | Abtasteinrichtung für ein optisches Aufzeichnungsmediums |
-
2000
- 2000-02-24 DE DE10008548A patent/DE10008548A1/de not_active Withdrawn
-
2001
- 2001-02-20 HU HU0204545A patent/HUP0204545A2/hu unknown
- 2001-02-20 EP EP01913695A patent/EP1264306A1/de not_active Withdrawn
- 2001-02-20 WO PCT/DE2001/000649 patent/WO2001063602A1/de not_active Application Discontinuation
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5165088A (en) * | 1989-05-09 | 1992-11-17 | Pioneer Electronic Corporation | Optical pickup with bilateral and vertical symmetry |
US5136558A (en) * | 1989-06-20 | 1992-08-04 | Applied Magnetics Corporation | Two axis electromagnetic actuator |
EP0536484A1 (de) * | 1991-10-08 | 1993-04-14 | Pioneer Electronic Corporation | Abtasteinrichtung für ein optisches Aufzeichnungsmediums |
Also Published As
Publication number | Publication date |
---|---|
HUP0204545A2 (en) | 2003-06-28 |
EP1264306A1 (de) | 2002-12-11 |
DE10008548A1 (de) | 2001-08-30 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
DE2954579C2 (de) | ||
EP0471101B1 (de) | Verfahren zum Positionieren eines Magnetkopfes gegenüber dem Speichermedium eines Magnetschichtspeichers | |
DE3344262A1 (de) | Halterung fuer ein optisches system und positionierungsvorrichtung fuer die verwendung in einem optischen lesegeraet | |
DE2661100C2 (de) | ||
DE2711921C2 (de) | Abstandsregelgerät | |
DE3000473C2 (de) | Optisch- mechanischer Abtaster, insbesondere für Video-Plattenspieler | |
DE3486252T2 (de) | Antriebsanordnung zur Anwendung in einem optischen Plattenspieler oder Aufzeichnungsgerät und Plattenspieler oder Aufzeichnungsgerät mit einer gleichen Anordnung. | |
DE2831504C2 (de) | ||
DE19730862C2 (de) | Optische Speichervorrichtung | |
DE3873005T2 (de) | Optischer plattenspieler. | |
DE3590219T (de) | Optischer Kopf für optische Plattenspieler | |
DE602005005094T2 (de) | Magnetischer Kreis und Stellantrieb für optisches Abtastgerät und optisches Aufzeichnungs- und/oder Wiedergabegerät das diesen Stellantrieb verwendet | |
DE3739995A1 (de) | Optische lese- und schreibkopfvorrichtung | |
DE19951862A1 (de) | Optische Abtasteinrichtung | |
DE19642343C2 (de) | Verfahren zum Regeln der Fokussierung und der Führung eines Lichtstrahls | |
EP0822542B1 (de) | Gerät zum Lesen und/oder Beschreiben optischer Aufzeichnungsträger | |
EP0134428B1 (de) | Lesevorrichtung zum optischen Abtasten von auf einem bewegten plattenförmigen Träger aufgezeichneten Informationen | |
DE68912779T2 (de) | System zur umschaltung des polarisationsmagnetfeldes für eine magneto-optische scheibeneinheit. | |
EP1264306A1 (de) | Optischer abtastkopf zum lesen von auf einem aufzeichnungsträger gespeicherten daten | |
DE2607275C3 (de) | Lichtstrahl-Abtasteinrichtung | |
DE68921733T2 (de) | Antriebsanordnung für eine optische Abtasteinheit. | |
DE69016908T2 (de) | Linsenantrieb. | |
WO2001088909A1 (de) | Gestaltung der führung einer optischen abtastvorrichtung | |
DE19814777A1 (de) | Optische Abtasteinrichtung mit verbesserter Ansprechcharakteristik | |
EP1245026B1 (de) | Verfahren zur regelung der nachführung einer abtastvorrichtung und laufwerk dafür |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AK | Designated states |
Kind code of ref document: A1 Designated state(s): CN HU JP US |
|
AL | Designated countries for regional patents |
Kind code of ref document: A1 Designated state(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LU MC NL PT SE TR |
|
121 | Ep: the epo has been informed by wipo that ep was designated in this application | ||
DFPE | Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101) | ||
WWE | Wipo information: entry into national phase |
Ref document number: 2001913695 Country of ref document: EP |
|
WWP | Wipo information: published in national office |
Ref document number: 2001913695 Country of ref document: EP |
|
NENP | Non-entry into the national phase |
Ref country code: JP |
|
WWW | Wipo information: withdrawn in national office |
Ref document number: 2001913695 Country of ref document: EP |