CN1128440C - Micromachined mirror with stretchable restoring force member - Google Patents

Micromachined mirror with stretchable restoring force member Download PDF

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Publication number
CN1128440C
CN1128440C CN99812840A CN99812840A CN1128440C CN 1128440 C CN1128440 C CN 1128440C CN 99812840 A CN99812840 A CN 99812840A CN 99812840 A CN99812840 A CN 99812840A CN 1128440 C CN1128440 C CN 1128440C
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CN
China
Prior art keywords
chain
flat base
tieing
base portion
reflector
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Expired - Fee Related
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CN99812840A
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Chinese (zh)
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CN1325530A (en
Inventor
J·D·德雷克
J·H·杰曼
J·D·格雷德
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Seagate Technology LLC
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Seagate Technology LLC
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    • 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
    • G11B7/12—Heads, e.g. forming of the optical beam spot or modulation of the optical beam
    • G11B7/122—Flying-type heads, e.g. analogous to Winchester type in magnetic recording
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B26/00—Optical devices or arrangements for the control of light using movable or deformable optical elements
    • G02B26/08—Optical devices or arrangements for the control of light using movable or deformable optical elements for controlling the direction of light
    • G02B26/0816—Optical devices or arrangements for the control of light using movable or deformable optical elements for controlling the direction of light by means of one or more reflecting elements
    • G02B26/0833—Optical devices or arrangements for the control of light using movable or deformable optical elements for controlling the direction of light by means of one or more reflecting elements the reflecting element being a micromechanical device, e.g. a MEMS mirror, DMD
    • G02B26/085—Optical devices or arrangements for the control of light using movable or deformable optical elements for controlling the direction of light by means of one or more reflecting elements the reflecting element being a micromechanical device, e.g. a MEMS mirror, DMD the reflecting means being moved or deformed by electromagnetic means
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B7/00—Mountings, adjusting means, or light-tight connections, for optical elements
    • G02B7/18—Mountings, adjusting means, or light-tight connections, for optical elements for prisms; for mirrors
    • G02B7/182—Mountings, adjusting means, or light-tight connections, for optical elements for prisms; for mirrors for mirrors
    • G02B7/1821—Mountings, adjusting means, or light-tight connections, for optical elements for prisms; for mirrors for mirrors for rotating or oscillating mirrors
    • 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
    • G11B7/085—Disposition or mounting of heads or light sources relatively to record carriers with provision for moving the light beam into, or out of, its operative position or across tracks, otherwise than during the transducing operation, e.g. for adjustment or preliminary positioning or track change or selection
    • G11B7/08547—Arrangements for positioning the light beam only without moving the head, e.g. using static electro-optical elements
    • G11B7/08564—Arrangements for positioning the light beam only without moving the head, e.g. using static electro-optical elements using galvanomirrors
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02N—ELECTRIC MACHINES NOT OTHERWISE PROVIDED FOR
    • H02N1/00—Electrostatic generators or motors using a solid moving electrostatic charge carrier
    • H02N1/002—Electrostatic motors
    • H02N1/006—Electrostatic motors of the gap-closing type

Abstract

The present invention relates to a mirror assembly(200)of micron dimensions for use in deflecting a beam of light. The mirror assembly includes a planar base(301)and a planar mirror(220)spaced apart from the planar base and disposed generally parallel to the planar base. The planar mirror has first and second end portions(220a, 220b)and a longitudinal axis(303)extending between the first and second end portions. First and second torsional members(306, 307)extend along the longitudinal axis and are connected to the respective first and second end portions for permitting the mirror to rock between first and second positions about the longitudinal axis relative to the planar base. The first and second torsional members are secured to the planar base. At least a portion of the mirror is made from a conductive material. First and second spaced-apart electrodes(322, 323)are carried by the planar base for driving the mirror between the first and second positions. A tether member(431)extends transversely of the longitudinal axis and is secured to the first torsional member and to the planar base. The tether member regulates the rocking of the mirror.

Description

But little processing reverberator with extension recovery power part
Technical field
The present invention relates to be used for optical transition, control the little processing reverberator with scanning system, relate to more specifically be used for that optical data is followed the tracks of, little processing reverberator of storage and retrieval system.
Background technology
But it is the phenomenon that a kind of limit static drives the working range of deflection micromachining device that static is drawn in.Usually, draw in that phenomenon occurs in that non-linear static driven surpasses the mechanical suspension ability of device and when realizing with the electrostatic force balance.Reverse in the reverberator one, the pending U.S. Patent Application No.09/231 that all on January 13rd, 1999 in this way submits to, type described in 317, static driven can cause reflector sheet to rotate around the axis that the torsion hinge suspension is limited.When torsion hinge provided by two answer torsion when balancing each other by the electrostatic attraction torsion that drive electrode provided, can realize the equilibrium angle deflection.The torsion hinge suspension can provide and the proportional answer torsion of the rotational angle of reflector sheet.Yet, rotating when reducing when separating between drive electrode and the ground connection reflector sheet because of reflector sheet, static torsion can non-linearly increase.Under some angle deviant, static torsion can become and reply the torsion of torsion institute energy balance greater than the linearity of hinge.Under this drew in angle, the remainder of electrostatic gap can spontaneously be crossed and deflection in the neighboring of reflector sheet, thereby the useful angle working range of reverberator is constrained to the angle that causes drawing in phenomenon less than meeting.
Static is drawn in problem and is proposed in some publications and analyzed.For example, Seeger and Crary propose a kind of method of drawing in phenomenon that prevents in the translation electrostatic actuator in " the stablizing of static driven mechanical hook-up " of transducer ' 97 proceedings (Chicago, Illinois) the 1133-1136 page or leaf in June, 1997.Their method is that a feedback condenser is connected with device, and it has come down to revise system to there is not the potential-energy function of the position of unstable operation point when drive electrode drives in operation strip.Though this method can be used for reversing the stable operation range of electrostatic equipment, caused to enlarge markedly driving voltage inadequately to charge to feedback condenser.
The static of the little processing reverberator of translation is drawn in problem and carried out discussion in " non-linearity flexure of the stable deflection of static driven micro-reflector " of Burns and Bright in the 3226th hurdle of the SPIE proceedings (Texas Jane Austen) in September, 1997.In the document, proposed to be used to have the argument of the deflection of non-linear deflection performance.Yet, do not propose to provide the design of non-linear behaviour.On the contrary, disclosed a kind of design that is used for compound deflection, this compound deflection comprises a main deflection and a secondary deflection, and wherein beyond certain deflection of main deflection, the extra restoring force with main deflection of the restoring force that secondary deflection provided is combined.Like this, this flexural design is the linearity of segmentation, rather than real non-linear.
Translation and the suspender that reverses the static driven micromachining device are modeled as thin beam or film usually.For less deflection and rotation, these structures can show as linearity.Therefore, act on structural load and deflect into ratio with it, proportionality constant equals specifically the spring constant to this deformation direction.For bigger deflection or rotation, these structures just no longer linear response in the load that is applied.Nonlinear form major part depends on the details of suspension geometry structure, but presents a kind of like this relation usually, and it is the overlapping of little deflection linear term and one cube of item basically, and this cube item is occupied an leading position for bigger deflection with rotating." manufacturing and the use of the wrinkling silicon diaphragm of little processing " at Jerman, sensor and actuator, in A21-A23 (1990) the 988-992 pages or leaves and in the U.S. Patent No. 5 of by name " the using the semiconductor variable parallel operation or the actuator of wrinkling supporting member " of authorizing Jerman, 116, in 457, provide an example of this relation, wherein used film to support the central protrusion part of little processing structure.Yet in these documents, Jerman does not use the non-linear deflection characteristic of these barrier films on producing.
Summary of the invention
Need a kind of improved microstructure reflector assembly, it has the answer torsion with the non-linear increase of angle of deviation of reverberator, in order to the non-linear electrostatic equipment driving force of compensated reflector assembly.This reflector assembly can preferably increase draws in the angle, thereby increases effective deflection ranges of reverberator.
Based on above consideration, the invention provides a kind of reflector assembly that is used to make the micron-scale of a beam steering, it comprises: a flat base portion; One separates with this flat base portion and is basically parallel to this flat base portion and the plane reflector that is provided with, and this plane reflector has first and second ends and and extends longitudinal axis between first and second ends; First and second torsion members that extend and be connected to first and second ends, shake between first and second positions around this longitudinal axis with respect to flat base portion along this longitudinal axis; First and second torsion members are fixed in the device of flat base portion; Plane reflector at least a portion is to be made by conductive material; By flat base portion entrained, be used between first and second positions driving first and second electrodes plane reflector, that separate; One with respect to longitudinal axis and chain tieing piece horizontal expansion, that be fixed in first torsion member; And chain tieing piece is fixed in the device of flat base portion, so that the shaking of this chain tieing piece scalable plane reflector.
In above-mentioned reflector assembly, first and second torsion members are fixed in the device of flat base portion and the device that chain tieing piece is fixed in flat base portion is comprised a frame unit that extends around plane reflector, first and second torsion members and chain tieing piece are fixed in this frame unit, and this frame unit is fixed in flat base portion and separates with flat base portion.
In above-mentioned reflector assembly, this chain tieing piece has a length, at least a portion of chain tieing piece has elasticity along this length, first torsion member comprises that an elongated portion and that extends along longitudinal axis is the flanges for adding rigidity part with respect to the basic of this elongated portion horizontal expansion, this flange portion have one outwardly with the separated end of elongate portion, chain tieing piece is fixed in this end of this flange portion, thereby flange portion shakes the stretching that strengthens chain tieing piece in the process between first and second positions at plane reflector.
The present invention also provides a kind of reflector assembly that is used to make the micron-scale of a beam steering, and it comprises: a flat base portion; One separates with this flat base portion and is basically parallel to this flat base portion and the plane reflector that is provided with, and this plane reflector has first and second ends and and extends longitudinal axis between first and second ends; Extend and be connected to first and second ends, first and second torsion members along this longitudinal axis to allow plane reflector to shake between first and second positions around this longitudinal axis with respect to flat base portion; First and second torsion members are fixed in the device of flat base portion; Plane reflector at least a portion is to be made by conductive material; By flat base portion entrained, be used between first and second positions driving first and second electrodes plane reflector, that separate; With respect to longitudinal axis and first and second chain tieing pieces horizontal expansion, that be fixed in first and second torsion members at least one; And first and second chain tieing pieces are fixed in the device of flat base portion, so that the shaking of the first and second chain tieing piece scalable plane reflectors.
In above-mentioned reflector assembly, first and second chain tieing pieces respectively have a length, and each at least a portion of first and second chain tieing pieces has elasticity along this length.
In above-mentioned reflector assembly, in first and second torsion members at least one comprises that an elongated portion and that extends along longitudinal axis is the flanges for adding rigidity part with respect to the basic of this elongated portion horizontal expansion, this flange portion have one outwardly with the separated first end of elongate portion, first chain tieing piece is fixed in the first end of flange portion, thereby flange portion shakes the stretching that strengthens first chain tieing piece in the process between first and second positions at plane reflector.
In above-mentioned reflector assembly, that this flange portion has is relative with first end, outwardly with the separated the second end of elongate portion, second chain tieing piece is fixed in this second end of flange portion.
In above-mentioned reflector assembly, this flange portion extends perpendicular to this elongated portion.
In above-mentioned reflector assembly, in first and second torsion members at least one comprises that an elongated portion and that extends along longitudinal axis is the flanges for adding rigidity part perpendicular to the basic of this elongated portion extension, this flange portion has outwardly and separated first and second ends of elongate portion, first chain tieing piece is fixed in the first end of flange portion, second chain tieing piece is fixed in the second end of flange portion, thereby flange portion shakes the stretching that strengthens first and second chain tieing pieces in the process between first and second positions at plane reflector.
In above-mentioned reflector assembly, first and second chain tieing pieces are fixed in first torsion member.
In above-mentioned reflector assembly, first and second chain tieing pieces along one with respect to longitudinal axis and the axis of horizontal expansion extends.
In above-mentioned reflector assembly, first and second chain tieing pieces extend along an axis that extends perpendicular to longitudinal axis.
Above-mentioned reflector assembly also comprises one group of first and second other chain tieing piece, and the first and second other chain tieing pieces of this group are fixed in second torsion member.
The present invention also provides a kind of reflector assembly that is used to make the micron-scale of a beam steering, and it comprises: a flat base portion; One separates with this flat base portion and is basically parallel to this flat base portion and the plane reflector that is provided with, and this plane reflector has first and second ends and and extends longitudinal axis between first and second ends; Plane reflector at least a portion is to be made by conductive material; But at least one is with respect to longitudinal axis and tensioning member horizontal expansion, that be fixed in plane reflector; But this tensioning member is fixed in the device of flat base portion,, but and should tensioning member shakes in the process and provide a non-linear restoring force plane reflector at plane reflector so that this plane reflector can shake between first and second positions around longitudinal axis.
That above-mentioned reflector assembly also comprises is that at least one is carried by flat base portion, be used to electrode that plane reflector is shaken around longitudinal axis.
Above-mentioned reflector assembly also comprise extend along longitudinal axis, first and second torsion members that are connected to first and second ends and the device that first and second torsion members is fixed in flat base portion.
In above-mentioned reflector assembly, but this tensioning member is connected in one in the torsion member, thereby is fixed in plane reflector.
The present invention also provides a kind of optical data stocking system, and it comprises: a supporting mass; One is rotatably mounted in this supporting mass and has the optical disc of a flat storage surface, and this storage surface has the data track of a plurality of concentric settings; One has the arm of near-end and far-end, and the near-end of arm is installed on pivotly on the supporting mass and the far-end of arm can be pivoted between first and second positions with respect to storage surface; One be installed on the arm far-end, near optical disc pneumatic suspension flight optical head storage surface in the rotary course on supporting mass; The optical launcher and the receiver of an emission of lasering beam that carries by this arm; And the reflector assembly of a micron-scale that carries by optical head, be used for reflection lasering beam between the storage surface of optical transmitting set and receiver and optical disc, to allow record and/or to read information on the data track of storage surface, this reflector assembly have a flat base portion and one and this flat base portion separate and be basically parallel to this flat base portion and the plane reflector that is provided with, this plane reflector has first and second ends and and extends longitudinal axis between first and second ends, this reflector assembly comprises along this longitudinal axis and extends and be connected to first and second torsion members of first and second ends and first and second torsion members be fixed in flat base portion so that the device that plane reflector can shake between first and second positions around longitudinal axis with respect to flat base portion, plane reflector at least a portion is to be made by conductive material, this reflector assembly has by flat base portion entrained, be used between first and second positions driving plane reflector, first and second electrodes that separate, this reflector assembly have with respect to longitudinal axis and horizontal expansion, be fixed in first and second torsion members first and second chain tieing pieces of at least one and first and second chain tieing pieces are fixed in flat base portion so that the device that the first and second chain tieing piece scalable plane reflectors shake.
In above-mentioned data storage system, first torsion member comprises that an elongated portion and that extends along longitudinal axis is the flanges for adding rigidity part perpendicular to the basic of elongated portion extension, this flange portion has first and second separated, relative with the elongate portion ends outwardly, first tethers is fixed in the first end of flange portion, second tethers is fixed in the second end of flange portion, thereby flange portion shakes the stretching that strengthens first and second chain tieing pieces in the process between first and second positions at plane reflector.
In above-mentioned data storage system, first and second chain tieing pieces are fixed in first torsion member, and also comprise one group of first and second other chain tieing piece, and the first and second other chain tieing pieces of this group are fixed in second torsion member.
Description of drawings
For ease of further understanding objects and advantages of the present invention, must be in conjunction with the accompanying drawings referring to the following detailed description, part identical in the accompanying drawing is represented with identical label.Vertical dimension shown in Fig. 8-12 and 16 is by exaggerative, so that understand accompanying drawing.
Fig. 1-3 deliberately is removed.
Fig. 4 is the schematic vertical view of band slightly of a preferred embodiment of magneto-optic stocking system of the present invention.
Fig. 5 is the stereographic map of magneto-optic system slide head of the magneto-optic stocking system of Fig. 4, and an embodiment that can control little processing reflector assembly is installed above it.
Fig. 6 is the cut-open view of the magneto-optic system slide head of Fig. 5.
Fig. 7 is the amplification view that the magneto-optic system slide head of Fig. 5 is cut open along the 7-7 line of Fig. 6.
Fig. 8 is the stereographic map that is fit to another embodiment of little processing reflector assembly that the optical head with Fig. 5 uses.
Fig. 9 is the vertical view of little processing reflector assembly of Fig. 8 along the part of the 9-9 line intercepting of Fig. 8.
Figure 10 is the stereographic map of partial cut-out of a part of little processing reflector assembly of Fig. 8.
Figure 11 is that little processing reflector assembly that an embodiment and of little processing reflector assembly of the present invention does not fasten is compared, and its driving voltage is to the curve map that is drawn by analysis of angle excursion.
Figure 12 is for fasten and the little processing reflector assembly do not fastened, square curve map that is drawn by analysis to angle excursion of the driving voltage data of Figure 11.
Figure 13 is another embodiment for little processing reflector assembly of the present invention, and its driving voltage is to the curve map that is drawn by analysis of angle excursion.
Figure 14 is the enlarged drawing of the part of the linearity of little processing reflector assembly of Fig. 8 and nonlinear suspension spare.
Figure 15 is the table of the size that is drawn by analysis of the linearity of embodiment of little processing reflector assembly of being analyzed among Figure 11 and 13 of expression and nonlinear suspension spare.
Figure 16 is the function of the angle deflection of the linearity of embodiment of little processing reflector assembly of being analyzed in Figure 11 and 13 and nonlinear suspension spare as applying moment, the curve map that is drawn by analysis.
Figure 17 is the cut-open view that the part of little processing reflector assembly of Fig. 8 is cut open along the 17-17 line of Fig. 9.
Figure 18 is the cut-open view that the little processing reflector assembly of this part of Figure 17 is in deflected condition.
Embodiment
In detail referring to accompanying drawing, part identical in the accompanying drawing is represented with identical label, can see the figure of an expression magneto-optic data storage and retrieval system at Fig. 4 below.In a preferred embodiment, magneto-optic (MO) data storage and retrieval system 100 comprises one group of Winchester type flight 106, and they are fit to use with one group of two-sided magneto-optic disk 107, and each flight head is used for a magneto-optic disk surface.Magneto-optic disk 107 rotatably is supported to stacked by a supporting mass 108, for simplicity, a dish only is shown among Fig. 4.In a preferred embodiment, be provided with hexad dish 107 stackedly.Each mask of dish 107 has the storage surface 109 on a plane, has the data track 110 of many concentric settings on this surface.For simplicity, several data tracks 110 only are shown among Fig. 4, and with respect to dish 107 size through amplifying, so that see clearly.
This group flight head or flight magneto optical head 106 are connected in a revolving actuator magnet and coil block 120 by an actuator arm 105, thereby are arranged on each smooth storage surface 109 top of magneto-optic disk 107.Each actuator arm 105 has a rigidity near-end 105a who is installed on pivotly on the supporting mass 108, thus allow a far-end or compliance suspension 105b in Fig. 4 the primary importance shown in the solid line and shown in dotted lines in Figure 4 one and the second place that separates of primary importance between pivot.Be understood that two positions shown in Fig. 4 only are exemplary, arm 105 can move to other position arbitrarily with respect to supporting mass 108.Flight magnet 106 is installed on the suspension 105b of arm 105.
At work, this group magneto-optic disk 107 is rotated by a spindle motor 195, thereby produces airlift power between this group flight magneto optical head 106, and will organize the magneto optical head 106 of flying and remain in a state of flight adjacent with each storage surface 109.More particularly, each fly each upper surface or lower surface 109 tops of being positioned at this group magneto-optic disk 107 are less than or equal to about 15 microinch places.This lifting force is resisted by the equal and opposite spring force that this group suspension 105b is applied.When not working, this group flight 106 remains in the state that stores or a position (not shown) that leaves the surface of this group magneto-optic disk 107 still.
System 100 also comprise the laser optic assemblies 101 that is installed on the supporting mass 108 and an optical switch 104 and arm 105 with one group of single mode polarization keep (PM) optical element or optical fiber 102.Optical fiber 102 is included in by in the entrained optical transmitting set and receptacle of the suspension 105b of arm 105.In exemplary embodiment, this group single mode polarization-maintaining fiber 102 respectively have a near-end 102a and who is connected in optical switch 104 respectively by among this group actuator arm 105 and the suspension 105b corresponding one be connected in corresponding one far-end in this group flight 106, be used for transmission laser beam 191,192 between supporting mass 108 and flight 106.Assembly 101 has a suitable lasing light emitter 111, and such as the linear polarization lasing light emitter, it is a Fabry Perot (Fabry-Perot) or distributed Feedback (DFB) lasing light emitter preferably, is used to produce outgoing laser beam.Lasing light emitter 111 is chosen to be in the scope of 635-685 millimicron and works, but also can use the lasing light emitter of other wavelength.That the usage that optical switch 104, flight 106 groups and single mode polarization-maintaining fiber are 102 groups is described in is that on April 18th, 1997 submitted to, through the U.S. Patent application No.08/844 of common transfer, in 208, the whole contents of this patent is quoted at this for reference.Optical switch 104 is electrically connected in a controller 112 by electric wire 113, is used for providing electric command signal to optical switch.Controller 112 is electrically connected in optical switch 104 by electric wire 114.
Each flight 106 comprises that 251, the one surperficial little processing of a sliding part body 244, one air-supported surperficial 247, one quarter-wave plate can control emitter assemblies (μ MM) 200, objective optics element 246, a magnetic coil 260 and a yoke 262 (seeing Fig. 2-4).The size of flight 106 and sliding part body 244 is made the operating distance that can hold between objective optics element 246, single mode polarization-maintaining fiber 102 and reflective substrate or the reflector assembly 200.Though sliding part body 244 can comprise industrial standard " small-sized ", " miniature ", " millimicro type " or " type slightly " sliding part, but also can use the sliding part body 244 of other size, determined by the above-mentioned size restrictions of the element that uses with flight magneto optical head 106.Therefore, in preferred embodiment, sliding part body 244 comprises a small-sized sliding part height (889 microns) and one and the suitable plane footmark area of footmark area (1600 * 2032 microns) of millimicro type sliding part.
Single mode polarization-maintaining fiber 102 is connected in sliding part body 244 along an axial cut-outs 243, and objective optics element 246 is connected in sliding part body 244 along a vertical corner otch 211.Though in preferred embodiment, axial cut-outs 243 is along an edge of sliding part body and be provided with, vertically otch 211 is arranged on a corner of sliding part body 244, but axial cut-outs 243 and vertically otch 211 also can be arranged on other position in the flight 106, for example be arranged between this edge and the central axis or and be provided with along central axis own.Those skilled in the art can recognize, be not along central axis but optical fiber 102 and objective optics element 246 are arranged on other position, also can work and influence the center of gravity of magneto optical head 106, thereby influence its flight dynamics characteristic.Therefore, the point that flight magneto optical head 106 connects suspensions may need to regulate, and changes with the off-centre of the center of gravity of compensation magneto optical head 106.Preferably, otch 243 and 211 can be designed to groove, v shape groove or any other suitable structure, is used for single-mode fiber 102 is connected with objective optics element 246 and in alignment with flight 106.
Reflector assembly 200 is expressed as in Fig. 5 and is connected in sliding part body 244.As discussed in more detail below, reflector assembly 200 comprises a small reflector face 220, and it is expressed as the dorsal part of the viewable side that is positioned at reflector assembly 200 in Fig. 5, thereby is to dot.In preferred embodiment, outgoing laser beam 191 and incident or return laser beam 192 pass a light path and arrive and leave surface recording layer 249 on the surface 109 of magneto-optic disk 107, and this light path comprises single mode polarization-maintaining fiber 102, reflector assembly 200, quarter-wave plate 251 and objective optics element 246.Outgoing laser beam 191 penetrates from optical fiber far-end 102b as a Gaussian beam.
In the process of write information, outgoing laser beam 191 optionally sends to magneto-optic disk 107 through a fixed line by optical switch 104, with by a selected impact point 248 being heated to substantially the Curie point of record/storages layer 249, thereby reduce the coercivity of record/storage layers 249.Preferably, it is constant that the light intensity of outgoing laser beam 191 keeps, and produces a time dependent vertical bias magnetic field by coil 260 simultaneously, with limit one perpendicular to magneto-optic disk 107 " on " or the magnetic domain of D score form.This technology is called magnetic field modulation (MFM).Then, along with the cooling of selected target point 248, information with code record in the record of each rotating disc 107/storage layer 249.
In reading the process of information, outgoing laser beam 191 (light intensity is compared less with the process of writing) optionally sends to magneto-optic disk 107 through a fixed line, make at any given impact point 248, Kerr effect (reflecting the back from record/storage layer 249 at outgoing laser beam 191) makes a laser light reflected bundle 192 have a clockwise or anticlockwise rotatory polarization, and this direction depends on the magnetic domain polarity at impact point 248 places.
Above-mentioned light path comes down to two-way.Therefore, reflection lasering beam 192 passes through flight 106 reception, and enters the far-end 102b of single mode polarization-maintaining fiber 102.Reflection lasering beam 192 is propagated and is penetrated from its near-end 102a along single mode polarization-maintaining fiber 102, and optionally is passed to laser optical element assembly 101 through fixed line transmission by photoswitch 104, is used for converting to subsequently electric signal.
Little processing reflector assembly or reflector assembly 200 can be the pending U.S. Patent Application No.09/192 that submitted on November 13rd, 1998,006[number of documents A-66166-1] the sort of type that discloses, its whole contents is quoted at this for reference.The size and dimension of reflector assembly 200 is similar to the semiconductor chip, has micron-scale.Reflector assembly 200 has first and second ends or end 200a and 200b, and has the first and second parallel sides 296 that form end 200a and 200b end face and 297 and extend third and fourth parallel side 298 and 299 (see figure 8)s between end 200a and the 200b.Here, first end 200a is called perform region 200a, and the second end is called sliding part join domain 200b.The length of reflector assembly 200 between side 296 and 297 can be 500 to 3000 microns, preferably be about 1850 microns, its width between side 298 and 299 can be 300 to 1000 microns, preferably be about 650 microns, its height between end face and bottom surface can be 75 to 600 microns, preferably is about 175 microns.
Reflector assembly 200 has a smooth base portion 301.Plane reflector 220 is parallel to this flat base portion 301 and is spaced from, and it has the first and second end 220a and 220b and and extends central longitudinal axis 303 (seeing Fig. 8-10) between these two ends.Longitudinal axis 303 extends through the center of reverberator 220 and perpendicular to the longitudinal axis of reflector assembly 200.Reverberator also comprise be arranged on symmetrically vertically or rotation 303 on the first and second half ones.
First and second torsion members 306 and 307 are individually fixed in first and second end 220a and the 220b of reverberator 220.Torsion member or hinged component 306 and 307 extend along longitudinal axis 303, and allow reverberator 220 to shake between first and second deflected position around longitudinal axis 303 with respect to flat base portion 301.When reverberator 220 is mobile between its first and second deflected position, it by its former or the planimetric position, as shown in Fig. 8-10.With discussed in detail, include stationary installation in the reflector assembly 200 as below, be used for first and second hinged components or hinge 306 and 307 are fixed in flat base portion 301.
Flat base portion 301 has one first or basalis 311, and it is as the non-yielding prop of the layer structure of reflector assembly 200.Substrate 311 is parallelepiped-shaped.The length of substrate 311 and width limit the length and the width of reflector assembly 200, and its thickness is 75 to 600 microns, preferably is about 175 microns.Thicker substrate can be formed by any suitable material relatively, and such as the glass of silicon, quartz and other relative higher temperature, in a preferred embodiment, substrate 311 forms wafer-like by N type silicon.
Be coated with a layer that is formed by one deck dielectric material at least in the substrate 311, it is included in (see figure 10) in the flat base portion 301.In a preferred embodiment of reflector assembly 200, dielectric layer 314 is laminates, it comprises that a thin layer of silicon dioxide 316 and that is arranged on substrate 311 tops covers thin layer 317 silicon dioxide layer 316, that made by any suitable antiacid erosion dielectric material, this antiacid erosion dielectric material is a hydrofluoric acid resistant dielectric material preferably, such as silicon nitride.The thickness of silicon dioxide layer 316 is 300 to 500 millimicrons, preferably is about 300 millimicrons.The thickness of silicon nitride layer 317 is 200 to 300 millimicrons, preferably about 250 millimicrons.Dielectric layer 314 also can singly be made of one deck silicon nitride.In other embodiment of reflector assembly 200, dielectric layer 314 can be made of the layer of one or more any other suitable dielectric material.
Be provided with patterned layer 319 (see figure 10)s of making by any suitable conductive material, such as polysilicon at the top of dielectric layer 314.The thickness of smooth polysilicon layer 319 is 100 to 300 millimicrons, preferably is about 250 millimicrons.Have in the patterned layer 319 at interval, especially in order to form first and second drive electrodes 322 and 323, they are positioned at below the reverberator 220 in final reflector assembly 200 and are spaced from.First and second electrodes 322 and 323 in vertical view altogether be shaped as octagon, and be similar to the octagon of reverberator 220. Drive electrode 322 and 323 octagon-shaped altogether are less than the octagon of reverberator 220.On flat base portion 301, form first and second conductive plates 331 and 332 and first and second conductive traces 333 and 334 by polysilicon layer 319.First electric trace 333 extends to first drive electrode, 322, the second electric traces from first conductive plate 331 and extends to second drive electrode 323 from second conductive plate 332.Between first and second conductive plates 331 and 332, form one the 3rd conductive plate 336 by polysilicon layer 319.
The perform region 200a of reverberator 220 comprises a reverberator platform 341, and it forms (seeing Fig. 8-10) by being positioned at flat base portion 301 tops and being spaced from parallel material upper strata 342.First and second hinges 306 and 307 are also formed by lamella 342, and the one end all is fixed in reverberator platform 341, and its other end all is fixed in the inner edge of framework 346.The marginal portion or the framework 346 that are formed by upper strata 342 extend around reverberator platform 341.Framework 346 is arranged among the 200a of perform region, and it has and extends through first and second holes 347 and 348 wherein, c-shaped substantially, is used to form reverberator platform 341 and first and second hinges 306 and 307.More particularly, hole 347 and 348 the similar bracket of shape.Hole 347 and 348 is provided with symmetrically around central longitudinal axis 303.Upper strata 342 is made by any suitable conductive material, and such as polysilicon, its thickness is 1.5 to 2.5 microns, preferably is about 2.0 microns.Length measured is 400 to 700 microns to framework 346 perpendicular to reflector axis 303, preferably is about 580 microns, and its width is 400 to 650 microns, preferably is about 650 microns.
Electrically-conductive reflector platform 341 is extra or ground-electrode as one, and its shape in vertical view is substantially oblong-shaped, and more specifically saying so is octagon.The elongated octagon of reverberator platform 341 and reverberator 220 at least with shown in dotted lines in Figure 9, at reverberator 220 zone that is produced when at 45 to be set in laser beam 191,192 routes the same big.The reverberator platform along central longitudinal axis 303 therein the length at heart place be 170 to 250 microns, preferably be about 220 microns, heart place is 140 to 200 microns perpendicular to the width that longitudinal axis 303 extends therein, preferably is about 170 microns.First and second hinges 306 and 307 are 15 to 60 microns along longitudinal axis 303 length measured, preferably are about 50 microns, and its width is 1 to 8 micron, preferably are about 3 microns.
Be provided with at least one patterned layer between the pattern part of lamella 342 peaceful base portions 301, it is made by any suitable expendable material, such as phosphorosilicate glass (PSG).This phosphorosilicate glass or separate layer 356 are arranged on the top of layer 319, and its thickness is 8 to 13 microns, preferably is about 10 microns.Phosphorosilicate glass layer 356 below reverberator platform 341 and a part of framework 346 is removed, so that a space or chamber 358 (see figure 10)s to be provided in reflector assembly 200.Chamber 358 extends to the expose portion of polysilicon layer 319 peaceful base portions 301 in these zones.Like this, reverberator platform 341 separates with dielectric layer 314, and is spaced from above first and second drive electrodes 322 and 323.Drive electrode is exposed to the bottom of reverberator platform 341.
Comprise in the reflector assembly 200 and be used for framework 346 and make framework 346 and reverberator platform 341 interconnective first and second hinges 306 and 307 are fixed in the device of flat base portion 301.For this reason, there are a plurality of roofbolts 361 vertically to extend between the downside and flat base portion of framework, are used for lamella 342 is fixed in flat base portion 301.In this roofbolt 361 one has been shown among Figure 10.Each roofbolt 361 is made by any suitable material, is to be made by a conductive material in an illustrated embodiment.More particularly, roofbolt 361 is made by polysilicon, and is fixed in lamella 342.Every roofbolt 361 is held on by shelving on the dish 362 that polysilicon layer 319 forms, and is electrically connected in ground connection conductive plate 336 by a conductive trace 363, and this trace is also formed by polysilicon layer 319.First and second part 363a of ground connection trace 363 and 363b are respectively along the length in the outside of first and second drive electrodes 322 and 323 and extend.One third part 363c of trace 363 vertically extends between part 363a and the 363b, and adjacent with 323b with the second bottom 322b of drive electrode 322 and 323.Device framework 346 is fixing or that be positioned flat base portion 301 also comprises a plurality of wall shape spare or walls 371 (Fig. 8 and 10) that extend between lamella 342 and the flat base portion 301.Wall 371 is made by any suitable material, such as conductive material.More particularly, wall 371 is made by polysilicon, and is fixed in lamella 342.Each wall is located on the pattern part of polysilicon layer 319.
Lamella 342 also is used to form a plurality of platforms 381,382 and 383 that contact with wall 371, and being respectively applied for provides electric signal to each conduction or interconnect pads 331,332 and 336.Be at least a kind of thin layer of conductive material by any suitable method in the top coating one of platform 381-383, so that first and second contact discs 391 and 392 and ground connection contact disc 393 to be provided respectively in the above.Contact that each is such or welded disc preferably by one be arranged on the lamella 342, thickness be about 10 millimicrons chromium thin layer and be arranged on this chromium layer top, thickness is about 500 millimicrons thicker gold layer and constitutes.Ground connection contact disc 393 is used to make reverberator platform 341 ground connection.
In the setting of the top of reverberator platform 341 or coated with skim 396, be used to provide an optical characteristics surface.Thin layer 396 is made of one or more layer material, and they are combined and produce high reflectance under optical maser wavelength.Specifically, thin layer 396 comprises that a thickness is about 5 millimicrons chromium thin layer, and it is overlying on the top of reverberator platform 341 by any suitable method.Comprise also in the thin layer 396 that a thickness is about 100 millimicrons thicker gold layer, it is overlying on the top of chromium layer by any suitable method.
The sliding part join domain 200b of reflector assembly 200 has occupied half (see figure 8) of pact of reflector assembly 200.The sliding part join domain has the groove that vertical and horizontal come into line or the grid of permanent groove 397, so that a plurality of high or boss 398 to be provided.Another part of lamella 342 or remainder 399 form the end face of boss 398, and wall 371 forms the side of boss.Boss 398 sees from vertical view and all makes suitable shape and size, and is square in an illustrated embodiment, and its size is about 150 microns * 150 microns.
The bottom of reverberator platform 341 is fixed with a plurality of ribs 411, is used to reverberator 220 that rigidity is provided.Rib 411 is made by any suitable material, is preferably made by the identical conductive material that forms roofbolt 361 and wall 371.Therefore, rib 411 is made by polysilicon.Rib 411 extends towards flat base portion 301 perpendicular to the bottom of platform 341, and is preferably between reverberator platform 341 and the flat base portion 301 and extends a half-distance at least.Whole periphery around octagonal reverberator platform 341 is extended with a peripheral rib 411.In peripheral rib 411, selectively be provided with one or more extra rib.In a preferred embodiment of reflector assembly 200, also be provided with the interior ribs 411 of intersection in addition, such rib discloses and is described in the pending U.S. Patent Application No.09/192 that submitted on November 13rd, 1998,006[number of documents A-66166-1] in.The end face of the bottom surface of reverberator platform 341 and first and second drive electrodes 322 and 323 separates one section 4 to 12 microns, preferably is about 10 microns distance, so that an air gap to be provided between rib 411 and electrode 322 and 323.The width of each rib 411 is 2 to 6 microns, preferably is about 4 microns, and the degree of depth is 4 to 8 microns, preferably is about 6 microns.
The device of the mechanical return force of providing is provided reflector assembly 200, comprises linear and non-linear suspension 429, and this restoring force is in response to first and second drive electrodes 322 and 323 electrostatic force that provided.The linear unit of suspension 429 or member comprise first and second torsion hinge 306 and 307, are used for providing one-component to this mechanical return force, and it is with first and second hinges 306 and 307 and the angle of deviation of reverberator 220 is linear increases.Suspension 429 also comprises a non-linear device or suspension, and it is a kind of providing with first and second hinges 306 and 307 and the suspension of any kind of the linear restoring force that increases of the angle of deviation of reverberator 220.For this reason, at least one is fixed with one first and second chain tieing piece 431 and 432 in first and second torsion hinge 306 and 307.More particularly, first and second torsion hinge 306 and 307 preferably respectively are fixed with one group of first and second stretchable or chain tieing piece or tethers 431 and 432 (seeing Fig. 9 and 10).The nonlinear component of answer torsion is a function of length, width and the thickness of chain tieing piece 431 and 432 with respect to the size of linear component basically.
Each flex member or tethers 431 and 432 best and lamella 342 formation one.Like this, each elongated tethers 431 and 432 outer end 433 are connected in framework 346.In this way, framework 346 be included in reflector assembly 200 be used for each tethers 431 and 432 is fixed among the device of flat base portion 301.Each elongated tethers 431 is connected to each hinge 306 and 307 with relative the inner 434 of 432.As the clearest expression in Fig. 9 and 10, each torsion hinge 306 and 307 is formed with an elongated portion 441, it extends between reverberator platform 341 and the framework 346 along longitudinal axis 303, and selectively is formed with one and forms one with elongated portion 441 and cross it and the flange portion or the flange 442 that extend.Flange 442 have that first an end 442a and who separates with elongated portion 441 separates with elongated portion outwardly outwardly and with the first end 442a second opposed end 442b.The first end 442a of flange 442 is fixed in the inner 434 of first tethers 431, and the second end 442b of flange is fixed in the inner 434 of second tethers 432.Owing to form like this, flange 442 and first and second tethers 431 and 432 that are fixed in it extend along an axis or a line that crosses elongated portion 441, preferably is provided with perpendicular to elongated portion 441 and longitudinal axis.
The size and dimension of each flange 442 is made and is become rigidity basically, thereby can be with respect to elongated portion 441 and bending in the process that longitudinal axis 303 pivots at reverberator 220.Each is the shape that flanges for adding rigidity 442 preferably has parallelepipedon substantially, more particularly, half length of measuring from a side of elongated portion 441 is 20 to 100 microns, 303 width of measuring that parallel to the axis are 4 to 8 microns, and the degree of depth of extending measurement from the upper surface of lamella 342 down is 4 to 10 microns.Flange 442 preferably and reverberator platform 341 separate one section 4 to 10 microns distance, be more preferably one section about distance of 5 microns.Elongated portion 441 can be different from elongated portion 441 partly cross sectional dimensions and shape between flange 442 and reverberator platform 341 in the cross sectional dimensions of part between flange 442 and the framework 346 and shape.Each tethers 431 and 432 length measured is 40 to 100 microns perpendicular to longitudinal axis 303, width roughly corresponding to or be narrower than the width of flange 442, the degree of depth is 0.2 to 1.0 micron.The shape of cross section of tethers makes it have elasticity, and can be along at least a portion of their length and bending, preferably along they whole length and bending.
Though first and second tethers 431 and 432 of suspension 429 are expressed as and are connected in first and second torsion hinge 306 and 307, are understood that, also can provide one to have a single group and only be connected in the tethers 431 of a hinge 306 or 307 and 432 suspension 429.Perhaps, can provide first and second tethers, one is connected in first hinge 306, and another root is connected in second hinge 307, and is parallel to first tethers in opposite direction and extends with respect to longitudinal axis 303.Perhaps, can provide the tethers of other structure, in order to regulate or to limit the pivoting action of reverberator 220 around longitudinal axis 303.Also be understood that, can provide one or many root systems chain, do not have flange, the elongated portion 441 of they and hinge 306 or 307 links into an integrated entity or otherwise is directly fixed on elongated portion, and this also within the scope of the invention.Be with or without provide under the situation that torsion hinge exists non-linear answer torsion, use flex member such as tethers, comprise other structure of coming suspended reflector 220 with the tethers that not necessarily will launch perpendicular to the reverberator longitudinal axis, also fall within the scope of the present invention.For example, can provide one or more tethers shape spare, be used for reverberator 220 is fixed in framework 346 pivotly and provides non-linear restoring force to reverberator.In an embodiment of this structure, four such deflections or chain tieing piece can be provided, these tethers are symmetrical arranged with respect to axis 303, and each such tethers extends with 45 ° or other pitch angle with respect to axis 303.
Derive following formula, so that understand better as the relation of reverberator 220 between the driving voltage of first and second drive electrodes 322 of a function of the angle of deviation of longitudinal axis 303 and 323, thereby a reflector assembly 200 is provided, and it has a suspension that has a non-linear force member.The rotation angle θ of suspension 429 and the torsion T that applies in reverberator 220 distolateral places sBecome following form:
T s＝k 1θ+k 3θ 3 (1)
In the formula, k 1Be the linear rotating spring constant of suspension 429, k 3It is cube spring constant of suspension 429.θ is to be unit with the radian, and for example, 2 degree approximate 0.035 radian.When the deflection of the angle of formation reverberator 220, T sWith apply the static torsion T that voltage V is produced by either side in drive electrode 322 and 323 eBalance each other.Suppose that reverberator 220 is comparatively firm, the angle deflection of reverberator is equivalent to the θ in the formula (1).Static torsion is by following formulate: T e = V 2 2 ∂ C ∂ θ - - - ( 2 )
In the formula, C is the electric capacity between reverberator 220 and drive electrode 322 and 323.The concrete geometry and the free space DIELECTRIC CONSTANT of the normally interelectrode initial air gap g of the electric capacity of this structure, drive electrode width b/2, drive electrode length a, angle excursion, reverberator 220 0A nonlinear function.When the geometry of reverberator 220 is relatively complicated,, can determine electric capacity with finite element method as a function of angle excursion for any given reverberator geometry.Yet, equal the simple occasion that drive electrode 322 and 323 length, half width equal the flat rectangular reflector sheet platform 341 of drive electrode width for length, can obtain the closed form relation of electric capacity.Only experience rotatablely moves, reflector sheet 220 can be because of not applying this device that translation takes place voltage from electrode 322 and 323 for supposition, and electric capacity is by following formulate: C = - ϵ 0 a θ ln ( 1 - bθ 2 g ) - - - ( 3 )
By finite element method analyzed the electric capacity of reverberator 220 can curve fitting in following formula: C = - A ϵ 0 a θ ln ( 1 - B bθ 2 g ) - - - ( 4 )
In the formula, A and B are fitting parameters, and they depend on the concrete rib 411 of reverberator 220 of given design and the geometry of reverberator platform 341.For the pending U.S. Patent Application No.09/192 that submits on November 13rd, 1998,006[number of documents A-66166-1] described in its Figure 10 in a standard of represented type intersect the rib reverberator, find that A and B are respectively for 0.8525 and 1.311.
During concerning between the angular deflection θ that determines driving voltage V and reverberator 220, can come the static torsion T of computing formula (2) with formula (3) and (4) eThen, can use relational expression T e=2T sMake formula (2) relevant with formula (1).For obtaining driving voltage V, derive following formula: V = 4 θ ( k 1 + k 3 θ 2 ) ϵ 0 aA [ ln ( 1 - B bθ 2 g ) + B bθ 2 g 1 - B bθ 2 g - - - ( 5 )
About formula (5), by each torsion hinge 306 and 307 and the design problem of corresponding tethers 431 and 432 suspensions that provided 429 need set k 1And k 3Relative size, so that efficient function relation to be provided between angular deflection and driving voltage.Another design constraint of reverberator 220 is its resonance frequency f Res, it is by following formulate: f res = 1 2 π k I m - - - ( 6 )
In the formula, k is effective spring constant of torsional mode, I mIt is the mass mement of inertia of reverberator 220.Because the inherent nonlinearity of suspension 429, this resonance frequency will be the function of angle excursion θ.Yet, for the employed servo loop control in reflector angles position, just be enough to design resonance frequency, suppose k=2k 1, wherein factor 2 also is the existence of considering two suspensions 429, lays respectively at the two ends of reverberator platform 341.Determine I through the finite element analysis that the reverberator to polysilicon belt intersection rib carries out m=5.36E-13kg mm 2For the torsional resonances design load of 30kHz, then with k 1Be defined as 0.0095mNmm (milli newton millimeter).
When if the power of drawing in of supposition reverberator 220 is created in angle of deviation about 1.5 and spends, then by hinge 306 and 307 and the method for designing of the suspension 429 that forms of the tethers 431 and 432 cube item that need guarantee formula (1) become significantly when the angle of deviation of 1.5 degree, thereby prevent to draw in.Making cube item under this angle is that 20% of linear term requires k3 should be about 290 to take advantage of k 1If k 1Value drawn in the epimere, then calculate k 3Be 2.77mN mm.In this design, be called design 1 here, drive electrode 322 and 323 with platform 341 lower surfaces between primary clearance suppose and to be about 10 microns.For having above-mentioned k 1And k 3The reverberator 220 of the band intersection rib of value, a=200 micron and b=140 micron calculates formula (5), and resulting relation is marked among Figure 11.Being plotted among Figure 11 on the same axis is identical relation, but k 3=0, its expression does not have the performance of the suspension 429 of tethers 431 and 432.As can be seen from Figure 11, along with k 3=0 slope of a curve trends towards zero, draws in more and more and is a problem.Can be clear from Figure 11, the suspension 429 of band tethers can prevent to draw under the situation of angle of deviation up at least 2 degree better.
Design 1 has provided a kind of relation of secondary that is substantially between angular deflection and driving voltage.Suppose that the servo loop control in the optical data stocking system can use secondary to concern the angle position of proofreading and correct reverberator, to be corrected in the derailed site error in the track following process, then this is a kind of very useful method.In Figure 12, the identical voltage data among Figure 11 is carried out square, and mark and draw with respect to angle excursion θ.Notice that just do not begin to demonstrate when the deflection of about 1 degree with the reverberator of tethers and significantly deviate from linearity, it is linear that the reverberator of band tethers then keeps basically, this can find out by it is compared with its least square regression line.
In the another kind design, be called design 2 here, make the relation between driving voltage V and the angular deflection θ be linearity as far as possible.For this design, we suppose that the resonance frequency of reverberator can slightly reduce, and can sharp influence the servo loop control of reflector locations.The advantage point of design 2 is that further the primary clearance between reverberator platform 341 lower surfaces and first and second drive electrodes 322 and 323 can be reduced to below 10 microns.This design is considered to reduce makes reverberator 22 around the necessary driving voltage V of longitudinal axis 303 pivots.Allow low slightly resonance frequency, can make k 1Be reduced to for example 0.0080mN mm.With k 3Be set at 2500 and take advantage of k 1, 20.0mN mm just, and initial air gap is decreased to about 7 microns, under the situations of angle of deviation, can provide near required linear relationship, as shown in figure 13 up at least 2 degree.Dotted line among Figure 13 is represented the slope to the formula (5) of 1 degree angle of deviation calculating.For this calculating, the coefficient A of formula (5) is identical with the situation of 10 microns primary clearances of design 1 with the B supposition.
In order to determine to provide k to designing 1 and 2 1And k 3The geometry of value carries out non linear finite element analysis with SDRC I-deas MasterSeries 6 softwares.The geometric parameter that can change and provide desirable value is shown among Figure 14.The table of Figure 15 provides the k of this analysis 1And k 3Result and design 1 and 2 required geometries.Dimensional units is a micron, and spring constant unit is mN mm.Get the Young modulus of 160GPa and 0.3 Poisson ratio, they are values of using always for the polysilicon lamella 342 that is used for the body plan suspension.Figure 15 represents that listed geometry can reasonably be adapted to specified design object in the discussion of front.
Figure 16 is provided by the curve of the angular deflection of tethers suspension design as a function of the static moment that is provided by first and second drive electrodes 322 and 323.The result of non linear finite element analysis marks and draws with polynomial curve fitting, and these matches only comprise having above listed k 1And k 3The linearity of coefficient and cube item.Curve and The results are complementary, and this hypothesis that shows exactly that basically tethers plays formula (1) is actually correct.
Reflector assembly 200 manufacture method be described in the pending U.S. Patent Application No.09/192 that submitted on November 13rd, 1998,006[number of documents A-66166-1].As more abundant description in this application, first and second torsion hinge 306 and 307 elongated portion 441 are formed by lamella 342.First and second tethers 431 and 432 also can be formed by lamella 342.Tethers 431 and 432 the required degree of depth or thickness can obtain by utilizing etching or other method that the top of lamella 342 is attenuated in required tethers position.Perhaps, can lamella 342 be etched away fully in the position of tethers 431 and 432, and apply other one any suitable material, such as the layer of the polycrystalline silicon material of lamella 342, form tethers through pattern formation and etching.Also have a kind of method to be, tethers 431 and 432 can be made of other one deck silicon nitride or low stress silicon-rich silicon nitride, and this layer warp suitably applies, forms pattern and etching and form tethers.The part of flange 442 in lamella 342 planes forms in the mode identical with elongated portion 441, and flange 442 is against parts below the lamella 342 and can uses the mode identical with rib 411 to form.In the embodiment of reflector assembly 200, such as design 2, its center rib 411 causes rib 411 poorly to contact flat base portion 301 with relative less clearance between the flat base portion 301, in flat base portion, can etch or otherwise form the groove (not shown) of appropriate depth and size, when longitudinal axis 303 moves, to hold rib 411 at reverberator 220.
The inclined surface 202 that each reflector assembly 200 adheres to sliding part body 444 by the sliding part join domain 200b with reflector assembly is connected in a flight 100.As the clearest expression among Fig. 2, wherein can see the bottom surface of substrate 311, reflector assembly 200 is aligned on the sliding part body 444, makes reverberator 220 reflection lasering beam 191,192 between the end of optical fiber 102 102b and target object 446.In an illustrated embodiment, reverberator 220 passes through an about angle of 90 ° and reflection lasering beam with respect to the axis that the incident beam direction of propagation limited.Preferably, the central authorities of laser beam 191,192 equal contact reflex devices 220.Each reflector assembly 200 can connect before flight 106 and/or test afterwards.Contact disc 391-393 is electrically connected in controller 112 by corresponding electric wire, as shown in Figure 2.
In the operation and use of system 100, the output of servo controller 112 will be controlled voltage and put in first and second drive electrodes 322 and 323 one, thereby reverberator 220 is pivoted between its first and second deflected position along opposite first or second direction around hinge 306 and 307.Driving voltage flows to first and second electrodes 322 and 323 by first and second contact discs 391 and 392.Maximum drive voltage is 100 to 200 volts, is more preferably to be about 135 volts.Drive electrode 322 or 323 and respective reflector half 220c of by substrate contact disc 393 ground connection or the electrostatic force between the 220d reverberator 220 is pivoted around rotation 303.
Reverberator 220 from its former in the position when its complete deflected position moves, from its former in the position along either direction around reflector axis 303 by 0 to 2.5 °, preferably be about 2 ° and pivot.Controller 112 provides drive signal with the nyquist rate of about 19kHz to first and second drive electrodes 322 and 323.The resonance frequency of reverberator 220 is 25 to 50kHz, is preferably 25 to 30kHz.Reflector assembly 200 is reflection lasering beam 191,192 between the storage surface 109 of the far-end 102b of optical fiber 102 and dish 107, carries out the optical recording of information and/or read on the data track 110 of storage surface 109 allowing.
Reverberator 220 is subjected to the constraint of the answer torsion of suspension 429 in this rotation process.As discussed above, suspension 429 comprises a linear structure, such as the elongated portion 441 of first and second torsion hinge 306 and 307, and a nonlinear member that comprises flange 442 and first and second tethers 431 and 432.As shown in Figure 17, when reverberator 220 is in it not during deflected position, tethers 431 and 432 and corresponding flange 442 be arranged in the plane of lamella 342.When reverberator 220 when axis 303 pivots, tethers 431 and 432 crooked and elongations, thus restriction reverberator 220 is pivoted to (seeing Figure 18) beyond the predetermined angle.Basic is that flanges for adding rigidity 442 can crooked or stretching in the reverberator motion process.Yet tethers the inner 434 is connected in first and second end 442a of flange 442 and the crooked and stretching that 442b can strengthen tethers 431 and 432.More particularly, make bigger under the elevating movement of tethers 431 and 432 and bending motion is directly fixed on hinge 306 and 307 than tethers elongated portion 441 occasions by separating the moment arm that the interval of the end 442a of position and 442a causes with pivot axis 303.
Tethers 431 and 432 is designed to, and for less angular deflection, they can provide the restoring moment of a linearity, and this moment is added to but the answer torsion that provided less than hinge 306 and 307.Linear answer torsion is provided by the bending of tethers.Along with the increase of reverberator 220 angular deflection, the stressed stretching of tethers and adapt to angular deflection.The stretching of tethers is non-linear, and more particularly, it is a cubic function of reverberator angle excursion.In this way, the suspension 429 with nonlinear member allows the stable angle deflection ranges of reverberators 220 to increase by the angle of drawing in that increases reverberator.Tethers 431 and 432 is connected in torsion hinge 306 and 307 can prevent that in the pivot process of longitudinal axis 303 reverberator 220 from producing undesirable bending because of the power of tethers at reverberator.
Thin follow the tracks of and near magnetic tracks 110 that short distance is searched a series of can be by around rotation 303 rotation reverberators 220 makes the angle of propagation of outgoing laser beam 191 change before being delivered to objective optics element 246 and realizes.Therefore, the luminous point 248 that reverberator 220 makes focusing moves along the radial direction of magneto-optic disk 107, so that the storage of the information of carrying out and/or retrieval, track following, and finds another data track from a data track 110.Thick tracking can be kept (see figure 4) by regulating an electric current that is transported to revolving actuator magnet and coil block 120.The track following signal that is used to follow the tracks of the concrete magnetic track 110 of magneto-optic disk 107 can be derived with thick, the thin tracking servo technology of well-known combination technically.For example, can limit magnetic track with a sampling sector servo form.This servo format can comprise the mold pressing hole that is carved in the magneto-optic disk 107 or be similar to data markers and the magnetic domain orientation that reads.
No matter how this group actuator arm 105 to move, can operate and then realize track following independently and search with one group of reflector assembly 200 of the present invention, thereby read and/or write information with more than one magneto-optic disk surface 109 at any given time.With one group of reflector assembly of working simultaneously 200 carry out independent track following and searching preferably need a component from separately read groove and thin magnetic track electronic circuit and reverberator driver circuit.The reduced size of reflector assembly 200 and quality help flight 106 is designed to have less quality and less profile.
Optical transmitting set as described herein and receiver can comprise one by read and/or writing head is entrained, near the lasing light emitter of reflector assembly.In such embodiment, optical transmitting set and receiver comprise a lasing light emitter and one or more suitable polarization sensor detector.This system can also can not need fiber optic component laser beam to be delivered to or to leave reflector assembly.
Reflector assembly described above can be used for other occasion except that the flight magneto optical head.For example, reflector assembly 220 can be used for any suitable optical recording and/or reading system.Application scenario is to use physical record method (for example record the CD-ROMS of data with physical pits or concave form, these pits are used to reflect phase place or the intensity with modulated incident light beam) from medium retrieval optical information.Little processing reflector assembly of the present invention also can be applicable to from having the medium retrieval optical data of data storing position, and these data storing positions can not have to provide the optical phase modulation under the situation in magnetic field.In addition, the little processing reflector assembly that is disclosed here is in the outside that need can be used for data recording and/or searching system than the occasion of I deflective reflector device.For example, reflector assembly 220 can be used for optics switching or other field in bar code scanning or the telecommunication.Here also can expect the reflector assembly 220 that has two following drive electrodes or do not have drive electrode, such as sensor.
Though above detailed description has been described some embodiment of little processing reflector assembly of the present invention, be understood that it only is exemplary more than describing, and does not limit the invention that is disclosed.Be appreciated that in scope and spirit of the present invention, can make amendment, maybe can add or remove different members size, shape and outward appearance and the manufacture method of each member of the present invention.Thus, be understood that, use the suspension of any reverberator 220, as long as it comprises that one is the answer torsion member of the nonlinear function of reverberator angle excursion, no matter this member is connected in one or a plurality of torsion hinge, is connected in any combination that reverberator itself still is them, all within the scope of the present invention.
By as can be seen above, a kind of improved little processing reflector assembly is provided, it has the answer torsion with the non-linear increase of reverberator angle of deviation, with the non-linear static driven power of basic compensated reflector assembly.This reflector assembly increases draws in the angle, thereby increases effective deflection ranges of reverberator.In one embodiment, this reflector assembly has one or more tethers, and they link to each other with the torsion hinge that is fixed in reverberator.These tethers stretch in the reverberator pivot motion course, reverberator is provided non-linear answer torsion.Torsion hinge preferably has the basic flanges for adding rigidity that is, tethers is connected in these flanges.Flange is used to strengthen the stretching of tethers.

Claims (20)

1. reflector assembly that is used to make the micron-scale of a beam steering, it comprises: a flat base portion; One separates with this flat base portion and is basically parallel to this flat base portion and the plane reflector that is provided with, and this plane reflector has first and second ends and and extends longitudinal axis between first and second ends; First and second torsion members that extend and be connected to first and second ends, shake between first and second positions around this longitudinal axis with respect to flat base portion along this longitudinal axis; First and second torsion members are fixed in the device of flat base portion; Plane reflector at least a portion is to be made by conductive material; By flat base portion entrained, be used between first and second positions driving first and second electrodes plane reflector, that separate; One with respect to longitudinal axis and chain tieing piece horizontal expansion, that be fixed in first torsion member; And chain tieing piece is fixed in the device of flat base portion, so that the shaking of this chain tieing piece scalable plane reflector.
2. reflector assembly as claimed in claim 1, it is characterized in that, first and second torsion members are fixed in the device of flat base portion and the device that chain tieing piece is fixed in flat base portion is comprised a frame unit that extends around plane reflector, first and second torsion members and chain tieing piece are fixed in this frame unit, and this frame unit is fixed in flat base portion and separates with flat base portion.
3. reflector assembly as claimed in claim 1, it is characterized in that, this chain tieing piece has a length, at least a portion of chain tieing piece has elasticity along this length, first torsion member comprises that an elongated portion and that extends along longitudinal axis is the flanges for adding rigidity part with respect to the basic of this elongated portion horizontal expansion, this flange portion have one outwardly with the separated end of elongate portion, chain tieing piece is fixed in this end of this flange portion, thereby flange portion shakes the stretching that strengthens chain tieing piece in the process between first and second positions at plane reflector.
4. reflector assembly that is used to make the micron-scale of a beam steering, it comprises: a flat base portion; One separates with this flat base portion and is basically parallel to this flat base portion and the plane reflector that is provided with, and this plane reflector has first and second ends and and extends longitudinal axis between first and second ends; Extend and be connected to first and second ends, first and second torsion members along this longitudinal axis to allow plane reflector to shake between first and second positions around this longitudinal axis with respect to flat base portion; First and second torsion members are fixed in the device of flat base portion; Plane reflector at least a portion is to be made by conductive material; By flat base portion entrained, be used between first and second positions driving first and second electrodes plane reflector, that separate; With respect to longitudinal axis and first and second chain tieing pieces horizontal expansion, that be fixed in first and second torsion members at least one; And first and second chain tieing pieces are fixed in the device of flat base portion, so that the shaking of the first and second chain tieing piece scalable plane reflectors.
5. reflector assembly as claimed in claim 4 is characterized in that, first and second chain tieing pieces respectively have a length, and each at least a portion of first and second chain tieing pieces has elasticity along this length.
6. reflector assembly as claimed in claim 4, it is characterized in that, in first and second torsion members at least one comprises that an elongated portion and that extends along longitudinal axis is the flanges for adding rigidity part with respect to the basic of this elongated portion horizontal expansion, this flange portion have one outwardly with the separated first end of elongate portion, first chain tieing piece is fixed in the first end of flange portion, thereby flange portion shakes the stretching that strengthens first chain tieing piece in the process between first and second positions at plane reflector.
7. reflector assembly as claimed in claim 6 is characterized in that, that this flange portion has is relative with first end, outwardly with the separated the second end of elongate portion, second chain tieing piece is fixed in this second end of flange portion.
8. reflector assembly as claimed in claim 6 is characterized in that this flange portion extends perpendicular to this elongated portion.
9. reflector assembly as claimed in claim 4, it is characterized in that, in first and second torsion members at least one comprises that an elongated portion and that extends along longitudinal axis is the flanges for adding rigidity part perpendicular to the basic of this elongated portion extension, this flange portion has outwardly and separated first and second ends of elongate portion, first chain tieing piece is fixed in the first end of flange portion, second chain tieing piece is fixed in the second end of flange portion, thereby flange portion shakes the stretching that strengthens first and second chain tieing pieces in the process between first and second positions at plane reflector.
10. reflector assembly as claimed in claim 4 is characterized in that first and second chain tieing pieces are fixed in first torsion member.
11. reflector assembly as claimed in claim 10 is characterized in that, first and second chain tieing pieces along one with respect to longitudinal axis and the axis of horizontal expansion extends.
12. reflector assembly as claimed in claim 11 is characterized in that, first and second chain tieing pieces extend along an axis that extends perpendicular to longitudinal axis.
13. reflector assembly as claimed in claim 10 is characterized in that, it also comprises one group of first and second other chain tieing piece, and the first and second other chain tieing pieces of this group are fixed in second torsion member.
14. a reflector assembly that is used to make the micron-scale of a beam steering, it comprises: a flat base portion; One separates with this flat base portion and is basically parallel to this flat base portion and the plane reflector that is provided with, and this plane reflector has first and second ends and and extends longitudinal axis between first and second ends; Plane reflector at least a portion is to be made by conductive material; But at least one is with respect to longitudinal axis and tensioning member horizontal expansion, that be fixed in plane reflector; But this tensioning member is fixed in the device of flat base portion,, but and should tensioning member shakes in the process and provide a non-linear restoring force plane reflector at plane reflector so that this plane reflector can shake between first and second positions around longitudinal axis.
15. the reflector assembly as claim 14 is characterized in that, it also comprise that at least one is carried by flat base portion, be used to electrode that plane reflector is shaken around longitudinal axis.
16. the reflector assembly as claim 14 is characterized in that, it also comprise extend along longitudinal axis, first and second torsion members that are connected to first and second ends and the device that first and second torsion members is fixed in flat base portion.
17. the reflector assembly as claim 16 is characterized in that, but this tensioning member is connected in one in the torsion member, thereby is fixed in plane reflector.
18. an optical data stocking system, it comprises: a supporting mass; One is rotatably mounted in this supporting mass and has the optical disc of a flat storage surface, and this storage surface has the data track of a plurality of concentric settings; One has the arm of near-end and far-end, and the near-end of arm is installed on pivotly on the supporting mass and the far-end of arm can be pivoted between first and second positions with respect to storage surface; One be installed on the arm far-end, near optical disc pneumatic suspension flight optical head storage surface in the rotary course on supporting mass; The optical launcher and the receiver of an emission of lasering beam that carries by this arm; And the reflector assembly of a micron-scale that carries by optical head, be used for reflection lasering beam between the storage surface of optical transmitting set and receiver and optical disc, to allow record and/or to read information on the data track of storage surface, this reflector assembly have a flat base portion and one and this flat base portion separate and be basically parallel to this flat base portion and the plane reflector that is provided with, this plane reflector has first and second ends and and extends longitudinal axis between first and second ends, this reflector assembly comprises along this longitudinal axis and extends and be connected to first and second torsion members of first and second ends and first and second torsion members be fixed in flat base portion so that the device that plane reflector can shake between first and second positions around longitudinal axis with respect to flat base portion, plane reflector at least a portion is to be made by conductive material, this reflector assembly has by flat base portion entrained, be used between first and second positions driving plane reflector, first and second electrodes that separate, this reflector assembly have with respect to longitudinal axis and horizontal expansion, be fixed in first and second torsion members first and second chain tieing pieces of at least one and first and second chain tieing pieces are fixed in flat base portion so that the device that the first and second chain tieing piece scalable plane reflectors shake.
19. data storage system as claimed in claim 18, it is characterized in that, first torsion member comprises that an elongated portion and that extends along longitudinal axis is the flanges for adding rigidity part perpendicular to the basic of elongated portion extension, this flange portion has first and second separated, relative with the elongate portion ends outwardly, first tethers is fixed in the first end of flange portion, second tethers is fixed in the second end of flange portion, thereby flange portion shakes the stretching that strengthens first and second chain tieing pieces in the process between first and second positions at plane reflector.
20. data storage system as claimed in claim 19 is characterized in that, first and second chain tieing pieces are fixed in first torsion member, and also comprise one group of first and second other chain tieing piece, and the first and second other chain tieing pieces of this group are fixed in second torsion member.
CN99812840A 1998-09-18 1999-09-17 Micromachined mirror with stretchable restoring force member Expired - Fee Related CN1128440C (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US10098998P 1998-09-18 1998-09-18
US60/100,989 1998-09-18

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CN1128440C true CN1128440C (en) 2003-11-19

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JP (1) JP4619538B2 (en)
KR (1) KR100473693B1 (en)
CN (1) CN1128440C (en)
AU (1) AU6254999A (en)
DE (1) DE19983566T1 (en)
GB (1) GB2362224B (en)
WO (1) WO2000017865A1 (en)

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US7002215B1 (en) * 2002-09-30 2006-02-21 Pts Corporation Floating entrance guard for preventing electrical short circuits

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US5153870A (en) * 1989-06-29 1992-10-06 Digital Equipment Corporation Rotary head actuator for optical disk
US5202875A (en) * 1991-06-04 1993-04-13 International Business Machines Corporation Multiple data surface optical data storage system
US5629794A (en) * 1995-05-31 1997-05-13 Texas Instruments Incorporated Spatial light modulator having an analog beam for steering light
US5661591A (en) * 1995-09-29 1997-08-26 Texas Instruments Incorporated Optical switch having an analog beam for steering light
JPH09152505A (en) * 1995-11-30 1997-06-10 Sharp Corp Deformable mirror and its manufacture, and optical device and recording and reproducing device
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WO1998009289A1 (en) * 1996-08-27 1998-03-05 Quinta Corporation Optical head using micro-machined elements
JPH10188319A (en) * 1996-12-26 1998-07-21 Sharp Corp Deformable mirror and optical recording and reproducing device using the same
WO2000013210A2 (en) * 1998-09-02 2000-03-09 Xros, Inc. Micromachined members coupled for relative rotation by torsional flexure hinges

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AU6254999A (en) 2000-04-10
DE19983566T1 (en) 2001-08-16
KR100473693B1 (en) 2005-03-08
GB2362224B (en) 2003-03-19
CN1325530A (en) 2001-12-05
JP4619538B2 (en) 2011-01-26
WO2000017865A1 (en) 2000-03-30
KR20010075212A (en) 2001-08-09
GB2362224A (en) 2001-11-14
GB0109131D0 (en) 2001-05-30
JP2002525691A (en) 2002-08-13

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