United States Patent £191
`Ikegame et al.
`
`lllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllll
`5,428,481
`Jun. 27, 1995
`
`US005428481A
`[11] Patent Number:
`[45] Date of Patent:
`
`[54] OPTICAL SYSTEM SUPPORTING DEVICE
`Inventors: Tetsuo Ikegame; lchiro Ikari, both of
`Hachioji, Japan
`
`[75]
`
`[73] Assignee: Olympus Optical Co., Ltd., Tokyo,
`Japan
`
`[21] Appl. No.: 607,683
`
`Nov. 1, 1990
`[22] Filed:
`Foreign Application Priority Data
`[30]
`Nov. 2, 1989 [JP]
`Japan ...........•...................... 1-285036
`Int. Cl.6 .......................... G02B 7/02; GllB 7/00;
`[51]
`GllB 7/09
`[52] u.s. Cl ..................................... 359/811; 359/814;
`359/824; 359/823; 369/44.16; 369/44.15
`[58] Field of Search ....................... 350/247, 252, 257;
`369/44.11, 44.14-44.19; 359/813, 814, 823-824
`
`[56]
`
`References Cited
`U.S. PATENT DOCUMENTS
`4,702,555 10/1987 Iguma et al ......................... 359/814
`4,766,583 8/1988 Oinoue et al ........................ 350/247
`4,861,138 8/1989 Suzulci ................................. 359/824
`4,911,534 3/1990 Henegouwen et al ............. 350/255
`4,922,477 5/1990 Miura .................................. 359/814
`5,018,836 5/1991 Noda et al .......................... 350/255
`5,056,891 10/1991 Masunaga ........................ 369/44.15
`5,073,883 12/1991 Mitsunori ............................ 359/814
`
`FOREIGN PATENT DOCUMENTS
`59-221839 12/1984 Japan .
`60-197942 10/1985 Japan .
`62-145539 6/1987 Japan .
`173641 7/1987 Japan ................................ 369/44.15
`155429 6/1988 Japan ................................ 369/44.15
`37733 2/1989 Japan ................................ 369/44.16
`150732 6/1991 Japan ... , ............................ 369/44.15
`
`Primary Examiner-Loha Ben
`Assistant Examiner-Thong Nguyen
`Attorney, Agent, or Firm-Stevens, Davis, Miller &
`Mosher
`
`ABSTRACI
`[57]
`An optical system supporting device in which an opti(cid:173)
`. cal system holding member is supported by springs to
`be movable in focusing and tracking directions; and
`each of the springs bas at least one portion which is
`oriented parallel with a tangential direction and one
`bending portion which is bent toward an optical axis of
`the optical system. Therefore, the holding member is
`made small in width with respect to the tracking direc(cid:173)
`tion; and thus the holding member can be made light in
`weight such that the driving sensitivity of the holding
`member is improved.
`
`14 Claims, 6 Drawing Sheets
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`Ba
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`0
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`LG Electronics, Inc. et al.
`EXHIBIT 1005
`IPR Petition for
`U.S. Patent No. 6,785,065
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`

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`U.S. Patent
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`June 27, 1995
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`Sheet 1 of 6
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`5,428,481
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`FIG_/
`PRIOR ART
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`21
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`z l:y
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`FIG.2
`PRIOR ART
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`33
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`U.S. Patent
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`June 27, 1995
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`Sheet 2 of 6
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`F/G_3
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`U.S. Patent
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`June 27, 1995
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`Sheet 3 of 6
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`f-F-~sa
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`U.S. Patent
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`June 27, 1995
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`Sheet 4 of 6
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`5,428,481
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`X
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`U.S. Patent
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`June 27, 1995
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`Sheet 5 of 6
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`U.S. Patent
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`June 27, 1995
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`Sheet 6 of 6
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`F/G_7A
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`

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`1
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`5,428,481
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`OPTICAL SYSTEM SUPPORTING DEVICE
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`10
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`15
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`20
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`2
`supporting device in the tracking direction particularly
`should be made small.
`However, in the conventional device shown in FIG.
`BACKGROUND OF THE INVENTION
`1, there are provided tracking coils 26 at both sides in
`5 theY direction of the lens holder 22; and the wires 25
`1) Field of the Invention
`are arranged outside one of the tracking coils 26
`The present Invention relates to an optical system
`straightly. Therefore, the width of the lens holder 22 in
`supporting device for use in an optical information re-
`the Y direction is determined according to the width of
`cording apparatus in which the optical information is
`the tracking coil 26 and thus the width of the lens
`recorded on an information recording medium such as
`holder can not be made small. It may be suggested to
`an optical disc and an optical card by illuminating a
`bend the tracking coil 26 into an L shape in order to
`light beam thereon.
`make the width of the lens holder 22 small, but a num-
`2) Prior Art Statement
`ber of assembling processes of the pick up device would
`When illuminating the light beam on the information
`be increased.
`recording medium in order to record the optical infor-
`On the other hand, the conventional device denoted
`mation thereon, a focusing control and a tracking con-
`in FIG. 2, succeeds in making the width (in the X direc-
`trol of the light beam are necessary with respect to
`tion) of the lens holder 27 per se small, so that the lens
`tracks formed on the recording medium. For the pur-
`holder 27 can be arranged in the vicinity of a spindle
`pose of the focusing and tracking control of the light
`motor (not shown), which is provided for driving the
`beam, an objective lens, which is arranged at an oppo-
`pick up device as a whole. However, between the lens
`site side of the recording medium, should be smoothly
`holder 27 and the fJ.xing member 34, there are extended
`moved in a focusing direction and a tracking direction.
`the metal wires 31 and 32 in the X direction, and thus
`The objective lens is supported by a lens holder, i.e.
`the size in the X direction of the device as a whole
`an optical system supporting device; and the movement
`thereof is conducted by moving the lens holder in the 25 becomes large. The information recording medium is
`focusing and tracking directions. Such optical system
`generally stored in a cartridge, and in the cartridge,
`there is provided an opening for passing a light beam
`supporting device is, for instance, disclosed in Japanese
`Patent Preliminary Publication No. 59-221839. FIG. 1 is
`therethrough. Therefore, when the lens holder 27 is
`a schematic perspective view showing the optical sys-
`moved in the X direction, the fJ.xing member 34 makes
`tern supporting device disclosed in this publication. An 30 contact with the opening of the cartridge, so that re-
`cording and read out of information at an outer portion
`objective lens 21 is held in an objective lens holder 22;
`of the recording medium could not be conducted.
`and the lens holder 22 is arranged on a base plate 23. At
`both sides of the base plate 23 in a tangential direction,
`are arranged fJ.xing members 24, 24. It should be noted
`that in this specifJ.cation a tracking direction is repre- 35
`sented by X direction, a tangential direction by Y direc(cid:173)
`tion and a focusing direction by Z direction, hereinafter.
`On inner walls of these fJ.xing members 24, 24, magnets
`are provided, respectively. Between one of the fJ.xing
`members 24 and the lens holder 22, four metal wires 25 40
`are extended in parallel with Y direction. The wires 25
`are arranged parallel to each other; and each end of
`these wires is secured to the fJ.xing member 24 and the
`lens holder 22. Therefore, the lens holder 22 is sup(cid:173)
`ported by the wires 25 so as to be movable in the focus- 45
`ing and tracking directions.
`In Japanese Patent Preliminary Publication No.
`60-197942, there is disclosed another optical system
`supporting device. FIG. 2 is a perspective view depict(cid:173)
`ing a structure of this device. In this device, the lens 50
`holder 27 holding an objective lens 28 therein is sup(cid:173)
`ported by four metal wires 29, 30, 31 and 32. As shown
`in FIG. 2, the wires 29 and 30 are extended in theY
`direction, and the wires 31 and 32 are extended in the X
`direction; and one end of each wire is fJ.xed to fJ.xing 55
`members 33 and 34 arranged on a base plate 35. In this
`device, the lens holder 27 is also arranged to be movable
`in the focusing and tracking directions.
`A critical commercial demand of an optical informa(cid:173)
`tion recording apparatus having such optical system 60
`supporting device is that it be made small in size. There(cid:173)
`fore, the optical system supporting device is also re(cid:173)
`quired to be made small in size. Further, in the optical
`information recording apparatus, it is required to ex(cid:173)
`pand a range over which the information can be re- 65
`corded on the recording medium and the information
`recorded thereon can be read out therefrom. In order to
`expand the recording/reproducing range, the size of the
`
`SUMMARY OF THE INVENTION
`The present invention has for its purpose to provide
`an optical system supporting device in which the width
`in the tracking direction can be made small. Therefore,
`the optical information recording apparatus having the
`optical system supporting device according to the in(cid:173)
`vention can be made small in size as a whole; and it is
`possible to record information even at an outer portion
`of the recording medium and to read out information
`recorded thereat.
`In order to carry out the above mentioned purpose,
`the optical system supporting device according to in(cid:173)
`vention comprising:
`holding means for holding an optical system;
`driving means for driving said holding means in fo(cid:173)
`cusing and tracking directions;
`supporting means for supporting said holding means
`to be movable in the focusing and tracking direc(cid:173)
`tions, comprising at least a couple of supporting
`members for supporting said holding means;
`a base plate for carrying said holding means, driving
`means and supporting means; and
`each of said supporting members comprising at least
`one parallel portion being in parallel with a tangen(cid:173)
`tial direction and one bending portion being bent
`toward an optical axis of said optical system, and
`these parallel portions and the bending portion
`being formed in series as a single unit.
`In the optical system supporting device according to
`the invention, the supporting means for supporting the
`lens holder, i.e. the optical system holding means, com(cid:173)
`prises a bending portion which is bent toward the opti(cid:173)
`cal axis of the optical system. Therefore, it is possible to
`make the width in the X direction of the lens holder
`small.
`
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`3
`BRIEF DESCRIPTION OF THE DRAWINGS
`FIGS. 1 and 2 are schematic perspective views show(cid:173)
`ing conventional optical system supporting devices,
`respectively;
`FIG. 3 is a schematic perspective view illustrating a
`first embodiment of the optical system supporting de(cid:173)
`vice according to the invention;
`FIG. 4 is a schematic plan view depicting the first
`embodiment of the optical system supporting device
`shown in FIG. 3;
`FIG. 5 is a partial perspective view representing a
`connecting portion between the supporting means and
`the lens holder;
`FIG. 6 is a schematic plan view showing a second
`embodiment of the optical system supporting device
`according to the invention; and
`FIGS. 7A and 7B are schematic views illustrating
`variations of the supporting means for supporting the
`lens holder according to the invention.
`
`4
`portion 6j of the spring 6 with the projection 2a of the
`lens holder 2. Therefore, the position of the spring 6 can
`be determined easily and correctly without using a
`special positioning member, Further, in the end portion
`5 6j, there is provided a notch portion 6h to which a
`terminal 13 of the focusing coil 4 or the tracking coil 5
`is connected by means of a soft solder. Since the termi(cid:173)
`nal13 is firstly held by the notch 6h and then the termi(cid:173)
`nal13 is secured thereto by the soft solder, the terminal
`10 13 is secured to the spring 6 in an efficient manner.
`As shown in FIG. 4, at both ends of said fixing mem(cid:173)
`ber 7 there are provided concave portions 7a, 7a into
`which the other ends 6e, 6e of the spring 6 are fixed. It
`should be noted that in the other end 6e of the spring 6,
`15 the numeral number 6d represents a projection for de(cid:173)
`termining the position of the spring 6, and 6/ a hole for
`sinking the adhesive agent. In each of the other ends 6e
`of the springs 6, there is further provided projection 6g.
`The projection 6g is secured to a land of a print sub(cid:173)
`strate (not shown) by means of a soft solder in order to
`supply an electric current to the focusing coil 4 and the
`DETAILED DESCRIPTION OF THE
`tracking coil 5 via the springs 6.
`PREFERRED EMBODIMENT
`Each spring 6 comprises a first parallel portion 6a
`arranged in parallel with the tangential direction, a
`FIGS. 3 to 5 are schematic views showing the first
`embodiment of the optical system supporting device 25 bending portion 6b bent toward an optical axis of the .
`according to the invention.
`objective lens 1 and a second parallel portion 6c parallel
`An objective lens 1 is arranged in an objective lens
`with the tangential direction. It should be noted that
`holder 2; and around a side wall of the lens holder 2 is
`these parallel and bending portions are formed in series.
`wound a focusing coil 4. At both sides in a tangential
`Because the bending portion is bent toward the optical
`direction of the lens holder 2 are mounted four tracking 30 axis of the optical system and the second parallel por-
`tion 6c is arranged at a side of the objective lens 1, a
`coils 5. A base plate 8 is formed by pressing and in a
`center portion of the base plate 8, is formed a concave
`distance between the second parallel portions 6c and 6c
`portion Sa through which a light beam can be passed.
`is the shortest in comparison with the distance between
`On the base plate 8, there are provided a couple of outer
`the first parallel portions 6a and 6a and the distance
`yokes 9a, 9a and a couple of inner yokes 9b, 9b extend- 35 between the bending portions 6b and 6b. That is to say,
`the second parallel portions 6c and 6c are closest to the
`ing in parallel with said concave portion 8a in the X
`direction. The inner yokes 9b, 9b are positioned in open-
`objective lens 1. As shown in FIG. 3, two springs 6 are
`ings 3 and 3 arranged in the lens holder 2. On inner
`provided at each end portion of the fixing member 7,
`walls of both the outer yokes 9a, 9a, there are provided
`respectively, in the Z direction; and the springs 6 and 6
`three magnets 10, 11, 11, respectively. The center mag- 40 arranged in the lower positions have the same structure
`as those of the springs 6 and 6 arranged in the upper
`net 10 is sandwiched by the side magnets 11, 11 and the
`polarity of the center magnet 10 is magnetized in an
`positions. The lens holder 2 is supported by these four
`opposite manner to that of the side· magnets 11, 11.
`springs movably in the X and Z directions.
`At one side of the base plate 8 in the Y direction,
`In accordance with the optical system lens holder of
`there is provided a fixing member 7. Four springs 6 are 45 the invention, the width in the X direction of the lens
`extended from the fixing member 7 to the lens holder 2
`holder can be made small. Therefore, a space formed in
`such that the lens holder 2 is supported by the springs 6
`the vicinity of the objective lens 1 becomes large so that
`so as to be movable in the X and Z directions. The
`a spindle motor (not shown) having a large diameter
`springs 6 are formed by etching a thin plate of beryllium
`can be used. Further, it is possible to arrange a sensor
`copper having a thickness of about 0.1 mm. As illus- 50 for detecting a position of the lens holder 2 in the X
`direction in the space. Furthermore, since the distance
`trated in FIG. 4, the springs 6 are covered by dampers
`12 made of butyl rubber.
`between the second parallel portions 6c, 6c of the
`FIG. 5 depicts a connecting portion bet:ween the
`springs 6, 6 is arranged to be narrower than the distance
`spring 6 and the lens holder 2. A projection 2a for ar-
`between the first parallel portions 6a, 6a, a stiffness of
`ranging an end of the spring 6 is provided at a predeter- 55 the springs 6 with respect to a rotation of the lens holder
`about the Y axis can be increased in comparison with
`mined portion of the lens holder 2; and in the projection
`2a there is provided a concave portion 2b. The concave
`the springs all portions of which are arranged in straight
`portion 2b is engaged with the end 6j of said spring 6;
`manner.
`and the end 6j is secured thereto by means of an agent.
`In the first embodiment, as shown in FIG. 4, the
`At the end portion 6j of the spring 6, there is provided 60 numerical references W a, W b and W c represent the
`a hole 6k through which said agent is sunk into a space
`widths in a direction perpendicular to the extending
`formed between the spring 6 and the projection 2a, so
`direction of each portion of the springs 6. The numeri-
`that the spring 6 is engaged with the projection 2a in a
`cal reference W a represents the width of the first paral-
`fixed manner. In the end portion 6j of the spring 6, there
`lei portion 6a, W b the bending portion 6b and W c the
`is provided a small projection 6i. The movement in the 65 second parallel portion 6c, respectively. Additionally
`each spring 6 is arranged such that the width W a of the
`Y direction of the spring 6 is limited by means of the
`projection 6i and the position of the spring 6 in the Y
`first parallel portion 6a is equal to the width W c of the
`direction is determined by the engagement of the end
`second parallel portion 6c and the width W b of the
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`member 2 is increased and the moment of inertia about
`bending portion 6b is larger than the widths W a and W c·
`the Y axis thereof becomes small. Thus the resonance
`For instance, it may be arranged that the widths W a and
`frequency is elevated. Further, it is possible to effi-
`Weare about 0.3 mm, respectively, and the width Wbis
`about 0.5 mm. The thickness of each spring 6 in Z direc-
`ciently prevent resonance in the projections 2a them-
`tion is uniform at all portions. By such arrangement, the 5 selves.
`The present invention is not limited to the above
`stiffness of the springs with respect to the rotations of
`the lens holder 2 about the X and Y axes and the stiff-
`explained embodiments and several modifications or
`ness of the springs in Y direction are increased. There-
`variations can be applied thereto. For example, the
`fore, it is possible to prevent that the optical axis of the
`springs 6 may be arranged in shapes as shown in FIGS.
`objective lens 1 is inclined and possible to make a reso- 10 7 A and 7B. That is to say, the springs 6 may have their
`shapes such that each has only one parallel portion and
`nance frequency of the objective lens high.
`In the plan view shown in FIG. 4, magnetic fluxes,
`one bending portion as shown in FIG. 7A; and such that
`which work with the tracking coil 5 and the focusing
`each has two parallel portions and one bending portion
`coil 4, are indicated. A magnetic flux generated by the
`but the bending portion is bent at a right angle as shown
`magnet 10 goes through one side Sa of the tracking coil 15 in FIG. 7B.
`5, further goes to the inner yoke 9b via the focusing coil
`In the present invention, the driving means for driv-
`4. On the other hand, a magnetic flux generated by the
`ing the lens holder 2 is not limited. Further, the present
`magnet 11 goes through the other edge 5b of the track-
`invention can be applied to a lens holder which is driven
`ing coil 5, in an opposite direction to the magnetic flux
`only in the focusing direction.
`generated by the magnet 10. Therefore, the position of 20 As stated above, according to the present invention,
`the optical system holding member, i.e. lens holder 2 is
`the optical beam illuminated on the track formed on the
`recording medium can be controlled by supplying a
`supported by springs each having a bending portion
`bent toward the optical axis of the optical system. Thus,
`given electric current to the focusing coil 4 and the
`tracking coil 5.
`it is possible to make the size of the holding member
`As stated above, in the first embodiment, flat-shaped 25 small in the tracking direction. Since the weight of the
`holding member also becomes light, the driving sensi-
`tracking coils 5 are secured on the side portions of the
`tivity of the holding member can be increased. Further,
`lens holder in the tangential direction. Therefore, the
`size of the optical system driving device in the tangen-
`since the supporting member, i.e. springs, comprises the
`tial and tracking directions can be made small. The
`bending portion, the holding member is not affected by
`magnetic flux which works with the focusing coil 4 30 a resonance mode of the springs so much.
`Furthermore, since the size of the lens holder in the
`does not give damage to a driving sensitivity of the lens
`holder 2. It should be noted that three magnets are
`tracking direction can be made small, the lens holder
`arranged at both inner walls of the outer yokes 9a, 9a,
`can move in a wide range so that it is possible to write
`respectively, but it may be possible to arrange only on
`in and read out the information on and from the infor-
`magnet magnetized in a multiple manner for the three 35 mation recording medium in a wide range. Moreover,
`the space formed at both sides of the lens holder be-
`magnets.
`FIG. 6 is a plan view showing the second embodi-
`comes large, and then it is possible to arrange the spin-
`ment of the optical system supporting device. In FIG. 6,
`die motor having a large diameter and a high efficiency
`the portions corresponding to the first embodiment are
`in this space.
`denoted by the same numerical references.
`40 What is claimed is:
`The one end portion 6j of the spring 6 is engaged with
`1. An optical system supporting device comprising:
`the projection 2a provided in the lens holder 2, and the
`holding means for holding an optical system;
`end portion 6j is fixed to the projection 2a by means of
`driving means for driving said holding means selec-
`an agent. On the other hand, the other end portion 6e of
`tively in a focusing direction, a tracking direction
`the spring 6 is fixed to the concave portion 1a provided 45
`and a direction which is a combination of said fa-
`in the fixing member 7 in the same manner. As clear
`cusing direction and said tracking direction;
`from FIG. 6, both of the end portions 6j and 6e of the
`supporting means for supporting said holding means
`springs 6 are formed to be hook-shaped toward the
`to be movable selectively in the focusing direction,
`inner side. Additionally the projections 2a of the lens
`the tracking direction and a direction which is a
`holder 2 are projected to the Z direction. Therefore, it 50
`combination of said focusing direction and said
`· is possible to make the size of the lens holder 2 in the X
`tracking direction and comprising at least a first
`direction smaller. It should be noted that, in FIG. 6,
`supporting member and a second supporting mem-
`there is no indication of damper 12 in order to make the
`ber for supporting said holding means;
`figure simple. Although there is no indication of the
`a base plate carrying said holding means, said driving
`springs arranged in the lower position, the lens holder 2 55
`means and said supporting means; and
`and the magnets 11 are put between the respective two
`each of said first supporting member and said second
`springs 6 arranged in the upper and lower positions of
`supporting member comprising at least one parallel
`the device.
`portion having a longitudinal axis oriented parallel
`In such structure of the springs 6 according to the
`to a tangential direction, said tangential direction
`second embodiment, the effective lengths of the springs 60
`extending perpendicular to both said tracking di-
`6, which are bent in the X and Z directions, can be made
`rection and said focusing direction, and one bend-
`long. Therefore, when the lens holder 2 is deviated in
`ing portion which (i) is serially connected to said
`the X direction, the deviation amount thereof in the Y
`parallel portion and (ii) has a longitudinal axis
`direction becomes small. And, as stated above, in the
`which (a) forms an angle with said longitudinal axis
`second embodiment, the projections 2a are not pro- 65
`of said parallel portion, (b) is oriented in a direction
`jected in the X direction but in the Z direction, and thus
`substantially perpendicular to said focusing direc-
`tion and (c) extends toward an optical axis of said
`the lens holder 2 can be formed small in size and light in
`weight. Therefore, the driving sensitivity of the holding
`optical system, said parallel portion and said bend-
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`ing portion being formed as a single unit, said paral(cid:173)
`lel portion including a first end portion connected
`to said holding means, said bending portion and
`said first end portion being spaced apart from one
`another with respect to said tangential direction.
`2. An optical system supporting device according to
`claim 1, wherein:
`said first and second supporting members are ar(cid:173)
`ranged symmetrically on opposite sides of said
`holding means.
`3. An optical system supporting device according to
`claim 2, wherein:
`said base plate comprises at least a first fixing member
`for fixing said first end portion of each of said first
`1 and second supporting members; said holding 5
`
`means comprises at least a couple of second fixing
`members for fixing a second end portion of each of
`said first and second supporting members;
`whereby said first and second supporting members 20
`are extended between the first fixing member and
`the second fixing member.
`4. An optical system supporting device according to
`claim 1, wherein:
`said supporting means comprises one parallel portion 25
`and one bending portion bent toward the optical
`axis of the optical system.
`5. An optical system supporting device according to
`claim 1, wherein:
`said bending portion is are bent toward the optical 30
`axis of the optical system at a right angle.
`6. An optical system supporting device according to
`claim 1, wherein:
`said first and second supporting members are pro(cid:173)
`vided in respective upper and lower positions of 35
`said supporting means.
`7. An optical system supporting device according to
`claim 1, wherein said first end portion is positioned
`entirely on one side of an imaginary line that extends (a)
`in said tracking direction and (b) through said optical 40
`axis and said end portion is positioned entirely on the
`opposite side of said line.
`8. An optical system supporting device comprising:
`holding means for holding an optical system;
`driving means for driving said holding means selec- 45
`tively in a focusing direction, a tracking direction
`and a direction which is a combination of said fo(cid:173)
`cusing direction and said tracking direction;
`supporting means for supporting said holding means
`to be movable selectively in the focusing direction,
`the tracking direction and a direction which is a
`combination of said focusing direction and said
`tracking direction and comprising at least a first
`supporting member and a second supporting mem- 55
`ber for supporting said holding means;
`a base plate carrying said holding means, said driving
`means and said supporting means; and
`each of said first supporting member and said second
`supporting member comprising at least one parallel 60
`portion oriented parallel to a tangential direction
`and one bending portion which extends toward an
`optical axis of said optical system, said parallel
`portion and said bending portion being formed as a
`65
`single unit, wherein:
`said first and second supporting members are ar- ·
`ranged symmetrically on opposite sides of said
`holding means;
`
`50
`
`8
`said base plate comprises at least a first fixing mem(cid:173)
`ber for fixing a first end portion of each of said
`first and second supporting members;
`said holding means comprises at least a couple of
`second fixing members for fixing a second end
`portion of each of said first and second support(cid:173)
`ing members;
`whereby said supporting members are extended
`between the first fixing member and the second
`fixing member;
`said first fixing member comprises concave por(cid:173)
`tions at both ends thereof, respectively, to which
`said first end portion of each of said first and
`second supporting members are fixed; and
`said couple of second fixing members comprise
`projections, respectively, to which said second
`end portion of each of said first and second sup(cid:173)
`porting members are fixed.
`9. An optical system supporting device according to
`claim 8, wherein:
`said supporting means is arranged such that a width in
`a direction perpendicular to extending directions of
`said bending portion is larger than a width of said
`parallel portion direction.
`10. An optical system supporting device according to
`claim 8, wherein:
`said concave portions are arranged in inner sides of
`said fixing members; and said projections are ar(cid:173)
`ranged in the focusing direction.
`11. An optical system supporting device according to
`claim 10, wherein:
`both ends of said supporting first and second mem(cid:173)
`bers comprise hook-shaped portions which are
`hooked toward an inner side.
`12. An optical system supporting device comprising:
`holding means for holding an optical system;
`driving means for driving said holding means selec-
`tively in a focusing direction, a tracking direction
`and a direction which is a combination of said fo(cid:173)
`cusing direction and said tracking direction;
`supporting means for supporting said holding means
`to be movable selectively in the focusing direction,
`the tracking direction and a direction which is a
`combination of said focusing direction and said
`tracking direction and comprising at least a frrst
`supporting member and a second supporting mem(cid:173)
`ber for supporting said holding means;
`a base plate carrying said holding means, said driving
`means and said supporting means; and
`each of said frrst supporting member and said second
`supporting member comprising at least one parallel
`portion having a longitudinal axis oriented parallel
`to a tangential direction, said tangential direction
`extending perpendicular to both said tracking di(cid:173)
`rection and said focusing direction, and one bend(cid:173)
`ing portion which (i) is serially connected to said
`parallel portion and (ii) has a longitudinal axis
`which (a) forms an angle with said longitudinal axis
`of said parallel portion, (b) is oriented in a direction
`substantially perpendicular to said focusing direc(cid:173)
`tion and (c) extends toward an optical axis of said
`optical system, said parallel portion and said bend(cid:173)
`ing portion being formed as a single unit, wherein:
`said supporting means comprises two parallel por-
`tions and one bending portion, and said bending
`portion is arranged between said parallel por(cid:173)
`tions in series.
`13. An optical system supporting device comprising:
`
`

`
`5,428,481
`
`5
`
`9
`holding means for holding an optical system;
`driving means for driving said holding means selec(cid:173)
`tively in a focusing direction, a tracking direction
`and a direction which is a combination of said fo-
`cusing direction and said tracking direction;
`supporting means for supporting said holding means
`to be movable selectively in the focusing direction,
`the tracking direction and a direction which is a
`combination of said focusing direction and said
`tracking direction and comprising at least a first 10
`supporting member and a second supporting mem(cid:173)
`ber for supporting said holding means;
`a base plate carrying said holding means, said driving
`means and said supporting means; and
`each of said first supporting member and said second 15
`supporting member comprising at least one parallel
`portion having a longitudinal axis oriented parallel
`to a tangential direction, said tangential direction
`extending perpendicular to both said tracking di(cid:173)
`rection and said focusing direction, and one bend- 20
`ing portion which (i) is serially connected to said
`parallel portion and (ii) has a longitudinal axis
`which (a) forms an angle with said longitudinal axis
`of said parallel portion, b) is oriented in a direction
`substantially perpendicular to said focusing direc- 25
`tion and (c) extends toward an optical axis of said
`Optical system, said parallel portion and said bend(cid:173)
`ing portion being formed as a single unit, wherein
`said first and second supporting members are ar-
`ranged symmetrically on opposite sides of said 30
`holding means,
`said base plate comprises at least a first fixing mem(cid:173)
`ber for ftxing a first end portion of each of said
`frrst and second supporting members; said hold(cid:173)
`ing means comprises at least a couple of second 35
`fixing members for fixing a second end porti