Optical component drive device including nonparallel elastic plates

The present invention is applied to a device for driving optical component parts, such as an objective lens, in accordance with displacement of a disk. A mobile body, on which the optical component parts are mounted, is supported by at least two plate springs that are not parallel with the disk, in such a manner that the mobile body can be driven in a focusing direction and a tracking direction. The plate springs can have an electric wiring function so that no wires extend from the mobile body.

FIELD OF THE INVENTION 
The present invention relates to an optical drive device provided in an 
optical recording and reproduction apparatus for driving optical component 
parts, such as an objective lens, in accordance with displacement of a 
disk. Particularly, the present invention relates to a device for driving 
optical component parts that includes plate springs that are used to drive 
the optical component parts in focusing and tracking directions, and that 
may have an electric wiring function, the drive device thus being made 
simple and made to include a mobile body of reduced weight, so as to be 
capable of stably driving the optical component parts at high speed. 
DESCRIPTION OF RELATED ART 
A conventional optical recording and reproduction apparatus has an optical 
component parts drive device of varying type in which plate springs are 
employed. In such an optical component parts drive device, two pairs of 
plate springs support a mobile body, as disclosed, for example, in 
Japanese Patent Publication No. 62-20903. 
In this example, however, it is essential to provide intermediary 
supporting members in order to tie together the two pairs of plate springs 
which are in turn necessary to support the mobile body in such a manner 
that the mobile body can be moved in two directions. This requirement 
hinders the weight of the mobile body from being reduced. In addition, the 
complicated structure makes dynamic characteristics unstable. 
When optical elements, such as a light-emitting element and a 
light-receiving element, are integrated with the mobile body, the 
inevitable need to provide electric wires for these elements makes the 
structure more complicated and makes dynamic characteristics more 
unstable. 
SUMMARY OF THE INVENTION 
An optical component parts drive device according to the present invention 
includes: a mobile body having optical component parts for radiating a 
spot of light onto a recording surface of a disk on which information is 
recorded, and also having a holder for retaining the optical component 
parts; driving means for driving the mobile body in two directions 
comprising a radial direction of the disk and a direction perpendicular to 
a plane defined by the surface of the disk; and supporting means for 
supporting the mobile body. The drive device is characterized in that the 
supporting means comprises at least four elastic plate springs, the plate 
springs having widths directed at an arbitrarily selected angle with 
respect to the plane defined by the disk. 
The plate springs may be integral with wires for conveying various signals.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
FIG. 1 shows a first embodiment of the present invention. Light 15 
generated from a light source 2 is made into a parallel beam by a 
collimating lens 3. Thereafter, the parallel beam is refracted by an 
optical path deflecting means 4 in a direction perpendicular to a plane 
defined by a surface of a disk 1, propagates through an objective lens 5, 
and forms a light spot on a desired position of a recording surface of the 
disk. The disk 1, however, may be displaced in a radial direction 
(hereinafter referred to as "tracking direction"; indicated by an arrow 
22) and a direction perpendicular to the plane defined by the disk 
(hereinafter referred to as "focusing direction"; indicated by an arrow 
21) when influenced by vibration of a spindle connected to a spindle motor 
6, and/or the eccentricity or the surface waving of the disk itself. 
Therefore, a mobile body having the objective lens 5 is driven in 
accordance with such displacement. 
The mobile body includes the objective lens 5, a holder 7 for retaining the 
objective lens, first coils 8a and 8b for driving the mobile body in a 
focusing direction, and second coils 9a to 9d for driving the mobile body 
in a tracking direction. 
As shown in FIGS. 2(a) and 2(b), the mobile body is supported by first end 
portions of four plate springs 10a to 10d having elasticity. The plate 
springs 10a to 10d have widths that are directed at arbitrarily selected 
angles 31a to 31d, respectively, with respect to a plane defined by the 
disk 1. The second end portions of the plate springs 10a to 10d are fixed 
to a base 11. As a result, the four plate springs are able to bend in the 
two directions, i.e., a focusing direction and a tracking direction, as 
shown in FIGS. 3(a) and 3(b); thus, the mobile body is able to move in 
these two directions. The provision of the angles 31a-31d serves to 
improve the rigidity of the plate springs against the movement of the 
mobile body in directions other than the above two directions, such as a 
tangential direction of the disk. 
The material and the shape of the plate springs 10 will be described. A 
material for forming the plate springs is preferably an elastic metal 
material such as stainless steel, phosphor bronze or beryllium copper. 
Each plate spring has a substantially rectangular or trapezoidal 
cross-sectional configuration having a thickness of 0.005 to 1 mm and a 
width of 0.1 to 2 mm. Although the plate springs 10a-10d may be made of a 
plastic material, the use of a metal material, as described above, is 
advantageous in terms of temperature characteristics and changes with the 
passage of time. 
Next, the angles 31a-31d will be described. The magnitude of the angles 
31a-31d determines a spring constant for the focusing direction and for 
the tracking direction. That is, the closer to 0 degrees the value of the 
angles 31a-31d, the smaller the spring constant for the focusing direction 
and the greater the spring constant for the tracking direction. On the 
other hand, the closer to 90 degrees the value of the angles 31a-31d, the 
greater the spring constant for the focusing direction and the smaller the 
spring constant for the tracking direction. Since the spring constants are 
very significant to the dynamic characteristics of the mobile body in the 
focusing and tracking directions, the values of the angles 31a-31d that 
determine these constants are important. It is advantageous if the four 
angles are of substantially equal values that range from 25 to 65 degrees. 
In the embodiment being illustrated, four plate springs support the mobile 
body. However, such four plate springs may be provided by using, e.g., two 
members 101, as shown in FIG. 4, thereby obtaining similar effect. 
Next, driving means will be described. As shown in FIG. 1, the first coils 
8a and 8b for driving the mobile body in a focusing direction have a 
hollow elongated-circular shape, and are able to generate a driving force 
in a focusing direction through an electromagnetic action involving 
magnetic flux generated by opposed magnets 12a-12b. Each of the first 
coils 8a and 8b is secured to one of the end faces of the holder 7 which 
oppose each other in a tangential direction of the disk, so as to drive 
the mobile body in a focusing direction with a driving force described 
above. The second coils 9a-9d for driving the mobile body in a tracking 
direction have a hollow elongated-circular shape, as in the case of the 
first coils 8a-8b, and are capable of driving the mobile body through an 
electromagnetic action involving magnetic flux generated by the opposed 
magnets 12a-12b. Two pairs, in total, of the second coils 9a to 9d are 
secured to the two end faces of the holder 7, with each pair on one of the 
end faces, as in the case of the first coils. Magnets 12a and 12b 
constituting the above magnets are disposed on a stationary section with a 
certain gap between each of these magnets, on one hand, and a 
corresponding first coil 8a-8b and corresponding second coils 9a-9d, on 
the other. 
Each of the first and second coils 8a-8b and 9a-9d comprises a coil of a 
metal wire mainly made of an electrically conductive material such as 
copper or aluminum. However, similar effect may be obtained by using an 
electrically conductive material, such as above, formed in patterns on an 
insulating sheet made of a polyimide resin, a polyurethane resin, or the 
like. Further, although in the embodiment described above, the first and 
second coils 8a-8b and 9a-9d are mounted on the holder 7 while the magnets 
12a-12b are disposed on a stationary section, the magnets 12a-12b may be 
mounted on the holder 7 with the first and second coils 8a-8b and 9a-9d 
being disposed on a stationary section, thereby obtaining similar effect. 
Further, although in the above-described embodiment, driving in a focusing 
direction and driving in a tracking direction commonly employ the magnets 
12a and 12b, driving operations in these two directions may employ 
individual magnets, and similar effect may be provided. Further, similar 
effect may be provided even when the first coils 8a-8b, the second coils 
9a-9d, and the above patterns have substantially rectangular shapes. 
FIG. 5 shows a second embodiment of the present invention. Optical 
component parts, such as a light source 2, a light diffracting means 14 
and an objective lens 5, are retained by a holder 7. A mobile body mainly 
comprises the holder 7, first coils 8a-8b for effecting driving in a 
focusing direction, and second coils 9a-9d for effecting driving in a 
tracking direction. 
Light generated from the light source 2 transmits through the light 
diffracting means 14, and is thereafter condensed by the objective lens 5, 
forming a light spot on a recording surface of a disk. Since the series of 
optical component parts from the light source 2 to the objective lens 5 
are mounted on the holder 7, no change occurs in the relative positions of 
the individual optical component parts even when the mobile body is 
displaced in a focusing or tracking direction. 
The mobile body is supported by plate springs 10a-10d. Plate springs 10a to 
10d constituting the above plate springs have widths directed at angles 
31a-31d with respect to a plane defined by the surface of the disk. 
Damping members 13a to 13d having viscosity are attached to the plate 
springs 10a to 10d, respectively. The above construction provides effects 
similar to those provided by the first embodiment. 
The damping members 13a-13d will be described. The damping members 13a-13d 
are mainly made of a material such as silicone rubber, natural rubber, 
butyl rubber, or ether-containing polyurethane. When the plate springs 
10a-10d receive excessive deformation energy caused by displacement of the 
mobile body, the damping members 13a-13d exhibit viscosity resistance such 
as to damp the energy. The damping members 13a-13d may be attached to 
substantially the entire surface of the plate springs 10a-10d. However, 
attaching to part of the plate springs also is effective. Further, a 
similar effect may be obtained by sandwiching a damping material 13 
between two plate spring pieces 10, as shown in FIG. 6. A damping material 
may be sandwiched between portions of plate spring pieces, and still 
similar effect may be obtained. 
FIG. 7 shows a third embodiment of the present invention. A mobile body has 
a holder 7. Eight spring plates 10a to 10h, in total, have first ends 
attached to two end faces of the holder that oppose each other in a 
tangential direction 23 of a disk, with four spring plates being attached 
to each end face. The second ends of the plate springs 10a to 10h are 
fixed to a fixing member. The plate springs 10a to 10h thus disposed have 
widths directed at angles 31a-31d with respect to a plane defined by a 
surface of the disk. The above construction provides effects similar to 
those provided by the first embodiment. Similar effects may be provided 
even when paired ones of the plate springs, such as plate springs 10a and 
10e, which have their longitudinal directions coinciding with each other, 
are formed as portions of a single plate spring member while the other six 
plate springs are similarly formed by using three plate spring members. 
FIGS. 8(a) and 8(b) show a fourth embodiment of the present invention. Four 
plate springs 10a to 10d are secured with widths thereof directed in such 
a manner as to maintain angles 31a-31d with respect to a plane defined by 
a disk. The plate springs have portions of lengths thereof lying in a 
space between a holder 7 and a base 11, which portions are not parallel to 
a tangential direction (indicated by arrow 23) of the disk over a part or 
substantially the entirety of the space. As a result, those plate springs 
that are opposed to each other when viewed from above, as shown in FIG. 
8(a), e.g., 10a and 10c are arranged in a substantially V-shaped pattern, 
and so are those plate springs that are opposed to each other when viewed 
from one side, as shown in FIG. 8(b)e.g., 10b and 10d. The above 
construction provides effects similar to those provided by the first 
embodiment. Although in the illustrated construction, the distance between 
the opposed plate springs is increased toward the base 11, similar effect 
may be provided when that distance is increased toward the holder 7 and 
decreased toward the base 11. 
Although the above descriptions concern embodiments of optical component 
parts drive devices for optical recording and reproduction apparatus, the 
present invention may be applied to optical component parts drive devices 
for various apparatus, and still similar effects may be provided. 
FIG. 9(a) schematically shows a fifth embodiment of the present invention. 
A fixing member 109 supports a mobile body 111, which has an optical unit 
102, a reflection mechanism 103, a lens 104 and coils 106, through four 
plate springs 105a, 105b, 105c and 105d (these being shown in FIG. 9(b)) 
in such a manner as to allow movement of the mobile body. Light emitted 
from the optical unit 102 is directed by the reflection mechanism 103 
toward the lens 104, transmits through the lens 104, and is condensed on a 
recording medium (not shown). Light reflected from the recording medium 
and indicating recorded information returns to the optical unit 102 by 
taking the above optical path in the reverse direction. An electrical 
signal is generated from light which has returned to the optical unit. On 
the basis of the electrical signal, the position of the mobile body is 
controlled by using electromagnetic force generated between the coils 106 
and magnets 107 due to current flowing in the coil 106. As shown in FIG. 
9(a), magnets 107 are mounted on element 108, which also acts as a fixing 
member, as well as a yoke for magnets 107. 
FIGS. 10(a) and 10(b) are views illustrating this embodiment, the views 
depicting the embodiment schematically in order to illustrate the 
operation of the plate springs 105a-105d. FIG. 10(a) shows a state in a 
neutral position. In this state, the deformation of the plate springs 
105a, 105b, 105c and 105d is small. 
FIG. 10(b) shows a state of being displaced in one of the focusing and 
tracking directions in which the mobile body 111 is able to move, for 
example, be displaced in the direction indicated by an arrow 201. In this 
state, the plate springs 105a, 105b, 105c and 105d are deformed in a 
complex deformation mode including torsional deformation and deflectional 
deformation. 
It has been found, in the production of this embodiment, that the behavior 
of a plate springs greatly varies depending on the width and thickness of 
the plate spring. Experiments have been conducted, finding that the 
behavior of a plate spring having a length L which is eight or more times 
a width W thereof, as shown in FIG. 11, is stable when the plate spring is 
configured to have a flatness ratio (i.e., the ratio (=T/W) of a thickness 
T of the plate spring with respect to the width W thereof) above 7%, 
whereas when the plate spring is configured to have a flatness ratio below 
7%, the behavior of the plate spring is unstable. It has also been found 
that stability is greatly improved when the flatness ratio is above 16%, 
as shown in the Table in FIG. 11. 
FIGS. 12(a) to 12(d) show various modifications of plate springs that may 
be used in this embodiment. The hatched portions indicate portions for 
mounting to the mobile body 111 and the fixing member 109. FIG. 12(a) 
shows a plate spring having a length L and a width W that satisfy the 
interrelationship shown in FIG. 11, this being the simplest among the 
modifications. 
FIG. 12(b) shows a modification in which, while the mounting portions have 
a width W1, a central linear portion of the plate spring has a width W2 
smaller than the width W1. This arrangement is effective for preventing 
unsatisfactory movement from being caused by a high rigidity of a plate 
spring when the plate spring is formed of a material having a relatively 
great thickness T. In this case, T/W2 is the flatness ratio that relates 
to the stability of behavior. 
FIG. 12(c) shows a modification in which the plate spring has a central 
linear portion having a width W3, and also has portions the width of which 
is reduced from the width W3. This arrangement is effective for preventing 
unsatisfactory movement from being caused by a low rigidity of a plate 
spring when the plate spring is formed of a material having a relatively 
small thickness T. In this case, T/W4 is the flatness ratio that relates 
to the stability of behavior. 
FIG. 12(d) shows a modification in which the plate spring has a central 
linear portion having a width of various values. That is, the width of the 
central portion changes gradually from a width W5 to a width W4. This 
arrangement serves to disperse the natural frequency of the plate spring, 
that is, to lower the peak of amplitude at the natural frequency, which is 
advantageous to control. 
FIG. 13 shows a modification of the fifth embodiment, in which plate 
springs of the type shown in FIG. 12(c) are combined. The drawing shows a 
state of being displaced in one of the focusing and tracking directions in 
which the mobile body 111 is able to move, for example, displaced in the 
direction indicated by an arrow 501. In this state, each plate spring 
undergoes torsional deformation in width reduced portions 502a and 
deflectional deformation in a central portion 502b. Thus, when a plate 
spring has width reduced portions at either end thereof, a 
dispersed-deformation mode is effected, in which movement is stabilized 
and the range of linear movement is widened. It has been confirmed, from 
the results of certain experiments, that relatively simple deflection 
rigidity has dominant influence on the natural frequency in this 
modification, and that deflection rigidity is the rigidity factor that 
requires consideration in design. 
FIGS. 14(a) and 14(b) show an example of wiring arranged through the plate 
springs of this embodiment. As shown in FIG. 14(a), four wires 601 are 
arranged substantially parallel to each other in each of the plate springs 
105 while extending from one end of the plate spring 105 to the other end. 
The wires are formed by etching a foil of a copper-alloy spring material 
containing beryllium, and have a substantially rectangular cross-sectional 
configuration, as shown in FIG. 14(b). 
As shown in FIG. 14(b), the outer form of each plate spring 105 of this 
embodiment is produced by coating a polyimide resin on two opposed side 
surfaces of the wires. Regarding a material for this purpose, an 
insulating material, other than polyimide, may be used. Regarding a 
production method, a method comprising other than resin coating, such as a 
method comprising application of a sheet-shaped material or injection 
forming, may be used. 
Another example is shown in FIG. 14(c). As shown in this drawing, it is 
possible to combine wires 601 in a layered structure with a wire, such as 
a wire 601a, having a different cross-sectional area. 
With the arrangement of each plate spring 105 shown in FIG. 14(a), there is 
a risk that portions of wires 601 at the width reduced portions 602 may be 
exposed on those surface portions of the outer form at either end. 
However, since the four plate springs 105 are not disposed in contact with 
each other, no substantial problem arises from the above risk. 
In this embodiment, four wires 601 are disposed in each of the four plate 
springs 105a-105d, thereby disposing sixteen wires in total. As shown in 
FIG. 9(b), since the plate springs 105a, 105b, 105c and 105d are isolated 
from each other, electricity has a small influence between the plate 
springs. However, four wires 601 that are disposed in proximity to each 
other in each plate spring 105 are likely to be electrically influenced 
therebetween. In view of this fact, this embodiment is arranged such that 
a first line for conveying a received-light signal output from the optical 
unit 102, a second line for a light-source driving signal to be input to 
the optical unit 102, and a third line for a coil driving signal for 
supplying current to the coils 106 for driving the mobile body 101, that 
is, signal lines for conveying current of different levels, are not 
provided in a single plate spring. Specifically, wires forming a 
received-light signal line are all disposed in the plate springs 105c and 
105d, wires forming a light-source driving signal line are all disposed in 
the plate spring 105b, and wires forming a coil driving signal line are 
all disposed in the plate spring 105a. When signal lines are thus 
arranged, it is possible to realize stable control operations. 
FIGS. 15(a) and 15(b) show a sixth embodiment of the present invention. As 
shown in FIG. 15(a), plate springs 701a to 701d of this embodiment 
cooperate with a fixing member 702 to support a mobile body 703 in such a 
manner that the mobile body is able to move in two directions comprising a 
focusing direction (indicated by an arrow 21) and a tracking direction 
(indicated by an arrow 22). 
This embodiment is distinguished from the foregoing embodiments in the 
manner in which the plate springs 701a to 701d are mounted. Those end 
portions of the plate springs 701a to 701d close to the fixing member 702 
are fixed to surfaces of the fixing member 702 that are perpendicular to 
the tracking direction, the plate springs 701a to 701d extended from the 
fixing member 702 to the mobile body 703 while twisting by approximately 
90.degree., and the plate springs 701a to 701d have the other end portions 
fixed to surfaces of the mobile body 703 which are perpendicular to the 
focusing direction. The twisting of the plate spring 701a has the shape 
shown in FIG. 15(b) when viewed from the direction indicated by an arrow 
704. 
Thus, in this embodiment, the four plate springs 701a to 701d are arranged 
such that the plate springs have first symmetrical surfaces that are 
perpendicular to the tracking direction, and second symmetrical surfaces 
that are perpendicular to the focusing direction. 
FIGS. 16(a) to 16(c) are views illustrating the operation of this 
embodiment. FIGS. 16(a) to 16(c) show different states of the plate spring 
701a when the end portion thereof that is close to the mobile body 703 is 
displaced in directions indicated by arrows 801, 802 and 803, 
respectively, with the other end portion of the plate spring being fixed 
to the fixing member 702. 
When the plate spring 701a is displaced in the direction indicated by the 
arrow 801, the plate spring undergoes deflectional deformation mainly in 
the vicinity of the end portion close to the mobile body 703. When 
displaced in the direction indicated by the arrow 802, the plate spring 
701a undergoes deflectional deformation mainly in the vicinity of the end 
portion close to the fixing member 702. When displaced in the direction 
indicated by the arrow 803, the plate spring 701a undergoes deflectional 
deformation mainly in the vicinity of a central portion, indicated by a 
displacement position 804. Thus, each of the plate springs 701a and 701d 
has portions capable of undergoing plane deformation in every direction 
within a plane defined by the focusing and tracking directions in which 
the mobile body 703 is able to move. Therefore, it is possible to drive 
the mobile body 703 with a small driving force, and to obtain isotropic 
performance. 
A manner of mounting the plate springs 701a to 701d, which is different 
from that shown in FIGS. 15(a) and 15(b), is possible. That is, those end 
portions of the plate springs 701a to 701d close to the fixing member 702 
may be fixed to surfaces of the fixing member 702 that are perpendicular 
to the focusing direction, with the other end portions of the plate 
springs 701a to 701d being fixed to surfaces of the mobile body 703 that 
are perpendicular to the tracking direction. This arrangement provides a 
similar effect. 
A similar effect may be obtained when the plate springs are disposed as 
shown in FIGS. 8a and 8b, in which the distance between opposed plate 
springs is increased toward the base 11 (toward the fixing member 702, in 
this embodiment). 
FIGS. 17(a) and 17(b) show a seventh embodiment of the present invention. 
In contrast with the sixth embodiment in which the plate springs 701a to 
701d are twisted by approximately 90.degree., the seventh embodiment is 
characterized in that a twist angle smaller than 90.degree. is adopted. An 
example of a twist angle shown by the embodiment being illustrated is 
45.degree.. However, any suitable angle may be selected in accordance with 
necessity of control. 
Those end portions of plate springs 705a to 705d close to a fixing member 
702 are fixed to surfaces of the fixing member 702 that are perpendicular 
to a tracking direction, the plate springs 705a to 705d extended from the 
fixing member 702 to a mobile body 706 while twisting by approximately 
45.degree., and the plate springs 705a to 705d have the other end portions 
fixed to surfaces of the mobile body 706 that form an angle of 
approximately 45.degree. with respect to a plane perpendicular to a 
focusing direction and that are parallel with a tangential direction 
(indicated by an arrow 23) of the relevant disk. The twisting of the plate 
spring 705a has the shape shown in FIG. 17(b) when viewed from the 
direction indicated by an arrow 707. Twisting in the opposite direction 
provides similar effect. 
Adopting the above arrangement and setting the twist angle to a desired 
value, makes it possible to easily balance the driving system and the 
rigidity of the supporting system, thereby making it possible to perform 
optimum control. 
A similar effect is provided when those end portions of plate springs 705a 
to 705d close to the fixing member 702 are fixed to surfaces of the fixing 
member 702 that are perpendicular to the focusing direction while the 
other end portions of the plate springs 705a to 705d are fixed to surfaces 
of the mobile body 706 that form a desired angle with respect to a plane 
perpendicular to the focusing direction and that are parallel with the 
tangential direction (indicated by the arrow 23) of the disk. 
A similar effect also is provided when those end portions of plate springs 
705a to 705d close to the mobile body 706 are fixed to surfaces of the 
mobile body 706 that are perpendicular to either the focusing direction or 
the tracking direction while the other end portions of the plate springs 
705a to 705d are fixed to surfaces of the fixing member 702 that form a 
desired angle with respect to a plane perpendicular to the focusing 
direction and that are parallel with the tangential direction (indicated 
by the arrow 23) of the disk. 
FIGS. 18(a) and 18(b) show an eighth embodiment of the present invention. 
This embodiment is characterized in that, in contrast with the sixth 
embodiment having isotropic performance, wires 708a to 708b are added as 
reinforcing members so as to increase rigidity. 
As shown in FIG. 18(a), those end portions of plate springs 701a to 701d 
close to a fixing member 702 are fixed to surfaces of the fixing member 
702 that are perpendicular to a tracking direction, the plate springs 
extended from the fixing member 702 to a mobile body 709 while twisting by 
approximately 90.degree., and the plate springs have the other end 
portions fixed to surfaces of the mobile body 709 that are perpendicular 
to a focusing direction. 
The wires 708a to 708d have their end portions close to the fixing member 
702 fixed to surface of the fixing member 702 that are perpendicular to 
the tracking direction, with the other end portions being fixed to 
surfaces of the mobile body 709 that are perpendicular to the tracking 
direction. The wires 708a to 708d are parallel to each other and also are 
parallel to a tangential direction of the relevant medium. Similarly to 
the plate springs 701a to 701d, these wires have isotropic rigidity with 
respect to every direction within a plane defined by the focusing and 
tracking directions in which the mobile body 709 is able to move. 
FIG. 18(b) is a fragmentary enlarged view of this embodiment, taken from 
the direction indicated by an arrow 710. This drawing shows the positional 
relationship between the plate springs 701a and 701c, and the wires 708a 
and 708c. 
Adopting the above arrangement enables a standard material, which is 
advantageous in terms of costs, to be selected for plate springs that also 
serve to provide electrical wiring, and also enables desired rigidity to 
be obtained by the use of inexpensive wires. 
FIGS. 19(a) and 19(b) show a ninth embodiment of the present invention. In 
this embodiment, four wires 708a to 708d support a mobile body 709 in such 
a manner as to allow movement of the mobile body, and wiring elements 801a 
and wiring elements 801b are disposed at locations on two opposed side 
surfaces of the mobile body 709. In this arrangement, it is desired, from 
the viewpoint of stability of moving performance, that the wiring elements 
have a sufficiently smaller elasticity than that of the wires. 
The wiring elements in this embodiment are such that, as shown in FIG. 
19(b), first ends of a plurality of wires 802 and second ends of the same 
are individually integrated by insulators 803, and that intermediate 
insulators 804 are provided at intermediate positions, thereby preventing 
contact between the wires while realizing a low elasticity. Each wire 802 
may be coated with another insulator, as in the case of a coated copper 
wire, so long as the wire has a desired cross-sectional configuration. 
Further, each wire 802 may be made of an electrically conductive material. 
However, in order to improve durability, a copper-containing spring 
material, such as beryllium copper, is preferable. 
A material having viscosity, such as rubber, is used to form the 
intermediate insulators 804, so as to damp vibration to thereby improve 
movement stability. 
If the intermediate insulators 804 are made of a viscous material having an 
even lower elasticity, the entire surface of the wires 802 may be covered. 
Next, signals will be described. In this embodiment, a line for a driving 
signal to be supplied to a driving means (not shown) for driving the 
mobile body 709, and a line for a driving signal to be supplied to a 
light-emitting means (not shown) within the mobile body 709 are formed in 
the wiring means 801a. On the other hand, a line for a signal from a 
light-receiving means (not shown) within the mobile body 709 is formed in 
the wiring means 801b. Thus, noise in a signal, particularly a signal from 
the light-receiving means, is reduced. 
As has been described above, according to the present invention, plate 
springs have widths angled with respect to a plane defined by a surface of 
a disk, so that a simple construction enables a mobile body to be 
displaced in two directions comprising a focusing direction and a tracking 
direction. This arrangement makes intermediary supporting members 
unnecessary, and realizes a simple construction of an optical component 
parts drive device. 
When plate springs serving as supporting means also serve to provide an 
electric wiring function, it is possible to eliminate a wiring system, 
which has been necessary as a system separate from a supporting system. 
This is very advantageous in terms of costs. 
When plate springs are used in their twisted position, it is possible to 
easily change characteristics, such as to reduce rigidity or to impart 
isotropic property to rigidity, in accordance with the aim of control. 
Thus, an optical component parts drive device is capable of realizing 
optimum control, and capable of being applied to a wide variety of 
apparatus.