JPH087310A - Apparatus for driving optical system - Google Patents

Abstract

PURPOSE:To obtain an optical system-driving apparatus wherein a supporting mechanism part between a tracking driving part and an optical element resonates a little. CONSTITUTION:A focus actuator 20 is constituted of a base 21, a spring receiver 22 fixed to the base, two parallel leaf springs 30a' and 30b' fixed to the spring receiver, a holder 23 supported by the leaf springs, focus coils 24a, 24b and an objective lens 26 secured to the holder, and magnets 25a and 25b secured to the base. The two leaf springs 30a' and 30b' are totally in the same shape, having wide parts 31, 32, 33 in a longitudinal direction. The wide parts 31 and 33 are connected by two slim bent parts 36a and 36b, and the wide parts 32 and 33 are connected by two slim bent parts 37a and 37b. Flanges 38b and 38e extending in a (-z) direction are formed at both ends of the wide part 33.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical system driving device provided in an optical recording / reproducing device for optically recording / reproducing information.

[0002]

2. Description of the Related Art Generally, an optical system driving device of an optical recording / reproducing apparatus follows an access actuator for accessing different tracks and a track swing due to eccentricity or the like mounted on a carriage driven by the access actuator. And a biaxial actuator that can be driven in two directions and has a focus function for following the surface contact of the recording medium. Thereby, the access operation, the tracking operation, and the focus operation of the optical element such as the objective lens are performed.

In the optical recording / reproducing apparatus, the access operation to the track of the recording medium and the tracking operation to follow the shake of the track are usually performed by using different drive circuits and drive mechanisms. Since both the access operation and the tracking operation have the same operation direction as the radial direction of the recording medium, they can be performed by a common drive circuit and drive mechanism. There is an optical system driving device which is reduced in size and cost by reducing the number of driving circuits and driving mechanisms by this method.
That is, an optical system driving device has been proposed in which an access actuator having a wide moving range also serves as a tracking actuator. An example of such an optical system driving device is shown in FIG.

In FIG. 12, a tracking actuator 10 composed of an access actuator is
A carriage 16 supported by the shafts 11a and 11b and bearings 17a and 17b so as to be movable in the radial direction (x direction) of the recording medium, tracking coils 15a and 15b fixed to the carriage 16, and each tracking coil 15
a, 15b, inner yokes 12a, 12b, outer yokes 13a, 13b arranged facing the inner yokes 12a, 12b, and magnets 14a, 14b fixed inside the outer yokes 13a, 13b. It consists of and.
The shafts 11a and 11b, the inner yokes 12a and 12b, and the outer yokes 13a and 13b are all fixed to a deck base (not shown).

A focus actuator 20 is attached to the carriage 16. The focus actuator 20 includes a base 21, a spring receiver 22 fixed to the base 21, two parallel plate springs 30a and 30b having one end fixed to the spring receiver 22, and plate springs 30a and 3b.
0b, the holder 23 attached to the other end, and the holder 23
The focus coils 24a and 24b are fixed to the holder 23, the objective lens 26 is also fixed to the holder 23, and the magnets 25a and 25b are fixed to the base 21 for exerting a magnetic field on the focus coils 24a and 24b. In this focus actuator 20, the objective lens 2
6 is supported by two parallel leaf springs 30a and 30b so as to be movable only in the vertical direction (z direction) of the recording medium, and in the radial direction (x direction) of the recording medium like a biaxial actuator. Can't move.

[0006]

In the optical system driving device shown in FIG. 12, the access actuator of the conventional general optical system driving device is the tracking actuator 10. A leaf spring 30a, between the carriage 16 (hereinafter referred to as a tracking drive unit), to which the tracking coils 15a and 15b receiving the driving force are fixed,
30b is present. In order to perform the tracking operation accurately, the movements of the objective lens 26 and the tracking drive unit must match in the control frequency band, and the resonance of the leaf springs 30a and 30b existing between them must be prevented so that no adverse effect is exerted. There is a need to.

As shown in FIG. 12, two leaf springs 3
13 and 14 are Bode diagrams showing the influence of resonance on the objective lens 26 during tracking drive in the configuration in which the objective lens 26 is supported by 0a and 30b. When the focus actuator 20 is neutral, that is,
When the position of the objective lens 26 in the recording medium vertical direction (z direction) is neutral and the leaf springs 30a and 30b are not bent, the resonance of the objective lens 26 during tracking drive exceeds 10 kHz, as shown in FIG. There is resonance,
This is not a problem because it does not affect the control frequency band. However, the focus actuator 2
When 0 is shifted in the z direction following the surface wobbling of the recording medium, the resonance of the objective lens 26 during tracking driving is, as shown in FIG. Resonance also appears. This resonance is in a mode as shown in FIG.
The tracking driving force is applied to the portions 0a and 30b which are bent by the shift of the focus actuator 20, and the shape of the bending is greatly excited. The resonance of the leaf springs 30a and 30b also appears as resonance in the movement of the objective lens 26. The resonance around 5 kHz is
It affects the control frequency band and interferes with servo control.

Therefore, it is difficult for the optical system driving device having the structure shown in FIG. 12 to accurately control the access operation and the tracking operation. Further, if an attempt is made to avoid the influence of resonance, an optical system driving device having a narrow control frequency band and extremely low performance will be obtained.

As a technique related to the optical system driving device, Japanese Patent Laid-Open No. 63-168845 discloses a support member having a thin hinge portion and a rib extending in the longitudinal direction at an intermediate portion thereof. If this structure of the support part is applied to the support mechanism of the focus actuator of FIG. 12, it is considered that the structure is strong against resonance when the focus actuator is shifted. However, for reasons of its construction, this support must be made of synthetic resin rather than metal. Synthetic resin has a large expansion coefficient due to temperature, and when the actual temperature deviates from the assumed temperature at the time of design, the supporting member expands and contracts in the longitudinal direction, and the objective lens deviates from the optical axis. For this reason, JP-A-63-16884
Even if the technical idea of No. 5 is applied to the optical system driving device of FIG. 12, a high performance optical system driving device cannot be obtained.

Further, Japanese Patent Application Laid-Open No. 1-112532 discloses a support member for a leaf spring having a flange and a collapsible portion in the focus direction in a total of four longitudinal directions on both sides of the holder in the tracking direction and above and below the focus direction. ing. By the way, the primary resonance frequency in the focus direction must be kept low due to problems such as power consumption during shifting. For that purpose, it is necessary to narrow or lengthen the width of the collapsible portion. However, when the width of the collapsible portion is reduced, the holder is movable in the tracking direction other than the focus direction because the support member is separated on both sides in the tracking direction. FIG.
When this is applied to the support member of the second focus actuator, the holder does not have a drive mechanism other than the focus direction, and therefore the movements other than the focus direction cannot be controlled. When the length of the collapsible portion is increased, resonance occurs when the focus actuator is shifted, as described above.

Japanese Utility Model Laid-Open No. 1-109821 discloses a support member for a leaf spring having a partially arcuate cross section. However, it is difficult to machine a part of the leaf spring into an arc shape, and such a supporting member becomes expensive.
Therefore, the use of such a supporting member causes an increase in the cost of the device, which is not desirable.

An object of the present invention is to provide a small-sized and inexpensive optical system driving device in which a common driving circuit and a driving mechanism perform an access operation and a tracking operation, in which resonance of a supporting mechanism portion between a tracking driving portion and an optical element is small. Is to provide.

[0013]

SUMMARY OF THE INVENTION The present invention comprises an optical element,
A holder for holding the optical element, a carriage to which the holder is attached, a holder support means for supporting the holder on the carriage so as to be movable in a substantially vertical direction of the recording medium, and a carriage for moving the carriage in a substantially radial direction of the recording medium. A carriage supporting means for supporting the carriage; and a driving means for applying a driving force for moving the optical element in a substantially vertical direction of the recording medium to the holder and a driving force for moving the optical element in a substantially radial direction of the recording medium to the carriage. In the optical system driving device, the holder supporting means includes at least one metal leaf spring whose longitudinal ends are fixed to the holder and the carriage, and the leaf spring extends in the vicinity of each fixed end. It has a plurality of elongated bent portions arranged in the width direction orthogonal to the direction, and the recording medium is substantially perpendicular to both ends of the wide portion between the elongated bent portions in the width direction. Characterized in that it has a flange portion extending.

[0014]

In the present invention, since the leaf spring supporting the holder has the flange portions at both ends of the wide portion, the rigidity of the wide portion is improved. Thereby, the resonance of the leaf spring interposed between the holder and the carriage is prevented. Since the plurality of bent portions are arranged side by side in the width direction, there is no concern that the holder will move in a direction other than the vertical direction of the recording medium. As a result, it is possible to obtain an optical system driving device with good performance in which the movements of the optical element and the carriage match.

[0015]

Embodiments of the present invention will now be described with reference to the drawings. First, the optical system driving device of the first embodiment will be described with reference to FIGS.

As shown in FIGS. 1 and 2, the tracking actuator 10 includes shafts 11a and 11b and bearings 17.
a carriage 17 supported by a and 17b so as to be movable in the radial direction (x direction) of the recording medium;
Tracking coils 15a and 15b fixed to 6;
Inner yokes 12a and 12b passing inside the tracking coils 15a and 15b, outer yokes 13a and 13b arranged to face the inner yokes 12a and 12b, and magnets fixed inside the outer yokes 13a and 13b. 14a, 14
b and. The shafts 11a and 11b, the inner yokes 12a and 12b, and the outer yokes 13a and 13b are all fixed to a deck base (not shown). Carriage 1
A reflection prism 18 is fixed to the lens 6, and a focus actuator 20 is mounted thereon.
The focus actuator 20 is fixed to the carriage 16 with its tilt adjusted by a tilt adjusting mechanism (not shown) so that the axis of the objective lens 26 faces the correct direction.

As shown in FIGS. 1 and 3, the focus actuator 20 is composed of a base 21, a spring receiver 22 fixed to the base 21, and two parallel elastic members having one end fixed to the spring receiver 22. Certain leaf springs 30a ', 30
b ', a holder 23 attached to the other ends of the leaf springs 30a', 30b ', focus coils 24a, 24b fixed to the holder 23, an objective lens 26 also fixed to the holder 23, and a focus coil 24a. , 24b
Magnets 25a, 2 fixed to the base 21 that exert a magnetic field on
5b and. In this focus actuator 20, a holder 23 that holds an objective lens 26
Is defined by two parallel leaf springs 30a 'and 30b',
The recording medium is supported so as to be movable only in the vertical direction (z direction). Although not shown, the leaf springs 30a ′, 30
Damping means is provided at b '.

Next, the two leaf springs 30a 'and 30b' will be described with reference to FIGS. 3 and 6A. The two leaf springs 30a 'and 30b' have exactly the same shape,
The leaf spring 30a 'will be representatively described below. The leaf spring 30a ′ has the wide portions 31, 3 in the longitudinal direction (x direction).
It has 2, 33. The wide portion 31 and the wide portion 33 are connected by two elongated bent portions 36a and 36b, and similarly, the wide portion 32 and the wide portion 33 are connected by two elongated bent portions 37a and 37b. . Wide part 3
Flanges 38b and 38e extending in the -z direction on both ends of
The flange portions 38a and 38d are partially formed at both ends of the wide portion 31, and the flange portions 38c and 38f are partially formed at both ends of the wide portion 32. The leaf spring 30a ′ having such a shape is formed by selectively etching a metal steel plate such as copper or stainless steel, which is a material thereof, to thereby form the wide portions 31, 32, 33 and the bent portion 36.
a, 36b, 37a, 37b and flange portions 38a to 38
After forming f, it is made by bending the flange portions 38a to 38f. The flat end of the wide portion 31 on which the flange portions 38a and 38d are not formed is fixed to the spring receiver 22, and the flat end of the wide portion 32 on which the flange portions 38c and 38f are not formed is located in the holder 23. Fixed.

The leaf springs 30a 'and 30b' are electrically connected to the focus coils 24a and 24b on the holder 23 side by soldering, and are electrically connected to the flexible substrate (not shown) on the spring receiving 22 side by soldering. . This flexible substrate is connected to a control circuit (not shown), so that the focus coils 24a and 24b are electrically connected to the control circuit. Leaf springs 30a ', 30
There are only two b ', but the focus coils 24a, 24
Since only two wires at both ends of b are connected, the number of leaf springs is sufficient to be two.

Next, the operation of the optical system driving device of this embodiment having the above-described structure will be described. Laser light emitted from a fixed optical system (not shown) is reflected by the reflection prism 18 and then condensed by the objective lens 26 to form a spot on a recording medium (not shown). The reflected light from the recording medium enters the objective lens 26 again, is reflected by the reflecting prism 18, and returns to the fixed optical system. The fixed optical system detects a focus error, a tracking error, and a recording signal.

When a focus error is detected, a current is supplied from the control circuit to the focus coils 24a and 24b, the holder 23 of the focus actuator 20 is moved in the z direction, and the distance of the objective lens 26 to the recording medium surface is adjusted. To be done. When a tracking error is detected, current is supplied to the tracking coils 15a and 15b, and the carriage 1 of the tracking actuator 10 is
6 is moved in the x direction, and the position of the objective lens 26 of the focus actuator 20 mounted thereon in the x direction (track direction) is adjusted. In this way, focus control and tracking control of the objective lens 26 are performed. The access control is performed by the tracking coil 15
This is performed by supplying a current to a and 15b and moving the carriage 16 carrying the focus actuator 20 to a large extent.

4 and 5 are Bode diagrams showing the influence of resonance of the objective lens 26 during tracking drive. FIG. 4 shows the focus actuator 20 when the z-direction position is neutral and the leaf springs 30a 'and 30b' are not bent.
In FIG. 5, the focus actuator 20 shifts in the z-direction by following the surface wobbling of the recording medium to move the leaf springs 30a ', 3'.
This is when 0b 'is bent. Not only when the position of the focus actuator in the z direction is neutral as shown in FIG. 4 but also when the focus actuator is shifted in the z direction as shown in FIG. 5, there is more turbulence than when neutral, but no problematic resonance occurs. As can be seen by comparing FIG. 4, which is the Bode diagram of the present embodiment, with FIG. 13, which is the Bode diagram of the conventional example, the present embodiment has excellent characteristics extending to a high range. This z
The leaf spring 3 has excellent resonance characteristics both in the direction neutral and in the shift.
This is because the rigidity of the wide portions 31, 32, and 33 is improved by the flange portions 38a to 38f of 0a 'and 30b'.
In particular, the rigidity of the wide portion 33 is increased by the flange portions 38b and 38e.

The primary resonance frequencies of the leaf springs 30a 'and 30b' in the z direction are the bending portions 36a, 36b and 37.
By narrowing the width (Y1, Y2) of a and 37b, the length (X) of the bent portions 36a, 36b, 37a and 37b can be made sufficiently small while keeping the length (X) small. Since the value of X is small, the resonance of bending of the bent portions 36a, 36b, 37a, 37b does not pose a problem in tracking drive. Further, since the plurality of bent portions 36a, 36b, 37a, 37b are arranged in the y direction, there is no concern that the holder 23 will move in the y direction other than the z direction.

In this embodiment, the leaf springs 30a 'and 30b' are used.
Both have a flange portion extending in the −z direction, the leaf spring 3
0a 'has a flange portion extending in the -z direction, and leaf spring 30b' has a flange portion extending in the + z direction.
The a'and 30b 'may be arranged to face each other.
In this case, all the flange parts are leaf springs 30a ′, 30
Since it comes inside b ', it is advantageous for thinning the optical system driving device.

The shapes of the leaf springs 30a 'and 30b' are shown in FIG.
Various modifications are possible without being limited to the one shown in (A). For example, the leaf spring used in this embodiment is shown in FIG.
As shown in (A), the length of the flange (Z1, Z2)
Are the same on the left and right, but as shown in FIG. 6 (B), leaf springs having different left and right flange lengths (Z1, Z2) may be used. In this case, since the left and right balance of the flange is lost, there is an advantage that resonance in the wide portion 33 that is wavy in the y direction can be suppressed.

Further, the leaf spring is not limited to one having two bent portions between the wide portions, and any number may be used as long as the number of bent portions is two or more. For example, as shown in FIG.
Three bent portions 36a, 3 are provided between the wide portion 31 and the wide portion 33.
A leaf spring having 6b and 36c and three bent portions 37a, 37b and 37c between the wide portion 32 and the wide portion 33 may be used. In this leaf spring, the central bent portions 36b, 3
7b are both formed at positions deviated from the center line 39, and the bent portions 36b and 37b are displaced in opposite directions. In this leaf spring, since the bent portions 36a to 36c and the bent portions 37a to 37c are asymmetrically formed,
The connection of the wide portion 33 or the like is unbalanced, and resonance of the wide portion 33 is prevented or reduced.

Furthermore, the number of bent portions provided between the wide portions 31 and 33 and the number of bent portions provided between the wide portions 32 and 33 may be different. Further, in this embodiment, the flange portion is provided on all of the wide portions 31, 32, 33, but when the distance from the fixed ends of the spring receiver 22 and the holder 23 to the bent portions 36a, 36b, 37a, 37b is short. In particular, the flange portions of the wide portions 31 and 32 do not have to be provided. That is, the flange portions provided on the leaf springs 30 a ′ and 30 b ′ are the flange portions 38 continuous with the wide portion 33.
Only two of b and 38e are enough. This facilitates the manufacture of the leaf spring and facilitates downsizing of the device.

The dimensions of the bent portion are as shown in FIG.
Total width of bends (Y1 + Y for (A) and (B)
In the case of 2 and (C), Y1 + Y2 + Y3) is preferably larger than X, and when smaller than X, closer to X is more preferable. Although these dimensions have a tradeoff with the primary resonance frequency of the leaf spring, it is desirable that (Y1 + Y2) /X≧0.2. Also, the distance Ya from the end of the wide portion of the bent portion is
Is preferably as small as possible. For example, on the Y1 side, it is preferably about 5 times or less than Y1.

In the above description, all the bent portions have a rectangular shape when viewed from above, but the bent portions are not limited to the rectangular shape and may be variously modified. For example,
The width (dimension in the y direction) is the smallest at the center of the bent part in the x direction,
It may be a constricted shape in which the width (dimension in the y direction) increases as it gets closer to the wide portion. This shape is rather preferable to rectangular. Further, as shown in FIG. 16, the bent portions arranged between the wide portions may be made non-parallel. In this case, it becomes more difficult to move in the y direction, and it becomes stronger against external impact.

Next, the optical system driving device of the second embodiment will be described with reference to FIGS. In the figure, members equivalent to those described in the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

In this embodiment, the magnetic flux direction of the magnetic circuit of the tracking actuator 10 is different from that of the first embodiment. As shown in FIGS. 7, 8 and 10, the outer yoke 1
3a and 13b are fixed in the + z direction of the inner yokes 12a and 12b. The magnets 14a, 14b are the outer yoke 13a,
It is fixed to 13b. Tracking coil 15a,
Reference numeral 15b denotes frame portions 19a, 1 formed on the carriage 16.
It is housed inside 9b. The frame portions 19a and 19b
Are provided to reinforce the tracking coils 15a and 15b and prevent their resonance.

As shown in FIGS. 10 and 11, the focus actuator 20 does not have a base as in the first embodiment, but a spring receiver 22 is formed on the −x side of the carriage 16 and protrudes upward in the + z direction. Is attached to the section. A tilt adjusting mechanism (not shown) is provided in this portion, and thereby the focus actuator 20 is held in an appropriate direction. The leaf spring 30a 'and one ends of the leaf springs 40a and 40b are fixed to the spring receiver 22. These leaf springs 30a', 40a and 40b are fixed.
The holder 23 is attached to the other end of b. As a result, the holder 23 is held so as to be movable in the z direction. The leaf springs 30a ', 40a, 40b are provided with damping means (not shown). An objective lens 26 is attached to the holder 23, and side surfaces thereof have focus coils 24a, 24 having different shapes from those of the first embodiment.
b is attached so that its axis is orthogonal to the side surface.

Unlike the first embodiment, the focus actuator of this embodiment does not have a focus driving magnet, and as shown in FIG.
The magnets 14a and 14b of the tracking actuator 10 are located outside the magnet 4a.
The magnetic field 4b is used for focus driving. Therefore, the focus actuator 20 does not require a focus driving magnet, and thus the cost can be reduced. Further, since the reaction force at the time of focus driving is not applied to the carriage 16 but is applied to the magnets 14a and 14b of the tracking actuator 10 fixed to the deck base (not shown), resonance of the carriage 16 is excited. Is prevented, and the characteristics are excellent.

Next, the leaf springs 40a and 40b on the lower side of the focus actuator 20 will be described with reference to FIGS. 9 and 11. The upper leaf spring 30a is
Since it is the same as the first embodiment, the description thereof is omitted. Since the leaf springs 40a and 40b have symmetrical shapes,
The leaf spring 40a will be described below as an example. The leaf spring 40a has three wide portions 41, 42, 4 along the x direction.
Three. The wide portion 41 and the wide portion 43 are connected by an elongated bent portion 46, and similarly, the wide portion 42 and the wide portion 43 are connected by an elongated bent portion 47. The flanges 4 extending in the + z direction are provided at both ends of the wide portion 43.
8b and 48e are formed, and flange portions 48a and 48d are partially formed at both ends of the wide portion 41, and similarly, flange portions 48c and 48 are partially formed at both ends of the wide portion 42.
f is formed. Leaf spring 40a having such a shape
Is formed by selectively etching a metal steel plate such as copper or stainless steel, which is the material thereof, to form the wide portions 41, 42, 4
3, the bent portions 46 and 47, and the flange portions 48a to 48f are formed, and then the flange portions 48a to 48f are bent. The leaf spring 40a has a narrower width than the leaf spring 30a 'of the first embodiment and is difficult to bend. However, the leaf spring 40a can be bent easily by half-etching the bent line portion in advance to make it slightly thin. The narrow flat plate-shaped end portion of the wide portion 41 on which the flange portions 48a and 48d are not formed is fixed to the spring receiver 22, and the narrow flat plate-shaped end portion of the wide portion 42 on which the flange portions 48c and 48f are not formed is formed. The end is fixed to the holder 23.

The leaf springs 40a and 40b are electrically connected to a flexible substrate (not shown) electrically connected to a control circuit (not shown) on the side of the spring receiver 22. On the holder 23 side, the plate spring 40a is electrically connected to one end of the focus coil 24a, and the plate spring 40b is electrically connected to one end of the focus coil 24b. Focus coils 24a, 24
The other ends of b are both soldered to the leaf spring 30a '.
As a result, the coil 24a and the coil 24b become
They are electrically connected in series via a '. By making such a connection, the focus coils 24a, 2
The work is easier than directly connecting the coil wires of 4b by twisting them together.

A laser beam emitted from a fixed optical system (not shown) passes through an opening formed in a protrusion formed on the carriage 16 to which a spring receiver 22 of a focus actuator 20 is attached, and two leaf springs 40a, 40
It passes through b and is reflected by the reflection prism 18 attached to the carriage 16 and is condensed by the objective lens 26 to form a spot on a recording medium (not shown).
The reflected light from the recording medium goes backward in the outward path and returns to the fixed optical system.

Other configurations and operations are almost the same as those in the first embodiment. In the optical system driving device of the present embodiment, the optical axis is set between the two leaf springs 40a and 40b, so that it is thinner than the first embodiment. The leaf spring 30b 'of the first embodiment replaces the leaf springs 40a and 40b and is divided into two in the y direction. However, in the leaf spring 30a', since the plurality of bent portions are arranged in the y direction, There is no concern that the holder 23 moves in the y direction other than the z direction.

Also in this embodiment, the shape of the leaf spring can be variously modified. The leaf spring 30a 'can be modified in the same manner as in the first embodiment. Leaf springs 40a, 40b
With regard to, for example, a plurality of bent portions may be arranged in the y direction instead of one. The length of the flange portion may be different on the left and right. Since the leaf springs 40a and 40b are narrower than the leaf spring 30a, the flange portion may be provided on only one side.

The present invention has been described above based on the embodiments, but the present invention is not limited to the above-mentioned embodiments, and various modifications can be made without departing from the scope of the present invention. .

Here, the summary of the present invention is summarized as follows. 1. An optical element, a holder for holding the optical element, a carriage to which the holder is attached, a holder support means for supporting the holder on the carriage so that the holder can move in a substantially vertical direction of the recording medium, and the carriage in a substantially radial direction of the recording medium. And a carriage support means for movably supporting the optical element and a drive force for moving the optical element in a substantially vertical direction of the recording medium to the holder, and a drive force for moving the optical element in a substantially radial direction of the recording medium to the carriage. The holder supporting means includes at least one metal leaf spring whose longitudinal ends are fixed to the holder and the carriage, and the leaf spring has respective fixed ends. Has a plurality of elongated bent portions arranged in the width direction orthogonal to the longitudinal direction near the recording medium, and the recording medium is provided at both ends in the width direction of the wide portion between the elongated bent portions. Optical system driving apparatus characterized by having a flange portion extending substantially vertically.

2. 2. The optical system driving device as described in 1 above, wherein the longitudinal direction of the leaf spring is substantially coincident with the radial direction of the recording medium. 3. In the preceding paragraph 1 or 2, the holder supporting means further includes another single metal leaf spring whose longitudinal ends are fixed to the holder and the carriage.
It has a plurality of elongated bent portions arranged in the width direction orthogonal to the longitudinal direction near each fixed end, and in the widthwise ends of the wide portion between the elongated bent portions in a direction substantially perpendicular to the recording medium. An optical system driving device having an extending flange portion, wherein these two leaf springs are arranged in parallel with each other in a substantially vertical direction of a recording medium.

4. In the preceding paragraph 1 or 2, the holder support means further includes another two metal leaf springs having longitudinal ends fixed to the holder and the carriage, and each of the two leaf springs is One or a plurality of elongated bent portions arranged in the width direction orthogonal to the longitudinal direction are provided near the fixed end of the recording medium, and the recording medium is substantially perpendicular to both ends of the wide portion between the elongated bent portions in the width direction. Characterized in that it has a flange portion extending in the direction, and is arranged in parallel with the plate spring in a direction substantially perpendicular to the recording medium, and both of them are arranged in parallel with each other in the width direction. Optical system driving device.

5. The optical system driving device according to any one of the preceding items 1 to 4, wherein the dimension of the flange portion in the substantially vertical direction of the recording medium is different at both ends in the width direction of the wide portion.

6. In the preceding paragraphs 1 to 5, the bent portion has a substantially rectangular shape, and the dimension in the longitudinal direction thereof is smaller than five times the total dimension of all the bent portions arranged in the width direction in the width direction. Optical system drive device.

7. In the preceding items 1 to 5, the bent portion has a substantially rectangular shape, and a distance from the end of the bent portion closest to the end of the wide portion is smaller than five times the dimension in the width direction of the bent portion. Optical system drive device.

[0046]

According to the present invention, the resonance of the support mechanism portion between the tracking drive section and the optical element is small, and the access operation and the tracking operation are performed by a common drive circuit and drive mechanism, which are small, inexpensive, and have high performance. An optical system driving device can be obtained.

[Brief description of drawings]

FIG. 1 is a perspective view of an optical system driving device according to a first embodiment of the present invention.

FIG. 2 is an exploded perspective view of the optical system driving device of FIG.

FIG. 3 is an exploded perspective view of the focus actuator shown in FIGS. 1 and 2.

FIG. 4 is a Bode diagram at the time of neutralization showing the characteristics of the device of the first embodiment.

FIG. 5 is a Bode diagram at the time of shifting showing the characteristics of the device of the first embodiment.

6 is a detailed explanatory view of a leaf spring of the focus actuator shown in FIG.

FIG. 7 is a perspective view of an optical system driving device according to a second embodiment of the present invention.

8 is a front view of the optical system driving device of FIG. 7. FIG.

9 is a detailed explanatory view of a leaf spring on the lower side of the focus actuator shown in FIG.

10 is an exploded perspective view of the optical system driving device of FIG.

11 is an exploded perspective view of the focus actuator shown in FIGS. 7 and 10. FIG.

FIG. 12 is a perspective view showing a configuration of an optical system driving device of a conventional example.

13 is a Bode diagram when the apparatus of FIG. 12 is in a neutral state.

FIG. 14 is a Bode diagram of the device of FIG. 12 during a shift.

FIG. 15 is a diagram for explaining a resonance mode near 5 kHz in FIG.

16 is a diagram showing a modification of a leaf spring applicable to the optical system driving device of FIG.

[Explanation of symbols]

16 ... Carriage, 23 ... Holder, 26 ... Objective lens,
30a ', 30b' ... Leaf spring, 33 ... Wide part, 36a,
36b, 37a, 37b ... Bent portion, 38b, 38e ... Flange portion.

Claims (4)

[Claims] 1. An optical element, a holder for holding the optical element, a carriage to which the holder is attached, a holder support means for supporting the holder on the carriage so as to be movable in a direction substantially perpendicular to a recording medium, and the carriage for recording. A carriage supporting means for movably supporting the medium in a substantially radial direction;
An optical system driving device comprising: a driving force for moving the optical element in a substantially vertical direction of a recording medium to a holder; and a driving means for applying a driving force to move the optical element in a substantially radial direction of the recording medium to a carriage, The holder supporting means includes at least one metal leaf spring whose both ends in the longitudinal direction are fixed to the holder and the carriage, and the leaf spring is arranged near each fixed end in the width direction orthogonal to the longitudinal direction. An optical system having a plurality of elongated bent portions arranged side by side, and having flange portions extending in a substantially vertical direction of a recording medium at both widthwise ends of a wide portion between the elongated bent portions. Drive. 2. The optical system driving device according to claim 1, wherein the longitudinal direction of the leaf spring is substantially coincident with the radial direction of the recording medium. 3. The holder supporting means according to claim 1 or 2, further comprising another sheet metal spring made of metal, the longitudinal ends of which are fixed to the holder and the carriage.
This leaf spring has a plurality of elongated bent portions arranged in the width direction orthogonal to the longitudinal direction near each fixed end, and the recording medium is provided at both ends in the width direction of the wide portion between the elongated bent portions. And a flange portion extending substantially in the vertical direction, and these two leaf springs are arranged in parallel with each other in the substantially vertical direction of the recording medium. 4. The holder supporting means according to claim 1 or 2, further comprising another two metal leaf springs having longitudinal ends fixed to the holder and the carriage.
Each of these two leaf springs has one or a plurality of elongated bent portions arranged in the width direction orthogonal to the longitudinal direction near each fixed end, and a wide portion between the elongated bent portions. Has a flange portion extending in a substantially vertical direction of the recording medium at both ends in the width direction of the recording medium, and is spaced apart from the leaf spring in a direction substantially parallel to the recording medium. An optical system driving device, characterized in that the optical system driving device is arranged separately.