JP2725504B2 - Objective lens drive - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an objective lens driving device, and more particularly, to an objective lens driving device used for an optical head of an optical disk device.

[0002]

2. Description of the Related Art FIGS. 3 and 4 show such a conventional example. In these figures, FIG. 3 shows a diagram of the conventional objective lens driving device viewed from above, and FIG. 4 shows a diagram of the objective lens driving device of FIG. 3 viewed from the lateral direction (the direction of arrow T shown in FIG. 3). .

[0003] objective lens driving apparatus of this type, the lens holding member 53 for holding the objective lens 52, the lens holding member 53 four sheets of focusing plate springs 54A, 54
B, a relay member 55 supported via 54C, 54D,
And a fixing portion 57 for supporting the left side (the left side shown in FIG. 4) of the relay member 55 via a leaf spring 56 for tracking.
A lens position detection sensor 59 is disposed near the right side (the right side shown in FIG. 4) of the relay member 55, and a detected member 58 detected by the lens position detection sensor 59 is mounted on the relay member 55. .

[0004] This will be described in more detail.
Are supported by a relay member 55 via four focusing leaf springs 54A, 54B, 54C, 54D arranged at a predetermined interval. Further, the four sheets of focusing plate springs 54A, 54B, 54C, 54D, the plate
The thickness direction is the direction of the axis 52A of the objective lens 52, that is, the focus direction (arrows C and D shown in FIG. 4).
Direction).

The relay member 55 is supported by a fixed portion 57 disposed between the lens holder 53 and the relay member 55 via a leaf spring 56 for tracking. The leaf spring 56 for tracking is arranged so that its thickness direction is perpendicular to the axis 52A of the objective lens 52, that is, in the track direction (the directions of arrows A and B shown in FIG. 3). Further , the fixing portion 57 is in a state of protruding from the supporting base material 60.
(Upward in FIG. 4) .

As shown in FIG. 4, the lens position detection sensor 59 is arranged so as to protrude from the supporting base material 60 and to be parallel to the focus directions C and D. The lens position detection sensor 59 is provided with a light emitting element 60A at the center and light receiving elements 60B and 60C on both sides thereof. here,
The height between the upper end 55A of the relay member 55 and the upper end 59A of the lens position detection sensor 59, that is, the length of the symbol F and the length of the symbol E shown in FIG.

The detected member 58 is formed of a reflective film or the like, and is mounted on the right central portion of the relay member 55 as shown in FIGS. 3 and 4 so as to correspond to the lens position detecting sensor 59. It has become. The detected member 58 is attached to the relay member 55 with an adhesive or the like.

[0008]

[SUMMARY OF THE INVENTION However, the area in the conventional example described above, since the lens position detection sensor 59 are arranged in parallel along the focusing direction, which accounts for the entire surface including the lens surface of the objective lens side However, there is an inconvenience that the size of the mounting frame is reduced.

The detected member 58 is adhered to the relay member 55 with an adhesive or the like. For this reason, when the adhesive or the like is deteriorated, the detected member 58 is peeled off.

[0010]

The object of the present invention is to improve the disadvantages of the prior art and, in particular, to improve the entire surface including the lens surface on the objective lens side.
It is an object of the present invention to provide an objective lens driving device that reduces the area occupied by the lens and increases the durability.

[0011]

According to the present invention, a lens holder for holding an objective lens and a side face of the lens holder are provided .
A relay member facing and disposed at a predetermined interval, and a lens holder interposed between the relay member and the lens holder, wherein the lens holder is in a direction along the axis of the objective lens. and four pieces of focus <br/> single leaf springs disposed parallel to that allowed to reciprocate to the lens from the center of the relay member
Single Torrakingu plate spring and said Torrakingu which and the lens holding member is protruded toward the's holder is allowed to reciprocate in the direction perpendicular to the axis of said objective lens
A fixing portion for holding a leaf spring for
Having a supporting member for supporting the lens holder and the relay member.
I do. Further, on the outside of the relay member described above with supporting Jihaha material side, anti
With the fixed installation of the light measurement type lens position detection sensor
The, les the detected member having a predetermined width is detected in this lens position detecting sensor from the foregoing edges of the support base material side of the relay member
Protruding toward the lens position detection sensor . Furthermore, the lens
The position detection sensor has a light emitting element in the center and both
Lens position detection sensor with a light receiving element on the side
That adopts a configuration that. This aims to achieve the above-mentioned object.

[0012]

The lens position detection sensor is fixedly provided outside the relay member on the supporting base material side of the relay member, and the detected member detected by the lens position detection sensor is protruded outward from the relay member. Therefore, the one having the same height as the lens holder is the relay member, and the area occupied by the objective lens side in the apparatus is reduced.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. In these figures, FIG. 1 shows a view of the objective lens driving device 1 in this embodiment viewed from above, and FIG. 2 shows the objective lens driving device 1 shown in FIG. 1 in the lateral direction (in the direction of the arrow R shown in FIG. 1). FIG.

The objective lens driving device 1 shown in FIGS. 1 and 2 has a lens holder 3 for holding an objective lens, the lens holder 3 is supported at one end, and the lens holder 3 is connected to the objective lens 2. Focusing leaf springs 4A, 4B, 4C, 4D arranged at predetermined intervals to allow reciprocating movement in the direction along the axis 2A of the lens, and the focusing leaf springs 4A, 4B, 4C. , 4D supporting the other end of the lens holder 3, disposed between the relay member 5 and the lens holder 3, supporting the lens holder 3 via the relay member 5, The tracking leaf spring 6 which allows the reciprocating movement of the objective lens 2 in the direction orthogonal to the axis 2A of the objective lens 2, and the tracking leaf spring 6 are supported. The objective lens driving device 1 and a fixing portion 7 is provided. And the supporting base material 2 of the relay member 5
A lens position detection sensor 9 is provided outside the relay member 5 on the 0 side, and a detected member 12 detected by the lens position detection sensor 9 protrudes outward from the relay member 5.

Further, the above-mentioned lens position detecting sensor 9 is
The reflected light measuring type position detecting sensor including the issuing element 9A and the light receiving elements 9B and 9C is used.
Is formed of a metal plate having a high reflectance.

Further, the detected member 12 is connected to the relay member 5.
And are formed integrally with it.

This will be described in more detail.3
Corresponds to the upper position (the upper position shown in FIG. 2) of the central part.
Object lens2Is held in a slightly protruding state. this
The lens holder 3 includes four sheets disposed at a predetermined interval.
Through the leaf springs 4A, 4B, 4C, 4D for focusing
And is supported by the relay member 5. Also, four focus
The shingle leaf springs 4A, 4B, 4C, 4DBoard thicknessOne
Direction is the direction of the axis 2A of the objective lens 2, ie,
In the focus direction (the directions of arrows J and K shown in FIG. 2)
It is arranged at a distance. For this reason, the objective lens holder 3
Are the focus directions J, shown in FIG.
K can reciprocate.

The relay member 5 is supported by a fixed portion 7 disposed between the lens holder 3 and the relay member 5 via a leaf spring 6 for tracking. Further, the tracking leaf spring 6 has an axial line 2 </ b > A of the objective lens 2 in the thickness direction.
, That is, in the track direction (the directions of arrows G and H shown in FIG. 1). For this reason,
Objective lens holder 3, focusing leaf spring 4A, 4
The B, 4C, 4D and the relay member 5 can reciprocate in the track directions G, H shown in FIG. Further, the fixing portion 7 is mounted on the support base material 20 in a state of protruding from the support base material 20.

A lens position detection sensor 9 is provided on the support base material 20 side of the relay member 5 and outside the relay member 5 (the right side shown in FIGS. 1 and 2). The detection member 12 protrudes outward from the relay member 5.

The lens position detection sensor 9 includes:
A light emitting element 9A is arranged at the center position, and light receiving elements 9B and 9C are arranged on both sides of the light emitting element 9A. The light emitting element 9A and the light receiving elements 9B and 9C are
As shown in FIG. 2, they are arranged upward.

The detection member 12 is formed of a highly reflective metal (e.g., stainless steel) or the like, the outside from the lower side of the relay member 5 (the lower side shown in FIG. 2) (right side shown in FIGS. 1 and 2 ). The detected member 1
Reference numeral 2 is disposed so as to face the upper surface of the light emitting element 9A in the lens position detection sensor 9 at a predetermined interval. The detected member 12 is formed integrally with the relay member 5.

Next, the operation of the above embodiment in detecting the lens position will be described.

First, when the objective lens holder 3 is moved in the track direction (the direction of the arrow G or H shown in FIG. 1) by being urged by a lens driving unit (not shown), the focusing leaf springs 4A, 4B, 4C, 4D The detected member 12 moves in the direction of the arrow L or M shown in FIG. 1 around the fixing portion 7 via the relay member 5. The lens position of the objective lens 2 can be detected by detecting the amount of movement of the detected member 12 by the lens position detection sensor 9.

The principle of this detection will be described below. First, in a position where the lens holder 3 is not moving, that is, in a state where the lens holder 3 is stationary, the lens position detection sensor 9
The light emitted from the light emitting element 9A is reflected by the detected member 12, and then the respective reflected lights separated into right and left are reflected by the respective light receiving sensors 9A.
The entire apparatus is arranged (set) so that the same light amount can be obtained by detecting at B and 9C.

Next, the lens holder 3 is moved in the direction indicated by the arrow G shown in FIG.
If it moves in the direction, the detected member 12 moves in the arrow L direction shown in FIG. Then, the reflected light amount of the light receiving element 9C increases, and the reflected light amount of the light receiving element 9B decreases. The amount of movement of the lens holder 3 is detected by detecting the differential output.

As described above, according to this embodiment,
A lens position detection sensor 9 is provided outside the relay member 5 on the support base material 20 side of the relay member 5, and a detected member 12 detected by the lens position detection sensor 9 projects outward from the relay member 5. Because of the provision, the portion having the same height as the lens holder 3 is up to the relay member 5, and the area occupied by the objective lens 2 side in the apparatus is reduced. For this reason,
The objective lens driving device 1 can be inserted into a window frame of a small-sized cartridge.

Further, since the detected member 12 is made of a metal plate having a high reflectance and the detected member 12 is formed integrally with the relay member 5, the detected member 12 does not have to be bonded to the relay member 5. Therefore, the problem of deterioration of the adhesive and the like has been solved. Therefore, the durability of the entire device increases. Further, since the relay member 5 and the detection member 12 is one piece, this
Eliminates work referred shaking affixed to the relay member part to be detected member 12 of this minute, number of working steps is reduced.

[0028]

The present invention is constructed and functions as described above. According to this, a lens position detecting sensor is provided outside the relay member on the supporting base material side of the relay member. Since the member to be detected is protruded outward from the relay member, the one having the same height as the lens holder is up to the relay member, and the area occupied by the objective lens side in the device is effectively reduced. Can be done. Therefore, the objective lens driving device can be inserted into a window frame of a cartridge of a relatively small model.

Further, the high metal plate reflectivity of the detected member, formed Then the detected member integrally with the intermediate member,
Since it is not necessary to bond the member to be detected in the relay member, the problem to degradation such as an adhesive is eliminated, it increases the durability of the entire apparatus.

[Brief description of the drawings]

FIG. 1 is a diagram of an objective lens driving device according to the present embodiment as viewed from above.

FIG. 2 is a view of the objective lens driving device shown in FIG. 1 viewed from a lateral direction.

3 and 4 are diagrams for explaining a conventional example.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Objective lens drive device 2 Objective lens 2A Axis 3 Lens holder 4A, 4B, 4C, 4D Focusing leaf spring 5 Relay member 6 Tracking leaf spring 7 Fixed part 7A Support part 9 Lens position detection sensor 9A Light emitting elements 9B, 9C Light receiving sensor 12 Member to be detected 20 Support base material

Claims (1)

(57) [Claims] A lens holder for holding an objective lens;
Opposed to the side surface of this lens holder and at a predetermined interval
A relay member provided, and a parallel member interposed between the relay member and the lens holder to allow the lens holder to reciprocate in a direction along the axis of the objective lens. > and four sheets of focusing plate springs disposed, 且projecting toward the lens holding member from the center of the relay member
One fixing part to which the lens holding member holds the single Torrakingu plate spring and said Torrakingu leaf spring which allowed to reciprocate in a direction perpendicular to the axis of said objective lens
And the lens holder and the relay section via the fixing section.
In the objective lens driving device having a support base material for supporting the timber, the outside of the relay member before Ki支 Jihaha material side, the reflected light measurement formula
A fixed position of the lens position detection sensor is provided, and a detected member having a predetermined width detected by the lens position detection sensor is moved from the end of the relay member on the support base material side to the lens position.
Protruding toward the position detection sensor, the lens position detection sensor having a light emitting element in the center part.
In addition, a lens position detection system having light receiving elements on both sides thereof
An objective lens driving device comprising a sensor .