JPS62295229A - Lens holding device - Google Patents

Abstract

PURPOSE:To obtain a lens holding device which is soft in the direction of the optical axis of a lens and can be moved smoothly, and has sufficient rigidity in nearly radial direction of a disk by providing an angle to at least one of the fitting plane of a leaf spring and a holder or the fitting plane of the leaf spring and a shifting stand to the plane at right angles to the optical axis of a lens. CONSTITUTION:A lens 11 that forms an image on a disk 12 is fixed to a holder 13. There are two planes 13a, 13b that intersect the optical axis of the lens 11 in the holder 13, and leaf springs 14a-14d are fixed thereto. On the other hand, there are two planes 15a, 15b making optional angle to a plane at right angles to the optical axis of the lens 11 in a shifting stand 15, and the other ends of leaf springs 14a-14b are fixed thereto. Accordingly, a large warp is formed inevitably in leaf springs 14a-14d. Thereby, the force that is apt to generate local and minute creases when plural leaf springs are fitted between the holder and shifting stand is absorbed by the large warped parts of plural leaf springs formed when plural leaf springs are fitted between the holder and shifting stand.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention Field of Industrial Application The present invention relates to a lens support device used in compact disc players, optical disc devices, and the like.

2. Description of the Related Art In recent years, in compact disc players and optical disc devices, there has been a movement to support objective lenses with leaf springs in order to improve reliability and ease of assembly.

An example of the conventional lens support device mentioned above will be described below with reference to the drawings. 3 is a top view of a conventional lens support device, and FIG. 4 is a sectional view of FIG. 3 viewed from the side. Reference numeral 1 denotes a lens that forms an image on the disk 2, and is fixed to a holder 3. The holder 3 has two surfaces 3a and 3b substantially orthogonal to the optical axis of the lens 1, and leaf springs 4a to 4d are fixed thereto. Leaf spring 4a~
The other end of the plate springs 4d is fixed to a transfer table 6 which is movable in a substantially radial direction of the disk 2 (in the direction of the arrow X) so that the leaf springs 4a to 4C are substantially parallel to each other. An optical bench 6 supplies light emitted from a semiconductor laser or the like to the lens 1 through various lens systems, and is usually fixed to the transfer table 5.

The operation of the lens support device configured as described above will be described below.

First, the lens 1 needs to follow the rotation of the disk 20, which normally has warpage, in the direction of arrow Y. Since various methods have been disclosed in the past regarding means for causing tracking and means for detecting tracking error, their description will be omitted here. Similarly, since the lens 1 follows the track provided on the disk 2 and scans an arbitrary track, it needs to be able to move in the direction of arrow X and follow an arbitrary track. Since various known means can be applied to the detection means, the description thereof will be omitted here. For the above-described operation, the leaf springs 4a and 4b are required to have characteristics that satisfy the following two items. First, when the lens 1 is moved in the direction of arrow Y, the leaf springs 4a and 4b need to be deformed so as to move softly and smoothly while maintaining the optical axis of the lens 1. Next, it is desirable that the optical axis of the lens 10 does not undergo vibrational displacement due to rapid acceleration or deceleration of the transfer table 5 in the direction of the arrow X.

From the above, the thickness of the leaf springs 4a to 4d is usually 10μ9.
Manufactured from a thin metal plate with a thickness of n~50μm, and the shape is also 4a~4.
d All of the same shape were often used.

Problems to be Solved by the Invention However, in the above configuration, the plate springs 4a to 4d are thin and have very low rigidity in the direction of arrow Y, so it is difficult to attach the plate springs 4a to 4d to the holder 3 or the transfer table 6. When tightening, it is common for the leaf spring 4a, for example, to wrinkle locally and minutely, as shown in FIG. There are various reasons for this, but one simple cause is that when the leaf springs 4a to 4d are installed between the holder 1 and the transfer table 5, the leaf springs 4a to 4b to 4d
This is caused by simply fixing it with a slack of only 5 to 10 μm relative to d. When a displacing force is applied to the lens 1 in the direction of the disk 2 indicated by the arrow Y from the state shown in FIG. A phenomenon occurs that increases instantaneously.

On the other hand, when the lens 1 is returned to its initial direction from this state, a phenomenon occurs in which the leaf spring 4a instantly wrinkles at a certain position and the displacement of the lens 1 suddenly decreases. This situation can be seen in the 6th
As shown in the figure. These phenomena indicate that there is a range in which the lens 1 cannot follow the disc 2, and specifically, it becomes a serious drawback that signals recorded on the disc 2 cannot be read in the range where this phenomenon occurs.

On the other hand, when the transfer table 5 suddenly accelerates or decelerates in the direction of the arrow X shown in FIG. Although the inertia force of the holder 3 is generated,
When this force is equally received by the leaf springs 4a to 4d, the lens 1
There is no displacement in the direction of arrow X, and no tilting of the optical axis occurs.

However, as shown in FIG. 5, for example, if local minute wrinkles occur in the leaf spring 4a, the leaf spring 4b
Since the rigidity in the direction of the arrow X of ~4d is different, when the inertial force is generated, the lens 1 is displaced and vibrates in the direction of the arrow X, and the optical axis of the lens 1 is vibrated. This vibration and displacement not only deteriorate the followability when the transfer table 5 follows an arbitrary track, but also cause serious drawbacks such as the ability to read the contents recorded on the disk 2 which cannot be followed.

In view of the above-mentioned problems, the present invention has a structure in which the leaf springs 4a to 4d that support the lens 1 can be easily attached to the holder 3 or the transfer table 6 without causing local and minute wrinkles. Good, the lens 1 can be moved softly and smoothly in the direction of the arrow while maintaining its optical axis, and the transfer table 6 can be moved in the direction of the arrow X.
The present invention provides a lens support device that does not cause displacement or vibration of the optical axis of the lens 1 due to sudden acceleration in the direction.

Means for Solving the Problems In order to solve the above problems, the lens support device of the present invention includes a lens, a holder for holding the lens, a plurality of leaf springs having one end fixed to the holder, and a transfer table to which the other end of a leaf spring is fixed, and at least one surface of the mounting surface of the leaf spring and the holder or the mounting surface of the leaf spring and the transfer table is aligned with the optical axis of the lens. It has a configuration in which an angle is provided with respect to a right-angled surface.

Effect The present invention has the above-described configuration, so that the force that tends to generate local minute wrinkles when attaching a plurality of leaf springs between a holder and a transfer table can be reduced by attaching a plurality of leaf springs between a holder and a transfer table. To absorb the large curved portions of a plurality of leaf springs that inevitably occur during installation. In other words, by adjusting the amount of curvature and releasing it, the serious drawback caused by localized and minute wrinkles that occur in conventional leaf springs can be eliminated.

EXAMPLE Hereinafter, a lens support device according to an example of the present invention will be described with reference to the drawings.

FIG. 1 shows a top view of the first embodiment of the present invention, and a top view of the second embodiment of the present invention.
The figure shows a sectional view seen from the side of FIG. 1
Reference numeral 1 denotes a lens that forms an image on the disk 12 and is fixed to a holder 13. The holder 13 has two surfaces 13a that are substantially orthogonal to the optical axis of the lens 11.

13b, to which leaf springs 14a to 14d are fixed. On the other hand, the transfer table 15 has two surfaces 15a having arbitrary angles with respect to the surface perpendicular to the optical axis of the lens 11.

1sb is the hole, and the other ends of the leaf springs 14a to 14b are fixed here. Therefore, the leaf springs 14a to 14d inevitably undergo a large curvature as shown in FIG.

Note that an optical bench 16 supplies light emitted from a semiconductor laser or the like to the lens 11 through various prisms, etc., and is usually fixed to the transfer table 16.

The operation of the lens support device configured as described above and the characteristics required of the leaf springs 14a to 14d are completely the same as those of the conventional example, so a description thereof will be omitted. Here, the lens 1 is placed on the transfer table 15.
1 6a, which is further angled with respect to the plane perpendicular to the optical axis of 1;
We will explain why local minute wrinkles do not occur simply by providing an Isb surface. Also in this configuration, the leaf spring 14
For example, when fixing between surfaces 13a and 13b of the holder 13 and surfaces 1sa and 1esb of the transfer table 16 with 14a slightly slackened with respect to 14b to 14d among a to 14d, a force that causes wrinkles may be applied. occurs. On the other hand, at this time, a large curvature inevitably occurs in the leaf springs 14a to 14d.

Therefore, the force that tends to cause wrinkles is from the leaf springs 14a to 1.
It is absorbed by the curved portion formed at 4d, and there is substantially a difference in the height of the curve, and local minute wrinkles do not occur. This phenomenon is thought to be caused by the same reason as the small wrinkles on the leaf spring 4a shown in the conventional example that disappear instantly when absorbed by the large curvature of the leaf spring 4a that occurs as the lens 1 is displaced. In other words, the present invention takes the state where the wrinkles of the conventional example have disappeared as a stable point, and inevitably creates a curvature in which wrinkles do not occur within the movement range of the lens 11 in the Y direction by attaching the leaf springs 14a to 14d. It can also be considered a thing.

As described above, according to the present embodiment, the leaf springs 14a to 14d
13a and 13b of the holder 13 and 1 of the transfer table 16
By fixing it to the 5a and Isb surfaces, it is inevitably curved, and this curved portion can absorb the force that would otherwise cause localized and minute wrinkles. This means that the leaf springs 14a to 1
This shows that the characteristics required for 4d can be easily obtained even during mass production.

In this embodiment, the transfer table 16 is provided with surfaces 16a and 1esb that are angled with respect to the plane perpendicular to the optical axis of the lens 11, but they may also be provided on the plate spring mounting surfaces 13a and 13b of the holder 13. It may be formed on both the holder 13 and the transfer table 16. In addition, in this embodiment, the transfer table 16 has 1sa and 1sb.
Although two inclined surfaces are provided, even when only one side is provided with an inclined surface, the same effect can be obtained because a curvature is created that balances the forces of the leaf springs 14a, 14b and 14C914d. Naturally 15a.

The direction of inclination of 16b can also be reversed.

Further, in this embodiment, the leaf springs 14a to 14d are provided separately and independently, but the leaf springs 14a and 14b, 14C and 14d are
It is also possible to configure each of them with one leaf spring. Furthermore, although the transfer table 16 is illustrated as moving straight in the direction of the arrow X, the present invention is not limited to this.

Effects of the Invention As described above, the present invention comprises a lens, a holder for holding the lens, a plurality of leaf springs having one end fixed to the holder, and a transfer table having the other ends of the leaf springs fixed. By setting at least one of the mounting surfaces of the leaf spring and the holder or the mounting surface of the leaf spring and the transfer table at an angle with respect to a plane perpendicular to the optical axis of the lens, the direction of the lens optical axis is It is possible to obtain a lens support device that is soft and can be smoothly displaced and has sufficient regularity in the approximately radial direction of the disk.

[Brief explanation of drawings]

FIG. 1 is a top view of a lens support device according to a first embodiment of the present invention, FIG. 2 is a sectional view of FIG. 1 viewed from the side, and FIG. 3 is a top view of a conventional lens support device. Fig. 4 is a sectional view of Fig. 3 when viewed from the side, Fig. 6 is a sectional view showing a state in which local and minute wrinkles have occurred in the leaf spring, and Fig. 6 is a sectional view showing a state in which the plate spring has localized and minute wrinkles. It is a graph showing the relationship between the displacement force and the amount of lens displacement when applying the displacement force in the direction. 1.11...Lens, 2.12...Mountain/disk, 3.13...Holder, 4 a to 4 d
, 14a to 14d----plate spring, 6, 16.
...Transfer table, 6.16...Optical table. Name of agent: Patent attorney Toshio Nakao and 1 other person 2nd
Fig. 4 Fig. 6 f, V passing, - ■ - ~ y5 ge 3 [ 2f NX L-to 4, wazu direction arm plan fL

Claims (1)

[Claims] It consists of a lens, a holder for holding the lens, a plurality of leaf springs having one end fixed to the holder, and a transfer table having the other ends of the leaf springs fixed, and a mounting surface for the leaf springs and the holder. Alternatively, a lens support device in which at least one mounting surface between the leaf spring and the transfer table is angled with respect to a plane perpendicular to the optical axis of the lens.