JPH0770059B2 - Optical disc player - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disc reproducing apparatus for reproducing information recorded on a disc.

[0002]

2. Description of the Related Art A pickup provided in an optical disk reproducing apparatus reproduces information recorded on a compact disk (CD) or a laser disk (LD), a signal for reproducing the information, and a focus error signal. And has a function of generating a tracking error signal. Further, with respect to the warp and inclination of the disc, the tilt mechanism moves the pickup in the focusing direction so that the beam from the pickup hits the disc substantially perpendicularly.

By the way, an optical disk reproducing apparatus such as an LD player equipped with such a tilt mechanism has a structure shown in FIG. 7, for example.

That is, the pickup P is fixed to the carriage 9b which moves along the guide shaft 9a. One end of the guide shaft 9a is supported by the support shaft 9d of the support member 9c. As a result, the guide shaft 9a is rotated in the arrow direction by the drive mechanism (not shown) with the support shaft 9d as the fulcrum. In the figure, 9e is a spindle motor, and 9f is a clamper.

When the inclination of the disc D is detected by a well-known detector (not shown), the guide shaft 9a of the disc D rotates in the direction of the arrow as shown in FIG. The objective lens P1 is controlled so that the optical axis O of the pair of lenses P1 is perpendicular to the surface and the objective lens P1 is moved in the direction of the arrow to achieve focusing.

When the disk D is tilted in the direction opposite to the state shown in FIG. 8, the guide shaft 9a and the objective lens P1
Performs the reverse of the above.

[0007]

However, in the above-mentioned optical disk reproducing apparatus having the conventional tilt mechanism, although the tilt angle due to the rotation of the guide shaft 9a is made small, the objective lens P1 at the time of focusing is set. Is moved only along the optical axis O, the holder 1
The stroke of itself will inevitably become large.

Therefore, for example, a relatively large magnetic circuit including a focus coil 2 for moving the holder 1 and a tracking coil (not shown) and the like is required, which hinders downsizing of the pickup. However, it also hinders downsizing of the optical disk reproducing device.

The present invention has been made in consideration of such a situation, and by reducing the amount of movement of the holder in the focus direction at the time of tilt rotation, the optical disk reproduction in which the size of the pickup can be reduced. The purpose is to provide a device.

[0010]

In order to achieve the above object, an optical disk reproducing apparatus according to the present invention comprises a base,
The tilt mechanism includes a tilt mechanism that pivotally moves a pickup having a holder that holds a coil for focus driving and cantilevered with respect to the base by a wire spring, to and from the recording surface of the disc. In the optical disc reproducing device whose fulcrum is on the inner circumference side of the disc, when the holder approaches the recording surface side of the disc according to the movement from the neutral position of the holder in the focus direction, It is characterized by further comprising holder tilting means for tilting the disk toward the outer peripheral side and tilting the holder toward the inner peripheral side of the disk when the holder is separated from the recording surface side of the disk.

[0011]

In the optical disk reproducing apparatus of the present invention, for example, when the disk bends upward and the disk is tilted, the tilt mechanism rotates the pickup and the focus drive means performs focus control to move the holder. It is controlled so that the optical axis of the holder is perpendicular to the recording surface of the tilted disk while being brought into and out of contact with the recording surface of the disk.

At this time, since the fulcrum of the tilt mechanism is on the inner circumference side of the disc, when the holder is rotated so as to approach the recording surface side of the disc by the rotation of the pickup by the tilt mechanism, the light of the holder is rotated. The axis inclines toward the inner peripheral side of the disk, and when the holder is rotated away from the recording surface side of the disk, the optical axis of the holder inclines toward the outer peripheral side of the disk.

On the other hand, there is provided holder tilting means for tilting the holder according to the movement from the neutral position of the holder in the focusing direction. When the holder is moved by the focusing means, the holder tilting means acts to move the holder to the disk. The optical axis of the holder inclines toward the outer peripheral side of the disk when approaching the recording surface side, and the optical axis of the holder inclines toward the inner peripheral side of the disk when the holder moves away from the recording surface side of the disk.

Therefore, in the case where the disc is bent upward, and the disc is tilted, the rotation of the tilt mechanism and the focus means adjust the gap to bring the holder closer to the recording surface of the disc, and the optical axis from the holder. When adjusting the optical axis of the holder so that it aligns with the optical axis perpendicular to the recording surface of the disc, the holder should be adjusted so as to oppose the rotation of the tilt mechanism when adjusting the optical axis of the holder. The tilting means acts so that the rotation of the tilt mechanism for making the optical axis of the holder perpendicular to the recording surface of the disc can be increased. From the viewpoint of adjusting the distance between the holder and the recording surface of the disc, this makes it possible to bring the holder closer to the recording surface of the disc only by rotating the tilt mechanism. Can be reduced.

As described above, in the optical disk reproducing apparatus of the present invention, since the stroke of the holder in the focus direction is smaller than that of the conventional one, it can be used in a magnetic circuit or the like having a drive coil for moving the holder. Is relatively small.

[0016]

Embodiments of the present invention will be described below in detail with reference to the drawings. In the drawings described below, the same parts as those in FIG. 8 are designated by the same reference numerals.

1 and 2 show an embodiment of a pickup according to the optical disk reproducing apparatus of the present invention.
This pickup is tilted by a tilt mechanism as shown in FIG.

As shown in these figures, the pickup is provided with a yoke base 10 having a mounting piece 10b in which a screw insertion hole 10a is formed. Further, the yoke base 10 is formed with a screw insertion hole 10c.
Further, the yoke base 10 is provided with yoke portions 11 and 11 that are arranged opposite to each other, and a magnet 12 is attached to each yoke portion 11.

A suspension base 13 is arranged on the upper surface of the yoke base 10. here,
The suspension base 13 is attached to the yoke base 10 by screwing the ends of the screws 13b inserted into the screw insertion holes 13a of the suspension base 13 into the screw insertion holes 10c of the yoke base 10.

The suspension base 13 is provided with a coil substrate 15a, via metal wire springs 14, 14 ,.
A holder 16 sandwiched between 15b is cantilevered. The holder 16 accommodates a light emitting unit 16b, an objective lens 16d, a light receiving unit 16e, and the like, which will be described later.

The coil substrates 15a and 15b are provided with
Exciting coils (not shown) described later are arranged in a flat shape.

A flexible wiring board 17 is interposed between the suspension base 13 and the holder 16, and its end portion is connected to the relay board 18.

The relay board 18 is provided with a mounting piece 18b having a screw insertion hole 18a. Here, the relay board 18 is attached to the yoke base 10 by the attachment piece 10
This is performed by screwing the end portion of the screw (not shown) inserted in the screw insertion hole 10a of b into the screw insertion hole 18a of the mounting piece 18b.

An exciting current is supplied to the coil substrates 15a and 15b through the wire springs 14. Further, read signals from the holder 16 and the like are input and output via the flexible wiring board 17.

The suspension base 13 is made of resin. Further, the suspension base 13 is provided with insert-molded terminals 13e, each wire spring 14 is connected to one end thereof, and is connected to the terminal portion 18e of the relay board 18 at the other end. Has become. FIG. 3 shows the holder 16 described above.
In the body 16a, a light emitting portion 16b that emits laser light, a mirror 16c that reflects the laser light to the disk D side, an objective lens 16d that collects the reflected light on the disk D, and a disk D A light receiving portion 16e for receiving the reflected light is stored.

Then, the laser light from the light emitting portion 16b is
After being reflected by the surface of the mirror 16c, it is focused on the disk D by the objective lens 16d. Disk D
The reflected light from the mirror 1 passes through the objective lens 16d and then the mirror 1
It is reflected by the inside of 6e and guided to the light receiving portion 16e.

The optical disk reproducing apparatus provided with the pickup having such a structure operates as follows.

First, after the pickup moves in the radial direction of the disk D along the guide shaft 9a, the information on the recording surface is read.

At this time, the laser light from the light emitting portion 16b is reflected by the surface of the mirror 16c and is focused on the disk D by the objective lens 16d. Disk D
The reflected light from the mirror 1 passes through the objective lens 16d and then the mirror 1
It is reflected by the inside of 6c and guided to the light receiving portion 16e.

Then, based on the reflected light from the disc D guided to the light receiving portion 16e, information reproduction and pickup focusing and tracking are performed. At this time, if the disk D is tilted, for example, as shown in FIG.
As shown in, the guide shaft 9a is rotated in the direction of the arrow, and at the same time, the focus is taken by the holder 16. During this focusing, control is performed so that the optical axis of the objective lens 16d in the body 16a of the holder 16 coincides with the optical axis O that is perpendicular to the recording surface of the disc D. Therefore, when the holder 16 moves to the recording surface side of the disk D and deviates from its neutral position in order to focus at the same time as the rotation of the guide shaft 9a, as shown in FIGS. 1 and 2,
Since the end of the flexible wiring board 17 is attached to one side surface of the holder 16 on the outer peripheral side of the disk, the flexible wiring board 17 is bent. This allows
The flexible wiring board 17 exerts a restoring force on the holder 16 for bending. Therefore, for example, as shown in FIG. 5, the holder 16 approaches the recording surface of the disc D while being inclined in the outer peripheral direction of the disc D. And the holder 16
Focusing is performed while the optical axis of the objective lens 16d in the body 16a is controlled to coincide with the optical axis O which is perpendicular to the recording surface of the disc D. When the outer circumference of the disk D is along the lower side, the guide shaft 9a and the body 16a move in the opposite direction. Then, the information on the recording surface of the disc D is read by the optical pickup.

Here, the reason why the movement amount of the holder 16 in the focus direction due to the rotation of the guide shaft 9a becomes smaller than that of the conventional one is as follows.

That is, as shown in FIG. 6, θ: warp angle (rad) of disc D (counterclockwise is positive) a: displacement of disc D l: distance from tilt fulcrum α: correction by tilt servo Rad (guide shaft 9
(Counterclockwise rotation of a is positive) t: Correction height by tilt servo s: Displacement of holder 16 β: Tilt angle (rad) accompanying displacement of holder 16 (counterclockwise is positive), and K = β When / s, the following formula is established. a = t + s (focusing condition) ..theta. =. alpha .-. beta. (inclination condition) ..beta. = K.s..t = 1 / tan.alpha ... Since .alpha. << 1, tan.alpha. , T = 1 / α ... When the displacement s of the holder 16 is calculated from this, s = a-t = a-l.alpha. = A-l. (. Theta. +. Beta.) = A-l. (. Theta. + K.s), and therefore s = (a-l. θ) / (1 + 1k).

Assuming that the displacement when the holder 16 is not tilted due to the focus displacement is s0 and the tilt correction angle is α0, θ = α0, and s0 = a−1, α0 = a−1 · θ. -Α0 = α-θ = β = K · s ... From the equation, s = (1 / (1 + l · K)) · s0 ... As seen from the equation, K>
When 0, | s | <| s0 | and | α | <| α0 |.

In other words, when the holder 16 is displaced from the neutral position in the positive focus direction (the direction from the neutral position toward the disk D), the holder 16 tilts toward the outer peripheral side of the disk D. When the holder 16 is displaced in the negative focus direction from the neutral position, the holder 16 performs the opposite operation.

Therefore, it is understood that the tilt servo correction angle is increased as compared with the conventional holder in which the holder is not tilted, but the focus stroke is reduced according to the distance from the tilt fulcrum.

As described above, in this embodiment, since the stroke of the holder in the focus direction is smaller than that of the conventional one, the magnetic circuit including the driving coil for moving the holder, the magnet, and other parts, etc. In that case, a relatively small one is sufficient. Therefore,
The pickup can be miniaturized.

In the present embodiment, when the holder is displaced from the neutral position in the positive or negative direction of the focus due to the tilt rotation, the holder is tilted due to the restoring force of the bending of the flexible wiring board. Although explained, the present embodiment is not limited to this example, and the center of gravity of the holder may be shifted in advance so that the holder is inclined with its displacement, or the number of turns of the coil of the coil substrate in the positive or negative focus direction may be changed. .

[0038]

As described above, according to the optical disk reproducing apparatus of the present invention, the amount of movement of the holder in the focus direction at the time of tilt rotation is made smaller than that of the conventional one, so that the holder is moved. For a magnetic circuit including the drive coil, the magnet, and other parts, a relatively small one is sufficient. Therefore, the pickup can be downsized.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of a pickup according to an optical disk reproducing apparatus of the present invention.

FIG. 2 is a perspective view showing an embodiment of a packup according to the optical disc reproducing apparatus of the present invention.

FIG. 3 is an explanatory view showing a holder of the pickup.

FIG. 4 is an explanatory diagram for explaining an operation of the optical disc reproducing apparatus including the pickup according to the embodiment of the present invention.

FIG. 5 is an explanatory diagram for explaining the operation of the optical disc reproducing apparatus including the pickup according to the embodiment of the invention.

FIG. 6 is an explanatory diagram for explaining the operation of the optical disc reproducing apparatus including the pickup according to the embodiment of the present invention.

FIG. 7 is an explanatory diagram showing a conventional optical disc reproducing apparatus having a tilt mechanism for tilting a pickup.

FIG. 8 is an explanatory diagram for explaining the operation of the conventional optical disc reproducing apparatus.

[Explanation of symbols]

 9a ... Guide shaft 9b ... Carriage 10 ... Yoke base 12 ... Magnet 13 ... Suspension base 14 ... Wire springs 15a, 15b ... Coil board 16 ... Holder 17 ... Flexible wiring board 17e ... Coverlay 17f ...... Resist film 18 …… Relay substrate D …… Disk.

Claims (2)

[Claims] 1. A tilt for rotating a pickup having a base and a holder, which is cantilevered by the wire spring with respect to the base and holds a coil for focus driving, to and from a recording surface of a disk by rotation. In an optical disk reproducing device including a mechanism, in which the fulcrum of the tilt mechanism is on the inner circumference side of the disk, the holder approaches the recording surface side of the disk in response to movement from the neutral position of the holder in the focus direction. In this case, there is provided a holder inclining means for inclining the holder toward the outer peripheral side of the disc, and inclining the holder toward the inner peripheral side of the disc when the holder is separated from the recording surface side of the disc. An optical disk reproducing device characterized by the above. 2. The holder inclining means comprises a flexible wiring board which connects the base and the holder and is attached to one side surface of the holder on the outer peripheral side of the disk, and which corresponds to the movement of the holder in the focus direction. The optical disk reproducing apparatus according to claim 1, wherein the holder is tilted by a restoring force of the bending of the flexible wiring board that occurs.