JPS6312422Y2 - - Google Patents

Description

[Detailed explanation of the invention] [Industrial application field] This invention can be seen in, for example, video discs.
The present invention relates to an optical disc playback device that can play both large-diameter optical discs such as 30 cm discs and small-diameter optical discs such as digital audio discs, and particularly relates to a rotational drive mechanism for the optical disc.

[Background technology and its problems]

At present, the main devices used to play back optical discs using laser light are 30 cm discs that contain video signals.
There are commercially available devices that play back video discs and 12cm so-called compact discs that contain audio signals.

The playback principle of these devices is the same in that recorded information is read from the reflected light of a laser beam irradiated onto an optical disc, so it is possible to read recorded information from the reflected light of a laser beam irradiated onto an optical disc. It is preferable for users to be able to play back records of 2000 on a single playback device.

However, since the innermost circumferential diameter of the recording track of a compact disc is set to 46 mm, the optical pickup device P that reads out the information on the recording track is attached to the rotation axis N of the motor M as shown in FIG. Even though it is necessary to approach the video disk to at least 23 mm or less, the hole diameter for chucking the large-diameter video disk is set to 35 mmφ, so the large-diameter video disk clamper Q can chuck the chuck on the same rotation axis N. In this case, even if the turntable R is 46mmφ, the range in which the clamper Q can press the video disc is as shown by the diagonal line.
This results in an extremely narrow range of mm.

Therefore, it is extremely difficult to control the video disk so that it rotates at a rotational speed of 1800 rpm without wobbling or slipping. Also, when pressing the clamper Q against the rotating turntable R, it is necessary to align the rotation centers of both, but in this case as well, it is quite difficult to move the clamper Q to the center of the turntable R without misalignment. Become.

[Purpose of invention]

This idea was made to solve these problems, and it has a structure that allows optical disks of different diameters to be chucked onto a single spindle motor shaft, and that does not cause misalignment during chucking. By doing so, it is possible to provide an optical disc reproducing device that can accurately reproduce recorded information on an optical disc without wobbling.

[Summary of the idea]

In order to achieve the above-mentioned purpose, this invention
For example, a clamper for video discs and a clamper for compact discs can be selectively opposed to a turntable fixed to a motor shaft that can drive optical discs of different diameters at a predetermined rotation speed. A clamping mechanism is configured on the side of the clamping mechanism, and an optical pickup device provided on the side of the clamping mechanism allows different types of optical discs to be played back by one device, and the central axis of the clamper is aligned with the turntable. By fitting into the center, vibration and noise during rotation are prevented.

〔Example〕

FIG. 2 shows an external view of the optical disc playback device of this invention, where C is a housing and T is a disc tray for carrying the optical disc to the internal turntable position. This disk tray T is provided with markings suggesting concentric circles l ₁ .l ₂ or steps to facilitate the positioning of large-diameter or small-diameter optical disks, and as will be described later, the disk tray T is loaded with The optical disc floats inside the casing C and is chucked by a turntable, giving it rotational force. In addition, the S of disk tray T
The part shown in FIG. 1 is a cutout that becomes a movement area of the optical pickup device.

FIG. 3 is a perspective view showing an overview of the chucking and rotational driving parts of the optical disk, in which 1 is a spindle motor, 2 is a turntable that partially fits into the chucking hole of the optical disk, and 3 is a holder for holding the spindle motor 1. It has a motor base. Reference numeral 4 denotes a clamp mechanism provided to press and press an optical disk (not shown) placed on the disk tray T onto the turntable 2 from below. According to the type of optical disk, either the large or small clamper 6.5 is selectively rotated to a position facing the turntable 2.

Reference numeral 7 denotes an optical pickup device for reading recorded information on the optical disk that has been chucked, and is configured to be moved in the radial direction of the optical disk by a feed screw 8.9 of a thread feed mechanism.

As seen in the above-mentioned schematic diagram, in the optical disc playback device of this invention, the spindle motor 1 for rotating the optical disc is provided on the top plate side of the casing C, and conversely, the clamp mechanism 4 for chucking is installed in the optical pickup device. It is located on the same side as 7.

Therefore, the optical pickup device 7 can approach the center of the optical disk without being affected by the outer diameter of the spindle motor 1. Moreover, the clamping mechanism 4 is configured so that a large-diameter clamper 6 and a small-diameter clamper 5 can be used depending on the type of optical disk, so that optical disks of different diameters can be used as described in FIG. It is possible to eliminate the defect that chucking is insufficient when chucking to the same rotating shaft.

FIG. 4 is a sectional view showing the turntable 2 and the clamp mechanism 4 in more detail, and shows the turntable 2 fixed to the shaft of the spindle motor 1.
A first circular protrusion 2a that fits into the chucking hole of a small-diameter optical disk and a second circular protrusion 2b that fits into the chucking hole of a large-diameter optical disk are arranged coaxially on the disk. These are each urged downward by coil springs 2c and 2d.

Further, the clamp mechanism 4 is supported by a rotating shaft 4a, and has a small diameter clamper 5 and a large diameter clamper 6.
is rotated by a cam plate, which will be described later, so that it is in a position facing the turntable 2, and at that point, the support shaft 5a.6a of the clamper 5.6 is pushed upward by the lever 10. There is. In addition,
Reference numerals 5b and 6b indicate central shafts in the support shafts 5a and 6a that are biased upward by spring coils as described later, and when the clamper 5 or 6 is pressed against the turntable 2, the center shafts of the turntable 2 are It is configured to fit into the recess 2f.

Therefore, for example, when a small-diameter optical disk (compact disk) is carried under the turntable 2 by the disk tray T, the small-diameter clamper 5 and the center shaft 5b are pushed up by the lever 10 and compacted. Press the disc onto turntable 2.

Then, the second protrusion 2b is pressed by the surface of the compact disc and pulled into the recess, but
The first protrusion 2a fits into the chucking hole of the compact disc, its tapered side surface positions the center, and the clamper 5 and the pressing surface 2e of the turntable 2 clamp the optical disc. At this time, the central axis 5b is aligned with the turntable 2.
Since the center of the turntable 2 and the support shaft 5a of the clamper 5 are fitted into the recess 2f, the center of the turntable 2 and the support shaft 5a of the clamper 5 are aligned to prevent core runout.

Furthermore, when a large-diameter optical disk (video disk) is similarly carried in, the rotating shaft 4a of the clamp mechanism 4 is rotated by a cam plate, which will be described later, so that the large-diameter clamper 6 faces the turntable 2. come to a position. Then, when the clamper 6 and the central shaft 6b are pushed upward by the lever 10, the second protrusion 2
b is inserted into the chucking hole of the video disc, the center position is determined, and the pressing surface 2g
The video disk is clamped by the clamper 6. At this time as well, the center shaft 6b fits into the recess 2f of the turntable 2, and alignment is performed.

Since the heights of the pressing surfaces 2e and 2g of the turntable 2 are different (1.2 mm) in accordance with the thickness of the optical disk, the distance between the chucked optical disk surface and the optical pickup device 7 is always constant. be able to.

FIG. 5 is a perspective view showing an embodiment of the clamp mechanism 4, in which the rotating shaft 4a of the clamp mechanism 4 supports the peripheral part of the first cam plate 11 and a roller that slides on the recess 11a. The arm 4b supporting the clamper 5.6 (not shown) and the arm 4c supporting the support shaft 5a.6a of the clamper 5.6 (not shown) are fixed and rotatable. A circular tapered surface 12a is formed on the second cam plate 12 that engages with the first cam plate 11, and the rod 10a supporting the lever 10 is positioned on this tapered surface 12a. There is.

Therefore, in this figure, when the first cam plate 11 is rotated in the direction of arrow A by a control motor (not shown), the arm 4b and the rotation shaft 4a are rotated counterclockwise, and the support shaft 6a is rotated in the direction of the arrow A. comes to the position of point P. At this time, the second cam plate 12 also rotates counterclockwise, so the rod 10a rides up on the tapered surface 12a, the position of point P rises, and the support shaft 6a is pushed upward.

That is, as shown in FIG. 4, the clamper 6 is pressed against the turntable 2.

Conversely, when the first cam plate 11 is controlled to rotate in the direction of arrow B, the spindle 5a of the small-diameter clamper 5 is rotated to the position of point P on the lever 10 by a similar operation. At this time as well, it is pushed upward by the rod 10a resting on the tapered surface 12a.

That is, according to this mechanism, the first cam plate 1
The clamper 5 or 6 can be selectively pressed against the turntable 2 by rotating the clamper 1 normally or reversely using a worm gear or the like.

6a and 6b show another embodiment of the clamping mechanism 4 in a plan view and a side view. In FIG. 6a, 5.6 is a clamper for small diameter and large diameter, and the support shaft Clamp arm 14 by 5a.6a
It is pivoted on a.14b. Clamp arm 14
A roller 14d that fits into the recess 15a of the cam plate 15 is pivotally supported at the tip of the cam plate 15, and the entire roller 14d is rotatably supported on the base.

A circular tapered surface 15b is formed on the cam plate 15 as in FIG. 5, and a roller 16 attached to the lever 20 is mounted on this tapered surface 15b as shown in FIG. 6b. The gears formed around the cam plate 15 are a worm gear 17,
It is interlocked with a control motor 19 via a pinion 18.

Note that 21 is a spring that urges the clamp arm 14c toward the cam plate 15;
Reference numeral 2 indicates a support plate that pushes up the support shaft 5a.6a of the clamper 5.6.

When the control motor 19 is driven to rotate in the normal direction from the state shown in FIG. 6A, for example, by a signal that detects the disk size, the cam plate 15 rotates in the direction of arrow A. Then, the roller 14d fits into the recess 15a of the cam plate 15 and rotates the clamp arm 14c clockwise. Therefore, the clamper 5.6 also rotates in the direction of the arrow A, and the small-diameter clamper 5 is positioned in the position of the clamper 6. At this time, the roller 16 on the tapered surface 15b of the cam plate 15 is once lowered along the tapered surface 15b, forming a state in which the clamper 6 and the turntable 2 are separated, and a small-diameter clamper is placed at the position of the clamper 6. When the clamper 5 is in position, it rises again and the clamper 5
Press turntable 2 with .

The optical disk is carried in by the disk tray T when the clamper 5.6 is lowered, and the control motor 19 is moved depending on the type of optical disk carried in.
The clamper 6 is configured to rotate forward or reverse, so when using a large-diameter video disc, the clamper 6 rotates forward or backward.
When using a compact disc with a small diameter, the clamper 5 floats up and comes into pressure contact with the turntable 2.

In the case of this embodiment, since there is only one cam plate 15, there is an advantage that it is possible to reduce the size.

FIGS. 7a and 7b are sectional views showing details of an embodiment of the clamper 5, and the same symbols as in FIG. 4 indicate the same parts. In this figure, a thrust receiving rod 5c is inserted into the lower end surface of the support shaft 5a, and an elevator rod 5d,
and supports a central shaft 5b which is slidably fitted into the elevator rod 5d. 5g ₁ and 5g ₂ are coil springs that bias the central shaft 5b and the clamper 5 upward, and 5g ₃ is a coil spring that biases the thrust receiver 5c downward.
Further, 5f is a holder that supports the clamper 5.

Note that the clamper 6 also has a similar structure, so a description thereof will be omitted. For the turntable 2, only the structural portion for a small diameter is shown.

In the state shown in FIG. 7a, the support plate 22 is
(or lever 10) is pushed upward,
The coil spring _5g3 is initially not compressed, and when the support shaft 5a, holder 5f, and clamper 5 move upward, and the flange formed at the bottom of the support shaft 5a comes into contact with the clamp arm 14a, the coil spring _5g3 is compressed. Compressed elevator rod 5d, center shaft 5
b increases. Therefore, the clamper 5 is
move away from f and press the optical disc against the turntable 2. At this time, the tip of the center shaft 5b fits into the recess 2f of the turntable 2 and is urged upward by the coil spring _5g1 , so the center of the turntable 2 and the center of the clamper 5 match, and the center of the seventh It is positioned as shown in Figure b.

Therefore, when turntable 2 rotates,
Since the clamper 5 also rotates in alignment with the center of rotation of the spindle motor 1, rattling and vibration caused by rotation can be prevented. The rotational force is also transmitted to the center shaft 5b and the elevator rod 5d, but the thrust receiving rod 5c supports the load with the thrust bearing portion 5e formed on its upper surface, but does not rotate, and the support shaft 5a also does not rotate.

As described above, the cam plate 1 constitutes the support shafts 5b and 6b of the clamper 5 and the other clamper 6 (not shown) and controls the rotation of the clamp mechanism 4 described above.
Even if the accuracy of the clamper 5 or cam plates 11 and 12 is not set strictly, the center of the clamper 5 or 6 can be pressed against the center of the turntable 2,
No vibration, noise, etc. are generated when the optical disk is driven.

In the above embodiment, the spindle motor 1 is arranged on the upper surface of the optical disk, but the arrangement shown in FIG. 3 may be reversed vertically.

Furthermore, for the rotation of the clamp mechanism 4, a clamp mechanism or the like may be used instead of the cam mechanism.

[Effect of idea]

As explained above, the optical disc playback device of this invention is configured so that the clampers for large and small diameters can be selectively pressed against the turntable, so optical discs of different diameters can be played by the same drive. The rotating shaft can be reliably chucked, and different types of optical discs can be played back with one playback device. Further, since the center of the turntable and the center of the clamper are arranged to coincide with each other during chucking, there is no vibration noise caused by rotation, and there is an advantage that the load torque of the motor is reduced and at the same time, misalignment adjustment is not required.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram when chucking optical discs of different diameters, Fig. 2 is a perspective view showing the external appearance of the optical disc reproducing device of this invention, and Fig. 3 is a schematic diagram of the optical disc clamper and driving part. , FIG. 4 is a sectional view showing an embodiment of the chucking part of this invention, FIG. 5 is a perspective view showing an embodiment of the clamping mechanism of this invention, and FIGS. 6a and b are views of the clamping mechanism of this invention. Plan view and side view showing other embodiments, No. 7
Figures a and b are cross-sectional views showing the structure of the support shaft of the clamper. In the figure, 1 is a spindle motor, 2 is a turntable, 2f is a recess, 4 is a clamp mechanism, 5 is a small-diameter clamper, 5b is a central axis, 6 is a large-diameter clamper, and 6b is a central axis.

Claims (1)

[Scope of utility model registration request] a motor driven at a predetermined rotation speed for optical discs of different diameters, and a turntable fixed to the shaft of the motor and having a recess formed in the center;
a clamping mechanism comprising first and second clampers configured to selectively face the turntable and provided with central shafts that fit into recesses of the turntable; An optical disc playback device comprising: a moving mechanism that selectively presses a second clamper against the turntable.