Disk player

Description: TECHNICAL FIELD [Detailed description of the invention]

【0001】

[Technical field to which the invention belongs]

The present invention relates to a disc player.

【0002】

[Conventional technology]

In an optical disc player, for example, a compact disc player, reproduction is performed by reading a signal recorded on the disc with an optical pickup. In this optical disc player, the optical pickup performs tracking and focusing operations on the disc by supplying a servo signal from the servo signal generation circuit to the drive coil arranged inside the optical pickup, whereby the signal is accurately read out. It is controlled as.

【0003】

By the way, recently, the flux generated from the power transformer which is the power supply means in the disc player and the power transformer which is the power supply means of other electronic devices (for example, audio amplifier) outside the disc player is the optical pickup. It was discovered that it had an adverse effect on operation. That is, if there is a power transformer near the optical pickup, an extra induced current unrelated to the servo signal flows through the drive coil in the optical pickup due to the flux generated from this power transformer, so that the optical pickup is based on the servo signal. The operation is different from the control, and the signal of the disk cannot be read accurately.

【0004】

[Problems to be Solved by the Invention]

However, in the conventional disc player, no measures have been taken using a power transformer as a flux source. The present invention has been made in view of these points, and provides a disc player capable of performing accurate optical pickup operation by preventing flux generated from a power transformer, which is a power supply means, from entering the optical pickup. With the goal.

【0005】

[Means for solving problems]

In order to achieve the above object, the disc player of the present invention supplies power to an optical pickup driven by a servo signal supplied to a drive coil, a servo signal generating means for generating a servo signal, and a servo signal generating means. A power supply means, a cover member provided so as to cover the optical pickup, and an electromagnetically shielded cover member as a whole, and an outer housing for accommodating the optical pickup, the servo signal generation means, the power supply means, and the cover member. And, it is equipped with.

【0006】

The disc player of the present invention configured as described above has a double shield structure in which the entire outer housing is electromagnetically shielded and the cover member of the optical pickup is also electromagnetically shielded. Since the adverse effect of the flux from the electronic device on the drive coil in the optical pickup can be effectively blocked, the optical pickup can be operated accurately.

【0007】

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, examples of the present invention will be described with reference to the drawings.

【0008】

FIG. 1 shows a portable compact compact disc player, in which 1 is an outer case (cabinet), and this outer case 1 is an outer case main body 1a and a disc mounted on the outer case main body 1a on the upper surface side thereof. It is composed of a lid 1b that is rotatably connected so as to open and close the portion 2. The turntable 3 and the optical pickup 4 are exposed on the disc mounting portion 2 of the outer housing body 1a. After the disc is placed on the turntable 3, the lid 1b is closed, and the disc is rotated and optical in this state. A predetermined playback operation is performed by moving the pickup 4 in the radial direction of the disc. Inside the outer housing body 1a, a servo signal generation circuit that generates a servo signal to be supplied to the power transformer, which is a power supply means, the drive motor of the turntable 3, and the optical pickup 4, although not shown in the figure. Including, various electronic circuits for reproducing the signal of the disk are housed.

【0009】

FIG. 2 shows a stationary compact disc player. In this stationary player, a turntable 3 and an optical pickup 4 are arranged in the back of the outer housing 1, and a tray 5 that appears and disappears from the front surface of the outer housing 1 is used. The disc is transported up to this point. That is, the disc is placed on the disc mounting portion 6 with the tray 5 protruding in front of the outer housing, and then the tray 5 is pulled in so that the disc is conveyed onto the turntable 3 in the outer housing. A playback operation is performed. Inside the outer housing 1, there is a power transformer 7, which is a power supply means, and a servo signal generation circuit, which is not shown in the figure but generates a servo signal to be supplied to the drive motor of the turntable 3 and the optical pickup 4. At first, various electronic circuits for reproducing the signal of the disk are housed.

【0010】

FIG. 3 shows the optical pickup 4 used in these compact disc players. To briefly explain the configuration of the optical pickup 4, reference numeral 10 denotes a pickup base, and the pickup base 10 is connected to a pickup feed mechanism configured in a disc player even if it is not shown. Reference numeral 11 denotes a movable body on which the objective lens 12 for emitting laser light and reading the signal of the disk is mounted. The movable body 11 is attached to the fixed base 13 fixed to the pickup base 10 via the support plate 14 in the direction of arrow a. It is oscillatingly connected and supported in the (tracking direction) and the arrow b direction (focusing direction). A drive coil (tracking coil and focusing coil) 15 is fixed to the movable body 11, while a magnet 17 is attached to the yoke 16 which faces the drive coil 15 and is fixed to the pickup base 10 side to drive the movable body 11. When a servo signal is supplied to the coil 15 from the servo signal generation circuit, the movable body 11 swings in the arrow a direction and the b direction due to the change in the magnetic force, that is, the tracking and focusing operations of the objective lens 12 are performed. Further, reference numeral 18 denotes a cover member for protecting the drive portion of the optical pickup, that is, by covering the entire drive portion with the cover member 18, dust and the like are prevented from entering. Reference numeral 19 denotes a through hole through which the laser beam emitted from the objective lens 12 passes.

【0011】

In the disc player having the optical pickup 4 configured in this way, the outer housing 1 is entirely electromagnetically shielded in order to protect the optical pickup 4 from the external flux (indicated by diagonal lines in FIGS. 1 and 2). part). That is, in the small portable player of FIG. 1, the entire outer housing 1 including the lid 1b is shielded, and in the stationary player of FIG. 2, the entire outer housing 1 is covered with a shield, and the front portion 5a of the tray 5 is covered. Is also shielded so that it will be integrated with the shield on the front of the outer case when the tray 5 is pulled in. Further, the optical pickup 4 in these disc players is also provided with an electromagnetic shield on the entire surface of the cover member 18 (the portion shown by the diagonal line in FIG. 3).

【0012】

Specific means of this electromagnetic shield include a method of applying a conductive paste for shielding (conductive copper paste, etc.) to a necessary part, a method of applying a conductive foil for shielding (electrolytic copper foil, soft aluminum foil, etc.), or a method for shielding. A method of pasting metal fibers, etc. can be considered (in either case, the chassis and ground are taken). All of these conductive pastes, conductive foils, and metal fibers for shielding are commercially available and can be easily obtained.

【0013】

By applying the electromagnetic shield to the cover member 18 of the optical pickup 4 as described above, the flux generated from the power transformer, which is the power supply means inside the disc player, does not enter the drive coil 15 of the optical pickup 4. Further, the flux generated from the player internal circuit such as the servo signal generation circuit inside the disc player and the external electronic device does not enter the drive coil 15 of the optical pickup 4. Further, when flux is generated in the drive coil 15 of the optical pickup 4, it is possible to prevent the flux of the drive coil 15 from adversely affecting the player's internal circuit and external electronic devices.

【0014】

However, if the cover member 18 of the optical pickup 4 is only electronically shielded, the player internal circuit is affected by the flux generated by the external electronic device, and if the flux is generated in the player internal circuit, this player internal circuit The problem remains that the flux of the above has an adverse effect on external electronic devices.

【0015】

On the other hand, since the entire outer housing 1 of the disc player is electromagnetically shielded, the flux generated from the power transformer or the like of an external electronic device does not enter the drive coil 15 of the optical pickup 4. Moreover, it does not adversely affect the internal circuit of the player.

【0016】

However, if the outer housing 1 is electromagnetically shielded, the drive coil 15 of the optical pickup 4 is affected by the flux generated in the player's internal circuit, and if the flux is generated in the drive coil 15, the drive coil 15 of the drive coil 15 is affected. There is a problem that the internal circuit of the player is adversely affected by the flux.

【0017】

In the disc player of this example, in order to make up for the drawbacks of the above two shields, the cover member 18 of the optical pickup 4 is electromagnetically shielded and the entire outer housing 1 is electromagnetically shielded, that is, the optical pickup 4 and the outer housing 1 are used. It has a double shield structure. As a result, the influence of the flux from the player internal circuit and the external electronic device on the drive coil 15 of the optical pickup 4 is blocked by the electromagnetic shield of the cover member 18, and the flux generated by the external electronic device is further removed from the outer housing. These double shields allow for stronger shielding, as they are also blocked by the entire electromagnetic shield of 1. Therefore, since the drive coil 15 in the optical pickup 4 is not adversely affected by the flux, the optical pickup 4 is faithful to the servo signal without any extra movement unrelated to the servo signal supplied to the drive coil 15. The tracking and focusing operations are performed, and as a result, the signal of the disc can be read accurately and stable reproduction is performed.

【0018】

Further, even when flux is generated in the drive coil 15 of the optical pickup 4, the double shield structure can prevent adverse effects on external electronic devices. Further, the adverse effect of the flux generated by the drive coil 15 on the player internal circuit can be prevented by the electromagnetic shield of the cover member 18. Further, the adverse effect of the flux generated in the external electronic device on the player internal circuit and the adverse effect of the flux generated in the player internal circuit on the external electronic device can be prevented by the electromagnetic shield of the outer housing 1.

【0019】

Although the embodiments of the present invention have been described above, it goes without saying that the present invention is applicable not only to the compact disc player as shown in the figure but also to other optical disc players such as a video disc player.

【0020】

[Effect of the invention]

As is clear from the above description, the disc player of the present invention has a double shield structure in which the entire outer housing is electromagnetically shielded and the cover member of the optical pickup is also electromagnetically shielded. Since the flux generated from the electronic device can be effectively blocked, the drive coil of the optical pickup is not adversely affected by the flux, and as a result, the optical pickup is operated accurately.

[Simple explanation of drawings]

[Figure 1]

It is a perspective view of the portable compact compact disc player which shows the Example.

[Figure 2]

It is a perspective view of the stationary compact disc player which shows the Example.

[Fig. 3]

It is an exploded perspective view of the optical pickup which shows the Example.

[Explanation of symbols]

1 ... outer housing, 4 .... optical pickup, 15 .... drive coil, 18 .... cover member