JPH0814941B2 - Double-sided disc playback device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (A) Field of Industrial Application The present invention relates to a pickup feeding device of a disc player for reproducing information recorded on both sides of the disc.

(B) Conventional technology When playing back a disc with information recorded on both sides with a compact disc player or an optical video disc player, remove the disc when the information on one side is completed and turn it over. After that, the other side had to be regenerated. However, this is extremely troublesome in operation, and continuous reproduction on both sides is impossible.

Further, in a player of a type in which a record board having a groove is reproduced by a reproducing needle instead of an optical type, for example, Japanese Patent Laid-Open No. 56-77
As disclosed in Japanese Patent No. 948 (G11B17 / 08), a technique has been proposed which enables double-sided reproduction of a record by a single signal reading means.

In this conventional technique, a guide rail is provided which is composed of a pair of linear guide portions that are arranged in parallel to each surface of the record and are arranged to face each other, and a U-shaped guide portion that connects the two guide portions. The tone arm is fixed to the movable base that moves on this guide rail, and each side of the record is reproduced while moving each linear guide. When changing the reproduction surface, the movable base is changed to a U-shaped guide. It is configured to move from one surface to the other surface via.

A plurality of rollers are pivotally supported on the movable base, the rail is sandwiched between at least two of these rollers, and in this state, a driving force is applied to the movable base so that the rollers roll on the rail. Since the movable base has a very simple structure that allows the movable base to move along the guide rail, some rattling occurs in the direction orthogonal to the moving direction when the movable base moves on the guide rail. But,
In this case, some rattling is not a problem. That is, the above-mentioned conventional technique is intended for a record player that traces the groove of a record board with a reproducing needle, and since the reproducing needle is supported by a tone arm via a cantilever, each surface of the record board is This is because, when reproducing, even if there is some rattling in the movement of the movable base on the linear guide portion, it can be sufficiently absorbed by the tone arm and the cantilever.

(C) Problems to be Solved by the Invention In recent years, as a disc player, an optical disc player that plays back optical information in a non-contact manner with the disc is becoming mainstream. In this optical disc player, signal reading from the disc is performed. Position control of the focus direction and the tracking direction of the pickup, which is a means,
Much higher accuracy is indispensable than the above-mentioned needle type player.

Therefore, when the above-mentioned conventional technique is adopted in this optical disc player, if slight rattling occurs during movement on the linear guide portion of the movable base, a heavy load is always applied to the focus servo and the tracking servo,
There is an extremely high risk of the worst case in which the signal cannot be read beyond the allowable range of the servo.

(D) Means for Solving the Problems Therefore, the period during which the reproduction of each surface of the disk by the pickup is executed, that is, the linear movement of the movable base, is completely independent of the drive mechanism such as rollers and gears which are indispensable for the movement of the movable base. In order to prevent rattling during the movement of the movable base only during the period of executing, the upper surface and the lower surface of the disk are opposed,
Guide poles are fixed to the upper and lower chassis, respectively, on the upper and lower sides extending along the linear movement direction of the movable base, and a single guide hole is formed on the movable base to fit each guide pole. By fitting the upper guide pole into the guide hole when playing the top surface of the disc, and by fitting the lower guide pole into the guide hole when playing the bottom surface, rattling of the movable base can be suppressed when playing any surface of the disc. In addition, when mounting each guide pole to each chassis, each guide pole is supported through a connecting member such as a screw while arranging a space to allow passage of the movable base between each chassis. , The guide hole is continuously provided with a notch to allow passage of the connecting member,
Further, the width of the notch is set to be smaller than the diameter of the guide hole.

(E) Operation Since the present invention is configured as described above, rattling of the movable base in the direction orthogonal to the moving direction of the movable base is minimized while the guide pole is fitted in the guide hole. Also, it is possible to support each guide pole on each chassis without hindering the movement of the movable base,
Stable double-sided playback of the disc is realized without burdening the servo system such as focus.

(F) Example Hereinafter, one example of the present invention will be described with reference to the drawings.

FIG. 2 shows the appearance of an optical video disc player, in which a disc tray (3) for setting a disc (2) on the front panel (1) is moved horizontally between the storage position and the pull-out position. It is possible.

FIG. 1 is a perspective view of a main part of a pickup feeding device,
The pickup (4) and the drive motor (5) are fixed on the movable base (6). A bracket (7) is adhered to the right end of the movable base (6), and a gear (8) is fixed to the motor shaft through the bracket (7). A pinion (9) meshing with the gear (8) is pivotally supported on the bracket (7). Two rollers (10) and (11) are pivotally supported on the left side surface of the movable base (6).

(12) is a rack that meshes with the pinion (9), and includes a lower linear portion (12a) that extends horizontally on the lower chassis,
An upper linear portion (12c) extending on the lower surface of the upper chassis in parallel with the lower linear portion (12a) and a U-shaped connecting portion (12b) connecting both linear portions are integrated. A guide groove (1) on which the pinion shaft (9a) can be loosely fitted is provided on the inner surface of the connecting portion (12b).
3) extends in a U shape.

(14) is a guide rail on which the rollers (10) and (11) slide, and similar to the rack (12), the lower linear portion (14a),
It is composed of an upper linear portion (14c) and a connecting portion (14b) connecting both linear portions. A guide groove (15) into which the roller shaft (10a) can be loosely fitted is provided on the inner surface of the connecting portion (14b), and a roller guide is provided on the sliding surface of the rollers (10) and (11). A groove (116) is formed.

(16) (17) are columnar guide poles fixed to the upper and lower chassis (20) (21) and are arranged in parallel with the linear portions of the rack (12) and the guide rail (14). There is.
The guide poles (16) (17) are screwed and fixed on the chassis by screws (19) with a cylindrical fixing member (18) interposed between the guide poles (16) and (17).

A fitting hole (22) for fitting with the guide pole (16) is formed on the lower surface of the movable base (6).
2) The lower side is cut out for the escape of the fixing member (18).

The disc (2) placed on the disc tray (3) has upper and lower linear portions (12a) (14a), (12c) (1).
It is clamped by the turntable (26) between 4c).

 Next, the operation of the apparatus of this embodiment will be described.

Regarding the STOP mode, the waiting position shown in A of FIGS. 4 and 5, that is, the connecting portion (12b) of the lower straight portions (12a) (14a)
(14b) The movable base (6) is located at the immediately preceding position.
Therefore, the pickup (4) never faces the disc (2).

In the PLAY mode, the drive motor (5) is driven, the drive force is transmitted to the pinion (9), and the position indicated by B while meshing with the rack (12), that is, the lower linear portion (12a) (1)
The movable base (6) moves to the tip position of 4a). At this position, the pickup (4) faces the innermost circumference of the surface A of the disc (2). After that, the disc motor (25) rotates, and the disc (2) is scanned by the pickup (4). During this scanning, the tracking control circuit of the pickup operates, and this output is supplied to the drive motor (5). As the surface A is scanned, the movable base (6) moves toward the outer peripheral surface of the disk (2), that is, the lower linear portion. It moves on (12a) and (14a) toward the connecting parts (12b) and (14b). When all the scanning of surface A is completed, the movable base (6)
Via the connecting portions (12b) (14b), the upper linear portion (12c) (1
4c) reaches the tip and reaches the innermost position of the B side of the disc (2), and at the same time, the disc motor (25) rotates in the reverse direction and the pickup (4) is scanned in the same manner as the A side and moved. The base (6) moves toward the outer circumference of the disc (2).

FIG. 6 shows a state in which the pickup (4) is scanning the disc (2), that is, the moving state of the lower linear portions (12a) and (14a) of the movable base (6). The guide pole (16) is in the fitted state with the fitting hole (22) to prevent the pickup (4) from rattling in the vertical and horizontal directions and to improve the tracking accuracy of the pickup (4). This is because. The same applies to the movement in the upper linear portions (12c) and (14c).

The moving state of the movable base (6) at the connecting portions (12b) and (14b) is shown in FIG. The pinion shaft (9a) and the roller shaft (10a) are loosely fitted in the guide grooves (13) (15) to maintain the meshing between the pinion (9) and the rack (12), and the rollers (10) (11) It moves into the roller guide groove (116) to guide the movement. When the scanning of the surface of the disc B is completed, the movable base (6) returns to the waiting position and enters the waiting state, the disc motor (25) stops, the disc clamp is released, the disc tray rises, and the disc is removed. To be done.

(G) Effect of the Invention As described above, according to the present invention, rattling in the direction orthogonal to the moving direction of the pickup at the time of reproducing a disc is minimized, and each guide pole is not hindered in the movement of the pickup. The support of each chassis is made possible, and the pickup can be moved smoothly.

[Brief description of drawings]

The drawings are all related to one embodiment of the present invention. FIG. 1 is a perspective view of a main part, FIG. 2 is an external view, and FIG. 3 is an explanatory view of a guide pole.
FIG. 4 is a top view, FIG. 5 is a side view, FIG. 6 is an illustration during horizontal movement, and FIG. 7 is an illustration during U-turn. (2) …… Disc, (4) …… Pickup, (6)
…… Movable base, (22) …… Mating hole, (20) (21) ……
Upper / lower chassis, (16) (17) …… Upper / lower guide poles, (18) …… Fixing members.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takaya Uemura 2-18 Keihan Hondori, Moriguchi City, Osaka Sanyo Electric Co., Ltd. (72) Hideki Ishida 2-18 Keihan Hondori, Moriguchi City, Osaka Sanyo Denki Within the corporation (56) References Japanese Patent Laid-Open No. 59-157872 (JP, A)

Claims (3)

[Claims] 1. An optical pickup that reproduces information from both sides of a first surface of a disc and a second surface that is a back surface of the first surface, and a movable base that integrally supports the pickup and is movable integrally. , A fitting hole provided in the movable base, and a linear movement guide of the movable base which is disposed so as to face the first surface and is parallel to the first surface, and the pickup is attached to the first surface. A first linear guide portion that can move forward and backward in a radial direction; and a linear movement guide for the movable base that is arranged parallel to the first linear guide portion and opposite to the second surface and parallel to the second surface. Then, a second linear guide portion that allows the pickup to move forward and backward in the radial direction of the second surface, and a movement guide between the linear guide portions of the movable base, which is disposed outside the outermost periphery of the disc. A third guide portion, and the first straight guide portion A first guide pole that is disposed in the first base and that guides the linear movement of the movable base by being fitted in the fitting hole only while the movable base is moving on the first linear guide. Both sides of the disk, which are arranged in parallel with the section and have a second guide pole that fits in the fitting hole and guides the linear movement of the movable base only while the movable base is moving on the second linear guide portion. Playback device. 2. A first chassis, which is arranged on behalf of the first surface, a second chassis, which is arranged opposite to the second surface, and the first and second guide poles, which are respectively the first and second guide poles.
The support member for connecting to a chassis is provided, and when the movable base is linearly moved, a notch portion is continuously provided in the fitting hole to allow passage of the support member. The described disk double-sided playback device. 3. The disk double-sided reproducing apparatus according to claim 2, wherein the notch is narrower than the diameter of the fitting hole.