Drive Control Method for Multi-Disk Player

The present invention relates to a drive control method for a multi-disk player in which a plurality of disks housed in a magazine are extracted from the magazine one by one for playing.

A multi-disk player in which a plurality of compact disks are housed in a magazine and the disks are sequentially extracted and played has been proposed, manufactured, and placed on the market by the present applicant. The structure of this multi-disk player is described in detail in Japanese Patent Application No. 219603/85 filed by the present application.

FIG. 1 shows the basic construction of the multi-disk player. Shown at 1 in FIG. 1 is a magazine in which six disks 3 are housed. Six trays 2 are fitted in the magazine 1 in such a manner that the trays can be moved into and out of the magazine. When the disks 3 are housed in the magazine 1, the disks are engaged in the trays 2. Each tray 2 is pulled out of the magazine 1 by a tray moving mechanism 4 so that the disk 3 in the extracted tray is aligned with the spindle of a motor 5. The spindle then clamps the disk and rotates the disk while being servo-controlled so that a tune recorded on the disk can be reproduced through an optical pickup (not shown). After the disk 3 has finished playing, the disk is put back into the tray 2 and the tray is housed back in the magazine 1 by operation of the tray moving mechanism 4. Shown at 6, 7 and 8 in FIG. 1 are, respectively, a motor for driving the tray moving mechanism 4, a motor drive circuit for driving the motor 6, and a controller which sends control signals to the motor drive circuit 7. A home position detecting switch 9 for generating an output when the tray 2 is housed in the magazine and a clamped position detecting switch 10 for generating an output when the disk is clamped by the spindle motor 5 are connected to the controller 8.

However, when the disk 3 is to be returned to the magazine 1 after playing is completed, the disk may sometimes collide against a part of the magazine, making it impossible to operate the tray moving mechanism 4. Such an event may occur, for example, due to tilting of the player or to an external shock. If it is impossible to operate the tray moving mechanism 4, there is a problem in that the disk cannot be changed for another, and manual intervention is required to free the mechanism.

The present invention was made in consideration of the above-mentioned problem.

Accordingly, it is an object of the present invention to provide a multi-disk player in which abnormalities in the disk changing action are automatically eliminated.

In accordance with the present invention, a multi-disk player controller is operated in accordance with an abnormality elimination method inclusive of a first step of reverse driving in such a direction as to pull a disk out of a magazine when the return of the disk into the magazine is not completed within a prescribed time, and a second step of driving to return the disk into the magazine after the disk is pulled out of the magazine in the first process.

FIG. 1 is a schematic view of a multi-disk player to which an abnormality elimination method according to the present invention is applied;

FIGS. 2A to 2D show states of operation of the multi-disk player; and

FIG. 3 is a flowchart of the inventive abnormality elimination method.

A preferred embodiment of the present invention will hereafter be described with reference to the attached drawings.

When a reproduced disk 3 is to be changed for another disk to reproduce the latter, as a first step, a controller 8 issues a command to a motor drive circuit 7 to rotate a motor 6 to drive a tray moving mechanism 4 backward (step 1). It is then waited for a prescribed time (X seconds) in steps 2 and 3 for a tray 2 carrying the reproduced disk 3 to be returned to a magazine 1 and a home position detecting switch 9 to be turned on. When the tray 2 is returned to the home position 1 within the prescribed time, steps 6 to 22 are employed.

However, if the disk 3 collides against the magazine due to tilting of the player, an external shock, or the like, the tray 2 bearing the disk cannot reach the home position within the prescribed time, thus making the player inoperative. In this case, step 4 is executed. If this is the first instance of such failure, an NG flag is set in step 5 to control the motor drive circuit 7 to stop moving the disk 3 in a step 25. A step 10 is thereafter exectuted to control the motor drive circuit 7 to move the tray 2 in such a direction as to pull the tray away from the magazine 1 to remove the disk 3 from the jammed position with the magazine.

It is then waited for the prescribed time (X seconds) in steps 11 and 12 for the disk 3 to be clamped by the spindle of the motor 5 and for the clamped position detecting switch 10 to be turned on. Thus, the disk 3 and the magazine 1 are removed from collision contact with each other, and the disk is subsequently clamped by the spindle of the motor 5, as shown in FIG. 2A. After that, steps 16 and 17 are executed. In these steps, if the playback display of the player is off or the currently clamped disk 3 is not the one to be reproduced next, step 1 is executed again to perform a disk return operation, as shown in FIG. 2B.

Since the disk 3 is thus properly located on the tray 2, the disk is normally returned to the home position, as shown in FIG. 2C, whereupon step 6 is executed.

If the disk 3 is not returned to the home position within the prescribed time, since this constitutes the second failure, a skip is made to step 23 to stop the movement of the tray 2 where it is and to turn off the playback display, hence placing the player out of operation.

In step 6, the return of the tray 2 is stopped, and in step 7 the first NG flag is cleared. Hence, if a command not for disk change but for reproduction stoppage has already been issued, the player is deactivated. If a command for disk change has already been issued, step 9 is carried out to use a disk selection mechanism (not shown in the drawings) to select another disk 3' through counting. A tray 2' bearing the disk 3' is then moved in step 10, as shown in FIGS. 2D, in such a direction as to clamp the disk. It is then waited in step 11 for the disk 3' to be clamped by the spindle of the motor 5.

After the disk 3 has been clamped by the spindle of the motor 5, steps 16 and 17 are executed, and, since the playback display of the multi-disk player is on and the number of the disk is the same as that of the one to be played next, steps 18, 19, 20, 21 and 22 are carried out to put the tray moving mechanism 4 out of operation and clear the above-mentioned first NG flag. At the some time, the servo controlling the motor 45, etc., is activated to read recorded tune number information recorded on the innermost portion of the recording area of the disk to search for a desired tune and to reproduce it.

Although the above-described embodiment relates to a multi-disk player for compact audio disks, the present invention is not limited thereto, but may be also applied to a multi-disk player for video disks or a recording/reproduction device in which a plurality of recording media can be exchanged and played by movement between a housed position and a playing position.

According to the present invention, a controller of the disk player is operated in accordance with an abnormality elimination method in which it is first detected that a disk cannot be properly returned to its magazine for exchange with another disk, the tray bearing the disk is then returned to a clamped position, and the disk is thereafter returned to the magazine. Accordingly, if the disk collides against the magazine and becomes jammed thereagainst so that the disk cannot be returned to the magazine, the jammed condition is automatically released. As a result, the reliability of the player is significantly enhanced.