JPH0438068B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pause device in a playback device for a disk on which information (for example, music) and a position index signal indicating the position of this information are recorded, and particularly to a pause device for a pickup means. This configuration is such that the playback information is continuous when playback is restarted after the feed is temporarily stopped.

Recently, devices have been proposed for optically or electrostatically recording and reproducing audio and video signals on a disk in a spiral manner. Since such a disc does not have grooves like conventional audio record discs, a tracking control signal is created based on the signal derived from the pick-up means,
Therefore, it is necessary to perform tracking control using this tracking control signal so that the readout point of the pickup means can perform track scanning correctly. That is, the pickup means has a tracking function.

Now, while a disc is being played back using the above-mentioned disc playback device, there may be cases where it is desired to temporarily stop the feeding of the pickup means. Considering tracking control in such a paused state, good playback cannot necessarily be expected in a paused state [particularly in audio disks, where information is repeatedly played over a certain period of time (for example, several seconds)] It is not very meaningful just to do so], and it is also conceivable not to perform tracking control. However, if you do so,
The tracking control system was greatly disturbed during the pause,
After that, it takes time for the control system to stabilize, which is not preferable. Therefore, it is necessary to operate the tracking control system even when the vehicle is temporarily stopped. Therefore, even in a temporary stop state where the feeding of the pick-up means has stopped, tracking control is performed within the period (for example, several seconds) within the range of its capability by the tracking function of the pick-up means itself. Information for this period will be repeatedly reproduced.

Now, what must be taken into consideration when canceling the paused state and starting playback again is to make sure that the readout points of the pick-up means are consecutive so that playback resumes from the paused position. It is necessary to make the reproduction information continuous in this way. However, even in the paused state, the tracking function is in operation, and the readout point of the pick-up means follows the spiral track within the range of its tracking capability. That is, the readout point of the pickup means has moved within the tracking capability range. Furthermore, the greater the tracking ability, the greater the movement range of the readout point. Therefore, whether or not the readout point at the time of pause and the readout point at the time of resumption of playback match depends on the timing of restarting playback, and it is extremely unlikely that the two will match.

Incidentally, in digital audio disks that have been proposed recently, in addition to information such as music, a position index signal relating to the position of the information (for example, the playing time of each song) is recorded on the disk. Therefore, the present invention reads out and records the position index signal at that point in time from the disk at the start of a pause, and then moves the readout point by a tracking operation during the pause and reads out the position index signal from the disk. When the position index signal differs from the stored position index signal, a track jump is performed to return the readout point of the pickup means to the original position.

Hereinafter, a detailed description will be given with reference to embodiments shown in the drawings.
In the drawing, a signal recorded on a disk (not shown) is read out by a pickup means 1, and by applying the output signal of this pickup means 1 to a tracking processing circuit 2, a tracking control signal is generated. Created. This tracking control signal is applied to the drive circuit 3, and this tracking control signal is applied to the drive circuit 3.
A drive coil (not shown) for controlling the position of, for example, a mirror or a lens (both not shown) constituting the optical pickup means 1 is actuated by the output of the optical pickup means 1, thereby achieving tracking control of the read beam. The configuration of such a tracking control system is already a known technique as disclosed in, for example, Japanese Patent Laid-Open No. 54-94007.

On the other hand, the signal read out by the pick-up means 1 is applied to the digital processing circuit 4, where it is digitally processed based on the clock, and music information data,
Synchronization signals, position index signals, etc. are demodulated. Among these demodulated signals, the position index signal is detected by the position index detection circuit 5.

Now, when the pause switch 6 is operated to set the disc playback device to a pause state, the gate 7 is driven and the position index signal at the start of the pause state is stored in the memory 8, and the comparator circuit 9 becomes the driving state. Now, in the paused state, the disk is rotated, and the readout point of the pick-up means 1 follows and scans the track by the tracking function of the pick-up means 1. Therefore, the position indicator signal read out by the pickup means 1 changes. This position index signal is applied to a comparison circuit 9 and compared with a value stored in memory 8. When a mismatch between the two is detected, the track jump pulse generating circuit 10 is driven, and the drive circuit 3 is operated by the track jump pulse outputted from this circuit 10 to perform a track jump. That is, the pick-up means 1
The readout point will return to the previous point. This operation is repeated throughout the pause period, and the readout point of the pickup means 1 is always located near the readout point at the start of the pause.

Next, the position index signal will be explained. For example, in currently proposed digital audio disks, control signals are recorded at regular intervals in gaps between music information (original digital data). This control signal is composed of 8 bits, of which 1 bit is considered to be used as an identification signal from the part between songs or the part where music is recorded. For example, "1" is recorded in the inter-song portion, and "0" is recorded in the music information portion. This is the simplest position indicator signal. Therefore, if the pause switch 6 is operated when the readout point of the pickup means 1 is between songs, "1" will be stored in the memory 8. During the temporary stop, the readout point is moved by the tracking function of the pickup means 1 itself, and when the position index signal detection circuit 5 detects "0", the comparison circuit 9 detects a mismatch. Then, the track jump pulse generating circuit 10 is activated, and track jump of the read point is performed. In this way, during a pause, the readout point is prevented from deviating from the inter-song section. That is, reproduction information is prevented from becoming discontinuous.

Next, consider a case where the performance time of a song (the performance time of one song or the continuous performance time from the first song) is recorded using some bits of the control signal, and this is used as a position index signal. Currently proposed digital audio disks have a constant linear velocity and a rotational speed of 200 to 500 rpm.
Varies within a range of m. If the performance time is recorded in seconds, a position index signal of the same value will be recorded during approximately 3 to 8 revolutions (tracks) of the disc. Therefore, for example, if "10 minutes and 10 seconds" is recorded in the memory 8 at the start of the pause, when the position index signal detection circuit 5 detects "10 minutes and 11 seconds" during the pause, A trackjump of the readout points is performed. Now, if this track jump is performed for one track, the time will advance by 2/3 seconds to 7/8 seconds from the position at the start of the pause, but there is no problem in practical terms. . Of course, the error can be reduced by subdividing the position index signal according to the number of rotations of the disk.

Incidentally, a number may be recorded instead of the performance time and this may be used as a position index signal. Moreover, it is of course applicable not only to a disk with a constant linear velocity but also to a disk with a constant angular velocity (constant rotation speed).

According to the present invention described above, the position at the start of the pause is memorized, and the tracking function operates during the pause, so that the readout point changes and becomes different from the memorized position. In this case, the track jump is performed and the readout point is changed, so that when reproduction is started again, the reproduced information can be substantially continued without skipping, which is extremely convenient.

[Brief explanation of drawings]

The drawing is a block diagram showing a pause device for a disc playback device according to the present invention. 1 is a pickup means, 5 is a position index signal detection circuit, 6 is a temporary stop switch, 8 is a memory, 9 is a comparison circuit, and 3 and 10 are a drive circuit and a truck jump pulse generation circuit constituting a truck jump setting means.

Claims (1)

[Claims] 1. In a disc playback device that plays back information recorded on a disc using an optical pickup means having a tracking function, a pause setting means for setting the playback operation of the disc playback device to a paused state; a storage circuit that stores a position index signal based on the reading position of the pickup means at the time of setting the pause; a comparison circuit for comparing the position index signal reproduced from the disk; and a track for causing the pickup means to perform a track jump in order to change the readout point of the pickup means in response to the output of the comparison circuit. 1. A pause device for a disc playback device, characterized in that a jump setting means is provided.