JPH0423341B2 - - Google Patents

Description

TECHNICAL FIELD The present invention relates to an information reproducing device, and particularly to an information reproducing device that reproduces information recorded on a recording medium.

BACKGROUND ART In a digital audio disk as a recording medium, for example, as shown in FIG. 2, concave portions called pits are provided on the disk surface to form a spiral track T, and the lengths of these pits and Information is recorded by intervals.

In this digital audio disk, as shown in Fig. 3, synchronization signals S ₁ , S ₂ , ...S ₉₈ , control signals C ₁ , C ₂ , ...C ₉₈ , and information signals I ₁ , I ₂ ...I ₉₈ are used as signal elements. A recording format is adopted in which a plurality of frames F ₁ , F _{2 .} . . F ₉₈ each including a predetermined number of bits are arranged to form a track T.
In this recording format, 1 means 98 blocks.
It is made up of a frame. Furthermore, time information is included in the control signal in each frame in the form of minutes, seconds, and block numbers. The same block number is recorded in all frames within each block B ₁ , B ₂ , B ₃ , B _{4 .} . . . Since one block can record the amount of information corresponding to the sound that exists for 1/75 seconds, the block number read during normal playback will change every 1/75 seconds. Become.

Information is read from a digital audio disk by irradiating light onto the pits of the disk and demodulating the reflected light from the recording surface, which is modulated depending on the presence or absence of pits. Such an information recording disk reading device is provided with a tracking servo device that controls the rotation of a tracking mirror so that the irradiated light always accurately tracks the recording track of the disk. The temporary stopping operation of the information reading device is performed by controlling the jump operation of the irradiation light so that the irradiation light returns one track each time it goes around the recording track. As a method of controlling the jump operation of the irradiation light, for example, the tracking servo loop is opened, and at the same time the tracking servo loop is opened, the tracking mirror is rapidly rotated to separate the irradiation light from the recording track that the irradiation light was tracking. A method is adopted in which the servo loop is closed again by introducing the recording track irradiation light to be tracked.

When the pause operation is canceled, reading is resumed from the frame that is being irradiated with the irradiation light.

For this reason, in conventional information reproducing devices, playback may occur from a frame that is earlier than the frame at the start of the pause operation, and the continuity of the information signal is impaired by the pause operation.
Since the rotation speed of the recording disk was 200 to 500 revolutions per minute, there was no problem when an audio signal was recorded as an information signal.

However, when digital data such as a subcode included in a control signal is recorded as an information signal, the effect of information loss due to a pause operation clearly appears, resulting in incomplete reproduction of information. Ta.

SUMMARY OF THE INVENTION An object of the present invention is to provide an information reproducing device that can prevent information from being lost due to pauses.

The information reproducing device according to the present invention responds to a pause release command so that the position where the information reproduced before the pause is recorded becomes the reproduction start position. After moving to the read position, the playback operation is started.

Embodiments Hereinafter, embodiments of the present invention will be described in detail with reference to FIG.

In FIG. 1, reference numeral 1 denotes a reading device consisting of an optical pickup and a tracking servo device that controls the rotation of a tracking mirror so that the information detection point of the optical pickup accurately tracks the track of the recording disk. It is a device. For example, EFM (Eight to Fourteen Modulus) obtained from a recording disk (not shown) by the reading device 1
-lation) signal is supplied to the demodulation circuit 2. The demodulation circuit 2 is configured to demodulate the EFM signal to reproduce an information signal and to form display data based on the obtained information. The display data output from the demodulation circuit 2 is supplied to a display device 3 such as a CRT display.

On the other hand, a control signal obtained from the recording disk by the reading device 1 is supplied to the control device 4. The control device 4 extracts time information such as a block number included in the supplied control signal and sends it to the frame counter 5, and also temporarily stops the frame in response to a pause command issued from an operation unit (not shown). The reading device 1 is controlled to perform a stop operation, and at the same time, a load pulse is sent out so that the output data of the frame counter 5 is preset in the counter memory 6. The control device 4 also changes the contents of the counter memory 6 to n (n=1, 2...) in response to a pause release command issued from an operation unit (not shown).
After sending out a countdown pulse so as to decrease the number of blocks, the tracking servo loop in the reading device 1 is opened, and at the same time the tracking mirror is rapidly rotated to move the information detection point back by, for example, one track. A configuration in which the operation of closing the servo loop is repeated until the contents of the frame counter 5 and the counter memory 6 match, and when the contents match, the supply of the read information to the demodulation circuit 2 is started. It is becoming.

In the above configuration, the playback start position when the pause is canceled is a block n blocks before the block played immediately before the pause, and is set with an accuracy of 1/75 second. Therefore, there is no information missing due to a temporary stop, and data can be displayed without errors.

In the above embodiment, the information playback start position when the pause is canceled is set by the block number, but the position of the information detection point may be moved over one track or more in the original direction when the pause is canceled. The information playback start position may be set by

Furthermore, when a pause is performed in the above embodiment, it is possible that only the counter counts up while one frame's worth of data is read as incomplete data. A function block is set to determine whether the data at the time of starting operation is complete, and if the data is incomplete, the pause is canceled without counting up and re-reading the data of the incomplete block. It is clear that the accuracy of preventing information loss can be improved by providing a function to set the time count.

Effects of the Invention As detailed above, the information reproducing apparatus according to the present invention is configured such that, in response to a pause release command, the position where the information already reproduced before the pause is recorded becomes the reproduction start position after the pause. Since the structure is such that the information detection point on the recording medium is moved to the position where a predetermined amount of information has already been read, and then the playback operation is started, there is no loss of information due to a pause, and the information is recorded on the recording medium. This allows the information to be processed without error. Furthermore, since the reproduction information before the generation of the pause command is duplicated and new information is reproduced subsequently, the user can confirm the continuity of the information from before the generation of the pause command.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a diagram showing tracks formed on a recording disk, and FIG. 3 is a diagram showing a recording format of a digital audio disk. Explanation of symbols of main parts: 1...reader, 4...control device.

Claims (1)

[Claims] 1. An information reproducing device having a function of temporarily stopping the reproduction of information recorded on a recording medium while not changing the relative moving speed of an information detection point by pick-up with respect to the recording medium in response to a pause command. An information reproducing apparatus comprising: a control means for starting a reproducing operation after moving the information detection point by a predetermined amount of information to a previously read position in response to a pause release command.