JPH0729334A - Reproducing device - Google Patents

Abstract

PURPOSE:To eliminate discontinuity of a reproducing sound and to prevent generating of noise by restoring a track to the original track with a tracking control and reproducing the dame track again when the outflow of a sound memory is likely to be surpassed by the write-in at the time of lowering a musical interval of the reproducing sound. CONSTITUTION:The device is provided with a surpassing detecting circuit 13, and a difference of timing speed between the write-in and the read-out of the memory 7 is detected by the circuit 13, and when the outflow is surpassed by the write-in of the memory 7, a track jumping command is issued to a tracking control part 14, so that the tracking control is performed on a pickup 2 in order to reproduce the same recording track 101 again. For example, when surpassing at the 5th successive frame is detected, the tracking control part 14 is controlled, and the pickup 2 is track-jumped to reproduce a track corresponding to the 5th successive frame again. At this time, when jumping is performed, a reproducing picture is disturbed for an instant, but no problem takes place when the jumping is performed during a period of vertical blanking.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reproducing apparatus, and more particularly to an optical disk reproducing apparatus having a pitch converting function for lowering the pitch of reproduced sound from an optical disk.

[0002]

2. Description of the Related Art A block diagram of a conventional reproducing apparatus of this type is shown in FIG. In FIG. 5, the storage information (video and audio information) on the optical disc 1 is read by the pickup 2 while being tracking-controlled by the tracking controller 14.

Of the pickup output, the video information is demodulated by the video demodulation unit 3, supplied to the monitor 4 and reproduced.

The voice information is demodulated by the voice demodulator 5, digitized by the A / D converter 19, and written in the memory 7 under the control of the write timing generator 10. The information stored in the memory 7 is read under the control of the read timing generator 11, converted into analog by the D / A converter 8, and supplied to the speaker 9 to be reproduced.

Here, a pitch setting section 12 is provided to convert the pitch of the reproduced sound, and the pitch of the reproduced sound is controlled by controlling the read timing of the memory 7 by the pitch setting of the pitch setting section 12. It has become.

FIG. 6 is a block diagram of another reproducing apparatus having a pitch converting function, and the same parts as those in FIG. 5 are designated by the same reference numerals.

In FIG. 6, the read output of the pickup 2 is demodulated by the video demodulation unit 3 and the audio demodulation unit 5, respectively.
The signals are digitized by the / D converters 15 and 19 and stored in the memories 6 and 7, respectively.

At this time, the frame number read by the frame No. decoder 18 is input to the write timing generation unit 10 and written in the frame memories 61 to 65 and 71 to 75 of the memories 6 and 7 in order one frame at a time. It will be rare.

For reading from the memories 6 and 7, the frame memories 61 to 65 are sequentially read one by one according to the read timings of the read timing generators 17 and 11.
And 71 to 75, respectively.

The digital signals read from the memories 6 and 7 are reproduced by being converted into analog signals by the D / A converters 16 and 8 and supplied to the monitor 4 and the speaker 9.

Also in this example, by controlling the read timing of the read timing unit 11 by the pitch setting unit 12,
The pitch of the reproduced sound can be controlled.

[0012]

In the above-mentioned conventional optical disc reproducing apparatus, when the pitch of the reproduced sound is lowered by the pitch setting unit 12, the cycle of the write clock to the memory 7 becomes shorter than that of the read clock (frequency is Write) will overtake the read, resulting in an unread frame.

FIGS. 7A and 7B are time charts showing such a situation, where FIG. 7A shows the operation of the block of FIG. 5, and FIG. 7B shows the operation of the block of FIG. Figure 7
As you can see from (A) and (B), when the pitch is lowered,
Since there are frames to be skipped, there is a drawback that noise occurs as a discontinuous sound during the skipped period.

Therefore, the present invention has been made in order to eliminate the drawbacks of the prior art, and its purpose is to reduce the memory read speed in order to lower the pitch of the reproduced sound. It is an object of the present invention to provide a reproducing device capable of preventing the generation of noise by eliminating discontinuity of read sound.

[0015]

A reproducing apparatus according to the present invention comprises a memory for storing audio information reproduced from a storage medium, write control means for determining a write timing of the memory, and read for determining a read timing of the memory. Control means, detection means for detecting the timing difference between the write timing and read timing, and tracking control means for performing tracking control of the recording medium according to the timing difference are included.

Another reproducing apparatus according to the present invention is a memory capable of storing video signals and audio signals of a plurality of frames reproduced from a storage medium, write control means for determining write timing of the memory, and read timing of the memory. Read control means for determining the difference between the write timing and read timing of the memory for storing the audio signal, and tracking control means for performing track jump control of the recording medium according to the timing difference. Means for prohibiting writing to the memory by the tracking control means until the pickup returns to the track at the time of jumping again, and for reading the contents already stored in the memory during the period. And means.

[0017]

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a block diagram of an embodiment of the present invention, which corresponds to the block of FIG. 5, and the same portions are denoted by the same reference numerals in both figures. In this embodiment, an outpacing detection circuit 13 is further provided in the configuration of FIG. The tracking control of the pickup 2 is performed so that the same recording track 101 is reproduced again by sending the track jump command to the control unit 14.

FIG. 2 shows such a situation as a time chart. When overtaking is detected in the fifth frame,
The tracking control unit 14 is controlled so that the pickup 2 performs a track jump to reproduce the same track (track corresponding to the fifth frame) again.
In this case, when the track jump is performed, a momentary disturbance occurs in the reproduced video, but there is no problem if the track jump is performed during the vertical blanking period.

FIG. 3 is a block diagram of another embodiment of the present invention, which corresponds to the block of FIG. 6 and the equivalent portions in both figures are designated by the same reference numerals. Also in this embodiment, an overtaking detection circuit 13 is provided in addition to the configuration of FIG.
When the overwriting detection circuit 13 detects the difference between the timing speeds of writing and reading with respect to the memory 7, and when the writing with respect to the memory 7 overtakes the reading, a track jump command is sent to the tracking control unit 14 and the same track again Trying to play.

FIG. 4 is a timing chart showing the operation of the block shown in FIG.

When the overtaking detection circuit 13 detects the overtaking (the portion indicated by B in FIG. 4), the track jump command A is sent to the tracking control unit 14 and the track jump control of the pickup 2 is performed.

In the example of FIG. 4, jumping from track No. 10 to track No. 8 is performed, and again track No. 8 to
No10 is played. During this time, writing to the memories 7 and 6 is prohibited, and during that time, the frame information of the memories 7 and 6 which has been already written is read.

In the above embodiment, the optical disk is CAV.
Even if the video disc is a (constant angular velocity) type CL
It is obvious that the V (constant linear velocity) type can be similarly applied.

[0025]

As described above, according to the present invention, when the read of the audio memory is about to be overwritten by the write when the pitch of the reproduced sound is lowered, the track is returned to the original state by the tracking control and the same track is reproduced again. Since the track is reproduced, the discontinuity of the reproduced sound is eliminated and the noise is not generated.

Further, since the original track is reproduced for the reproduced video as well, there is an effect that it can be applied to any of the video discs in both the CAV system and the CLV system.

[Brief description of drawings]

FIG. 1 is a block diagram of an embodiment of the present invention.

FIG. 2 is a time chart showing the block operation of FIG.

FIG. 3 is a block diagram of another embodiment of the present invention.

FIG. 4 is a time chart showing the operation of the blocks of FIG.

FIG. 5 is a block diagram showing an example of a conventional reproducing apparatus.

FIG. 6 is a block diagram showing another example of a conventional reproducing apparatus.

7A is a time chart showing the operation of the block of FIG. 5, and FIG. 7B is a time chart showing the operation of the block of FIG.

[Explanation of symbols]

 1 Optical Disc 2 Pickup 3 Video Demodulation Section 4 Monitor 5 Audio Demodulation Section 6 Video Memory 7 Audio Memory 8, 16 D / A Converter 9 Speaker 10 Write Timing Generation Section 11 Read Timing Generation Section 12 Pitch Setting Section 13 Overtaking Detection Section 14 Tracking Control Part 15, 19 A / D converter

Claims (4)

[Claims] 1. A memory for storing audio information reproduced from a storage medium, a write control means for determining a write timing of the memory, a read control means for determining a read timing of the memory, the write timing and the read timing. And a tracking control means for performing tracking control of the recording medium according to the timing difference. 2. The read control means includes a pitch control means for controlling the pitch of a reproduced sound, and a means for changing the read control timing according to the control of the pitch. The playback device described. 3. A memory capable of storing video signals and audio signals of a plurality of frames reproduced from a storage medium, write control means for determining a write timing of the memory, and read control means for determining a read timing of the memory.
Detecting means for detecting a difference between a write timing and a read timing of the memory for storing the audio signal, a tracking control means for performing a track jump control of the recording medium according to the timing difference, and a pickup by the tracking control means. From the track jump to the time of returning to the jumping track again, means for prohibiting writing to the memory, and the time period includes means for reading the contents already stored in the memory. Playback device. 4. The read control means includes pitch control means for controlling the pitch of a reproduced sound, and means for changing the read control timing according to the control of the pitch. The playback device described.