JPS6120950B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a digital disk recording and playback device, and particularly to a digital disk recording and playback device that converts and records analog signals such as audio into digital, and plays back the audio for almost simultaneous monitoring. Regarding equipment.

Conventionally, magnetic disks, optical PCM disks, and the like are known as general digital disks. In such conventional digital disks, in order to convert analog signals such as audio or music from analog to digital and record them digitally on a magnetic disk,
As shown in FIG. 1, an analog audio input signal from an audio input terminal 1 is converted into a digital signal by an analog-to-digital conversion circuit 2, and the digitally converted digital signal is sent to a time axis changing memory circuit 3.
a or 3b through the first switching means 4a, and the time axis changing memory circuit 3a or 3b
This digital signal is compressed on the time axis and written to the magnetic disk 5 by the second switching means 4b.
It is designed so that it is supplied through and stored there.

To explain the operation of the above-mentioned conventional circuit, suppose that the digital signal from the digital-to-analog converter circuit 2 is written in the first time axis changing memory 3a as shown in the time chart in FIG. 2A. For example, first and second switching means 4a and 4
By switching b by a control circuit (not shown), the digital signal in the first time axis changing memory 3a is compressed in time axis through the second switch means 4b, as shown in the time chart in FIG. 2B. The data is read out from the first time axis changing memory 3a and recorded on the magnetic disk 5. At this time, the digital signal from the analog-digital conversion circuit 2 is stored in the second time axis change memory 3b.
It is written as shown in FIG. 2C. In this state, when the first and second switch means 4a and 4b are switched, a digital signal is written in the first time axis change memory 3a, and the time axis is compressed from the second time axis change memory 3b. The digital signal is read out and placed on the magnetic disk 5 as shown in FIG. 2D.
recorded in Thereafter, in the same manner, the time-base compressed digital signals alternately read out from both the time-base change memories 3a and 3b are sequentially supplied to the magnetic disk 5 and are intermittently recorded in time. It is an object of the present invention to provide a recording/playback device that can extremely easily and substantially simultaneously monitor audio signals recorded using such a digital disk recording/playback device.

In the present invention, when audio phrases are recorded concentrically on a magnetic disk, the audio phrases in half of the concentric circle are stored in the first time axis change memory, and the audio phrases in the other half of the concentric circle are stored in the second time axis change memory. The data is recorded alternately in the time axis change memory.

An example of the present invention will be described in detail with reference to FIGS. 3 and 4. In FIG. 3, the same parts as in FIG. 1 are designated by the same reference numerals, and repeated explanation thereof will be omitted.

In the example of the present invention shown in FIG.
Time axis change memories 3a and 3b explained in the figure
In addition, third and fourth time axis change memories 6a and 6b for time axis extension are provided, and as shown in FIGS. 4B and 4D, the time axis intermittently recorded on the magnetic disk 5 is The compressed digital signal is reproduced from the magnetic disk 5 in the middle of the intermittent recording period, as shown in FIGS. 4E and 4G. Then, the reproduced time axis compressed digital signal is written into the third and fourth time axis changing memories 6a and 6b through the third switching means 7a. The digital signals read from both time axis changing memories 6a and 6b have their time axes restored, as shown in FIGS. The original audio signal is supplied to the digital-to-analog conversion circuit 8 through the audio output terminal 9 and taken out at the audio output terminal 9. The third and fourth time axis changing memories 6a and 6b are read and taken out alternately by switching means 7a and 7b. In addition, Fig. 4 A to D
Since these are similar to the time charts shown in FIGS. 2A to 2D, their explanation will be omitted.

With this configuration, the digital signal of the magnetic disk 5 is transmitted to the fourth signal at the moment when the head of the magnetic disk 5 finishes scanning a half circumference of the concentric track, and the moment when the head starts scanning a half circumference of the same concentric track. As shown by the arrows AB and CD in the figure, the data is compressed onto the magnetic disk 5 and recorded as shown in FIG. As shown by arrows BE and DG, the third and fourth time axis change memories 6a
and 6b, the signals are written as they are compressed on the time axis, and are further expanded to form analog playback signals as shown by arrows EF and GH in FIG. In this embodiment, in consideration of the storage capacity of the time axis change memory 3a, etc., the length of one phrase of the audio signal is set to a short time of, for example, a fraction of a second, and the time axis is compressed. The recording period of the digital signal is much shorter than the phrase length. Therefore, the digital recording state of each phrase of the audio signal can be monitored substantially simultaneously by the analog playback signal delivered to the output terminal 9.

It should be noted that although the above embodiments are explanations regarding magnetic disks, it is clear that the present invention can also be applied to optical disks and the like.

[Brief explanation of the drawing]

FIG. 1 is a system diagram of a conventional digital disk recording/playback device, FIG. 2 is a time chart of FIG. 1, FIG. 3 is a system diagram of a digital disk recording/playback device of the present invention, and FIG. This is a time chart for explaining an example. In the figure, 1 is an audio input signal terminal, 2 is an analog-digital conversion circuit, 3a, 3b, 6a and 6
b is time axis change memory, 4a, 4b, 7a and 7
b is a switching means, 5 is a magnetic disk, and 8 is a digital-to-analog conversion circuit.

Claims (1)

[Claims] 1. An analog signal such as an audio signal is supplied to a time-base compression circuit via an analog-to-digital conversion circuit, and a time-base compressed digital signal from the time-base compression circuit is intermittently transferred to a disk-shaped recording medium. and reproducing the time-base compressed digital signal of the preceding recording period during the intermediate period of the recording period in which the time-base compressed digital signal is intermittently recorded, and the reproduced time-base compressed digital signal is supplied to a time axis expansion circuit, and the time axis restored digital signal from the time axis expansion circuit is derived via a digital-to-analog conversion circuit to obtain an original analog signal. playback device.