JPH0772961B2 - Track interval detector - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to detection of a track interval of a reproducing device.

[0002]

2. Description of the Related Art After amplifying an output signal to an appropriate level, a peak hold circuit is used to form a discharge circuit having a predetermined time constant, and an output level and a charge / discharge time interval suitable for detecting a track interval are determined. After rectifying this signal, it was compared with the reference voltage and used as the inter-track detection signal.

[0003]

In the prior art, regardless of the signal component, the threshold for discriminating between the music and the signal and the time interval thereof were constant, so that continuous pianissimo was misidentified as the music. In some cases, noise existing between songs was regarded as a signal, and the operation of detecting the intervals between songs was often mistaken.

[0004]

According to the present invention, an input circuit is provided so that an input reproduction signal is converted into a digital signal through an A / D conversion circuit and an arbitrary signal level can be detected by a microcomputer. The signal level and the time interval are divided into several sections to obtain a two-dimensional array, and the elements in the two-dimensional array are evaluated by the evaluation values (A, B, C, D,
E, ...), the evaluation values are weighted, the evaluation values are arranged in time series, and the evaluation time series {T = T1, T
2, · Ti, ·} (Ti = A, B, C, D, E,
..) is a device for detecting the music interval by distinguishing between the music interval and the signal section from the result of adding n evaluation weights.

[0005]

As described above, the weight of the evaluation value, which is the reliability of the evaluation, is changed depending on the signal level and the time interval thereof, and the reliability is low, which disturbs the distinction between the music and the signal such as pianissimo or pulsive noise. The reliability of the inter-track detection can be improved by allowing the signal to be time-sequentially judged including the past data.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the block diagram of FIG. The signal reproduced by the reproducing apparatus 1 is A / D converted by the A / D converter 2 and stored in the memory 3 as digital data.
Memorized in. The stored signal is sequentially read by the level comparator 4 to detect the signal level and the interval time.

As shown in FIG. 2, for example, the signal level is -3.
0 dB or more, −30 to −35 dB, −35 to −40 d
B, -40 to -45 dB, 5 ranks or less of -45 dB, while the interval time is 0.5 sec or less, 0.5 to 1
sec, 1 to 2 sec, 2 to 4 sec, and 4 to 8 sec are divided into five ranks, respectively, detected, two-dimensionally arrayed in terms of signal level and time interval, and five kinds of evaluation values A to E are respectively obtained, and a memorizing means. In 5, for example A = + 2 (considered as an immediate signal),
B = + 1 (likely signal), C = 0 (unknown), D = -1
(It seems to be between songs) and E = -2 (which is considered as an immediate song interval), and the song interval determination means 6 sets three evaluation time series (n = 3), and sums the three sums in a continuous time series. When the weight reaches +2, it is regarded as a signal, and when it reaches -2, it is regarded as a space between songs.

When the input data is sampled, it is assumed that, for example, the time series {Ti} of the evaluation values is as follows. Evaluation value {A, B, B, C, B, C, D, C, D,} Weight {+ 2, + 1, + 1,0, + 1,0, -1,0,
−1} In the evaluation values B, C and D, n = 3, that is, 3 including the current value.
Since it is determined by adding the individual weights, the final evaluation value D is −
2, it is determined that there is a space between songs. Example 2) Assume that the time series {Ti} of evaluation values is as follows. Evaluation value {E, D, C, B, D, B, C, B} Weight {-2, -1,0, + 1, -1, + 1,0, +
1} Here, three weights are added to give +2 at the last B, and it is determined here that there is a signal.

Therefore, the level comparing means 4, the weighting means 5 and the judging means 6 are implemented by the processing of the microcomputer 8 from the memory 3 and a control command is issued to the control means 7. The weighting value and the number of weight additions can be stored and controlled for each signal by using the learning function of the microcomputer 8. Even if the signal level near the threshold value is difficult to determine, the existence of the intermediate value by the evaluation value exists. By referring to the past data by time series evaluation, it is possible to obtain a more reliable inter-track detection device.

[0010]

As described above, according to the present invention, the signal level near the threshold value, which is difficult to determine, is also evaluated in time series, so that a more reliable inter-track detection device can be obtained by referring to past data. be able to.

[Brief description of drawings]

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

FIG. 2 is a diagram showing a two-dimensional array of signal levels and time intervals.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 reproducing apparatus 2 A / D converter 3 memory 4 level comparing means 5 memorizing means 6 inter-track judging means 7 control means 8 microcomputer

Claims (1)

[Claims] 1. A digital recording / reproducing apparatus , comprising:
Memory for temporarily storing data and reading from that memory
Signal levels of different signals are compared and divided into multiple ranks.
The time interval for the above signal level to be
Means for dividing into two-dimensional sections and each of the two-dimensional sections
Means for weighting the elements and
Judge by adding a predetermined number of time-series one-dimensional arrays of the above signals
That means comprises a song between the detection device, characterized in the formation Succoth to detect between tracks.