JPS5952416A - Pcm sound recording and reproducing device - Google Patents

Abstract

PURPOSE:To perform high-precision IC-implementation, by providing a means of generating a compensation state signal to the error compensating circuit of an AD and a DA converter. CONSTITUTION:For example, when play music is recorded on a recording medium 1, the means of generating the compensation start signal 2 detects recording contents being silence for a time T necessary for compensation between pieces of play music or in play music and makes the compensation in this nonmusic period. A shift register 23' is a partial circuit of a signal processing part 23 and stored with a digital sound signal in the compensation period T. A digital comparator 41 detects silence. A shift register 42 is stored with comparison results for the compensation period and an AND circuit 43 outputs the compensation start signal 2 when detecting the continuation of silence for the compensation period T. In this constitution, when the nonsound period is as long as the period T, the AND circuit 43 outputs a signal with a level ''1'', which is used as the compensation start signal. The compensation start signal 5 for a sound recording system is obtained associatively with a power source switch, etc.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention is based on PCM (Pulse Code rY4od
uAa1. +'on) related to recording/playback equipment, especially I
High-precision AD (analog/AD) suitable for C (integrated circuit)
The present invention relates to an I) CM recording and reproducing device comprising a digital) converter and an A (digital-to-analog) converter.

[Background of the invention]

The I'CM recording and playback device converts analog audio signals into A
All or one of the functions of converting into a digital value via a D converter, recording it on a recording medium such as a magnetic tape, and extracting this recorded content]) and reproducing it back to the original analog audio signal via an A converter. It is a device with parts. This can be explained using the block diagram shown in FIG.

This will be explained more specifically. In FIG. 1, (W) above the broken line indicates a recording system, and (R) below the broken line indicates a reproduction system, and 1 is a recording medium 1, such as a magnetic tape or a disk. The input analog straddle signal 11 is passed through the low-pass filter 1
2, the signal is sent to the sampling/holding circuit 13, where its amplitude is extracted and held at fixed time intervals by the sampling pulse SP, converted into a digital signal by the AD converter 14, and error detected by the 9th order signal processing unit 15. A code for synchronizing the data is added, an increment (data rearrangement) is performed, and the data is recorded on the recording medium 1 via the recording amplifier 16. When reproducing the recorded content, the data is read out in bit and frame synchronization by the synchronization processing circuit 22 via the reproduction increaser 21, and the data is processed in the secondary signal processing unit to process code errors and absorb jitter. After that, the input analog audio signal is restored by the DA converter 24 and the low-pass filter section and outputted as 26.

A, D converter in this PCM recording and playback device)
4 and the DA converter 24, a converter of approximately 14 to 16 bits is required from the standpoint of realizing high-fidelity recording and playback. I) In order to economically realize a 0M recording and playback device, the above-mentioned high-precision converter is required, but it guarantees performance of 1/I bit or more over a long period and a wide temperature range. High precision AD converter, DA
It is extremely difficult to convert the converter to 1C.

As a converter that can meet the above requirements, the present inventors first developed an error correction method that reduces the effects of variations in component elements, temperature fluctuations, changes over time, etc. by correcting the nonlinear errors of the converter. D with circuit-friendly AD converter (Japanese Patent Application No. 52-124514) and 1-mode error correction circuit
A converter (Japanese Patent Application No. 5'4-8231) was proposed. However, in order to incorporate this proposed converter into a CM recording and reproducing device and fully utilize its performance, it is necessary to operate the error correction circuit at certain intervals.

[Purpose of the invention]

An object of the present invention is to provide a PCM recording and playback device in which AD and DA converters are equipped with error correction circuits, by providing means for generating a correction start signal for these error correction circuits, thereby achieving high accuracy. Moreover, it is an object of the present invention to provide a PCM recording and reproducing device having an AD and DA converter that can be integrated into an IC.

[Summary of the invention]

The features of the present invention are to achieve the above objects.

The present invention is configured to include an error correction circuit in at least one of the AD converter and the DA converter, and correction start signal generating means for providing a correction start signal to these error correction circuits.

[Embodiments of the invention]

The present invention will be explained below with reference to the drawings.

First, for convenience of explanation, one embodiment of the present invention regarding a reproduction system will be described with reference to FIG. In FIG. 2, 2 is the correction start signal, and 3 is during the correction period.

This is a gate circuit that cuts off the output of the DA converter 24.

4 is a generation circuit that generates the correction start signal 2;

Other symbols are the same as in FIG. The first method of generating the correction start signal 2 is 1, for example, when a performance song is recorded on the recording medium 1.

This method detects that the recorded content is silent during the time T (usually about 10 to 100 milliseconds) required for correction between or within a performance song, and performs correction during this silent period. A specific example of the circuit configuration is shown in FIG. In FIG. 3, 23' is a shift register of the partial circuit of the signal processing unit z3 that stores the digital audio signal of the correction period T, and 41 is a shift register for detecting that the digital audio is silent. 42 is a shift register that stores the comparison result for the correction period (in the case of silence, a high level "1" is set); 43 is silent during the correction period T;
That is, the contents of the shift register 42 are all "1".

This is an AND circuit that outputs a correction start signal 2 when it detects. According to this circuit configuration in FIG. 3, the silent period is a period T
If this continues for a while, a signal of level "1" is output from the AND circuit 43, which can be used as a correction start signal.

A second method for obtaining the correction start signal is to generate the correction start signal in conjunction with a power switch or a drive switch necessary for reproduction. This method (although the configuration is simpler than the first method above).

]Since correction is performed once per tape (or one disk), in the case of long-term recording media, correction will be performed approximately once every few hours.In the case of the first method, This requires high stability in the DA converter. A third method for obtaining a correction start signal is to apply a correction start signal to a recording medium in advance.

Or a silent signal that can be used as a correction start signal.

This is a method of recording. Specifically, (1) the above-mentioned signal is recorded between each performance song, (2) address information such as the performance song name or performance number is given between each performance song, and the address signal is used as the correction start signal. This is a method such as doing. For example, if you record the above signal between each performance song, you can record it for each performance song (
Correction can be made every few minutes to several tens of minutes), and there is no need to provide a special circuit to generate a correction start signal.As mentioned above, the first to third corrections for the reproduction system Each start signal generation circuit has its own features and is effective.

Next, an embodiment of the present invention regarding the @ row system will be described with reference to FIG. In Figure 4, 13. M, 15°1
6 is a sampling/holding circuit which has the same function as shown in FIG. 1 and digitally records the input analog audio signal on the recording medium 1;
An AD converter, a signal processing section, and a recording amplifier are respectively shown, and 5 is a correction start signal, and 6 is a silent address signal. The first method for obtaining the correction start signal 5 is to generate the correction start signal 5 in conjunction with a power switch or a drive switch necessary for recording, similar to the second method for the reproduction system. The second method is described in the above-mentioned correction start signal necessary for the reproduction system or the third method of the reproduction system; j! G
The sound address call is a method in which when recording a signal, the signal is also used as a correction start signal for the recording system. Both of the above two methods are effective when employed in the correction start signal generating means, as in the case of the reproduction system described above.

〔Effect of the invention〕

As described above, according to one aspect of the present invention, a PCM recording and playback device having an AD and DA converter connected to an error corrector is equipped with means for generating an error correction start signal, so that the AD and DA converter This makes it possible to implement a highly accurate and economical PCM recording and playback device.

[Brief explanation of drawings]

Fig. 1 is a block diagram for general explanation of 1] CM recording and playback device, Fig. 2 is a block diagram of an embodiment of the present invention for a playback system, and Fig. 3 is a detailed diagram of a part of Fig. 2. FIG. 4 is a block diagram of an example of the present invention for a recording system. Explanation of symbols 1 Recording medium 2, 5... Correction start signal 3 Gate circuit 4 Correction start signal generation circuit 6... Silence numbering is signal 11 Analog audio signal 12:25 Low pass filter 13・Sampling holding circuit 14...D converter 15.23
... Signal processing section 24 ... DA converter 41 ... Digital comparator Z3', 42 ... Shift register patent attorney Junnosuke Nakatoshi

Claims (1)

[Claims] (1) Converting an analog audio signal into a digital value via an AD converter and recording it on a recording medium, and extracting the recorded content and reproducing it to the original analog audio signal via a DA converter. A PCM recording and playback device, characterized in that at least one of the AD converter and the DA converter is equipped with an error correction circuit, and a correction start signal generating means for supplying a correction start signal to these error correction circuits. PCM with
Recording and playback equipment. (2. In the apparatus according to claim 1, the correction start signal generating means has logic for detecting that the recording/playback content is silent during the correction required time in the error correction circuit. A PCJvl recording and reproducing device comprising a circuit and means for using the output of the logic circuit as a correction start signal. (3) The device according to claim 1. The correction start signal generating means comprises: There is a power switch for the recording and playback device (characterized in that it consists of means for generating a correction start signal in conjunction with each drive switch for each recording and playback, and the ON operation of Sochi) (1# Recording and playback Apparatus. (4) In the apparatus according to claim 1, the correction start signal generating means records a correction signal on the recording medium or generates a correction signal recorded in advance on the recording medium. 7) C, characterized in that it consists of means for generating a correction start signal for the recording system or the playback system when extracting the signal for use.
M recording and playback equipment.