JPS601610A - Pcm signal recorder - Google Patents

Abstract

PURPOSE:To record the sounds or music with high quality by changing the feed speed of a recording medium in accordance with the quantizing frequency of a PCM signal to be recorded and therefore varying the recording time to the recording medium. CONSTITUTION:The audio signal sent from an audio signal souce 1 such as a tape recorder, etc. is supplied to a 16-bit linear PCM encoder 2 to undergo the A/D conversion into a 16-bit PCM signal having the quantizing frequency of 16. The audio signal is also supplied to an 8-bit differential PCM encoder 3 to undergo the A/D conversion into an 8-bit PCM signal having the quantizing frequency of 8. Then 16 output terminals which obtain the parallel PCM signals of 16 bits of the encoder 2 are connected to a fixed contact group 4a at one side of a changeover switch group 4 containing 16 changeover switches respectively. At the same time, the 8-bit parallel PCM signals obtained from the encoder 3 are supplied successively to 16 latch circuit 3a which store temporarily the PCM signals equivalent to two clocks. Then 16 output terminals of the circuits 3a are connected to a fixed contact group 4b.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a PCM signal recording apparatus W that records PCM signals of audio signals such as voices and music in parallel as a plurality of tracks.

BACKGROUND TECHNOLOGY AND PROBLEMS Ahead button A recording magnetic head device in which a plurality of magnetic heads are arranged and fixed in parallel in the vertical direction is used to record audio, music, etc.
A PCM signal recording and reproducing apparatus has been proposed that records CM signals in parallel as a plurality of tracks and reproduces them. In such a PCM signal recording and reproducing device, since it is considered to improve the quality of audio, music, etc., the number of quantizations is set to a relatively large number, for example, 16, so that 16-bit PCM signals can be recorded in parallel. A recording magnetic head device in which 16 magnetic heads are arranged and fixed in a row in the vertical direction is used to record on a magnetic tape in parallel as 16 tracks.
I configured it to play this.

In such a PCM signal recording and reproducing apparatus, it is not necessary to set the number of quantizations to 16, for example, for audio, music, etc. that do not particularly require high quality.

Purpose of the Invention In view of the above, the present invention provides a PCM signal recording device capable of obtaining high-quality audio, music, etc. as described above, which records audio, music, etc. that do not require high quality in PCM. The purpose is to be able to record for longer periods of time.

SUMMARY OF THE INVENTION The present invention is capable of effectively utilizing the recording medium by changing the feeding speed of the recording medium according to the number of quantizations of the PCM signal to be recorded.

Embodiment Hereinafter, one embodiment of the PCM signal recording apparatus of the present invention will be described with reference to the drawings.

In Figure 1, (1) indicates an audio signal source such as a microphone, radio receiver, record player, tape recorder, etc., and the audio signal from this audio signal source (1) is converted into a 16-bit quantization number of 16. 16-bit linear PCM encoder 12 that converts A-D into a PCM signal of
1 K, and an 8-bit differential PCM encoder (3) that converts the audio signal from the audio signal source-m into an 8-bit PCM signal with a quantization number of 8.
supply to.

In this case, the 16-bit linear PCM encoder (2) obtains a PCM signal of high quality audio signal. For example, in 16-bit linear PCM conversion, the clock frequency f8 is 44. When I KHz, the frequency characteristic of the audio signal is 9 in the frequency range of 20Hz to 20KHz.
8 dB, providing high quality audio.

The 16 output terminals from which 16-bit parallel PCM signals are obtained from the 16-bit linear PCM encoder (2) are connected to a switch group (4
) are respectively connected to one of the fixed contact groups (4a).

In addition, the 8-bit differential PGM encoder 3) performs differential PCM conversion, so even if the quantization number is 8 (8 bits), it is difficult to obtain a PCM signal of an audio signal that is sufficiently useful for practical use. Ru. For example, in 8-bit differential PCM conversion, when the clock frequency f5 is 44.1 JG (z), the frequency characteristic of the audio signal is 20 Hz to 20
At the frequency of KI-1z, there is a level of 78 dB, which is sufficient for practical use. This 8-bit differential PCM decoder (3)
In the output (Ill 8-bit parallel PCM
The signal can be obtained from this 8-bit parallel PC.
16 latch times 1i to store 2 clocks worth of M signals! G(3a) is supplied with 100 times, and 1 is supplied to these 2 clocks.
The latch circuit (3a) outputs an output signal from the 16 output terminals of the latch circuit (3a) every time.
The output terminals are respectively connected to the other fixed contact group (4b) of the changeover switch group (4).

16 movable contacts (4C) of this changeover switch group (4)
A recording magnetic head device (6) as shown in FIG. 2 in which, for example, 16 thin-film magnetic heads are arranged and fixed in parallel in a direction perpendicular to the running direction of a magnetic tape via a recording amplifier circuit (5). magnetic heads (6a), (6b)...
(6p) respectively. In FIG. 2, az is an erasing head, (12a) is a control signal erasing head, and (1
Reference numeral 31 indicates a reproducing magnetic head device, and this reproducing magnetic head device (13) has 16 reproducing magnetic heads (13a
), (13b) ... (13p) is the old magnetic tape)
The magnetic heads (13a), (13b) are arranged and fixed in parallel in a direction perpendicular to the traveling direction of the
p) magnetic head for recording/stopping (9a) (9b)...
The track recorded in (9p) is played back.

(13q) is a control track reproduction head.

Also, in this example, an 8-bit differential PCM encoder (3)
The signal obtained on the output side of the discrimination signal generation circuit (7) is supplied to the discrimination signal generation circuit (7), and the discrimination signal obtained on the output side of this discrimination signal generation circuit (7) is transmitted via a manually controlled connection switch (8). A control signal as shown in FIG. 2 is supplied to the tape speed control circuit (9) and the recording head (1).

In this case, the connection switch (8) is the changeover switch group (41
When the movable contacts (4c) are connected to the other fixed contacts (4b), the connection switch (8) is turned on and the changeover switch group (4) When each movable contact (4c) is connected to one of the fixed contacts (4a), the connection switch (8) is turned off.

Also, in this case, the tape speed control circuit (9)
If Ill is the maximum number of quantizations, for example 16, then if the currently selected number of quantizations N1 is, for example, 8, then the speed of the magnetic tape O1l at the time of maximum quantization is 1, and in this example, It is assumed that a discrimination signal from a discrimination signal generation circuit (7) is supplied to a tape speed control circuit (9). Other configurations are the same as before.

With the button in Figure 1, you can get high quality audio, music, etc.
When a PCM signal is recorded, each movable contact (4c) of the changeover switch group (4) is connected to one fixed contact (4a) of the changeover switch group (4) in the hole.
) and turn off the connection switch (8).

The 16-bit PCM signal obtained at the output side of the 16-bit linear PCM encoder (21) is sent to the magnetic heads (6a), (6b) and
...(6p) K is supplied, and as shown in Figure 3, 16 nodrak (Ila), (Ilb) ...(], ]p)
When recorded and played back, you can get high-quality audio, music, etc. just like before.

Next, when recording audio, music, etc. of conferences, lectures, etc. that do not require high quality, each movable contact (4c) of the changeover switch group (4) is connected to the other fixed contact (4b), and the connecting switch is connected. (8) is turned on.

In this case, the audio signal from the audio signal source (1; (6a), (6b
)...(6p), and the magnetic tape flu) has 16 tracks (lla), (llb) as shown in Figure 3.
) ・-(month p) is recorded. In this case, the discrimination signal from the discrimination signal generation circuit (7) is supplied to the tape speed control circuit (9), and this discrimination signal is recorded on the control track (1), q) of the old magnetic tape. At this time, since the output signal from (3a) is output every two clocks, the PC'
The recording density of the M signal is the same as when recording the output signal of the above-mentioned 16-bit linear PCM encoder (21).

Therefore, in this case, if the recording density of the PCM signal on the magnetic tape αυ is the same and the length of the magnetic tape (11) is 2.
Can be recorded twice as long.

When reproducing a magnetic tape (Ill) recorded using the PCM signal recording device pressure as shown in FIG. 1, a PCM signal reproducing device as shown in FIG. 4 is used. In this figure, parts corresponding to those in FIGS. 1 and 2 are denoted by the same reference numerals, and detailed explanation thereof will be omitted.

In Figure 4, 16 recorded on the magnetic tape fll+
Book truck (lla), (llb) ... (llp
) with 16 reproducing magnetic heads (13a), (13b)
...16-bit PC reproduced by (13p)
The M signal is connected via a regenerative amplifier circuit (14) to each movable contact (15a) of a changeover switch group (151) consisting of 16 changeover switches, and one fixed contact (15a) of each changeover switch group 01. 15b) 〲M column K 16 HIRA) PCMy' Coater (1e) 16 input terminals [
At the same time, the other fixed contact (15c) of each of the changeover switch group 051 is connected to 16 latch circuits (17a) provided in parallel at the front stage of the 8-bit differential PCM decoder aη.
) to their respective input terminals. 44. in the 16-bit PCM decoder f161. The audio signal is decoded in synchronization with the IKHz clock and the audio signal obtained on the output side is connected to the selector switch (one fixed contact (18a) of 181).
K supply. In addition, the 16-bit signal supplied to the 16 latch circuits (17a) is supplied 8 bits at a time to the 8-bit differential PCM decoder a71 in synchronization with the clock of 44.1 Kt (z). +
171 decoded audio signal with the selector switch (
181 to the other fixed contact (18b). The audio signal obtained at the movable contact (IRc) of this changeover switch (1 (to)) is supplied to the speaker (A) via the audio output circuit 01 for reproduction. The signal thus obtained is supplied to the discrimination signal reproducing circuit c21). This discrimination signal regeneration circuit (
When the discrimination signal is not obtained on the output side of the changeover switch group (+51), connect each movable contact (15a) of the changeover switch group (+51) to one fixed contact (15b), and connect the movable contact (]Re) of the changeover switch 081. One fixed contact (18
a) K connection, magnetic tape (11) at steady speed,
High-quality playback audio, music, etc. can be obtained.

Further, when a discrimination signal is obtained on the output side of the discrimination signal reproducing circuit (21), the tape speed control circuit (9a) is turned on, and each movable contact (15
a) is connected to each other fixed contact (] 5c),
The movable contact (18c) of the changeover switch is connected to the other fixed contact (18b), and the 8-bit differential PCM decoder (
The audio signal decoded by In is sent to the speaker (20)
is played. Therefore, in FIG. 4, it is sufficient to control and automatically reproduce a predetermined recorded audio signal according to the signal recorded by the PCM signal recording device.

Incidentally, in the above embodiment, an example in which the quantization number is 16 and 8 has been described, but it may be 10.12 instead of 80, or the maximum quantization number may be other cases. Of course, this is also a good thing. Further, the present invention is not limited to the above-described embodiment W, and it goes without saying that other configurations can be adopted without departing from the gist of the present invention.

Effects of the Invention According to the present invention, in a PCM signal recording device that can obtain high-quality audio, music, etc., if audio, music, etc. that do not require high quality are recorded using PCM, it will take a long time due to holes. can be recorded, making effective use of magnetic tape.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing an embodiment of the PCM signal recording device of the present invention, Figs. 2 and 3 are diagrams for explaining the present invention, and Fig. 4 shows an example of the PCM signal reproducing device. FIG. (1) is an audio signal source, 121 is a 16-bit linear PCM encoder, (3) is an 8-bit differential PCM encoder, (4) is a changeover switch group, (5) is a recording amplifier circuit, and (6) is a recording magnetic head device. , (7) is a discrimination signal generation circuit, (9) is a tape speed control circuit, 001 is a control signal recording head, and (If) is a magnetic tape. Agent Tei Ito 2 Susuke

Claims (1)

[Claims] A PCM signal recording device characterized in that the recording time on the recording medium is changed by changing the feeding speed of the recording medium according to the number of quantizations of the PCM signal to be recorded.