JP2524492B2 - Recording device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording apparatus, and in particular, tracks sequentially formed on a recording medium are respectively divided in a direction perpendicular to the recording direction, and different information signals are recorded in respective divided areas. Recording device

[Prior art]

Generally, when recording and reproducing an analog information signal, if the relative speed between the recording medium and the head, the characteristics of the recording medium and the head, etc. do not change, the recording and reproducing characteristics depend on the recording track width. For example, if the track width is halved, the output level will drop to 1/2 and the SN ratio will be It is said to fall. Therefore, the signal-to-noise ratio of the information also decreases accordingly.

On the other hand, the wider the track width, the better the recording / reproducing characteristics of a digital information signal such as a pulse code modulation (PCM) signal. That is, if the decrease in the SN ratio at the time of recording / reproduction due to the change in the track width is within a range in which error correction with respect to a bit error is possible, there is no problem with the decrease in the SN ratio of the information signal. Therefore, the track width required for recording the digital information signal can be determined based on this error correction capability.

FIG. 1 is a diagram showing a recording track pattern by a video tape recorder (VTR) capable of recording a PCM audio signal which has been conventionally proposed. As shown in FIG. 1, in a conventional VTR of this type, a track is formed by using the same rotating magnetic head, the track is divided into two areas in the recording direction, and one of the divided areas is recorded with a video signal. Area 1 and the other area are PCM audio signal recording area 2.
Therefore, in the conventional VTR, the track width of the PCM audio signal recording area 2 must be equal to the track width of the video signal recording area 1. Therefore, PCM signal recording area 2
However, there is a problem in that the amount of information that can be recorded cannot be increased even if there is room to narrow the track width.

〔Purpose〕

The present invention has been made in view of the above problems, and divides the recording track in a direction perpendicular to the recording direction,
It is an object of the present invention to increase the amount of information that can be recorded in a recording device that records different information signals in divided areas.

〔Example〕

An embodiment in which the present invention is applied to a VTR will be described with reference to FIGS. 2 to 7. In the figure, 3 is a cylinder drum, which is a main rotary head A1, B1 (for recording and reproducing video signals and PCM audio signals) and an auxiliary rotary head A.
2, B2 (for recording / reproducing exclusively for PCM audio signals) are arranged so as to rotate with a phase difference of 90 degrees from each other, as shown in FIGS. Auxiliary rotating head A2, B2
Has a head width corresponding to 1/2 of the track width formed by the main rotating heads A1 and B1, and is arranged so as to scan almost 1/2 of the track formed by the main rotating heads A1 and B1. . The azimuth angle is + θ degrees for the main rotating head A1 and the auxiliary rotating head B2, and −θ for the main rotating head A2 and the auxiliary rotating head B1.
It is every time.

Now, the track width formed by the main rotating heads A1 and B1 (3rd
(Indicated by Tw in the figure) is almost equal to their head width Hw, the ratio of head widths of the main rotary heads A1 and B1 and the auxiliary rotary heads A2 and B2 is naturally 2: 1.

Next, regarding the mounting height of each head (position in the direction of the rotation axis), the main rotation heads A1 and B1 are preceded by a phase difference of 90 degrees with respect to the auxiliary rotation heads A2 and B2, and the magnetic tape 4 is moved. Since tracing is performed, even if the magnetic tapes 4 are mounted at the same height, the trace position shifts by the running amount of the magnetic tape 4, that is, (1/2) Tw. Therefore, when it is desired to obtain a trace locus as described later, the head arrangement shown in FIG. 3 is used. That is, if Tw = Hw, the lower ends of the head A1 and the head A2 are at the same height, and the lower ends of the head B1 and the head B2 are shifted by (1/2) Tw. Incidentally, 4 is a recording medium such as a magnetic tape.

Next, a method of recording a video signal and a PCM signal will be described with reference to FIG.

(I) First, the main rotating head A1 (azimuth angle: + θ degree)
By this, scanning is performed at a predetermined angle with respect to the running direction of the recording medium 4, a track A is formed, and a video signal and a PCM audio signal are recorded in the respective areas 1 and 2 (FIG. 4 (a)). reference).

(Ii) Next, the auxiliary rotating head A2 (azimuth angle: -θ
The PCM audio signal recording area 2 of the track A whose degree is the same as that of (i) is scanned in parallel with the recording direction to form a track whose track width is 1/2 of the track A as shown in FIG. 4 (b). And record other PCM audio signals.

(Iii) When the scanning by the auxiliary rotary head A2 is completed,
Scanning is performed by the main rotating head B1 (azimuth angle: -.theta. Degree) to form a track B as shown in FIG. 4 (c) and a PCM audio signal and a video signal are recorded in respective recording areas. . Then, similarly to the operation in the case of (ii), another PCM audio signal is recorded in the PCM signal recording area 2 of the same track B by the auxiliary rotary head B2 (azimuth angle: + θ degree) (fourth). See FIG. (D)).

(Iv) After that, the main rotary head A1 and the auxiliary rotary head A
2. The operations (i) to (iii) are repeated by the main rotary head B1 and the auxiliary rotary head B2 to record the PCM audio signal and the video signal.

Next, a circuit configuration for realizing the above recording will be briefly described. FIG. 5 is a diagram showing a circuit configuration of this embodiment. In FIG. 5, A1, A2, B1, and B2 are heads described above, SW1 to SW4 are switching circuits for recording / reproducing switching, and SW5 to SW16 are head operations that are turned on when the control input signal is high level. It is a timing control switch.

FIG. 6 is a timing chart showing control timing signals of the control switches SW5 to SW16, and FIG. 7 is a diagram showing an example of a circuit for generating the control timing signals. SW1 to SW4
Is connected to the R-side terminal during recording and to the P-side terminal during reproduction by a mode controller (not shown).

The terminal 18 in FIG. 7 is a terminal to which a rectangular wave signal (PG) of 30 Hz which is phase-synchronized with the rotation of the heads A1, B1, A2, B2 is supplied. This PG is a signal as shown in FIG.
When (a) is high level, the head A1 is the video signal recording area 1
Is traced, and the timing is determined so that the head B1 traces the area 1 at the low level.
Therefore, SW5 and SW11 are controlled by PG (a) itself supplied to the terminal 18, that is, the output signal from the terminal 35. In addition, SW6 and SW12 are terminals 36, which is the PG (a) inverted by the inverter 19.
Is controlled by the output signal (b).

The rising and falling edges of PG (a) detected by the edge detector including the inverters 19 and 20 and the exclusive OR circuit 21 are supplied to the monomulti 22 as trigger pulses. The mono-multi 22 holds the high level for 1/90 seconds after the trigger and outputs a signal as shown in FIG. 6 (c). This signal (c) is inverted by the inverter 23, and the AND gate
Input to 25,26. The AND gates 25 and 26 are supplied with signals obtained by delaying PG (a) by the inverters 19 and 20 for a minute time, and the output signals (d) of these AND gates 25 and 26,
(E) is output from terminals 37 and 38, respectively. The control signal (d) output from the terminal 37 controls SW7 and SW13, and the control signal (e) output from the terminal 38 controls SW8 and SW14.

Further, PG (a) is supplied to a frequency doubler circuit 29 including a PLL circuit and the like to obtain a 60 Hz rectangular wave signal as shown in FIG. 6 (f). The 60 Hz rectangular wave signal (f) is supplied to a falling edge detection circuit composed of an inverter 30 and a NOR gate 31, and the falling edge detection pulse triggers the monomulti 32. The mono-multi 32 holds the high level for 1/90 seconds like the mono-multi 22 and obtains a signal as shown in FIG. 6 (g).
Further, this signal (g) is supplied to the terminals 39, 40 as a timing control signal as shown in FIGS. 6 (h) and (i) via the AND gates 27, 28 via the inverter 33. Terminal 3
Timing control signal (h) SW9, SW15 output from 9
The control signal (i) output from terminal 40 is SW10, SW16
Control each.

Recording as shown in FIG. 4 can be realized by the circuit configuration shown in FIGS.

By dividing the tracks in the PCM audio signal recording area 2 in this way, the amount of information that can be recorded in the PCM audio signal recording area can be increased.

The following signals can be considered as signals that can be recorded in the area 2 by the heads A2 and B2 with the above-mentioned configuration.

First, when the number of quantization bits of the PCM audio signal which can be recorded in the area 2 with the heads A1 and B1 is set to 8 bits, the data of the upper 8 bits is quantized by 16 bits and the upper 8 bits of the data are stored as before.
Record at A1 and B1, and record the lower 8 bits of data at Head A2,
It is possible to record at B2. With such a configuration
Recording of PCM audio signals quantized with 16 bits is possible, and high quality sound of reproduced audio signals can be realized. Further, in this case, the PCM audio signal recorded by the VTR which has only the heads A1 and B1 as usual (the signal recorded in the recording pattern as shown in FIG. 1) can be reproduced by the heads A1 and B1. Further, the PCM audio signal recorded by the VTR of this embodiment can be reproduced only in the upper 8 bits in the heads A1 and B1, and the PCM audio signals recorded in the heads A2 and B2 are not reproduced at all because the azimuth angles are greatly different. It does not become a disturbing signal. Thus, while maintaining compatibility with the conventional VTR, the VTR of the above embodiment can record a PCM audio signal with higher sound quality.

Similarly, if the sampling frequency of the PCM audio signal that can be recorded in the area 2 with the heads A1 and B1 is 30 KHz, every other sampled data is recorded with the heads A1 and B1 as in the conventional case. It can be configured to record the remaining sampled data at heads A2 and B2. In this way, if the data recorded in the heads A1 and B1 and the data recorded in the heads A2 and B2 are configured to be interlaced with each other, the conventional VT
While maintaining compatibility with R, it is also possible to reproduce higher frequency sounds.

Furthermore, it is also possible to record another channel audio signal with the heads A2 and B2, or to record another signal such as a character multiplex broadcasting signal, and in these cases, compatibility with the conventional VTR is maintained. .

Further, the main head and the auxiliary head can be integrally formed.

Further, in the above embodiment, the case where the PCM audio signal recording area is divided into two tracks has been described, but it is needless to say that the PCM audio signal recording area can be divided into three tracks or more as long as error correction for a bit error is possible.

〔effect〕

As described above, according to the present invention, the standard information signal and the information signal having a larger amount of information can be recorded using the same recording medium as the conventional one, so that the amount of recordable information is increased. be able to. Further, the standard information signal can be reproduced from the recording medium on which the two information signals are recorded, by the conventional device, without interference by the information signal having a larger information amount.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of a recording pattern by a conventional recording / reproducing apparatus, FIG. 2 is a top view showing an embodiment of the present invention and an example in which a head is attached to a cylinder, and FIG. 4A, 4B, 4C, and 4D are views showing an example of the recording pattern by the head shown in FIG. 2, and FIG. FIG. 6 shows a circuit configuration of the embodiment, and FIG. 6 shows a control switch SW.
FIG. 7 is a timing chart showing the control timing signals of 5 to SW16, and FIG. 7 is a diagram showing an example of a circuit for generating those control timing signals. A, B …… Track A1, B1 …… Main rotation head A2, B2 …… Auxiliary rotation head 1 …… Video signal recording area 2 …… Pulse code modulation signal recording area 4 …… Recording medium

Claims (1)

(57) [Claims] 1. A first rotary head and a second rotary head having different azimuth angles and rotating with a phase difference of 180 °, and head widths narrower than those of the first rotary head and the second rotary head, respectively, and
A third and a fourth rotary heads having different azimuth angles and rotating with a phase difference of 180 °. The first and second rotary heads have different azimuth angles between adjacent tracks for a predetermined period. A recording / reproducing apparatus capable of recording / reproducing a standard information signal to / from a tape-shaped recording medium by forming one helical track on each of the adjacent recording tracks, which is provided between adjacent tracks by all of the first to fourth rotary heads. The information signal having a larger amount of information than the standard information signal is recorded on the tape-shaped recording medium by forming two helical tracks in the predetermined period so that the azimuth angles are different from each other. Recording / playback device.