JPS6379480A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To respectively record and reproduce a video and a sound substantially with four heads by forming audio tracks on the deep layer part of a magnetic layer by a sound only head and forming video tracks on a surface layer part by a video only head. CONSTITUTION:Four sets of double azimuth heads 2-5 attached and fixed at equal angular intervals of 90 deg. on the rotating plane of a rotating body 1. The double azimuth head 2 is constituted of the video only head V1a and the sound only head A1a and other heads are constituted of the same members. The respective double azimuth heads 2-5 have the video only head (V) and the sound only head (A) fixed separately to ends divided and formed into two branches of a head support 10. The azimuth angles for the video only head (V) and the sound only head (A) are respectively formed to + or -6 deg., + or -30 deg. and the audio tracks are formed on the deep layer part of the magnetic layer of a magnetic tape and the video tracks are formed on the surface layer.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a magnetic recording/reproducing device, and particularly to a magnetic recording/reproducing device that uses two magnetic tapes.
9 on a rotating body that is wound over an angular range of 70
The present invention relates to a magnetic recording and reproducing device that records and reproduces information signals in a standard mode using four rotary heads mounted at equal angular intervals of 0°.

Conventional technology Conventionally, magnetic tape has an angular range of 270° (actually, the angular range for overlap recording is added to this, so it is larger than 270°, but in this specification, for convenience, the angular range is 270°).
This will be explained assuming that it is 0°. ) A helical scan system in which video signals are recorded on a magnetic tape and played back using four rotating heads mounted at equal angular intervals of 90" on a rotating body that is wound diagonally across the length of the magnetic tape. A magnetic recording/reproducing device based on this method is known.

According to this magnetic recording/reproducing device, the magnetic tape can be rotated at 180°.
Video signals are recorded and played back on the magnetic tape by two rotating heads placed opposite each other on the rotating surface of a rotating body that is wound obliquely over an angular range of . By increasing the rotational speed of the rotating body by 3/2 and selecting the tape running speed, the diameter of the rotating body can be reduced to 2/3 times that of other conventional magnetic recording and reproducing devices. Moreover, it has the advantage that it is possible to form tape patterns that are completely compatible with each other.

Problems to be Solved by the Invention However, in the above-mentioned four-head magnetic recording/reproducing apparatus, since the audio signal was recorded by a fixed head, the quality of the reproduced audio signal was not sufficient.

For this reason, it is conceivable to record and reproduce audio signals using a rotary head. In this case, either the frequency-division multiplexed signal of the frequency-modulated audio signal and the video signal is recorded simultaneously using the same rotating head, or the frequency-modulated audio signal is recorded in the deep part of the magnetic layer of the magnetic tape using the audio QJ rotating head. It has been known for a long time that However, in the former method, the band of audio signals to be recorded and reproduced is limited by the video signal, and an audio signal separation filter or the like is required.

The latter method does not have the above problems, but when applied to the 4-head magnetic recording/reproducing device, the number of heads that can be attached to the same rotating body becomes 8, resulting in so-called head striking. jitter will increase. Also,
There is a problem in that a space is required to mount the rotary head exclusively for audio, and the number of man-hours required for drilling the head mount hole increases.

The present invention was created in view of the above points, and it records video signals and audio signals respectively using essentially 4 heads.
An object of the present invention is to provide a magnetic recording/reproducing device that can reproduce data.

Means for Solving the Problems The magnetic recording and reproducing apparatus of the present invention comprises a rotating body in which four sets of double azimuth heads, each consisting of a video-only head and an audio-only head having different azimuth angles, are mounted at equal angular intervals of 90 inches. A magnetic tape is wound over an angular range of 270 degrees, and an audio-only head forms an audio track in the deep part of the magnetic layer of the magnetic tape, and a video-dedicated head forms a video track in the surface part of the magnetic layer. do.

Function: After the audio tracks 1 to 1 in which audio signals are recorded in the deep part of the magnetic layer of the magnetic tape are formed by the above-mentioned audio dedicated head, the audio track is A video track on which a video signal is recorded by a dedicated video head is formed on the surface layer of the magnetic layer at a certain position. −
A set of double azimuth heads can be attached and fixed to the rotating surface of a rotating body in the same manner as one rotating head.

In addition, the audio-dedicated head is placed at the head track center relatively higher than or at the same height as the video-dedicated head by a track pitch corresponding to the audio track pre-recording time, and the track width of the video-dedicated head is arranged at the same height as the video-dedicated head. The track width of the audio-only head is selected to be less than or equal to the track width of the video-only head.

Embodiment FIG. 1 shows the head arrangement, etc. of a first embodiment of the apparatus of the present invention. In the figure, four sets of double azimuth heads 2, 3, 4, and 5 are fixedly mounted on the rotating surface of a rotating body 1 at equal angular intervals of 90°. The double azimuth head 2 consists of a video-only head 1a and an audio-only head A1a, and similarly, the double azimuth heads 3, 4, and 5 are video-only heads V.
2a, V1b and V2b and audio dedicated heads A2a, A1
b and A2b. The heads v1a and Vlb each have a gap of, for example, an azimuth angle of +6°, and the heads V2a and V2b each have a gap of, for example, an azimuth angle of −6°. Further, the heads Ala and Alb each have a gap of, for example, an azimuth angle of +30°, and the heads A2a and A2b each have a gap of, for example, an azimuth angle of −30”. That is, the double azimuth head 2
~5 consists of two heads each having a gap of the same azimuth angle.

A magnetic tape 6 is attached to a guide ball 7 on the circumferential surface of the rotating body 1.
and 8 and a tape guide formed on a fixed drum (not shown), so that the tape is wound obliquely over an angle range of 210°. Each of the above-mentioned double azimuth heads 2 to 5 has a structure as shown in FIG. has been done.

Since the head support 10 is divided into two parts, the relative height of both heads V can be finely adjusted. In addition, the space for the head support 10 fζJIJ is
Mounting one rotary head in a conventional two-head VTR takes up the same amount of space.

Next, various examples of double azimuth heads will be explained. The above-mentioned double azimuth heads 2 to 5 have the same relative positional relationship between the two heads except for the difference in the combination of azimuth angles. This will be explained with reference to FIGS. 6 to 6.

FIGS. 3A, 3B, and 3C show the head height positional relationships of the first to third embodiments of the double azimuth head 2, respectively. In FIGS. 3(A) to (C), for example, NTSC
When recording color video signals, one of the recording tracks
The track pitch (track pitch corresponding to the recording time of one field) is 58 .mu.m in the standard mode, and the track width of the video dedicated head V1a is selected to be 58 .mu.m, which is equal to this track pitch. Furthermore, since the audio track is recorded in advance and the video track is superimposed and recorded, the track width of the audio-only head A1a is selected to be an appropriate value less than or equal to the track width of the video-only head V1a.

Further, the track width of the audio-only head A1a needs to be wider than a predetermined width because it is necessary to obtain a C/N ratio above a certain level.

Furthermore, in order to ensure compatibility, it is desirable that the track center lines of the video track and the audio track coincide. Therefore, since the double azimuth head starts sliding on the magnetic tape every 1/3 field at equal angular intervals of 90°, the height of the audio-only head Ala is increased by the track pitch corresponding to the audio head advance recording time. It is better to make it higher than the dedicated head Via.

Furthermore, in consideration of tape compatibility with existing audio deep recording type VTRs, the azimuth angles of the video-only head and audio-only head should be similar to the azimuth angles of the video-only head and audio-only head of the above-mentioned VTR (for example, ± 6°, ±3
Of course, the preceding recording time of the audio track with respect to the video track recorded at the same location on the magnetic tape must be within O~2 fields, and +6°(
A video track recorded with a head with an azimuth angle of -6°) and an audio track recorded with a head with an azimuth angle of -30° (+30°) need to be recorded at the same location. Each of the embodiments shown in FIGS. 3(A) to 3(C) satisfies these conditions.

In the first embodiment shown in FIG. 3 (A>), the head V1a and the head Ala are at the head track center, and the 1983 μm head A1a is located at a higher position than the head Via.The above 19.3 μm is The track pitch (58x1/3) corresponds to the recording time of 1/3 field.Here, during recording, the video dedicated head Via
2b, the video signal (specifically, for example, a frequency division multiplexed signal of a low-Vi converted carrier color signal and a frequency-modulated luminance signal is the same for two or less) in the time relationship as shown by the solid line in FIG. 5(A). is selectively supplied, and the audio dedicated head Ala
-A2b is selectively supplied with the audio signal @ (specifically, for example, the frequency modulated audio signal 2 and below is the same) in a time relationship as shown by the broken line in FIG. 5 (Δ).

As a result, as shown in FIG. 4(A), the audio signal is transferred to the magnetic tape by the audio dedicated head A2a, which is attached 90 degrees ahead of the video dedicated head V1a, which is 1/4 rotation of the rotating body 1. 1/4 rotation from the recording start point of audio track "A2" recorded in the deep part of the magnetic layer of
In other words, the track pitch is 19.3μ in 1/3 field.
After a delay (recording time corresponding to m), a video l-rack Tv'+, in which a video signal is recorded on the surface layer of the magnetic layer by the video dedicated head Via, begins to be formed on the audio track T^2. Here, the 1-to-rack center lines of the video track "Vl" and the audio track "TA2" are coincident. Also, recording of the video track "Tv1" and the audio track "A2" is started at the same time.

Thereafter, according to this embodiment, a track pattern as shown in FIG. 6 (Δ) is formed in the same manner.

In FIG. 6 (A>, track T, “V2a
'1a TVlb, then TV2b, video dedicated head V1a.

A video track with a 1-rack pitch of 58 μm, in which video signals are recorded for each field by V2a, Vl b, and V2b, is formed on the surface layer of the magnetic layer.
Tracks TA2a, TA1b, TA precede the field.
□l) ' Audio dedicated heads A2a and A in the order of TAla
An audio track is formed in the deep part of the magnetic layer by lb, A2b, and Ala.

Next, in the second embodiment shown in FIG. 3<8), the head V1a
and head A1a is the head track center, 58μ
The head A1a is located at a higher position than the head V1a by m. Further, the distance from the lower end of the head V1a to the lower end of the head A1a is selected to be hl. Video signals are selectively supplied to the heads 1a to V2b in the time relationship shown by solid lines in FIG.
Audio signals are selectively supplied to a to A2a in the time relationship shown by broken lines in FIG. 5(B).

As a result, as shown in FIG. 4(B), the head Via records and forms video tracks T and 11 on the surface layer of the magnetic layer, and at the same time, the head Ala records and forms an audio track "A11" on the deep layer of the magnetic layer. After 1 field, head V2a moves to audio track TV1 on the surface of the magnetic layer at the same position as 11.
2 is formed.

Video track T, 12 and audio track T A1
The center lines of both tracks of No. 1 coincide.

In the same manner, according to this embodiment, a track pattern as shown in FIG. 6(B) is formed.

In FIG. 6(B), the same components as those in FIG.
a, TV2a is the track T, T of FIG. 4(B)
The track TA1a corresponds to the 4th V11
Vl2 Corresponds to track "A11" in Figure (B).

Next, in the third embodiment shown in FIG. 3(C), the head V1a
and head A1a are Herad Truck Center, 96.
The head Ala is located higher than the head V1a by a track pitch of 6 μm, that is, corresponding to 5/3 field recording time. Further, the distance from the lower end of head V1a to the lower end of head Ala is selected to be h2. For heads V1a-V2b, see FIG.
), video signals are selectively supplied to heads Ala to A2a in a time relationship as shown by solid lines, and audio signals are selectively supplied to heads Ala to A2a in a time relationship as shown by broken lines in FIG. 5(C).

As a result, as shown in FIG. 4(C), the video track TV21 is recorded on the surface layer of the magnetic layer by the head V1a, and the audio track TA21 is magnetically recorded by the head A1b 2/3 field ahead of this. The audio track is recorded 573 fields after the start of recording of audio track TA21.
A video track T, 22 begins to be formed by the head V2a in the surface layer portion of the magnetic layer at the same position as A21. The track center lines of the video track TV22 and the audio track A21 are aligned.In the same manner, according to this embodiment, a track pattern as shown in FIG. 6(C) is formed. In FIG. 6(C), the same components as those in FIG. 6(A) are given the same reference numerals, and their explanations are omitted. Note that the tracks 'Vla and V2a are the tracks 'V21 and V21 in FIG. 4(C), respectively. Equivalent to TV'22, 1-rack"
Alb corresponds to track "A21" in FIG. 4(C).

Although the above has been an explanation of the embodiment related to the head arrangement shown in FIG. 1, the present invention can also be applied to the head arrangement shown in FIG. In FIG. 7, the same components as those in FIG. 1 are designated by the same reference numerals, and their explanations will be omitted. On the rotating surface of the rotating body 1, there are four sets of double azimuth heads 12, 13, 14 and 15.
are installed at equal angular intervals of 90 inches.The double azimuth heads 12 to 15 each consist of a video dedicated head and an audio dedicated head, each having a gap of an azimuth angle in an opposite direction.

Examples in which the above conditions are satisfied at the head position shown in FIG. 7 will be described with reference to FIGS. 8 to 11. The double azimuth heads 12 to 15 have the same relative positional relationship except for the combination of azimuth angles, and the video dedicated heads V1a to V2b are respectively installed at the same height position, so the double azimuth heads are 12 will be explained as an example.

The fourth embodiment shown in FIG. 8(A) is a video-dedicated head V1a.
and the audio-only head A2a are arranged so that the track centers of both heads coincide.

Video signals are selectively supplied to the heads V1a to V2b in the time relationship shown by the solid line in FIG. 10(A), and to the heads A1a to A2b, the video signal is selectively supplied in the time relationship shown by the broken line in FIG. 10(A). The audio signal is selectively supplied.

As a result, as shown in FIG. 9A, the head A2a records and forms the lower audio track 41 in the deep part of the magnetic layer, and at the same time, the head V1a records and forms the video track TV41 in the surface part of the magnetic layer. In this embodiment, the recording time difference is 0.

Video track” V41 and audio track TA4
The center lines of both tracks of No. 1 coincide. In the same manner, according to this embodiment, a track pattern as shown in FIG. 11(A) is formed. Figure 11 (A), Figure 6 (
Components that are the same as those in A) are given the same reference numerals and their explanations will be omitted. In addition, in FIG. 11(A), the track TVi
a corresponds to the track TV41 in FIG. 9(A), and track TA2a corresponds to the track TA41 in FIG. 9(A).

Next, in the fifth embodiment shown in FIG. 8(B), the head V1a
and head A2a is the head track center, 38.
The head A2a is located at a higher position than the head V1a by 7 μm. Further, the distance from the lower end of head Vla to the lower end of head A2a is selected to be h3. Video signals are selectively supplied to the heads V1a to V2b in the time relationship shown by the solid line in FIG. 10(B), and to the heads Ala to A2a, the video signal is selectively supplied in the time relationship shown by the broken line in FIG. 10(B). The audio signal is selectively supplied.

As a result, as shown in FIG. 9(B), an audio track TA51 is recorded in the deep layer part of the magnetic layer by the head A2b shown in FIG. The video track "VS2" is inserted into the head V1a of FIG.
is formed.

Video track TV51 and audio track T^51
The center lines of both tracks coincide. Similarly below,
According to this embodiment, a track pattern as shown in FIG. 11(B) is formed. In Figure 11 (B), Figure 11 (
Components that are the same as those in A) are given the same reference numerals and their explanations will be omitted. In addition, in FIG. 11(B), the track “Vl
a corresponds to the track "VS2" in FIG. 9(B), and track T^2b corresponds to the track TA51 in FIG. 9(B).

Next, in the sixth embodiment shown in FIG. 3(C), the head V1a
and head A1a is the head track center, 77.
The head A2a is located at a higher position than the head Via by a track pitch corresponding to 3 μm1, that is, 4/3 field recording time. Further, the distance from the lower end of the head Via to the lower end of the head A1a is selected to be h4. For heads V1a-V2b, see FIG.
The video signals are selectively supplied to the heads A1a to A2a in the time relationship shown by the solid line in C), and the audio signals are selectively supplied to the heads A1a to A2a in the time relationship shown by the broken line in FIG. 10C.

As a result, as shown in FIG. 9(C), the head v1a records and forms the video track TV61 on the surface portion of the tat'1 layer, and precedes this by 1/3 field as shown in FIG. An audio track T A61 is recorded and formed in the deep part of the magnetic layer by the head Δ1a, and a video track is recorded by the head V2a in the surface part of the magnetic layer at the same position as the audio track A61 after 4/3 field from the start of recording of the audio track T and 61. Tv6□ begins to be formed.The track center lines of the video track TVO2 and the audio track 1°A61 are aligned.In the same manner, according to this practical example, as shown in FIG.
A track pattern as shown in ) is formed. In FIG. 11(C), the same components as those in FIG. 11(A) are given the same reference numerals, and their explanations will be omitted. Note that in FIG. 11(C), the track Tv1a.

"V2a is the track "VS2", "V" in FIG. 9(C)
The track T1a corresponds to the track "A61" in FIG. 9(C).

Note that during playback, the playback signals that are played back simultaneously from three sets of double azimuth heads that are sliding on the magnetic tape at the same time can be switched in the same way as during recording to obtain playback output in the same order as the recording order. can. Further, although the above description was about recording an NTSC color video signal in the standard mode, the present invention can be similarly applied to an apparatus that records and plays back a PAL or SECAM color video signal in the standard mode. Can be applied. Note that when the tape running direction and the head scanning direction are approximately opposite directions, the audio-dedicated head is placed lower than the video-dedicated head.

Effects of the Invention As described above, according to the present invention, substantially four heads allow
After recording the audio signal in the deep part of the tape magnetic layer, the video signal can be recorded in the surface part of the tape magnetic layer at the same position.This allows extremely high quality playback compared to the conventional 270° winding 4-head VTR. It is possible to obtain audio signals, there is no increase in jitter due to head striking, the head installation space is the same as conventional equipment, and the number of man-hours for drum processing can be almost the same as conventional equipment. .

[Brief explanation of the drawing]

FIG. 1 is a plan view showing the head arrangement of the first embodiment of the device of the present invention, FIG. 2 is a perspective view showing an embodiment of the double azimuth head configuration of the device of the present invention, and FIGS. C
) are diagrams showing respective examples of the height positional relationship of the two heads constituting the double azimuth head of the device shown in FIG. 1, and FIGS. C) An enlarged view of the main part of the track pattern obtained by the device having the head configuration shown in FIG. 5 (A) to (C) are respectively similar to FIGS.
6(A) to (C) are diagrams schematically showing the selective supply of signals to the double azimuth head having the configuration shown in FIG. FIG. 7 is a diagram showing the track pattern of the second track pattern of the device of the present invention.
Plan views showing the head arrangement etc. of the embodiment, FIGS. 8(A)-(
C) is a diagram showing each example of the height positional relationship of two heads constituting the double azimuth head of the illustrated device in FIG. 7, and FIGS. 9(A) to (C) are respectively FIG. 8(A) 10(A) to 10(C) are enlarged views of the main parts of the track patterns obtained by the apparatus having the head configuration shown in 1 to 10C, respectively.
A diagram schematically showing the selective supply of signals to the double azimuth head configured as shown in FIG. 11(A) to (C).
) are diagrams showing track patterns produced by the apparatus having the head configurations shown in FIGS. 8(A) to 8(C), respectively. 1...Rotating body, 2-5.12-15...Double azimuth head, 6...Magnetic tape, Vl a, Vl b
. V2a, V2b...head dedicated to video, △1a. Al b, A2a, A2b... Heads exclusively for audio. Patent Applicant Victor Company of Japan Co., Ltd. Figure 1 Figure 2 Figure 5 (A) (C) Figure G Figure 1n (C) Figure il1

Claims (2)

[Claims] (1) Four sets of double azimuth heads are installed at equal angular intervals of 90° on the rotating surface of a rotating body around which a running magnetic tape is wound over an angular range of 270°, and each set of double azimuth heads is composed of a video-only head and an audio-only head with different azimuth angles, and an audio track in which an audio signal is recorded in the deep part of the magnetic layer of the magnetic tape is recorded by the audio-only head of each of the four sets of double azimuth heads. The 4-layer film is formed on the surface layer of the magnetic layer.
A video track on which a video signal is recorded is formed by the dedicated video head of each set of double azimuth heads, and during playback, each recorded signal of the audio track and video track is played back by the four sets of double azimuth heads. A magnetic recording/reproducing device characterized by: (2) Of the video-dedicated head and the audio-dedicated head constituting each set of double azimuth heads, the audio-dedicated head is moved at the head track center for a track pitch corresponding to the pre-recording time of the audio track with respect to the video track. The video-dedicated head is placed relatively high or at the same height as the video-dedicated head, and the track width of the video-dedicated head is selected to be one track pitch or less of the video track, and the audio-dedicated head is placed at the same height as the video-only head. 2. The magnetic recording and reproducing apparatus according to claim 1, wherein the track width is selected to be less than or equal to the track width of the video-dedicated head.