JPH01258202A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To obtain a clear picture at the time of reproducing by constituting a revolving erase head in composite structure with a revolving audio-head and freely switching the supply of an erasing current to the revolving erase head and the supply of a control voltage to a movable video head. CONSTITUTION:At the time of standard mode recording, the tape pattern of each head and the passing position of revolving erase heads 5a and 5b are shown in a figure. Then, after a track, which is formerly recorded, is exactly erased by the revolving erase head 5a, a picture is recorded by an audio-head 2L. After the next record is erased by the revolving erase head 5b, a sound is recorded by an audio-head 4L and next, the picture is recorded by a video head 2R. At the time of insert end, the track, which is formerly recorded, is exactly erased by the erase head 5b and after that, the sound is recorded by the head 4L. Further, the picture is recorded by the video head 2R and at this time point, the recording is finished and the track is linked to the preceding recording track which follows the track. At the time of three-times mode recording, after the record is erased, the recording of the sound and picture is started with being delayed by one period and 11/2 period.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a video tape recorder (
Regarding a magnetic recording/reproducing device applied to a magnetic tape (hereinafter referred to as a VTR), a movable video head configured to be movable in the width direction of a magnetic tape so as to match a recording track during special playback such as still playback or slow playback. The present invention relates to a magnetic recording/reproducing device equipped with the following.

[Prior Art] Fig. 8 is a plan view showing an outline of a rotating drum device in a conventional magnetic recording/reproducing device. In the figure, (1) is a rotating drum, and (2L) and (2R) are for standard mode. The video heads (+6L), +6R) are video heads for 3x mode, and both of these heads (2L), (2R1 and (6tl, +6R1) are integrated into one.(
4L), +4R1 is the audio head, (5) is the rotating erase head, (3) is the balancer, and this balancer (3) is the
) has a rotation angle of 180° with respect to the rotary erasing head (5).

Each of the above heads +2L), +2R), (6t), +6
R), +4L,).

A specific numerical example of the head width of (4R) and (5) and the mounting dimension to the rotating drum (1), that is, the step difference, is as shown in FIG.

Next, the operation of the above configuration will be explained.

The tape pattern of each head and the passing position of the rotary erasing head (5) during standard mode recording are as shown in FIG. 10, and during this standard mode recording, as shown in the timing chart of FIG. 5) After accurately erasing the track recorded on "J",
Audio is recorded in the audio head (4R) with a delay of 1/3 period, and then recorded in the video head (2L) with a delay of 1/3 period.
The image is recorded. Furthermore, at the end of the insert, the previously recorded track is accurately erased by the rotating erase head (5), and then audio recording is finished with a delay of 5/6 cycles, and video recording is started with a further 1/3 cycle delay. ends and connects with the previously recorded track that follows it.

The tape pattern of each head and the passing position of the rotary erasing head (5) during 3x mode recording are as shown in Fig. 11, and during this 3x mode recording, the rotational erasing head (5) passes as shown in the timing chart of Fig. 12. After the previously recorded track is erased by the head (5), audio recording starts with a delay of 1/3 cycle, and video recording starts with a further delay of 1·+1/31 cycle. Furthermore, at the end of the insert, after the previous recording track is completely erased by the rotating erase head (5), one recording of the audio is completed with a delay of 2.(5/6) cycles, and then the recording of the audio is completed with a delay of 1.+1/31 cycles. Recording of the video ends after a delay and is connected to the previous track that follows.

Furthermore, regarding the operation of the above configuration, FIGS.
This will be explained with reference to l.

In Fig. 14, (8) is the magnetic tape, (vl) is the normal feeding speed of the magnetic tape (8), and the relative trajectory drawn on the magnetic tape (8) by the video head is the 14th
As shown in figure (a), (Al) and the interval (P)
is the track pitch. By the way, the tape feed speed (Vl) during still playback when the tape feed speed is zero
corresponds to O, and the relative trajectory at that time is (A1).

Next, during slow playback when the feed speed is (Vs), the 14th
As shown in Figure (b), a relative trajectory (As) is obtained. In other words, the video head has a relative trajectory (
^), that is, the recorded trace is not accurately traced and becomes a shifted trajectory (As), which lowers the signal level picked up by the head and causes noise.

As described above, the configuration shown in FIG. 8 has the disadvantage that color noise, color bleeding, audio noise, etc. occur at the joint portion and the insert portion, and good image and sound quality cannot be obtained.

A movable video head is used to solve this problem. FIG. 13 is a plan view showing an outline of a conventional rotary drum device equipped with a movable video head.The magnetic recording/reproducing device shown in the same figure is designed to move the video head to a magnetic tape during playback in order to improve the playback image quality. The movable video head is configured to be movable in the width direction of the magnetic recording track so as to faithfully trace the magnetic recording track.

In FIG. 13, (7R) and (7R) are the movable video heads, and other components that are the same as those in FIG. 8 are given the same reference numerals, and detailed explanation thereof will be omitted.

Now, as shown in Fig. 14(c), the movable head (7L) (
By moving the head R) from the fixed position in the direction of the arrow TT1, that is, in the width direction of the tape (8), and changing the trajectory of the head from (7A) to (7AI), the magnetic tape (8) and the head +7L), ( Match the relative trajectory of 7R) with TA). Even at other tape feed speeds than slow playback,
By moving the head in accordance with the feed speed, it is possible to make the relative trajectory coincide with tA), and clear image quality without noise can be obtained even at a speed other than the normal feed speed.

Regarding the drive method for controlling the movable video heads f7L) and f7R), an actuator using an electromagnetic method or a piezoelectric element is usually used as an actuator for moving the head in the tape width direction. However, the head is installed in the part that is displaced by the applied voltage. Further, the applied voltage is supplied to the actuator through a brush that is in contact with the shaft of the rotating drum +13.

[Problem to be Solved by the Invention 1] In the conventional magnetic recording and reproducing apparatus configured as described above, a movable head is used together with a video head and an audio head for reproduction in order to eliminate noise during variable speed reproduction. If this configuration is adopted, there is a problem that there is not enough space to install a rotary erasing head, which is necessary to improve the image quality and sound quality at the time of splicing and inserting.

This invention was made to solve the problems mentioned in -F. With a simple configuration, a movable head and a rotary erasing head can be installed, and it is possible to remove noise during variable speed playback and perform recording such as splicing. The purpose of the present invention is to provide a magnetic recording/reproducing device with good image quality and sound quality during editing.

[Means for Solving the Problems] A magnetic recording/reproducing device according to the present invention includes a composite head having a composite structure of a rotary audio head and a rotary erasing head, a movable video head movable in the width direction of a magnetic tape, and a rotary audio head and a rotary erasing head. and is configured to be freely switchable between a state in which a control voltage is supplied to the movable video head through a brush brought into contact with the shaft of the rotating drum during playback, and a state in which an erasing current is supplied to the rotary erasing head through the brush during recording. It is characterized by what it did.

[Function] According to the present invention, during recording, by supplying an erasing current to the rotating erasing head through the brush,
It securely erases previously recorded tracks, prevents color noise, color bleeding, and audio noise from occurring in splices and inserts, allowing you to record with good image and sound quality.

Also, during playback, by supplying a control voltage to the movable head 5 through the brush, the movable head is always aligned with the recording track even during variable speed playback such as slow playback, resulting in clear image quality without noise. can be played.

[Embodiment of the Invention] Hereinafter, an embodiment of the present invention will be described based on the drawings.

FIG. 1 is a plan view showing an outline of a rotating drum device in a magnetic recording/reproducing apparatus according to an embodiment of the present invention. In the same figure, (+1 is a rotating drum, +2L1.
is a standard mode video head (6L).

(6R) is a video head for 3x mode, (7L),
+7R) is a movable video head, and this movable video head f7Ll, +7R) is configured to be movable in the width direction of the magnetic tape via an actuator to be described later.

+4L), 14R) are audio heads, (5a)
, 15b) are rotating erasing heads, one rotating erasing head (5a) is configured with an audio head (4L), and the other rotating erasing head (5b) is configured with an audio head (4R) in a composite integral structure. , these composite heads are the video head +2L) +6R) , (2
R), +6L) has a rotational angle delay of 60°.

Each of the above heads (2L1. (2R), (6L), (6
R), +4L).

The head width of (4R), (5a), and (5b) and the height difference in mounting to the rotating drum (1) are as shown in FIG. 2 when expressed as a specific numerical example.

Next, the operation of the above configuration will be explained.

The tape pattern of each head during standard mode recording and the passing position of the rotating erase head (5a), (sbl) are as shown in Figure 3, and during standard mode recording, the rotating After accurately erasing the previously recorded tracks using the erasing head (5a), audio is recorded using the audio head (4R), and video is further recorded using the video head (2L).Next, the rotating erasing head (5b) ) to erase the next recording track, the audio head (4L) records the audio, and then the video head (2R) records the video. Also, when the insert is finished, the rotating erase head (5b) erases the previous track. After accurately erasing the recorded tracks, the audio head +4L+-e audio is recorded.
Furthermore, video recording is performed by the video head (2R), and by ending the recording at this point, it is connected to the previous recording track that follows.

The tape pattern of each head and the passing position of the rotary erase head (5) during 3x mode recording are as shown in Figure 4, and during this 3x mode recording, the rotational erase head (5) passes as shown in the timing chart of Figure 5. After the previously recorded track is erased by the head (5a), audio recording starts with a delay of one cycle, and video recording starts with a further delay of 1/31 cycles.Furthermore, when the insert ends, After completing erasing of the previous recorded track by the rotary erasing head (5b), recording of audio ends with a delay of 2 cycles, and recording of video ends with a delay of 1/31 cycle, and the following Connect with the truck.

By the control operation as described above, good image quality and sound quality without color noise, color bleeding, audio noise, etc. in the joint portion and the insert portion can be obtained.

Figure 6 shows a movable video head (7L), +78) and a rotary erasing head (5a) in the magnetic recording/reproducing apparatus having the above configuration.
) and (5b), in which (7L1) and (7Rl) are movable video heads (7L3, +7R1 actuator coils,
(5all.

(5bl) is the actuator coil of the rotating erasing heads (5a) and (5b), (10) is the brush that is in contact with the shaft of the rotating drum (1), and tl+1. +123 is a capacitor that prevents DC voltage from being applied to the actuator coils (5al) and (5bl), (14)
~(16) is a relay.

(+3L), (13R) is a movable video head (7L)
, (7R), (1
7) is an oscillation circuit for erasing current, and (18) is a driving circuit for erasing current. Each of the relays (14) to (16) is configured to switch to the fR1 side during recording and to the Pl side during playback. ing.

Next, the operation shown in FIG. 6 will be explained.

During recording, each relay (14) to (16) is (R1
Since the erase current generated in the oscillation circuit (17) is switched to the drive circuit (18) and the relays (14) to (1)
6) Rotating erasing head (5a) through the brush (lO)
, (5b). At this time, the actuator coil (7) of the movable video head +7Ll, [7R]
LI], (The inductance of 7R11 is the rotary elimination bed (5a), (5b) of the actuator coil (5
al), (5bl), the actuator coil (几+3.
(The current flowing to the 7R11 side can be ignored.

Then, when each relay (14) to (16) switches to the (P) side during playback, the control voltage generation circuit +13Ll
.

The control voltage generated at (+3R) is applied to relays (!4) to (
15), the movable video head (7) through the brush (10)
L), (7R) actuator coil +711)
, (TRI).
Through a process similar to that shown in , reproduction with clear image quality and no noise is achieved. At this time, the rotating erasing head (5a)
.

Actuator coil (5al) of (5b), (5
DC blocking capacitor (II) on the bl) side, +121
exists, this actuator coil (Il+,
(No current flows to the +21 side.

In the above embodiment, during recording, the erasing current is passed through the relay (15) to the coils (5all, (5bl)).
However, similar effects can be obtained by arranging the supply through the relay (14) as shown in FIG.

[Effects of the Invention] As described above, according to the present invention, the rotating erasing head is configured in a composite structure with the rotating audio head, and
By configuring the supply of erase current to the rotary erase head and the supply of control voltage to the movable video head to be switchable, it is possible to install the rotary erase head and the movable video head side by side with a simple structure. As a result, it is possible to obtain clear images without noise during variable speed playback, and good image and sound quality can be obtained during recording and editing such as splicing and inserting.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing an outline of a rotating drum device in a magnetic recording/reproducing apparatus according to an embodiment of the present invention, FIG. 2 is an explanatory diagram showing the width of each head and an example of the step difference in mounting to the rotating drum, and FIG. 3 , Figure 4 is an explanatory diagram of the track pattern, and Figure 5 is an explanatory diagram of the track pattern.
The figure is a timing chart showing the control operation during recording.
7 is a block diagram of a drive system according to another embodiment. FIG. 8 is a plan view showing an outline of a rotating drum device in a conventional magnetic recording/reproducing device. Figures 10 and 11 are explanatory diagrams showing the width of each head and examples of mounting steps on the rotating drum. Figures 10 and 11 are explanatory diagrams of the track pattern of the one shown in Figure 8. Figure 12 is an explanatory diagram of the conventional track pattern shown in Figure 8. A timing chart showing control operations during recording by a magnetic recording/reproducing device, FIG. 13 is a cross-sectional view showing an outline of a rotary drum device showing another conventional example, and FIGS. 14(a) to 14(f).
c) is a track pattern diagram for explaining the operation of the movable video head. (1)...Rotating drum, +2L), (2R)...
Video head for standard mode, (4L1. (4R1...
・Audio head, (5ali5bl ・, Rotating erase head, (6L), (6R) ・Video head for 3x mode, (7L1. +7R1...Movable video head, (10)...Brush, (+31. ), ++3
R)... Control voltage generation circuit, (14) to (15)...
・Relay, (17)... Erasing current oscillation circuit. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Claims] (1) A composite head with a composite structure of a rotating audio head and a rotating erasing head, a movable video head configured to be movable in the width direction of the magnetic tape so as to match the recording track during playback, and an axis of a rotating drum during playback. A magnetic recording/reproducing apparatus comprising drive switching means for supplying a control voltage to the movable video head through a brush brought into contact with the movable video head and supplying an erasing current to the rotary erasing head through the brush during recording.