KR0141015B1 - Multi channel magnetic recording and reproducing apparatus - Google Patents

Abstract

The present invention relates to a magnetic recording and reproducing apparatus which reverses phase shift directions of multi-channel color signals recorded in one track pitch to eliminate color signal interference between recording patterns between channels.

According to the present invention, one track can be controlled by controlling the phase shift direction as long as recording mono (EP) when recording a multi-channel video, even when the tape speed during recording and playback is a standard mode, and when recording a single video signal. By reversing the phase shift directions of the two-channel color signals recorded within the pitch, the color signal interference between the recording patterns between the channels is eliminated during playback, and both channels have the same azimuth angle and phase shift direction as the standard mode head of the VCR. The color signal of the two-channel video signal can be perfectly reproduced.

Description

Multi-channel Magnetic Recording and Reproducing Equipment

1 is a block diagram showing a conventional multi-channel magnetic recording and reproducing apparatus

FIG. 2 is a recording pattern diagram in which multiple channels are recorded on a tape by FIG.

3 is a block diagram showing a multi-channel magnetic recording and reproducing apparatus of the present invention.

4 is a recording pattern diagram in which multiple channels are recorded on a tape by FIG.

* Explanation of symbols for the main parts of the drawings

11, 12: recording processing unit 13: recording phase control unit

21,22: recording mode selector 31 to 36: head

41, 42: playback mode selection section 51, 52: playback processing section

53: playback phase control unit Tp: track pitch

Gb: Guardband Ct: Control Track

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic recording and reproducing apparatus capable of multichannel recording and reproducing at one track pitch. In particular, a phase shift direction of color signals of a plurality of channels recorded in one track pitch is reversed. A multi-channel magnetic recording and reproducing apparatus for eliminating color signal interference of the present invention.

In a typical video cassette recorder (hereinafter referred to as a VCR), the tip of the head touches the tape surface to record or reproduce. At this time, the portion where the magnetic flux is discharged out of the head at the tip of the head is called a gap. The length of this gap is the track width for recording and reproduction.

Incidentally, the angle between the gap direction of the recording head and the gap direction of the reproduction head is referred to as Azimuth.

At this time, when the track is recorded on the tape and the head is shifted during playback, the signal of the adjacent track is also reproduced, resulting in a bit on the screen.

Therefore, in order to eliminate the leakage of the signal from this adjacent track, that is, the crosstalk, a combination of the gradient azimuth recording method and the color signal processing method using line correlation is used.

Here, inclined azimuth recording is a method of recording the gaps of two heads (for example, A and B) differently, wherein the A and B heads are 180 on a rotating drum. It is mounted facing each other.

That is, when the angles of the gaps of the two video heads A and B are inclined by a certain angle in the reverse direction with respect to the trace direction of the head, they are alternately recorded on the tape as angles corresponding to the respective heads.

At this time, the Video Home System (hereinafter referred to as VHS) VCR sets the azimuth angle θ to 6 The two heads simultaneously have azimuths in opposite directions.

For example, A head left 6 Ramen, B head to the other direction is right 6 Has an azimus.

On the other hand, during playback, the head A traces the track recorded by the head A by the operation of the servo, and the head B traces the track recorded by the head B. Therefore, even if the head is shifted to the adjacent track, azimuth loss causes Crosstalk signals from adjacent tracks are suppressed.

Here, azimuth loss means that when the gap direction of the reproducing head is inclined by a predetermined angle with respect to the gap direction of the recording head, the reproduction output decreases as compared with the case where the gap directions of both heads coincide.

On the other hand, since the chroma signal is recorded with 40F _H low-conversion, the azimuth loss alone does not sufficiently suppress the crosstalk.

Therefore, the crosstalk is eliminated with respect to the color signal by the phase shift method.

At this time, the phase shift direction is defined according to the azimuth angle of the head. In other words, if the azimuth angle of the head is positive, the phase is shifted by 90 degrees every 1H in the clockwise direction. Record while shifting the phase gradually.

Thus, for a VHS VCR, 180 Since the head pair having a difference is controlled by head switching, the phase shift direction is automatically reversed for each track on the recorded tape.

Therefore, if the phase is returned to its original state by reverse operation during reproduction, color signal interference (crosstalk) with adjacent tracks can be reduced.

On the other hand, multiheads (for example, 4 heads) are employed to improve the image quality during special playback.

That is, a pair of heads A 'and B' for a long time mode (Extend Play; EP) in addition to a pair of heads A and B for a wide standard mode (SP) having azimuth inverse to each other is placed on a rotating drum. I place it at right angles.

At this time, in the standard mode SP, since the recording head is 58 µm in track width as the wide dedicated head, the SN ratio is improved and high quality is obtained as compared with the recording and reproduction method in the narrow common head. In the long time mode EP, the switch is used for a narrow storage head.

Using this method, recording and playback are performed on the dedicated heads of the standard / long time modes (SP / EP), and both the standard and long time modes (SP / EP) can perform double speed playback and high speed picture search.

In addition, if the recording mode is different, the tape traveling speed also changes, and the pitch of the video track recorded on the tape also changes.

1 is a block diagram showing a conventional multi-channel magnetic recording and reproducing apparatus for simultaneously recording and playing two broadcast channels on one tape by adding another rotating head pair to the multi-head. 5-199488.

Referring to FIG. 1, a first recording processor 11 for converting a first video signal into a recordable signal and a second recording processor 12 for converting a second video signal into a recordable signal are configured.

The first recording processor 11 is connected to a switching unit 21 for selecting two channels and a long time mode (2CH / EP) or a standard mode (SP) according to a recording mode signal. At this time, since two-channel simultaneous recording must be performed in the dedicated head for a long time, the two-channel output terminal 2CH and the long-term mode output terminal EP are commonly connected.

Accordingly, the first rotation head pairs 31 and 32 for the long time mode are mounted on the two channels and the long time mode output terminal 2CH / EP of the switching unit 21, and the standard mode output terminal SP is used for the standard mode. Head pairs 33 and 34 are mounted.

The second recording processor 12 is also connected to a switching unit 22 for selecting two-channel recording.

The second channel output terminal 2CH of the switching unit 22 is provided with second pairs of rotary heads 35 and 36 for a long time mode.

In this case, the first rotation head pairs 31 and 32 have an azimuth angle inverse relationship with each other, the relative position is at 1 to 80 degrees, and record the first image signal. The first rotational head pair 31 and 32 have the same azimuth angle, the relative position is 180 degrees, and the same rotational plane as the first rotational head pair 31 and 32 N, where N is 1 to 180 degrees. It is arranged in a positional relationship to record the second video signal.

On the other hand, the first rotary head pair (31, 32) and the standard head pair (33, 34) has a switching unit 41 for selecting the two-channel and long time mode (2CH / EP) or standard mode (SP) during playback The switching unit 41 is connected to a first reproducing processor 51 for reproducing a signal picked up by the head pair 31, 32 or 33, 34.

The second rotary head pair 35 and 36 is connected to a switching unit 42 for selecting a two channel mode (2CH) during reproduction, and the switching unit 42 is connected to the head pair 35 and 36. A second reproduction processing unit 52 for processing to reproduce the signal picked up by the is connected.

At this time, the control signal is configured to record information in synchronization with the vertical synchronizing signal of any one of the first and second video signals on the control track Ct.

Here, the first rotary head pairs 31 and 32 and the standard mode pairs 33 and 34 mounted on the rotating drum are used in the conventional HiFi VHS VTR for public use, and the second rotary head pair 35, Only 36 is added on the rotating drum for two-channel recording.

In FIG. 1 configured as described above, the video signals are two channels, and video signals of the first and second channels are input through the respective input terminals 1 and 2. At this time, the video signal of the first channel input to the input terminal 1 is processed by the recording processor 11 for recording.

This is the same as the recording process of a conventional home VCR. That is, the luminance signal is subjected to processing such as emphasis, FM modulation, and the color signal is converted to a low frequency.

When the two channel and the long time mode (2CH / EP) are selected by the switching unit 21, the first video signal passing through the recording processing unit 11 has a track width at the track pitch at + θ and -θ. The first rotary head pairs 31 and 32 which are narrower than 1/2 are supplied and recorded on the tape.

On the other hand, the video signal of the second channel is subjected to the processing necessary for recording in the recording processing unit 12. At this time, the recording process is the same as that of the recording processing unit 11 above.

In addition, when the two-channel mode 2CH is selected by the mode signal in the switching unit 22, the second image signal passing through the recording processing unit 12 has the azimuth angle + θ and − through the switching unit 22. At θ, the track width is supplied to the second pair of rotary heads 35 and 36 narrower than half the track pitch and recorded on the tape.

On the other hand, the reproduction head at the time of reproduction uses the same head as the recording head. Therefore, when the two-channel and long time mode (2CH / EP) is selected by the switching 41, the first video signal is picked up from the tape by the first rotary head pairs 31 and 32, and the second image signal is picked up by the switching unit 41. In the first reproduction processing section 51, the magnetic signal is converted into an electrical signal, and this electrical signal is amplified and demodulated.

Then, when the two channel mode (2CH) is selected by the switching unit 42, the second video signal is picked up from the tape by the second rotary head pair (35, 36) and the second reproduction through the switching unit 42 In the processing unit 52, the magnetic signal is converted into an electric signal, and the electric signal is amplified and demodulated.

That is, the first and second reproduction processing units 51 and 52 perform the same reproduction processing (de-emphasis, FM demodulation, color frequency conversion, etc.) as in the conventional VCR.

At this time, the outputs of the first and second reproduction processing units 51 and 52 are selected by the user, and the selected reproduction signal, that is, the video signal of the first channel or the video signal of the second channel, is displayed on the screen.

On the other hand, the recording track when the first and second video signals are recorded on the tape by the first and second rotating heads 31, 32, 35 and 36 will be described with reference to FIG.

Here, when recording two-channel video signals, the servo system of the VCR is set to the standard mode. For example, in the VHS-VTR, the track pitch in the standard mode is 58 mu m, and the tape speed is set to 3.3 cm.

The track widths of the first and second rotary heads 31, 32, 35, and 36 are set to about 26 mu m, which is smaller than 1/2 of the track pitch.

That is, the first and second rotary head pairs 31, 32, 35, 36 are set to 26 µm, which is slightly narrower than 1/2 of the track pitch of 58 µm in the standard mode in order to be used for the long time recording mode. In addition, the azimuth angle is set to + θ of the heads 31 and 36 and -θ of the heads 32 and 35.

At this time, in consideration of the recording state, the first video signal is alternately track pitch Tp by the heads 31 and 32 alternately between the track ① having an azimuth angle of + θ and the track ③ having an azimuth angle of -θ. Records each track sequentially. In addition, the tracks 2 and 4 are alternately recorded at the track pitch Tp by the heads 35 and 36 mounted on the same rotational surface as the heads 31 and 32, respectively.

Here, the azimuth angles are different between ① and ②, ③ and ④ tracks to prevent interference between the two video signals.

In other words, Tp denotes the track pitch in the standard mode, and the video signals of channels 1 and 2 are track width approximately 1/2 and the azimuth angle by the heads 31 and 35 within one track pitch. The tracks 1 and 2 are recorded, and then the heads 32 and 36 record the signals of both channels at an azimuth angle of ± θ as the tracks 3 and 4.

Therefore, as the track pattern on the tape, each track is arranged like (1) in channel 1, (2) in channel 2, (3) in channel 1, and (4) in channel 2.

At this time, since the track width of each head is 26 µm and the track pitch is 58 µm, a 6 µm non-recorded area becomes possible, and if the mounting position of the head is set so that the position is between tracks in which the motion angles are continuous, The guard band 6 is enabled between the tracks 2 and 3, and between the tracks 1 and 4, i.e., between the tracks of the same azimuth angle.

This guard band 6 is an area where no signal is recorded, and suppresses crosstalk of the luminance signal.

The servo system is set to the standard mode at the time of reproduction of the tape recorded in such a track pattern, and the video signals of channel 1 are sequentially reproduced by the first and third track signals by the first rotating heads 31 and 32. The video signals of channel 2 are sequentially reproduced by tracks 2 and 4 by the second rotating heads 35 and 36.

Thus, the above-described FIG. 1 enables not only standard mode and long time mode recording and reproducing of a conventional VCR, but also recording and reproducing of a two-channel video signal.

However, the first diagram described above equalizes the recording processing units 11 and 12 for processing the video signals of the channel 1 and the channel 2 so that the phase shift directions of the color signals are the same as those in FIG. Becomes the same.

Therefore, when the tracks ① and ③ are reproduced by the heads 31 and 32, interference due to the color signals of the tracks ② and ④ appears, and when the tracks ② and ④ are reproduced by the heads 35 and 36, the tracks ① and ③ are displayed. There was a problem in that interference by color signals appeared.

In addition, although the video signals of the channel 1 and channel 2 recorded in FIG. 1 are reproducible in the VHS VCR standard mode, the recorded pattern is a phase shift direction between tracks having different azimuth angles (for example, ①② track and ③④). Since the same phase) is the same as the phase shift direction of the normal VCR standard mode head and the azimuth angle, only one of the video signals of channel 1 or channel 2 is used, and the video signals of the other channel have different phase shift directions. Since color signals of other channels cannot be reproduced, video signals of channels with different standard mode heads, azimuth angles, and phase shift directions have a problem of outputting black and white images.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a phase shift direction such as a long time mode when recording a two-channel video signal even when the tape speed is a standard mode, and a standard mode when recording a single video signal. By eliminating the phase shift directions of the two-channel color signals recorded in one track pitch to each other, the color signal interference between the recording patterns between the channels is eliminated, and the color signals of all the two-channel video signals are perfectly reproduced. A channel magnetic recording and reproducing apparatus is provided.

A feature of the present invention for achieving the above object is that the relative position in the same azimuth relationship with the first rotating head pair and the first rotating head pair where the gap azimuth angle is 180 degrees relative to each other in an inverse relationship with each other. A multi-channel magnetic recording and reproducing apparatus in which two tracks are formed at one track pitch in a standard mode by a second rotational head pair at 180 degrees to record and reproduce a plurality of video signals. A first recording processor for reproducing the first video signal by forming a track of 2n-1 (n = 1,2,3,4 ...) on the tape by the first rotary head pair; A second playback signal and a second video signal input to form a track of 2n (n = 1, 2, 3, 4 ...) on the tape by the second rotary head pair to record the second video signal; A second recording processor, a second reproduction processor for reproducing the same, and one track pitch of the standard mode; Phase control for generating phase control signals to the first and second recording processing units and the first and second reproducing processing units so that the phase shift directions of the color signals between the formed (2n-1) th tracks and the 2nth tracks are inversed to each other. The point is comprised by means.

Hereinafter, with reference to the accompanying drawings, a preferred embodiment of the present invention will be described in detail.

3 is a block diagram of the multichannel magnetic recording and reproducing apparatus of the present invention.

Referring to FIG. 3, the first and second recording processing units 11 and 12 converting the video signals of the two channels into a recordable form, and the first rotation in which the relative position is 180 degrees from the gap azimuth angle in inverse relationship with each other. Head pairs 31 and 32, standard mode dedicated head pairs 33 and 34, and first rotary head pair 35 having a relative position of 180 degrees in an azimuth relationship with the first rotary head pairs 31 and 32. 36, the first and second reproduction processing units 51 and 52 for converting the signals picked up through the heads 31 to 36 into a reproducible form, and a switching unit for selecting two channels or a single mode during recording or reproduction. Since the configuration of (21, 22, 41, 42) is the same as that of the above-described first diagram, the same reference numerals are used and description thereof will be omitted.

That is, FIG. 3 is a phase control signal connected to the first and second recording processing units 11 and 12 to control a phase shift direction of a color signal according to a mode signal during recording. And a phase control signal connected to the recording phase control unit 13 outputting the signal to the first and second reproducing processing units 51 and 52 to control the phase shift direction of the color signal according to the mode signal during reproduction. The first and second reproducing phase control sections 53 output to the second reproducing processing sections 51 and 52 are provided in FIG.

According to the present invention configured as described above, video signals of the first and second channels are input through the respective input terminals 1 and 2. In this case, the image signal of the first channel input to the input terminal 1 is processed by the recording processing unit 11 such as an emphasis, FM modulation, and the like, and the color signal is converted to a low frequency.

In addition, the video signal of the second channel input to the input terminal 2 is the same as the first recording processing unit 11 for recording in the second recording processing unit 12, the luminance signal is processed such as emphasis, FM modulation, etc. And the color signal is converted to a low frequency.

At this time, the recording phase control unit 13 controls the phase shift direction of the color signals of the first and second recording processing units 11 and 12 according to the mode signal, that is, whether it is a multichannel mode or a short channel mode.

That is, in the two-channel mode, the recording phase controller 13 controls the phase control signal such that the color signal phase shift direction of the first recording processor 11 and the color signal phase shift direction of the second recording processor 12 are reversed. Is generated and output to the first and second recording processing units (11, 12).

At this time, since the two-channel mode, the input terminal of the switching probe 21 is connected to the two-channel and long-term mode output terminal (2CH / EP) according to the mode signal, the input terminal of the switching unit 22 is a two-channel output terminal It is connected to (2CH).

Accordingly, in the video signals of the first and second channels passing through the first and second recording processing units 11 and 12, the phase shift directions of the color signals are reversed, so that the first channel rotates the video signals in the first rotation. The data is recorded on the tape by the head pairs 31 and 32, and the video signal of the second channel is recorded on the tape by the second rotation head pairs 35 and 36.

At this time, when recording video signals of two channels, the servo system of the VCR is set to the standard mode.

For example, in the VHS-VCR, the track pitch of the standard mode is set to 58 µm and the tape speed is set to 3.3 cm, and the track widths of the first and second rotary heads 31, 32, 35, and 36 are 1 of the track pitch. It is set to about 26 µm smaller than / 2.

Thus, as shown in FIG. 4, the speed of the tape is the standard mode, and the first video signal is tracked by the first rotational head pair 31 and 32 with the azimuth angle + θ and the azimuth angle. Each track is sequentially recorded at the track pitch Tp, and a second image signal is mounted on the first rotating head pairs 31 and 32 and the rotating surface. 36, tracks (2) having an azimuth angle -θ and tracks (4) having an azimuth angle + θ are alternately recorded at track pitch Tp.

Here, Tp denotes the track pitch in the standard mode, and the video signals of the channel 1 and the channel 2 are shifted by the heads 31 and 35 in one track pitch, and the track width is about 1/2, and the azimuth angle is ± θ. The tracks 1 and 2 are recorded, and then the heads 32 and 36 record the signals of both channels at an azimuth angle of ± θ as the tracks 3 and 4.

That is, the tracks 1 and 3 are formed by the first rotation head pairs 31 and 32, and the tracks 2 and 4 are formed by the second rotation head pairs 35 and 36. At this time, azimuth angles are different between adjacent tracks without the guard band Gb (for example, between ① and ②, ③ and ④ tracks) to prevent interference between the two video signals, and adjacent tracks with the guard band Gb. The liver (eg, between ② and ③, between ④ and ① tracks) is formed with the same azimuth angle.

On the other hand, in the phase shift direction of the color signal, as shown in Fig. 4, the phase shift directions are reversed between the tracks ①, ②, ③, and ④ having different azimuth angles, and have the same azimuth angles ② and ③. The phase shift direction is the same between the tracks ④ and ①.

That is, the signals recorded by the heads 31 and 36 having + θ azimuth angle are clockwise, and the signals recorded by the heads 32 and 35 having −θ azimuth angle are every 1H in the counterclockwise direction. The phase shift direction of the color signal was changed by 90 °. Thus, it is compatible with conventional VHS VCRs.

On the other hand, in the tape recorded in the above track pattern, the servo system is set to the standard mode at the time of reproduction, and the reproduction head is the same as the recording head.

At this time, in the two-channel mode, the output terminal of the switching unit 41 is connected to the two channel / long time mode input terminal 2CH / EP according to the mode signal, and the output terminal of the switching unit 42 is connected to the two channel input terminal 2CH. Since the first video signal is picked up from the tape by the first rotation head pairs 31 and 32, de-emphasis, FM demodulation, color frequency conversion, etc. are performed in the first reproduction processing unit 51 through the switching unit 41. do.

The second video signal is picked up from the tape by second pairs of rotary heads 35 and 36, and de-emphasis, FM demodulation, color frequency conversion, etc. are performed by the second playback processing unit 52 through the switching unit 42. Is performed.

That is, the first video signal is sequentially reproduced by the first and third track heads 31 and 32, and the second video signal is reproduced by the second rotary heads 35 and 36. The track signal is played back in sequence.

The outputs of the first and second reproduction processing units 51 and 52 are selected by the user, and the selected reproduction signal, that is, the video signal of the first channel or the video signal of the second channel, is displayed on the screen.

At this time, the reproduction phase control unit 53 outputs a phase control signal for changing the color signal phase shift direction in the opposite direction to the recording time to the first and second reproduction processing units 51 and 52 to restore the original video signal. It removes the color signal interference of other video signals coming from adjacent tracks.

That is, the signal reproduced by the heads 31 and 36 having a + θ azimuth angle is counterclockwise, and the signal reproduced by the heads 32 and 35 having a −θ azimuth angle is clockwise every 1H. The phase shift direction of the color signal was changed by 90 °. Thus, it is compatible with conventional VHS VCRs.

On the other hand, when the mode signal is a single image signal recording mode, since the switching unit 22 is connected to the ground, no signal is recorded by the second rotation head pairs 35 and 36. Therefore, when the first switching unit 21 is connected to the two channels and the long time mode (2CH / EP), a single video signal is recorded on the tape in the long time recording mode (EP) by the first rotating head pairs 31 and 32. When the standard mode SP is connected, a single video signal is recorded on the tape in the standard mode SP by the standard head pairs 33 and 34.

Therefore, it is compatible with a normal VHS VCR.

In addition, the present invention makes it possible to reproduce the multichannel video signal recorded on one tape in the standard mode using the standard mode heads 33 and 34, thereby making it compatible with the conventional VHS VCR.

As described above, according to the multi-channel magnetic recording and reproducing apparatus according to the present invention, even if the tape speed at the time of recording and reproducing is the same as the long time recording mode (EP) when recording two channels, the standard mode when recording a single video signal. By controlling the phase shift direction as in (SP), the phase shift directions of the two-channel color signals recorded in one track pitch are reversed to each other, thereby eliminating the interference of the color signals between the recording patterns between the channels at the time of reproduction. Since the standard mode head and the azimuth angle and the phase shift direction are the same, the color signal of the two-channel video signal is perfectly reproduced.

Claims (3)

In the normal mode, the first rotary head pair has a relative position of 180 degrees in an inverse relationship with the gap azimuth angle, and the second rotary head pair has a relative position of 180 degrees in an azimuth relationship with the first rotary head pair. A multi-channel magnetic recording and reproducing apparatus in which two tracks are formed at one track pitch to record and reproduce a plurality of video signals. A first recording processing unit for recording a first video signal by forming a track of 1 (n = 1, 2, 3, 4 ...), a first reproducing processing unit for reproducing the same, and a second video signal receiving the second video signal; A second recording processor for recording a second video signal by forming a track of 2n (n = 1, 2, 3, 4 ...) on the tape by two rotational head pairs, and a second reproduction processor for reproducing the same; The color signal between the (2n-1) th track and the 2nth track formed at one track pitch in standard mode. Phase shift the multi-channel magnetic recording and reproducing apparatus orientation is inversely related to each other is established consisting of the phase control means for generating a phase control signal to the first and second recording and processing the first and second playback processing. The multi-channel magnetic recording and reproducing apparatus according to claim 1, wherein the first recording processing unit has an inverse relation between the (2n-1) th track and the 2nth track formed at one track pitch of the standard mode. . The multi-channel magnetic recording and reproducing apparatus according to claim 1, wherein a guard band is formed between tracks in which the same azimuth angle is continuous in the recording pattern recorded by the first recording processing section.