JPS5853422B2 - Kirokusai Seisouchi - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic recording/reproducing device, particularly a video tape recorder, capable of recording or reproducing audio and images by running a relatively wide tape at very low speed.

For example, video recorders (V, T, R) are classified into fixed head type and rotary head type based on the scanning method on the tape.

Among these, in the fixed head system, in order to improve resolution and wow/flutter, the tape speed is increased as much as possible to improve performance.

Therefore, it is unreasonable because it consumes an extremely large amount of tape compared to the recording time.

On the other hand, the rotating head method was devised to eliminate the drawbacks of the fixed head method, and by using the so-called helical scan method, it is possible to obtain images with good tape utilization, low distortion, and good resolution.

However, on the other hand, it requires a precise follow-up mechanism for the rotating head part, and the tape loading structure is also complicated, making it difficult to provide it at a low price.

In view of these points, the present invention provides a novel magnetic recording and reproducing device, in particular V, T, which can obtain almost the same effect as a rotating head system using a fixed head system with a relatively simple structure.
Its purpose is to provide R.

In order to achieve this object, the present invention adopts the following basic configuration.

First, a tape is wound so-called α around the circumferential surface of a comparatively large rotating drum, the rotating drum is rotated at high speed, and the tape is wound at a very low speed, and the head portion is fixed to the outside of the rotating drum.

The above-mentioned tape is wound around a supply tape cartridge mounted inside the rotating drum and a take-up tape reel having a rotation axis in the direction of the rotation axis of the supply tape cartridge. The tape is taken up by the slow rotation of the tape reel on the take-up side, and back tension is applied to the tape cartridge on the supply side so that a very constant speed transfer can be achieved.

Further, a tracking control device is disposed in the head section in order to correctly follow the recording track of the tape during playback.

FIGS. 1, 2, and 3 show a plan view, a front view, and a central vertical cross-sectional view of essential parts of an example of a magnetic recording/reproducing apparatus to which the present invention is applied.

In the figure, 1 is a main drum that rotates at high speed, 2 is a drive motor (first motor) directly connected to the main drum, 3 is a supply tape cartridge, 4 is a take-up reel, and 5 is a drive for the take-up reel. Each motor (second motor) is shown.

As will be described later, this second motor 5 is not driven during recording or normal playback, but is driven only for special purposes such as fast-forward playback, slow playback, still playback, and reverse playback.

Reference numeral 6 indicates a magnetic tape, which is wound around the supply side tape cartridge 3, wound on the main drum 1 in an α shape, and transferred at a very low speed to the take-up side reel 4 during recording or reproduction. Ru.

Reference numeral 7 denotes a head assembly, which includes a servo head for controlling tape tracking as the main drum 1 rotates at high speed, a recording/reproducing head, and an erasing head.

As shown in FIGS. 3 and 4, the main drum 1 is composed of a rim-shaped tape guide section 11 and a cartridge receiving section 12 on the supply side.

A helical tape guide recess 13 is provided on the outer surface of the tape guide section 11 so that the tape 6 can be wound approximately once around the circumference of the main drum 1.

Further, one end of the tape guide recess 13 is connected to a first tape guide 14 for guiding the tape to the supply side tape cartridge 3, as shown in FIG. 1, and the other end is connected to the take-up side reel 4, as shown in FIG. It is connected to a second tape guide 15 for guiding the tape.

In FIG. 1, reference numeral 16 denotes the tape 6 to which the first tape guide 14 is attached and the tape 6 of the supply tape cartridge 3.
Shows the relief recess for pulling out.

As shown in FIG. 6, the first tape guide 14 has a flange 17 formed at its upper part, which restricts the upper part of the tape 6 drawn out from the supply tape cartridge 3.

Further, a pair of detection parts 18 for end sensors of the tape 6 are embedded in this guide 14.

Referring again to FIG. 1, reference numeral 22 denotes a tape fixing pinch roller, which corresponds to the first tape guide 14 and is used to prevent unnecessary feeding of the tape 6.

Reference numeral 23 indicates a pressing spring/support shaft that supports the pinch roller 22.

Note that the end of the tape 6 is connected to the supply side tape cartridge 3.
and a tape 6 corresponding to the detection section 18.
Aluminum foil or the like is pasted at the location.

A tube body 19 is attached to the starting end of the tape 6.

FIG. 7 is a diagram showing a state in which the tape 6 and the leader tape 20 are connected.

A pin 21 is provided at the end of the leader tape 20 to be fitted into the tubular body 19 of the tape 6, and the tape 6 wound around the supply side tape cartridge 3 is guided by the leader tape 20 to the main drum. 1 and then loaded onto the take-up reel 4.

As shown in FIGS. 2 and 3, the tape cartridge receiving portion 12 on the supply side includes a boss portion 26 that supports the rotating shaft 2a of the first motor 2, and a recessed stepped portion 2 continuous to the boss portion 26.
7 is provided.

Two slip rings 28 for detecting the end sensor of the tape 6 are formed concentrically on the upper surface of the boss portion 26.

29 is the lead wire, which runs from the boss part 26 to the recessed step part 2.
7 is buried and connected to the pair of detection sections 18 described above.

A pair of brushes 35 are in contact with the end sensor detection slip rings 28, respectively.

For example, a plunger solenoid and a DC power source are connected to the terminals of the pair of brushes 35.

Thus, when the plunger solenoid is "on" (at the end of the tape 6), the brake 25 for the first motor 2 is activated.

In FIG. 4, a hole 30 provided at a lower position of the boss portion 26 is provided for fitting the take-up reel 4.

Reference numeral 31 indicates a pair of support shafts installed on the bottom plate of the recessed stepped portion 27, and as shown in FIG. I support it.

Therefore, a relief portion 34 is provided in a portion of the recessed step portion 27 so that the flairsha roller 32 can roll into contact with the rim portion 4a of the take-up reel 4.

Reference numeral 24 indicates a pin installed on the bottom plate of the recessed step portion 27, and this pin 24 connects the supply side tape cartridge 3 to the main drum 1.
This is a guide pin when installing the

For this purpose, the cartridge 3 is formed with a recess into which the pin 24 is fitted (see FIG. 1).

The supply tape cartridge 3 is composed of a winding frame 36 and a cover 37, as shown in FIGS. 3 and 8.

The winding frame 36 has a substantially U-shaped cross section, and its center hole 38
is formed to match the outer diameter of the boss portion 26 of the main drum 1.

In FIG. 3, numeral 39 indicates a brake for stopping the winding frame 36.

The cover 37, which freely rotates with respect to the winding frame 36, has a substantially inverted cross section, and is provided with a drawer portion 40 for holding and pulling out the starting end of the magnetic tape 6 wound around the winding frame 37. ing.

As shown in FIG.
A recess 41 for guiding the tape and a long hole 42 for the tape are formed.

Earlier, it was explained that back tension is applied to the supply side tape cartridge 3 when it is mounted on the main drum 1 and driven, but specifically, as shown in FIG. A third flare roller 44 is provided at the bottom thereof, which is fitted onto the boss portion 26 of the main drum 1 via a felt pad 43 and which rolls into contact with the second flare roller 23.

Therefore, the back tension is applied to the supply tape cartridge 3 via the felt pad 43 by the rotation of the first, second, and third flare rollers 32°33.44 as the take-up reel 4 rotates at a slow speed. This is obtained by rotating the tape in the direction opposite to the tape transport direction.

As shown in FIG. 3 and FIG.
A belt 48 is passed between a pulley/friction wheel 4T fitted concentrically to the rotating shaft 2a of the motor 2, and a first belt pulley 49 and a first belt pulley 49 in rolling contact with this pulley/friction wheel 47. A belt 51 is passed between the second belt pulley 50 and an idler 53 which is in rolling contact with the pulley 52 of the second belt pulley 50.
is configured such that it is in rolling contact with the rim 54 of the take-up reel 4.

The idler 53 is rotatably attached to the free end of a lever 56 that rotates around the shaft 55 of the second belt pulley 50.

Although the lever 56 is always prevented from contacting the rim 54 of the take-up reel 4 by the tension spring 5T, it comes into contact with the rim 54 of the take-up reel 4 due to centrifugal force only when the main drum 1 rotates at high speed. (The example in Figure 5 shows the main drum 1.
(indicates a stopped state).

Reference numeral 58 denotes a rotating disc directly connected to the rotating shaft 2a of the first motor 2, on which shafts 59.55 of the first and second belt pulleys 49.50 are mounted, and furthermore, a lever stop pin 60 is mounted.
has been planted.

Reference numeral 61 indicates a centrifugal force type sub-brake for the main drum 1, which is an L-shaped bar 62 with a brake lining 63 provided at one end and a weight 64 provided at the other end.

The L-shaped bar 62 has a support shaft 65 that is erected from the rotating disk 58.
It is rotatably fitted to the

Reference numeral 66 denotes a tension spring, which, as shown in FIG.
When the main drum 1 rotates at high speed, the centrifugal force of the weight 64 acts to release the brake against the force of the spring 66.

Reference numeral 67 indicates the main brake of the take-up reel 4 (see FIG. 3), and reference numeral 68 indicates the brake of the second motor 5.

The head assembly 7 is constructed as shown in FIGS. 9 and 10.

That is, this head assembly 7 has a head arm 73 rotatably attached to a horizontal shaft 72 protruding from a base 71.
has been established.

The head arm 73 includes a first link 75 that rotates around a support shaft 75a having a tracking control permanent magnet 74 attached to one end thereof, a second ring 76 connected to the first link 75, and a second ring 76 connected to the first link 75. It consists of a head mount 77 attached to the tip of a link 76.

A tracking control voice coil 78 corresponds to the permanent magnet 74.

The main drum 1 is mounted on the head mount 77 as shown in FIG.
The recording/reproducing head 80, the first and second tracking servo heads 81, 82, and the erasing head 8
3 are arranged.

The arrangement of the respective heads will be explained in detail with reference to FIG. 11.

Reference numeral 6a indicates a recorded track of the magnetic tape 6, and 6b indicates a joint of the magnetic tape 6, the left half of which represents the start point of the track, and the right half thereof the end point of the track.

First and second tracking servo heads 81.82
The center-to-center distance d is set to p(n+α) [where p track pitch, n is a positive integer, and α is O (α<p/2]), and tracking control is performed also at the seam 6b. I'm trying to make it happen.

In this case, the first and second tracking servo heads 81 and 82 are positioned at different positions relative to the transport direction of the tape 6 to compensate for the lack of a horizontal synchronizing signal near the seam 6b of the tape 6. There is.

The distance between the tracking servo head 81 and the recording/reproducing head 80, and the distance between the tracking servo head 82 and the recording/reproducing head 80 are integral multiples of the distance corresponding to the horizontal synchronization signal. be selected.

Again in FIGS. 9 and 10, reference numeral 85 indicates a head retraction mechanism for separating the head mount 17 from the circumferential surface 1a of the main drum 1.
and a tension spring 88.

The permanent magnet 87 is provided at the lower end of the head arm 73 so that the head arm 73 rotates about the horizontal axis 72 when the coil 86 is excited.

Reference numeral 89 indicates a stopper, and reference numeral 90 indicates a recess thereof.

FIG. 12 shows a block diagram of a tracking control circuit that drives the head assembly 7 during reproduction.

In the figure, 91 and 92 indicate envelope detectors of the first and second tracking servo heads 81 and 82, respectively, to which control signals for the first and second heads 81 and 82 are supplied.

The output terminals of these detectors 91 and 92 are connected to the input terminal of a difference detection circuit 93.

This difference detection circuit 93 is supplied with a difference signal generated as a difference between the signals based on the track deviation of the first and second tracking servo heads 81 and 82.

Therefore, while the recording/reproducing head 80 is faithfully tracing a predetermined track as shown in FIG.
The output of 3 becomes zero.

The output terminal of this difference detection circuit 93 is connected to the input terminal of a band limiting circuit 94.

This band limiting circuit 94 is for adjusting input transient response characteristics, gain, etc.

The output end of the band limiting circuit 94 is connected to an amplifier 96 via a switch 95, and further connected to the tracking control voice coil 78 of the head assembly 7 described above.

78a indicates its terminal. The switch 95 is turned on momentarily (
For example, it is necessary to cancel the tracking control at 0.1 m5) and bring the head track position of the tape 6 to the reference position of the head assembly 7, so when the tracking control is canceled, the tracking control voice coil 78 is set to the reset reference This is a selector switch that supplies voltage.

FIGS. 13 to 15 are explanatory diagrams for recording and reproducing audio and video. In this case, in consideration of the tape usage rate, audio and
It uses a video signal multiplex modulation method.

First, an NTSC color video signal having a frequency spectrum as shown in FIG. 13A is supplied to the input terminal 101 shown in FIG.
FM signal with a frequency deviation of Hz, while the first
The audio signal as shown in FIG.
6 and using a carrier of about 0.7 MHz, A
M signals are obtained, and eventually a superimposed signal as shown in FIG. 14 is obtained.

This signal is then supplied to the recording/reproducing head 80 and recorded on the tape 6.
recorded in

Reproduction of the tape is performed according to the block diagram shown in FIG. 15B.

That is, the output signal from the recording/reproducing head 80 is supplied to a video signal output terminal 109 via a bandpass filter 107 and an FM demodulator 108, and is also supplied to an audio signal output terminal via a bandpass filter 110 and an AM demodulator 111. 112.

In addition, instead of explaining the above-mentioned audio and video signal multiplex modulation method, the video signal is separated into a luminance signal and a chrominance signal, and the chrominance signal is low-frequency converted to about IMHz. , the audio signal is made into an AM signal using a carrier of about 0.5 MHz, which is lower than the low frequency conversion color signal, and these three types of modulated signals can be recorded on the tape 6 in a superimposed manner.

In addition, the video recording/reproducing head 80 of the head assembly 7
A new audio recording/playback head is installed at a position shifted one track pitch from the position of
Audio can be recorded in parallel with the video signal at the same time.

In this case, tracking control during playback is performed based on the video track, and an audio-only erasing head can be provided separately in the video playback state.

Furthermore, like the conventional V, T, and H, an audio recording/reproducing head is provided near the first tape guide 14 of the main drum 1, and the signal from the recording/reproducing head is taken out to the outside using a slip ring or the like. I can do it.

In this case, although the transport speed of the tape 6 is relatively slow as described above, an audio band of about 3 KHz can be obtained.

Next, the mainly mechanical operation of the magnetic recording/reproducing apparatus according to the present invention will be explained by dividing it into a recording process and a reproducing process.

First, the supply tape reel 3 is attached to the main drum 1.

Then, the leader tape 20 is connected to the tape 6 of the supply tape reel 3 as shown in FIG.

In this case, all the brakes are working, but by releasing the brake 25 of the first motor 2 and rotating the main drum 1 several times, the tape is wound around the tape guide recess 13 of the main drum 1 and further wound. It is wound onto the side reel 4 and loading is completed.

After that, all the remaining brakes except the brake 68 of the second motor 5 are released and the main drum 1 is rotated at a predetermined number of revolutions (x
soorpm).

In this case, the second motor 5 does not rotate, but the main drum 1
, the first belt pulley 49 fitted to the shaft 59 rotates along the pulley/friction wheel 47.

Therefore, rotational force is transmitted from the first belt pulley 49 to the second belt pulley 50 and the idler 53, and the idler 53 is transferred to the take-up reel 4 by the centrifugal force accompanying the high speed rotation of the main drum 1. The winding reel 4 starts rotating at a slow speed, and the tape 6 is wound at a predetermined slow speed (for example, 7 to 20 mV'S).

Furthermore, due to the slow rotation of the take-up reel 4, the rim 5
4, from the first fuller roller 32 to the second,
The rotation is transmitted to the third flare roller 33°44.

On the other hand, the cover 37 of the supply side tape cartridge 3 is rotated at high speed together with the main drum 1, but the reel 36 of the cartridge 3 is rotated due to the frictional action of the felt pad 43 interposed between it and the third flare roller 44. It is driven in the opposite direction to the direction in which the tape 6 is transported.

Therefore, back tension is applied to the tape 6 in the direction opposite to the tape transport direction.

With the above steps, preparations for recording onto the tape 6 are completed.

Therefore, by driving the head assembly 1 to bring each head into contact with the tape 6, a recording pattern as shown in FIG. 16 is recorded on the tape.

In this case, tracking control of the head assembly 7 is not performed.

When stopping the tape 6 in the middle of recording, the first motor 2
The power is turned off and the brake 25 is activated to stop the recording operation.

Alternatively, when the tape 6 comes near the end due to the recording operation, the aluminum foil stuck to the end of the tape 6 comes into contact with the pair of detection parts 18 for the end sensor.

Therefore, the first motor 2 is powered off via the end sensor detection slip ring 28, and its brake 25 is activated.

In this case, as the rotational speed of the main drum 1 decreases, the centrifugal force type auxiliary brake 61 is activated, and the idler 53 is released from rolling contact with the rim 54 of the take-up reel 4, thereby stopping its rotation.

Next, the case where the tape 6 wound on the take-up reel 4 is rewound to the supply tape cartridge 3 will be explained.

First, the winding frame 36 of the supply tape cartridge 3 is braked by the brake 39 (see FIG. 3).

Thereafter, by rotating the main drum 1 at a low speed (1801 pI) with the take-up reel brake 67 released, the cover 37 of the supply tape cartridge 3 rotates together with the main drum 1.

Therefore, the tape 6 is attached to the drawer section 40 of the cover 31.
The film is rewound to the winding frame 36 under the guidance of the .

Incidentally, by pasting aluminum foil to the starting end of the IJ-dar tape 20 in the same manner as described above, it is possible to perform an end sensor and stop the rotation of the main drum 1.

When rewinding the tape 6 during recording (reproduction), it is performed by changing the rotational speed of the first motor 2 from a constant speed (high speed) state to a low speed and performing the same operation as described above.

When performing fast forwarding during recording (playback) of the tape 6, the number of revolutions of the first motor 2 is changed from a constant speed to a low speed, and the brake 67 for the take-up reel is braked, so that the tape 6 is moved to the main drum. The second tape guide 15 guides the tape so that it is fast-forwarded and wound around the take-up reel 4.

Next, the process of playing tape 6 will be explained.

In normal reproduction, loading is performed in the same way as in recording, but this time it is necessary to activate the head assembly 7.

That is, during this reproduction, although the tracking between the tape 6 and the recording/reproducing head 80 slightly deviates as shown in FIG. , 82, the track is controlled to immediately correct even the slightest deviation, so that the track can always be reproduced in a normal state.

If you want to perform fast-forward playback instead of normal playback, use the second
By releasing the brake 68 of the motor 5 and rotating the second motor 5 in the opposite direction to the first motor 2, the take-up reel 4 is rotated at an increased speed.

In this case, desired fast-forward playback can be performed by appropriately adjusting the rotational speed of the second motor 5.

Note that when not performing tracking control, the first
The recording/reproducing head 80 follows a path shifted from the recording pattern a shown in FIG. 7B as shown in pattern b.

Also, if you want to perform slow playback instead of normal playback,
The second motor 5 is driven to rotate in the same direction as the first motor 2.

In this case as well, when tracking control is not performed, the recording/reproducing head 80 follows a path shifted in position as shown in pattern C.

When performing further still playback, the second motor 5 is switched to the first
The motor 2 rotates in the same direction as the rotation direction of the motor 2, but in this case, it is necessary to rotate at a higher speed than in the case of slow playback.

That is, the rotation of the second motor 5 is controlled by the slow rotation drive unit 45.
Adjust so that the rotation of the idler 53 itself stops.

In this case as well, when tracking control is not performed, the recording/reproducing head 80 follows a path deviated from its position as shown in pattern d.

Note that pattern e occurs during reverse playback, but since the explanation of the operation during reverse playback is clear from the above description, the explanation thereof will be omitted.

Therefore, even during special playback as described above, by performing the above-described tracking control, the recording pattern a can always be faithfully tracked by the recording/reproducing head 80.

As explained in detail above, according to the present invention, a reel wound with recording tape is stored and mounted on a rotating drum, and the recording tape is guided and transferred along the outer peripheral surface of the rotating drum.
The basic structure is markedly different from that of conventional magnetic recording and reproducing devices, as the recording tape is recorded or reproduced using a head disposed opposite the outer circumferential surface of the rotating drum. Since the spun reel is not exposed to the outside at all, the space factor of this type of device can be greatly improved and the device can be made smaller.

That is, in conventional V, T, and H of this type, as mentioned at the beginning, regardless of whether it is a fixed head type or a rotating head type, the reel or cartridge on which the tape is wound is all located at an independent location. It has a structure that occupies .

Therefore, in the past, the space occupied by the reel was larger than that of other components, and as a result, the overall device had to become larger accordingly.

However, according to the present invention, the size of the entire device can be made extremely compact as described above, and as a result, various associated effects such as reduction in material for the casing can be achieved.

In addition, since the recording tape is guided and transferred along the outer circumferential surface of the rotating drum (for example, α-wound), and a head is provided facing the outer circumferential surface of the rotating drum, high-density and long-term Recording and reproducing characteristics can be improved.

In other words, in the rotary head type V, T, and R, which eliminate the drawbacks of the conventional fixed head type, the rotary head must be controlled by a mechanism and circuit with a special configuration, and as a result, complexity is inevitable. Met.

However, according to the present invention, since the head is kept in a fixed state, only a simple tracking control mechanism for correctly following the tape track is required, which greatly simplifies the structure.

In addition, since the recording tape is guided and transferred along the outer periphery of a rotating drum that rotates at high speed, there is no restriction on the width of the tape, and a tape width of, for example, about 2 inches can be obtained. By obtaining narrower tracks than the T and H tracks, tracks can be formed diagonally on the tape, allowing high density recording with very slow tape transport speeds.

In the above example, as already mentioned, 7 to 2 Oram/s
It is sufficient that the speed is approximately 1/20 of the conventional V, T, H speed of 19071L7IL/s.

Therefore, the tape is approximately 1/20 compared to conventional tape.
It can be said that the length of is sufficient.

Note that the above example is one preferred embodiment of the present invention.

Therefore, various modifications and changes can be made without departing from the spirit of the invention.

That is, in the above example, it was explained that one head assembly is disposed on the main drum, but as an alternative, a second head assembly of the same structure may be disposed at a position 180 degrees out of phase. It would also be possible to provide a configuration in which the winding angle of the tape with respect to the main drum is halved and the frictional resistance of the tape is reduced.

Furthermore, it is not prohibited to provide a plurality of head assemblies.

[Brief explanation of the drawing]

FIG. 1 is a partially omitted plan view showing an example of a recording/reproducing apparatus according to the present invention, FIG. 2 is a front view, FIG. 3 is a vertical sectional view taken along the line ■-■ in FIG. 1, and FIG. A partially cutaway perspective view for explaining the main drum, FIG. 5 is a bottom view on line V-■ in FIG. 2, FIG. 6 is a perspective view for explaining the first tape guide, and FIG. A perspective view for explaining the leader tape, FIG. 8 is a cutaway perspective view of the supply tape cartridge, FIGS. 9 and 10 are a linear plan view and a front sectional view of the head assembly, respectively, and FIG. 11 is a tape and head FIG. 12 is a block diagram of the tracking control circuit, FIGS. 13A, B, and 14 are frequency spectrum diagrams for explaining the present invention, and FIGS. 15A and B are respectively FIG. 16 is an explanatory diagram showing the recording path of the tape, and FIGS. 17A and B are explanatory diagrams explaining the reproducing path of the head. 1 is a main drum, 3 is a tape cartridge on the supply side, 4 is a take-up reel, 6 is a magnetic tape, 1 is a head assembly, 36 is a winding frame, 31 is a cover, 45 is a slow rotation drive unit,
80 is a recording/reproducing head, and 81 and 82 are first and second tracking servo heads, respectively.

Claims (1)

[Claims] 1. A tape supply reel wound with a recording tape is housed and attached to a rotating drum, the recording tape is guided diagonally along the outer peripheral surface of the rotary drum, and the supply reel housed and attached to the rotary drum is rotated. The tape is transported by winding it on a tape take-up reel having a rotating shaft in the axial direction, and the rotating drum is rotated, and the recording tape is recorded on the recording tape by a head disposed opposite to the outer peripheral surface of the rotating drum. A recording and reproducing device characterized in that it performs , or reproducing.