JPH0676204A - Rotary magnetic head device - Google Patents

Abstract

PURPOSE:To suppress increase in a transmission loss by arranging other head corresponding to other coil adjacent to a coil in the rotary transmission corresponding to a head on a position where it is not in contact with a magnetic tape while reproducing the video head. CONSTITUTION:A pair of video heads 22a, 22b for a standard mode for recording and reproducing a video signal are arranged on positions opposing each other by 180 deg., and a pair of video heads 23a, 23b for special reproduction are arrnaged in the vicinity of the heads 22a, 22b. Further, a pair of narrow track video heads 24a, 24b for a long time mode are arranged on a position separated from the heads 24a, 24b by prescribed angles respectively, and a pair of heads 25a, 25b for recording and reproducing an FM audio are arranged on a position separated from the heads 24a, 24b by prescribed angles respectively, and a pair of flying erase heads 26a, 26b are arranged close to it. Even when lekage between the coils in the rotary transmission is present since a necessary regenerative signal is not affected by noise interference due to leakage, the number of short rings 30 inserted between the coils in the rotary transmission is minimized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary magnetic head device used in a magnetic recording / reproducing apparatus.

[0002]

2. Description of the Related Art A conventional device is disclosed in Japanese Patent Laid-Open No. 220220/1990.
As described in the publication, in order to reduce crosstalk in the rotary transformer, a means for short-circuiting each coil is provided between the coil of the rotary transformer and the recording / reproducing amplifier connected thereto.

However, a disturbing signal from the control track, which is detected at a high level when the rotary head starts contacting the tape, leaks between the coils of the rotary transformer even if the unused coils are short-circuited. ,
There is a drawback that the S / N ratio of the reproduced signal is deteriorated.

An example of such a conventional defect will be described with reference to FIGS. 1, 2, 3, 4, 5, and 6.
FIG. 1 is a partial cross-sectional view of a rotary magnetic head device, and FIG. 2 is a layout view of a conventional rotary drum head. FIG. 3 is a partial sectional view of a conventional rotary transformer, FIG. 4 is a circuit diagram of the conventional rotary transformer of FIG. 3, and FIG.
5 is a phase relationship diagram of a signal reproducing period of each head in the conventional example, FIG.
FIG. 4 is a magnetic pattern diagram on a magnetic tape.

In the magnetic pattern of FIG. 5, the control signal 21 is recorded at a strong level near the lower side of the video track 20. Since the video head starts reproduction from the video track near the control track, the control signal 21 is detected (jumps) as noise. In particular, the standard mode head having a wide head track width strongly detects this noise signal level. Since the level of this noise signal is strong, it leaks between adjacent coils in the rotary transformer.

On the other hand, in the long time mode, since the recording pitch width is narrow and the reproduction signal detected by the video head for the long time mode is weak, the interfering signal from the control track leaking between the adjacent coils in the rotary transformer is generated. It adversely affects the playback image quality. That is, in FIG. 2, the noise signal from the control track is generated in the FM audio head 6d for the standard mode, and the video head 7b for the long time mode is generated due to the wiring relationship between the rotary transformer and the head in FIGS. There is a drawback that the signal being reproduced is disturbed by the FM audio head 6d for standard mode. FIG. 6 shows the phase relationship during the signal reproduction period of each head in the conventional example. In this figure, it can also be seen that noise from the standard mode video head 6b leaks to the FM audio signal for the long mode reproduced by the 7c head and interferes.

[0007]

The above-mentioned prior art takes into consideration the crosstalk of video signals and audio signals.
No consideration is given to the disturbing signal from the control track which is detected at a high level when the rotary head starts contacting the tape. That is, in a multi-head rotary magnetic head device, another rotary head often starts contacting the tape during reproduction of a video signal. In particular, the more heads there are, the more opportunities there are. Although it is a signal detected by another head, since this signal is at a high level, there is a problem that it leaks to the signal being reproduced as crosstalk between the coils of the rotary transformer.

An object of the present invention is to prevent the interfering signal due to the above-mentioned leakage from entering the signal being reproduced without increasing the transmission loss in the rotary transformer.

[0009]

To achieve the above object, during reproduction of a video head, another head corresponding to another coil adjacent to a coil of a rotary transformer corresponding to the video head is transferred to a magnetic tape. The arrangement of the coils of the rotary transformer and the arrangement of the heads on the rotary drum are selected as the positional relationship in which the contacts do not start.

Further, since the facing area per one coil can be made wider by reducing the number of coils (the number of channels) of the rotary transformer, a pair of heads for flying erase is connected in parallel or in series, and the corresponding rotary transformer is connected. The coil can be one coil. Further, a flexible printed wiring board whose both sides are electrically shielded is used for the connection.

Further, the shield member of the flexible printed wiring board is fixed by a double-sided adhesive tape.

Further, the shield member of the flexible printed wiring board is grounded to the metal member of the rotary drum.

Further, a double-sided flexible printed wiring board is used as a shield for the flexible printed wiring board, one surface is a wiring pattern and the other surface is a shield member, and the wiring pattern surface is shielded with a conductive paste through an insulating sheet. is there.

Further, a capacitor is mounted on the flexible printed wiring board so that the flying erase function can be satisfied by inputting a small electric power depending on the resonance condition.

Regarding the arrangement of the coils in the rotary transformer, one short ring is arranged between the FM audio and flying erase coils and the video signal coil to make crosstalk practically problem-free. No other short ring is provided.

[0016]

[Operation] Since the recording pitch width is narrow in the long time mode and the reproduction signal detected by the head for the long time mode is weak, it is necessary to pay attention to the positional relationship between the coils of the rotary transformer connected to the head for the long time mode. There is. That is, the coil adjacent to the coil of the rotary transformer connected to the long time mode head needs to correspond to the head in which the tape contact does not start during the reproduction period from the long time mode head. By doing so, the noise signal from the control track does not become an interfering signal.

Further, since the facing area of the rotary transformer per coil does not decrease because the short ring is not provided more than necessary, the transmission loss as the rotary transformer does not increase, which is suitable for high image quality.

[0018]

EXAMPLES Examples are shown in FIG. 7, FIG. 8, FIG. 9, FIG.
1 and FIG. 12 will be described.

FIG. 7 is a positional relationship diagram of the head on the rotary drum of one embodiment of the present invention. The rotation direction is counterclockwise (counterclockwise).
Is. FIG. 8 is a circuit diagram of a rotary transformer of an embodiment of the present invention, FIG. 9 is a phase relationship diagram of a signal reproducing period of each head of an embodiment of the present invention, and FIG. 10 is a rotary transformer of an embodiment of the present invention. 11 is a partial sectional view, FIG. 11 is a layout view of terminals of a rotary transformer coil according to an embodiment of the present invention, and a flexible printed wiring board diagram for connecting a flying erase head, and FIG. 12 is FIG.
It is a partially expanded sectional view of the flexible printed wiring board of FIG.

In FIG. 7, 22a and 22b are mutually 1
A pair of standard mode video heads 23a and 23b for recording and reproducing video signals, which are arranged at positions facing each other by 80 degrees
2a and 22b, a pair of special reproduction video heads, 24a and 24b are a pair of narrow track long time mode video heads, which are arranged at predetermined angles from 23a and 23b, respectively. 24 for 25a and 25b
a pair of FM audio recording / reproducing heads arranged at positions separated by a predetermined angle from a.
26b is a pair of flying erase heads arranged near 25a and 25b.

In FIG. 8, the rotary transformer coils 27, 28 and 29 are arranged in this order from the inside of the rotary transformer 37. 30 is a short ring. The rotating transformer coil has a flying erase head 26a.2 for 28.
6b are connected in parallel.

Since the coils corresponding to the audio recording / reproducing heads 25a and 25b and the flying erase heads 26a and 26b can be separated from the video signal system by the short ring 30, leakage in the rotary transformer should be taken into consideration only in the video signal system. good.

Regarding the video signal system, the rotary transformer 37
From the inside (short ring 30) of the rotary transformer coil 31 (corresponding to the video head for long time mode), 32
(Corresponds to special playback video head), 33 (corresponds to standard mode video head), 34 (corresponds to long mode video head), 35 (corresponds to special reproduction video head), 36 (standard mode video head) (Corresponding to the head) is arranged in order. With the above arrangement, as can be seen from FIG. 9, during the operation period of the long-time mode video head, the rotary transformer coil corresponding to the long-time mode head changes to the head corresponding to the adjacent coil. Since there is no start of tape contact, there is the effect of not being disturbed by the noise signal from the control track.

In FIG. 10, a wiring base plate 38 is mounted on the rear surface of the facing surface of the rotary transformer 37 for terminal connection of the coil lead wire, and a flexible surface for connecting the flying erase head is mounted on the surface of the wiring base plate 38. A printed wiring board 39 was attached.

Both sides of the flexible printed wiring board 39 are shielded by an electric shield member, and the shield member is grounded to the disk 4 which is the metal portion of the drum by the conductive paste 40.

FIG. 11 is a view of the rear side of the facing surface of the rotary rotary transformer from above with the rotary drum removed, showing the arrangement of the terminals of the rotary transformer coil and the flexible printed wiring board for connecting the flying erase head. . 27a to 36a are terminals of the rotary transformer coils 27 to 36, and are connected to terminals for connecting to the head. 42 and 43 are terminal fittings for connecting to the head and are fixed to the connection base plate 38, and one ends 42a and 43a are connected to the terminal 35a of the rotary transformer coil 35 and the other end 4
2b and 43b are contacts for connecting to the head. The other terminals of the rotary transformer coil are also the same, so they are omitted.

The terminal 28a of the flying erase rotary transformer coil 28 is connected to one ends 44a and 45a of the terminal fitting, and the flexible printed wiring board 3 is further provided.
The terminal metal fittings 46a-4 at a position facing each other by 180 degrees
It is connected to 7a.

Reference numeral 41 denotes a condenser mounted on the flexible printed wiring board, which is a rotary transformer coil 2.
8 are connected in parallel.

FIG. 12 shows a flexible printed wiring board 39.
In the enlarged view of the cross section of the wiring base plate 38 side, the adhesive 39a, the protective film 39b, the conductive paste 39c, the back cover film 39d, the copper foil pattern 39e, the base 39f, the shielding pattern 39g, and the front cover film 39h are shown.

[0030]

According to the present invention, even if there is a leak between the coils of the rotary transformer, the required reproduction signal is not disturbed by noise due to the leak, so that a short ring inserted between the coils of the rotary transformer. Can be the minimum,
Since it is possible to suppress an increase in transmission loss without increasing the number of grooves in the rotary transformer, it is possible to provide a high-performance rotary magnetic head device.

Further, since the flexible printed wiring board whose both surfaces are shielded by the electric shielding member is used, even if the flying erase head is used in a ratio of 1 to 2, only one coil of the rotary transformer is required, and the number of grooves in the rotary transformer is sufficient. There is also an effect that can be dealt with without increasing.

Further, the configuration is such that a capacitor is connected to the primary side (head side) of the flying erase circuit, and the flying erase function can be satisfied by inputting a small amount of power, so the leakage of the flying erase signal is minimized. You can

Further, since the electrostatic shield effect can be further enhanced by grounding the shield part, leakage of FM signals outside the rotary transformer can be reduced and a high performance rotary magnetic head device can be provided.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view of a rotary magnetic head device,

FIG. 2 is a layout diagram of a conventional rotary drum head,

FIG. 3 is a partial sectional view of a conventional rotary transformer.

4 is a circuit diagram of a conventional rotary transformer of FIG. 3,

FIG. 5 is a magnetic pattern diagram on a magnetic tape,

FIG. 6 is a phase relationship diagram of a signal reproducing period of each head of a conventional example,

FIG. 7 is a positional relationship diagram of heads on a rotary drum according to an embodiment of the present invention,

FIG. 8 is a circuit diagram of a rotary transformer according to an embodiment of the present invention,

FIG. 9 is a phase relation diagram of a signal reproduction period of each head according to an embodiment of the present invention,

FIG. 10 is a partial sectional view of a rotary transformer according to an embodiment of the present invention,

FIG. 11 is a layout view of terminals of a rotary transformer coil according to an embodiment of the present invention and a diagram of a flexible printed wiring board for connecting a flying erase head.

12 is a partially enlarged sectional view of FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Fixed drum, 2 ... Bearing, 3 ... Rotating shaft, 4 ... Disk, 5 ... Wafer drum, 6a / 6b ... Standard mode video head, 6c / 6d ... Standard mode FM audio head, 7a / 7b ... Long-time mode video head, 7c, 7d ... Long-time mode FM audio head, 8 ... Rotation transformer rotor, 9 ... Rotation transformer stator, 10a-10d, 12a-12d ... Rotation transformer standard mode transmission coil, 11a to 11d, 13a to 13d ... Coils for transmitting a long time mode of a rotary transformer, 14a to 14d, 15a to 15d ... Transistors for coil short circuit, 16a to 16d ... Recording amplifier, 17a to 17d ... Prereproduction amplifier, 18 ... Magnetic tape , 19 ... Audio track (linear), 20 ... Video track, 21 ... Control signal , 22a / 22b ... Standard mode video heads, 23a / 23b ... Special playback video heads, 24a / 24b ... Long time mode video heads, 25a / 25b ... FM audio recording / playback heads, 26a / 26b ... Flying erase heads , 27, 29 ... Flying erase transmission coil of rotary transformer, 28 ... Flying erase transmission coil of rotary transformer, 30 ... Short ring, 31, 34 ... Long-time mode transmission coil of rotary transformer, 32, 35 ... Rotation transformer special reproduction transmission coil, 33, 36 ... Rotation transformer standard mode transmission coil, 37 ... Rotation transformer rotor, 38 ... Wiring base plate, 39 ... Flexible printed wiring board, 39a ... Adhesive agent, 39b ... Protective film, 39c ... Conductive paste, 39d Back cover film, 39e ... Copper foil pattern, 39f ... Base, 39g ... Shielding pattern, 39h ... Front cover film, 40 ... Conductive paste, 41 ... Capacitor 42, 43 ... Terminal fitting, 42a, 43a ... One end of terminal fitting , 44a, 45a, 46a, 47a ... One end of the terminal member for flying erase.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kiyomi Nemoto 1410 Inada, Katsuta City, Ibaraki Prefecture Hiritsu Manufacturing Co., Ltd. AV Equipment Division

Claims (6)

[Claims] 1. A pair of first video heads for recording and reproducing video signals, which are arranged at positions opposite to each other on a rotating drum by 180 degrees, and a pair of first video heads arranged near the first video head. A second video head, a pair of third narrow track video heads arranged on the rotating drum at positions separated by a predetermined angle from the second video head, and the third narrow track video head A pair of fourth heads for FM audio recording / reproduction, which are arranged at respective positions separated from each other by a predetermined angle, and a fifth head for flying erase, which is arranged near the fourth head. , A planar rotary transformer having individual coils connected to each of the heads, and in contact with the third narrow track video head during reproduction of the third narrow track video head. The arrangement of the coils of the rotary transformer and the arrangement of the heads on the rotary drum are selected so that another head connected to another coil adjacent to the coil of the rotary transformer does not start contact with the magnetic tape. Characteristic rotary magnetic head device. 2. A pair of heads for flying erase arranged on the rotary drum at positions opposed to each other by 180 degrees, said pair of heads for flying erase being connected in parallel or in series, said flying erase A flexible printed wiring board is provided on the back side of the facing surface of the rotary transformer in order to connect to the coil of the rotary transformer corresponding to the application head, and both sides of the flexible printed wiring board are shielded by an electric shielding member. The rotary magnetic head device according to claim 1, wherein 3. A pair of heads for flying erase, which are arranged at positions opposite to each other by 180 degrees on a rotary drum, the pair of heads for flying erase are connected in parallel or in series, and the flying erase is provided. In order to connect to the coil of the rotary transformer corresponding to the application head, a flexible printed wiring board is provided on the back side of the facing surface of the rotary transformer, and both sides of the flexible printed wiring board are fixed with double-sided adhesive tape for electrical shielding. The rotary magnetic head device according to claim 1, wherein the rotary magnetic head device is shielded. 4. A pair of heads for flying erase, which are arranged at positions opposed to each other by 180 degrees on a rotary drum, wherein the pair of heads for flying erase are connected in parallel or in series. A flexible printed wiring board is provided on the back side of the facing surface of the rotary transformer in order to connect to the coil of the rotary transformer corresponding to the head for use, and both sides of the flexible printed wiring board are shielded by an electric shielding member, and 2. The rotary magnetic head device according to claim 1, wherein the electrical shield member is grounded to a metal member of the drum. 5. A pair of heads for flying erase, which are arranged at positions opposed to each other by 180 degrees on a rotary drum, are connected in parallel or in series, and the pair of heads for flying erase are connected in parallel or in series. In order to connect to the coil of the rotary transformer corresponding to the use head, a flexible printed wiring board is provided on the back side of the facing surface of the rotary transformer, and one side of the flexible printed wiring board is provided with a wiring pattern, and 2. The rotary magnetic head device according to claim 1, wherein one side is provided with an electrically shielding pattern, and the wiring pattern surface side is shielded by a conductive paste member via an insulating sheet. 6. A flying erase device comprising a pair of heads for flying erase arranged on the rotary drum at positions opposed to each other by 180 degrees, the pair of heads for flying erase being connected in parallel or in series. In order to connect to the coil of the rotary transformer corresponding to the head for use, a flexible printed wiring board is provided on the back side of the facing surface of the rotary transformer, and a capacitor is mounted on the flexible printed wiring board. The rotary magnetic head device according to claim 1.