JPH0917072A - Magnetic recording / reproducing device - Google Patents

Abstract

(57) [Summary] [Object] The present invention relates to a magnetic recording / reproducing apparatus for recording / reproducing by winding a magnetic tape around a rotating drum, and an object thereof is to improve the linearity of a tape pattern. [Structure] A magnetic tape 2 is used when the lower drum 24 of a rotary drum 21 composed of an upper drum 23 and a lower drum 24 is mounted and fixed on a chassis at its bottom.
In this configuration, the threaded holes 29a to 29c formed corresponding to the portion other than the portion on which the lead 28 around which 2 is wound are formed and fixed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic recording / reproducing apparatus for recording / reproducing by winding a magnetic tape around a rotary drum.

[0002]

2. Description of the Related Art A so-called DAT (Digital Audio Tape Recorder) is known as a magnetic recording / reproducing apparatus. This DAT has a structure in which a magnetic tape is pulled out from a small tape cassette by a tape loading mechanism and wound around a rotary drum over a predetermined range (for example, 135 °) to perform digital recording / reproduction. In this case, a lead for guiding the magnetic tape is formed on the rotary drum, and the accuracy of the lead affects the linearity of the track (tape pattern) of the magnetic tape.

FIG. 5 is a block diagram of a conventional DAT rotary drum. 5A is a plan view, FIG. 5B is a front view,
FIG. 5C is a bottom view. A rotary drum 11 shown in FIGS. 5A to 5C is composed of an upper drum 12 and a lower drum 13 formed of, for example, an aluminum alloy, and the upper drum 12 extends from a drum motor provided on the chassis side. It is attached to the rotating shaft. Recording heads 14a, 14b and reproducing heads 15a, 15b are provided facing the lower end peripheral edge of the upper drum 12, and a printed circuit board 16 for each of the heads 14a, 14b, 15a, 15b is provided on the upper surface.

On the other hand, the lower drum 13 is fixed on the chassis, and the rotary shaft of the drum motor penetrates through a hole 13a in the central portion. Further, the lower drum 13 is provided with leads 18 for guiding the running of the magnetic tape 17 to be wound. To attach the lower drum 13 to the chassis, a drum base is interposed in the chassis and three places 19a to 19a are provided as shown in FIG.
Although it is screwed by c, its one point 19a is generally at the center of the portion around which the magnetic tape 17 is wound and is performed under the lead of tape running.

By the way, since the lower drum 13 is attached by screwing, the tightening force deforms the lower drum 13 to displace the lead 18. Here, FIG. 6 shows a diagram of lead displacement by the rotating drum of FIG. As shown in FIG. 6, the lead 18 is about +1.4 μm from the inlet to the outlet of the magnetic tape 17 to −1.
It was measured that there was a wavy displacement at 6 μm.

FIG. 7 is a block diagram of another conventional rotary drum. 7A to 7C are shown in FIGS. 5A to 5C.
7A to 7C, the rotary drum 11 shown in FIGS. 7A to 7C has a flange-shaped tapered portion 13b formed below the lower drum 13, and other configurations are shown in FIGS.
It is similar to (C). That is, the rotary drum 11 shown in FIGS.
By forming b, rigidity is reinforced, and when the lower drum 13 is screwed and fixed on the chassis, deformation of the lower drum 13 and displacement of the lead 18 are reduced. As a result, the displacement of the lead 18 can be slightly improved.

[0007]

FIG. 8 shows an explanatory view of a tape pattern due to lead displacement. As shown in FIGS. 5 and 6, when the lead 18 is displaced by screwing and fixing the lower drum 13, the recording heads 14a and 14b are formed on the magnetic tape 17 guided by the lead 18 as shown in FIG. The tape pattern of the track 17a is distorted in accordance with the displacement of the lead 18 to cause a phase shift, which deteriorates the linearity. There is no problem when recording and reproducing with the same device (same rotating drum 11), but when reproducing with a different device (other rotating drum) the magnetic tape recorded by the device is reproduced. There is a problem that compatibility may occur due to an error.

When the taper portion 13b is formed on the lower drum 13 as shown in FIG. 7, the linearity of the tape pattern of the track of the magnetic tape 17 is slightly improved, but the compatibility is improved as described above. There is a problem that it is not enough to secure it stably, and the lower drum 1
There is a problem that a metal mold and processing are required to form the taper portion 13b in 3 and the cost becomes high.

Therefore, the present invention has been made in view of the above problems, and an object thereof is to provide a magnetic recording / reproducing apparatus for improving the linearity of a deep pattern.

[0010]

In order to solve the above problems, a magnetic tape is wound around a rotary drum at a predetermined angle and the tape is run for recording and reproduction, and the rotary drum has a predetermined number of recording heads. And a magnetic recording / reproducing apparatus including an upper drum on which a reproducing head is mounted and rotated, and a lower drum on which leads for guiding the magnetic tape are formed and which are mounted and fixed on a chassis by a predetermined number of attachment members. In the above-mentioned magnetic recording, the lower drum is attached and fixed on the chassis by a predetermined number of the attaching members at a predetermined position of a bottom portion corresponding to a portion other than the portion where the leads are formed around which the magnetic tape is wound. A playback device is configured.

[0011]

As described above, according to the first aspect of the invention, when the lower drum constituting the rotary drum is mounted on the chassis at the bottom, the magnetic drum is wound at a position corresponding to a portion other than the portion where the leads are formed. It is attached by an attachment member. As a result, the influence of the attaching force of the attaching member on the lead portion is reduced, the lead displacement is reduced, and the linearity of the tape pattern on the magnetic tape can be improved.

[0012]

FIG. 1 is a block diagram showing an embodiment of the present invention.
1A is a plan view of the rotary drum, FIG. 1B is a front view, and FIG. 1C is a bottom view. A rotary drum 21 shown in FIGS. 1A to 1C is a DAT that winds a magnetic tape 22 around the rotary drum 21 at a predetermined angle, rotates the rotary drum 21 and runs the tape to perform recording / reproduction.
It is mounted on a magnetic recording / reproducing apparatus such as a streamer or a VTR.

1A to 1C, the rotary drum 21 is made of an aluminum alloy or the like as described above, and is composed of an upper drum 23 and a lower drum 24. The upper drum 23 has a rotating shaft extending from a drum motor (not shown) provided on the chassis and is a lower drum 2.
4 through the hole 24a, and is attached to the tip of the rotary shaft with a screw or the like. On the peripheral edge of the lower surface of the upper drum 23, the recording heads 25a and 25b facing each other and the corresponding reproducing heads 26a and 26b are mounted at intervals of 90 degrees, for example. Then, on the upper surface of the upper drum 23, each head 25a,
The printed circuit board 27 on which the signal patterns corresponding to 25b, 26a and 26b are formed is fixed by screws.

On the other hand, the lower drum 24 is formed with a hole 24a for penetrating the rotary shaft of the drum motor in the central portion as described above, and has a stepped shape on the side peripheral surface of the magnetic tape 2.
The lead 28 that guides 2 is formed to be inclined. The magnetic tape 22 loaded on the lead 28
Is wound at an angle of 135 °, for example. Further, the lower drum 24 is fixed at its bottom surface with a drum base (not shown) on the chassis with screws, and three threaded holes 29a to 29c for that purpose are formed on the bottom surface. In this case, the threaded holes 29a to 29c are formed in a portion other than the portion corresponding to the lead 28 formed on the side peripheral surface. Then, the drum base is screwed and fixed by an attachment member (not shown) such as a screw.

Here, FIG. 2 shows an internal plan view of a DAT having the rotary drum shown in FIG. DAT31 shown in FIG.
On the chassis 32, a cassette loading / unloading mechanism 33, a reel driving section 34, the rotary drum 21, a tape loading mechanism 35, etc. are arranged. As described above, the rotating drum 21 has screw holes 29a-2 on the bottom surface of the lower drum 24.
The chassis 32 is screwed and fixed to the drum base by 9c. All of these mechanisms and the like are configured so that they can be assembled to the chassis 32 from above the chassis 32, and the assembly process is simplified.

The cassette loading / unloading mechanism 33 is for loading the tape cassette at a predetermined recording / reproducing processing position in the apparatus 31, and in this embodiment, for example, the cassette loading / unloading mechanism in which the loading mechanism moves up and down with respect to the cassette holder. Is used. The tape cassette is inserted / removed in / from the cassette holder 36 in the eject state, and the loading mechanism is raised to tape-load the tape cassette in the state of being inserted in the cassette holder 36, so that the tape cassette is moved to a predetermined recording / reproducing processing position in the apparatus 31. It is installed.

The reel drive section 34 is a supply reel 3 around which the magnetic tape 22 of the mounted deep cassette is wound.
7 and the take-up reel 38 are rotationally driven, and the drive source thereof is a capstan motor. The reels 37, 38 are configured such that their rotation speeds, rotation directions, etc. are controlled by the mode of the device 71 (for example, recording / playback mode, fast-forward / rewind mode, search mode, etc.).

The tape loading mechanism 35 is a mechanism for pulling out the magnetic tape 22 from the tape cassette and winding it around the rotary drum 21 at a predetermined angle (135 ° in this embodiment). The tape loading mechanism 35 employs so-called M loading, and a pair of loading bases 39a,
39b is moved along the guide grooves 40a and 40b, and the magnetic tape 22 is loaded or unloaded accordingly.

The loading bases 39a and 39b have guide rollers 41a and 41b and an inclined post 42 on their upper portions.
It has a structure in which a and 42b are erected. These guide rollers 41a, 41b and inclined posts 42a, 42b
Has a function of pulling out the magnetic tape 22 from the tape cassette as the loading bases 39a and 39b move and forming a predetermined tape path in the loading completion state. FIG. 2 shows the device 31 in a loading completed state.

The loading bases 39a, 39b
In the loading state, the positioning is performed by contacting the positioning pins 43a and 43b implanted in the chassis 32. In FIG. 2, the loading bases 39a and 39b have positioning pins 43a and 43.
It shows a state of being in contact with b. In addition, the positioning pin 4
The tape drop prevention poles 44a,
44b is provided.

The magnetic tape 22 loaded by the tape loading mechanism 35 is attached to the pinch roller 4
5, the capstan 46 is pressed against the capstan 46, the capstan 46 is rotated in a predetermined direction by the capstan motor, and the tape is run in the rotation direction according to the normal mode and the reverse mode.

Therefore, FIG. 3 shows a diagram of lead displacement of the rotary drum of FIG. As described above, since the rotary drum 21 is screwed and fixed to the drum base with the threaded holes 29a to 29c in the portion other than the portion corresponding to the lead 28 on the bottom surface, the influence of the tightening force on the lead 28 is reduced. The change in the lead 28 due to the deformation of the lower drum 24 is reduced, and as shown in FIG.
It was measured that the displacement was stopped at about −0.5 μm.

As a result, the track (tape pattern) formed on the magnetic tape 22 at the time of recording has linearity according to the displacement of the lead 28, and the linearity is improved as compared with FIG. 6 described above. It is clear that
In addition, the taper portion as shown in FIG.
Since it is not necessary to form it in No. 4, the mold production and processing become easy, the cost required for the means for rigidity reinforcement becomes unnecessary, and the cost increase can be prevented.

Next, FIG. 4 shows a block diagram of another embodiment of the present invention. FIGS. 4A to 4C correspond to FIGS. 1A to 1C, and the rotary drum 21 shown in FIGS. 1A is formed by forming a taper portion 24b in the shape of a circle.
Is the same as that of (C). That is, although the rigidity is reinforced by the taper portion 24b, the cost of forming the taper portion 24b is high. Lead 2 due to the tightening force of the stopper
8 can be further suppressed, and the linearity of the tape pattern on the magnetic tape 22 can be further improved.

[0025]

As described above, according to the invention of claim 1, when the lower drum constituting the rotary drum is mounted on the chassis at the bottom, the portion other than the portion on which the lead around which the magnetic tape is wound is formed. By using a structure in which the attachment member is attached at a position corresponding to the position, the influence of the attachment force of the attachment member on the lead portion is reduced, the lead displacement is reduced, and the linearity of the tape pattern on the magnetic tape is reduced. Can be improved.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an embodiment of the present invention.

2 is an internal plan view of a DAT equipped with the rotary drum of FIG. 1. FIG.

3 is a diagram showing lead displacement of the rotary drum of FIG. 1. FIG.

FIG. 4 is a configuration diagram of another embodiment of the present invention.

FIG. 5 is a configuration diagram of a rotary drum of a conventional DAT.

6 is a diagram showing lead displacement by the rotary drum of FIG.

FIG. 7 is a configuration diagram of another conventional rotating drum.

FIG. 8 is an explanatory diagram of a tape pattern due to lead displacement.

[Explanation of symbols]

 21 Rotating Drum 22 Magnetic Tape 23 Upper Drum 24 Lower Drum 24b Tapered Part 25a, 25b Recording Head 28 Leads 29a to 29c Screw Cutting Hole 31 DAT

Claims (1)

[Claims] 1. A magnetic tape is wound around a rotary drum at a predetermined angle and the tape is run to perform recording / reproduction. The rotary drum has a predetermined number of recording heads and reproduction heads and is rotated. And a lower drum on which a lead for guiding the magnetic tape is formed and which is attached and fixed to a chassis by a predetermined number of attachment members, wherein the lower drum is wound with the magnetic tape. A magnetic recording / reproducing apparatus characterized in that the magnetic recording / reproducing apparatus is mounted and fixed on the chassis by a predetermined number of the attaching members at a predetermined position of a bottom portion corresponding to a portion other than the portion where the leads are formed.