JPH04205844A - Head drum device - Google Patents

Abstract

PURPOSE:To reduce the damage caused to a magnetic tape at loading by a method wherein one part or the whole of lead part is removed in a region in which one end of the magnetic tape comes into contact with the circumferential face of a fixed drum outside the prescribed tape run position on the circumferential face of the fixed drum. CONSTITUTION:One part or the whole of lead parts 21a, 21b is cut out in the area that a region 22 in which the lower edge of a magnetic tape passes on the circumferential face of a head drum during the process of a loading is at the lower than a route where the lower edge of the magnetic tape passes at a normal tape run on the circumferential face of the head drum. Consequently, it is possible to reduce the interference of the magnetic tape with the lead parts 21a, 21b at the loading. Thereby, the damage caused ob the magnetic tape is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a head drum having a lead portion that regulates the running height of a magnetic tape wound by a loading post, such as used in a cassette type VTR, for example. Regarding equipment.

BACKGROUND OF THE INVENTION In recent years, magnetic recording and reproducing devices using magnetic tape have become popular by winding a magnetic tape around a head drum device to record and reproduce signals. This type of device is suitable for example for V
Like the H3 system VTR, it is widely used. The configuration will be explained below with reference to FIGS. 4, 6, and 7.

The magnetic tape l is wound around a pair of flanged reels 2a and 2b located in the same plane, and is wound into a tape cassette (
(not shown).

When the tape cassette is installed in the apparatus, a pair of reels 2a and 2b are placed as shown in FIG.

In this state, the lower edge of the magnetic tape 1 is connected to the reel 2a,
Including the part wrapped around 2b, it lies within only one plane. This plane is called the reference plane 3. Hereinafter, the vertical direction is assumed to be a direction perpendicular to the reference plane 3. The head drum 4 includes an upper rotating tram 4a and a lower fixed drum 4b.
It is mounted on a chassis 5 parallel to the reference plane 3 and is inclined with respect to the reference plane 3. Further, as shown in FIG. 4, the fixed drum 4b is provided with a stepped lead portion 6 for regulating the running height of the magnetic tape 1 by contacting the lower edge of the magnetic tape 1 along a predetermined running path. 1 in a helical manner along the path 7 that the lower edge of the magnetic chip 1 follows on the fixed drum 4b when being guided.
It is provided continuously over 80 degrees or more. A pair of loading posts) 8a, 8b are guided by a pair of guide grooves 9a, 9b provided on the shirt 5, and are respectively located at a first position 10a, a fob (position shown in FIG. 6), a second position 11a, 11b (position shown in FIG. 7). As in the 6th time, the first position 10a
, 10b, the pair of loading posts 8a, 8b and the magnetic tape 1 are not in contact with each other. This state is called the pre-loading state. Also, as shown in Fig. 7, the second position 1
1a.

When the pair of loading posts 8a, 3b are located at t-11b, the pair of loading posts t-8a, 8
b guides the magnetic tee 11 along a predetermined travel route. This state is called the post-loading state.

The operation of this configuration will be described below with reference to FIGS. 6 and 7. As explained earlier, in the state before loading, the magnetic tape l and the pair of reels 2a and 2b are in the sixth position.
It is installed as shown.

From this state, the pair of loading posts 8a.

8b starts moving and pulls out the magnetic tape l.

As the pair of loading posts 8a and 8b move, the winding angle of the magnetic tape 1 around the head drum 4 increases.

8b is the second digit F! When reaching lla and 11b, the magnetic tape 1 takes a predetermined running route as shown in FIG.

At this time, the running height of the magnetic tape 1 on the head drum 4 is regulated by the lead portion 6. This state is called the post-loading state. The above is the loading operation in which the magnetic tape 1 is wound around the head drum 4 from the pre-loading state to the post-loading state.

Problems to be Solved by the Invention However, in such a conventional head drum device, especially during the loading operation of the magnetic tape 1, the lead section 6 and the magnetic tape 1 interfere, causing damage to the lower edge of the magnetic tape 1. There was an issue. Figure 4 below,
This will be explained using FIGS. 5 and 8.

FIG. 5 shows only the height of the lead portion 6 of such a conventional head drum device. However, the horizontal axis in Figure 5 shows the winding from the starting point 12 (Figure 4) to the ending point 12 (Figure 4).
4), and the joint axis indicates the height of the lead portion 6. The height of the reference plane 3 is indicated by a chain line in FIG. Furthermore, assuming that the lead portion 6 does not exist, the region 14 created by the trajectory of the lower edge of the magnetic tape 1 on the circumferential surface of the head drum during the process of winding the magnetic tape 1 around the head drum 4 can be hatched. It shows. As shown in FIG. 5, a region 14 exists below a portion of the lead portion 6. As shown in FIG. Therefore, in this part, during the loading operation, the magnetic tape l and the lead part 6 are connected to each other as shown in FIG.
and interfere with each other, resulting in a situation where they overlap. This state exists until just before the loading operation ends, forcing the magnetic tape 1 to undergo unnecessary deformation, resulting in damage such as scratches near the lower edge of the magnetic tape 1 or deformation into a wakame-like shape. was occurring.

As described above, the conventional head drum device has a problem in that the magnetic tape 1 is damaged by the loading operation. In particular, if the magnetic tape l is thin and has low rigidity, the damage it receives will be large, resulting in a serious problem.

The present invention has been made to solve the above-mentioned problems, and provides a head drum device that hardly causes unnecessary deformation of the magnetic tape 1 during the loading operation and is less likely to cause damage to the magnetic tape 1. It is something to do.

Means for Solving the Problems In order to solve the above objects, the present invention provides a rotating drum, a fixed drum having a lead portion that regulates the running height by coming into contact with one edge of the magnetic tape, and a magnetic tape. During the process in which the magnetic tape is guided from a non-travel position to a predetermined running position by a plurality of moving loading posts, the area where one edge of the magnetic tape contacts the fixed drum circumferential surface A part or all of the lead portion is missing within a range outside the predetermined traveling position of the lead portion.

According to the present invention, due to the above-described structure, the magnetic tape holder is less likely to interfere with the magnetic tape holder during the loading operation, and damage to the magnetic tape can be significantly reduced.

EXAMPLE Below, the configuration of the first embodiment of the present invention is shown in FIG.
This will be explained in the second session and with reference to FIGS. 4, 6, and 7. A pair of reels 15a, 15 in the same plane
The magnetic tape 16 wound around the magnetic tape 16 is stored in a tape case (not shown) and mounted in the same manner as in the conventional example shown in FIG.

At this time, considering the part wound around the pair of glue 15a and 15b, there is only one plane created by the lower edge of the magnetic tape 16, and this plane is defined as the reference element surface 17. In addition, FIG. 2 shows the locus that the lower edge of the magnetic tape 16 passes over the circumferential surface of the heel l''F ram 18 during the process of winding the magnetic tape 16 around the head drum 18, assuming that the lead portion 21 does not exist. The area 19 created by the head tram 18 is shown by hunting. The head tram 18 is composed of an upper rotating drum 18a and a lower fixed drum 18b, and is attached obliquely to the shear 20 parallel to the reference element surface 17.Fixed. The drum 18b is provided with a stepped lead portion 21. This lead portion 21 has a first
It is as shown in Fig. 2. In other words, the lead portion 21 follows the path 22 to the extent that the path 22 that the lower edge of the magnetic tape 16 follows one day above the head drum while being guided along a predetermined running path is below the region 19.
The magnetic tape 16 is connected to the head drum 1 in the area above the first half lead portion 21a provided along the area 19.
It is provided only in the vicinity of the separation point 25 from the point 8, and consists of the second half lead portion 21b.

A pair of loading posts 26a and 26b are a pair of guide grooves 27a provided on the chassis 20.

27b, respectively the first position 28a,
28b, and second positions 29a and 29b.

The operation of the above configuration will be explained. First, the loading operation will be explained. A pair of loading posts 26a from the state before loading.

When the magnetic tape 26b begins to move, the magnetic tape 16 is guided by a pair of loading posts 26a and 26b and begins to be wound around the head drum 18. A pair of loading posts 26
As the movement of a and 26b progresses, the magnetic tape 16 is moved.
The amount of winding on the drum 18 increases, and finally the pair of loading posts 26a, 26b move to the second position 29a,
When reaching 29b, the loading operation ends and a post-loading state is entered. In this process, the magnetic tape 1
The lower edge of 6 is only in area 19.
8, the first half lead portion 21a and the magnetic tape 16 do not interfere with each other. The second half lead part 21b is
As shown in FIG. 2, since it exists above the area 19, it interferes with the magnetic tape 16 during the loading operation. However, since the second half lead portion 21b is provided only near the detachment point 25, it does not interfere with the magnetic tape 16 until just before the loading operation. Furthermore, the interference between the magnetic tape 16 and the IJ-toad section 21 increases as the area of the region 19 below the second half lead section 21b increases. From this, it can be seen from the second time that the interference between the second half lead portion 21b and the magnetic tape 16 is extremely small compared to the conventional example. Therefore, during the loading operation, the magnetic tape 16
The damage received by the device is extremely small compared to the conventional example.

As described above, according to this embodiment, damage to the magnetic tape 16 during the loading operation can be significantly reduced compared to the conventional example.

In addition, in order to ensure the regulation of the running position of the magnetic tape 16 in the fifth embodiment, the second half lead section 21b is provided, but by eliminating this second half lead section 21b, damage to the magnetic tape 116 can be further reduced. It is possible.

Next, a second embodiment will be explained using FIG. 1 and FIG. 3. As shown in FIG.
There is a range 24 in which only the lower side of the path 22 exists. Further, during the loading operation, the lower end of the magnetic tape 16 first contacts the peripheral surface of the head tram 18 in the range 23 above the path 22. As shown in FIG. 3, the lead portion 2I is composed of a first half lead portion 21a provided along the path 22 in the range 23 and a second half lead portion 21b provided near the tape separation point. In addition,
The detailed configuration is the same as that of the first embodiment, so a description thereof will be omitted. Furthermore, the difference in the existence range of the region 19 is due to the loading posts 26a and 26b during the loading process.
This is caused by differences in position, angle, etc. The operation will be explained below. Since the range 24 is the same as that in the first embodiment, the explanation will be omitted. When the loading operation starts, the lower edge of the magnetic tape 16 initially contacts the head drum 18 above the lead portion 21 in the range 23 . As the loading operation progresses thereafter, the lower edge of the magnetic tape 16 moves within the area 19 (i.e., tries to move below the lead section 21. However, due to the presence of the lead section 21, it cannot move below this). I can't.

At this time, the interference between the gate part 21 and the magnetic tape 16 is caused by the magnetic tape 116 between the loading post and the henodotram 18.
Since the damage is absorbed by the slight deformation of the magnetic tape 16, the damage to the magnetic tape 16 is small. Therefore, even if the lead portion 21 is not missing in the range 23, it will not be a big problem, and this configuration also makes it possible to provide a head drum device that is capable of stable loading operation with less damage to the magnetic tape 16. can.

In addition, in the first embodiment and the second embodiment, the rotating drum was arranged on the upper side and the fixed drum was arranged on the lower side, but the present invention is not limited to this structure, and for example, It can also be applied to a configuration in which fixed drums are arranged above and below so as to sandwich a rotating drum in the center. in this case,
It is also possible to provide a lead portion on the upper fixed drum.

Further, the present invention is not limited to the configuration described here, and can be applied to any head drum device that involves a loading operation.

Effects of the Invention As is clear from the above embodiments, according to the present invention, in the process of loading operation, the area where the lower edge of the magnetic tape passes on the circumferential surface of the head tram is the area of the magnetic tape located on the predetermined running path. The structure is such that part or all of the lead section is missing in the area below the path that the lower edge follows on the circumferential surface of the head drum, so interference between the magnetic tape and the lead section during loading operation is reduced compared to conventional methods. This makes it possible to provide a head drum device that causes less damage to the magnetic tape.

[Brief explanation of the drawing]

FIG. 1(a) is a front view of the head drum device according to the first embodiment of the present invention, FIG. 1(b) is a partial projection view of the same, and FIG. 2 is an exploded view showing the height of the lead portion of the device. 3 is a developed view showing the height of the lead portion of the second embodiment, FIG. 4(a) is a front view of a conventional head drum device, and FIG. 4 (with) is a partial projection view of the same. , FIG. 5 is a developed view showing the height of the lead part of the same device, FIG. 6 is a state diagram of a magnetic tape device equipped with the same device before loading, and FIG. 7 is a state diagram after loading.
FIG. 8 is a sectional view showing deformation of the magnetic tape during a loading operation. 16...magnetic tape, 18a...rotating drum, 18b...fixed drum, 2I...
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Claims (2)

[Claims] (1) A rotating drum, a stationary drum equipped with a lead portion that regulates the running height by contacting one edge of the magnetic tape, and a plurality of moving loading posts for moving the magnetic tape from a non-travel position to a predetermined position. A region where one edge of the magnetic tape contacts the circumferential surface of the fixed drum during the process of being guided to a running position is outside a predetermined running position of the magnetic tape on the circumferential surface of the fixed drum. A head drum device characterized in that part or all of the lead portion is missing. (2) A rotating drum, a fixed drum equipped with a lead portion that regulates the running height by coming into contact with one edge of the magnetic tape, and a plurality of moving loading posts that allow the magnetic tape to be moved from a non-running position to a predetermined position. The height position of one edge of the magnetic tape that first contacts the circumferential surface of the fixed drum in the process of being guided to the running position is such that the one end of the magnetic tape is located at a predetermined running position on the circumferential surface of the fixed drum. A head drum device characterized in that part or all of the lead portion is missing within a range outside the edge.