JPH0366058A - magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To perform the stable tape traveling irrespective of its traveling direction by providing a protrusion part opposite to the tape between a guide post immediately after the tape outlet side and a tape separating point on the outer side of the tape separating point on the tape outlet side of a lower drum. CONSTITUTION:A notched part 14 is provided on the lower drum 1 to prevent a tape wrapping angle from increasing due to swelling of the tape 3 toward the drum 1 side. Moreover, plural protrusion members 5 are provided in the notched part 14 in their positions opposite to the tape in the vicinity of the tape separating point in the tape traveling direction at the normal recording and reproducing time. The member 5 is made of stainless steel, etc., and imbedded in a stepped hole 6, and its protrusion amt. is settled not to come into contact with the tape 3 during the normal recording and reproducing time, but in contact with the tape only when the tape is swollen. By this method, the stable tape traveling can be performed irrespective of the tape traveling direction.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to improving tape running characteristics, particularly in a magnetic recording/reproducing device equipped with a rotating magnetic head device.

(Background technology) In recent years, devices such as VTRs (video tape recorders) have been rapidly downsized, and as a result, rotating drum units have also been inevitably downsized, making it possible to wind tape around the rotating drum in a small space. The tape running route (tape bus) has also become complicated.

FIG. 5 shows an example of such a downsized tape bus for an 8 mm VTR, and FIG. 6 shows an enlarged view of the vicinity of the tape detachment point of the drum unit indicated by point A in FIG.

In FIG. 5, numeral 8 is a rotating drum unit having magnetic heads arranged at predetermined intervals around its outer periphery, and consists of a rotating upper drum and a fixed lower drum.

9 is a capstan for transporting the tape 3 at a predetermined speed; 1;
0 is a pinch roller which pinches and transports the tape together with the capstan; 11 is a supply reel; and 12 is a pick-up reel.

The tape bus shown in the figure is formed by guide posts 16 to 24, and in particular, the tape is wound around the drum unit at a predetermined angle by a supply side guide post consisting of guide posts 19 and 20 and a take-up side guide post consisting of guide posts 21 and 22. It is configured so that it can be used.

Reference numeral 16 denotes a tension regulator turbine 17, 18, 23, 24 for detecting tape tension, which is a guide post that forms the tape path together with the above-mentioned guide posts 19 to 22.

In such a configuration, considering the tape running characteristics, during normal recording and playback, the tape is pulled out from the supply reel 11 with a certain tension, then supported by each guide post, and wound around the drum unit 8. Thereafter, it is conveyed by a capstan 9 and a pinch roller 10, and wound onto a pick-up reel 12.

At this time, the tape tension gradually increases from the supply reel 11 to the capstan 9.

When the tape runs in reverse, the tape is conveyed by the capstan 9 and the pinch roller 10 as soon as it is pulled out from the pick-up reel 12.

After that, the supply reel 11 is passed through the drum 8 and guides.
is wound up. At this time, the tape is on supply reel 11.
The tension gradually decreases from the supply reel 11 to the capstan 9 because it is wound with a constant torque.

Therefore, near the tape separation point near the capstan 9 on the drum, the tension of the tape varies greatly depending on the running direction.

Therefore, when the tape is running in the normal recording or playback direction, it is stretched linearly with respect to the guides, as shown by the broken line in Figure 6, but when it is running in the opposite direction, the tape tension decreases, as shown by the solid line. The rigidity of the tape itself also plays a role, and the tape has a tendency to bulge out from the guides as it travels.

This situation becomes conspicuous because the angle of tape winding increases as the diameter of the rotating drum decreases as the device becomes smaller.

(Problems to be Solved by the Invention) In the tape path described above, the tape swells when running in reverse, so the wrapping angle of the drum unit 8 increases, and the tape at the separation point between the drum unit and the tape 3 increases. The bulge increases the contact area with the drum unit, increasing the running load, causing problems such as unstable tape running, unnecessary load on the drive system, and in the worst case, the tape becoming loose. There was danger.

(Means for Solving the Problems) The present invention has been made to solve the above-mentioned problems, and is characterized by recording and reproducing signals by winding a magnetic tape around a rotating drum unit. A magnetic recording/reproducing device for performing magnetic recording, wherein a lower drum that guides the magnetic tape is placed at a position facing the tape in the vicinity of the tape separation point in the tape running direction during normal recording or playback, and does not contact the tape during normal recording or playback. , the magnetic recording/reproducing apparatus is provided with a protrusion that contacts the tape when the tape runs in a direction opposite to the tape running direction during normal recording or playback.

Another feature is that on the lower drum surface facing the tape outside the tape exit point on the tape exit side of the lower drum and between the exit side first guide post and the lower drum exit side tape exit point. The objective is to provide a hard protrusion member that protrudes to the extent that it does not come into contact with the tape during normal running.

(Function) This supports the slack of the tape during reverse running and waiting, prevents the tape from increasing at corners when it is wound around the lower drum, and enables smooth tape running.

(First Embodiment) Hereinafter, one embodiment of the magnetic recording/reproducing apparatus according to the present invention will be described in detail with reference to the respective figures.

1 and 2 show a first embodiment of the present invention,
Fig. 2 is a side view of the drum unit of the present invention, and Fig. 1 is an enlarged view of the tape path on the tape output side of the lower drum. In each figure, 1 is a fixed lower drum, 2 is a lower drum 1 13 is a plurality of rotating magnetic heads provided at predetermined positions on the outer circumferential surface of the upper drum; 14 is a tape output side of the drum through which the tape runs in the opposite direction; When the tape tension decreases and the tape swells toward the drum, the tape is wrapped around the lower drum l at the notch portion (the broken line is the outer peripheral surface of the drum before the notch) to prevent the corners from increasing. Guide post immediately after the tape exit side during normal recording and playback, 3 is the tape, 4 is the tape separation point relative to the lower drum on the tape exit side, 5
is a protruding member disposed within the notch 14, which contacts the tape that swells due to a decrease in tension when the tape runs in the reverse direction, thereby preventing surface contact between the tape and the lower drum. The protruding member 5 is spherical, and its material is stainless steel, which is harder and more resistant to wear than the drum material aluminum. As shown in the figure, this ball is embedded in a stepped six 6 formed in a notch 14 formed in the lower drum 1, and its protrusion amount is such that it does not come into contact with the tape during normal recording and playback. , and, as described above, is configured to come into contact with the tape only when the tape swells, thereby preventing sticking due to surface contact with the drum surface. Moreover, as is clear from the side view of FIG. 2, it becomes more stable when a plurality of balls 5 are arranged as protruding members.
Effective.

As mentioned above, slack occurs in the tape 3 during reverse running, and the tape 3 wraps around the lower drum 1 more than the designed detachment point 4, leading to deterioration in running performance. Tape 3 to lower drum 1 by supporting
This prevents an increase in the number of wraps and allows for smooth tape running. Further, since a gap is maintained between the tape and the lower drum by the protruding member 5, air can flow smoothly without being hindered, and a good air bearing effect can be obtained.

(Second Embodiment) A second embodiment of the present invention is shown in FIGS. 3 and 4.
Here, a bar made of a hard material such as stainless steel is used as the protruding member 5'', and is installed in the V groove 7 formed in the lower drum 1. Even with this shape, the tape 3 does not reach the lower drum 1 when running in reverse. It is possible to prevent the increase in winding and sticking of the ball, and it is easy to reduce the cost compared to the example using a plurality of balls described above.

(Effects of the Invention) As explained above, according to the present invention, on the outside of the tape separation point on the tape exit side of the lower drum, the tape is opposed to the guide post immediately after the tape exit side and between the tape separation point. By providing a protrusion on the lower drum surface, it is possible to achieve stable tape running conditions regardless of the tape running direction without significantly increasing costs through complicated machining. Corresponding to a VTR having a PCM recording area as well as a recording area, the effect of winding the tape around the drum is more pronounced as the corner becomes larger.

[Brief explanation of drawings]

Fig. 1 2 A sectional view of the lower drum showing the first embodiment of the present invention Fig. 2: A side view of Fig. 1 Fig. 3: A sectional view of the lower drum showing the second embodiment of the invention Figure 4: Side view of Figure 2 Figure 5: An example of a downsized tape bus for an 8mm VTR Figure 6: Enlarged view of the vicinity of the tape detachment point of the double drum unit 1, lower drum 2, and first guide post on the exit side 3, tape 4, exit tape separation point 5, protrusion member 9, capstan 10, pinch roller 11, supply reel 12, take-up reel

Claims (2)

[Claims] (1) A magnetic recording and reproducing device that records and reproduces signals by winding a magnetic tape around a rotating drum unit, in which the lower drum that guides the magnetic tape is placed near the tape separation point in the tape running direction during normal recording or reproduction. A protrusion is provided at an opposing position, which does not contact the tape during normal recording or playback, but contacts the tape when the tape runs in a direction opposite to the tape running direction during normal recording or playback. Magnetic recording and reproducing device. (2) The magnetic recording/reproducing device according to claim 1, wherein the protrusion is made of a harder material than the lower drum.