JPS59162663A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To reduce the load of tape running by making the tangent direction at a point, where a winding tape is wound around a rotary head drum at the half of the winding angle, and the inclination direction of the rotary head drum to a plane different from each other to reduce the tension of the tape after passing the rotary head drum. CONSTITUTION:In a reproducing device, a guide roller 10 is provided between a post 9 and a rotary head drum 10, and the direction of an arrow K is made different to make the tape height at a point P different. When the height of a tape T is increased by Q in comparison with tapes T1 and T2, guard lines are changed as follows: a guard line F2 is moved in parallel to a position F3 by the change of height Q if the inclination of a reference plane of the tape T1 to that of the tape T is denoted as gamma2; and similarly with respect to the tape T2, a parallel movement corresponding to an inclination angle gamma1 is generated by the change of height Q, and a guard line E2 is changed to a position E3. Thus, the arrangement of an inclined post 12-3 is easily designed, and it is suitable for a small-sized path.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a magnetic recording/reproducing device such as a VTR.

Conventional configuration and problems In a VTR using a parallel two-reel cassette, video signals are recorded and played back by winding the tape diagonally around the rotating head drum. It is necessary to return the tape to the same state as the tape in the cassette. Conventionally proposed tape loading methods include an M loading method and a U loading method, each of which has advantages and disadvantages. It is a well-known fact that M loading is a tape path that is more advantageous in making the device smaller and thinner than U loading. Unfortunately, however, the basic design of M loading is to eliminate all twisting and height of the tape with a tilted post placed at the entrance/exit of the rotating head drum, so the winding around the two tilted posts becomes a dog when running. It has the fate of being extremely heavy in load compared to U-loading.

FIG. 1 shows a conventional M loading tape path, in which the tape exits the supply reel 2 of the tape cassette 1 through cassette bosses) 3a, 3b, tension posts 4. Guide roller 5. Full width erase gutter 6, impedance roller 7, guide roller 8. It reaches the inclined post 9. The tape leaving the rotating head drum 11 is returned to the inclined post 12. Guide roller 13° sound erasing head 14. Audio control head 15. Fixed guide post 16. capstan 17
, pinch roller 18. Guide roller 19. The cassette bosses 20a + 20b are wound onto the H take-up reel 21.

If the winding angle of the tape T wound around the rotary head drum 11 is θ1, then the M method has an inclination K in the X-axis direction when the angle θ1-θ2 is taken as the Y-axis. At this time, the height of the tape T at the intersection P between Y(-) and the outer periphery of the rotary head drum 11 is the same as the height of the tape T in the tape cassette 1. θ2−V2θ1 has the following meaning. For example, when evaluating the rotary head drum 11 without tilting it, the coordinates of the tape L at the point where it enters the rotary head drum 11 and the tape N at the point where it leaves the rotary head drum 11 are as follows.The coordinate axes at this time are as shown in FIG. X(+)
-X(→.

Y(g)-Y(→, Z-〇 indicates the height of the tape T in the cassette 1.

L-(-a, b, c), """("L b
We have a HO'J relationship. This means that even if it is tilted in the K direction, the values of a and C change, but the relationship between L and N does not change. The tape T1 extending from L to the inclined post 9 and the tape T2 extending from N to the inclined post 12 have the same inclination angle with respect to the reference plane on which the tape T in the cassette exists. When the rotary head drum 11 is used as a reference, the tape T1 from L to 9 is raised with respect to the reference plane, and the tape T2
The condition that the tape height must be the same as the tape height in the cassette near the inclined post 9.12 is summarized as follows. Tape height C
The value is "○" for supply reel 2 → inclined post 9.

It goes from 9 to negative and then goes down steadily, but halfway through it starts to go up again. Then, at point P, it becomes rOJ again. After passing point P, the value takes on a positive value and starts to rise, but midway through, it starts to fall again and reaches rOJ at 12. From then on, the number is "○" up to 21.

As explained above, if the inclination is determined by setting θ2″=θ1, it can be said that the tape leading to the inclined post 9.12 is symmetrical with the point P as the center. ，
The winding angle of the tape that must be wrapped around 12 will still be equal.

The effect of the slanted post that asks whether the tape is T2 after leaving the rotating head drum 11 is
It must be said that the tension is very high. In other words, as tape tension increases, stick-slip occurs, which affects the reproduced image as jitter.

In the future, when long-term recording and VTR systems become lighter and more compact, it is expected that thinner tapes will be used, and it is thought that such tapes will generate abnormal tension that exceeds the allowable stress of the tape. It will be done.

Purpose of the Invention The present invention takes advantage of the advantages of M loading, such as parallel loading, the fact that the tape loading locus is performed on a plane parallel to the mounting surface of the tape cassette, and the advantage of being compact, lightweight, and thin. The purpose of this project is to provide a magnetic recording/reproducing device with a new tape path that reduces the tape running load, which is a disadvantage of the conventional magnetic recording and reproducing device.

Structure of the Invention The present invention includes a tape loading device configured to pull out the tape from the tape cassette only in a plane parallel to the mounting surface of the tape cassette and wind the tape around a rotating head drum at a predetermined angle. The tangential direction at the point where the tape is wound around the rotary head drum by a rod of the winding angle and the direction of inclination of the rotary head drum with respect to the plane are set in different directions, and the point that becomes the tangent to the rotary head drum is set in different directions. , a magnetic recording and reproducing apparatus characterized in that the tape is set on the rotary head drum at a point that exceeds a winding angle from a winding start point. Refer to and explain.

FIG. 2 shows one embodiment of the present invention, and the same parts as those in FIG. 1 are given the same numbers and their explanation will be omitted. The difference between the embodiment shown in FIG. 2 and the conventional example shown in FIG. 1 is that a guide roller 10 is provided between the post 9 and the rotary head drum 10, and
The points are that the direction of the point P is different, and the height of the tape at the point P is different. The guide roller 10 is not necessarily required.

The basic points regarding the tape path without the guide roller 1Q will be explained in relation to the conventional art with reference to FIGS. 3 to 5.

What is shown in FIG. 3 is a state diagram of the tape near the inclined boss l-9. The tape T reaching the inclined post 9 is at the same height as the cheese in the cassette 1. The height of the tape T1 from the inclined post 9 to the rotating head tram 11 is lower at point L,
Since it is rising from L towards 9, its inclination angle is η
When this happens, a point matching the height of the tape T is found on the extension line of the rising tape T1. For the tape T, a vector J in the tape traveling direction is parallel to the mounting surface of the cassette 1, and a vector H in the tape width direction is perpendicular. The above is also applied to tape T1, and for this tape T, vector J is parallel and H
There exists a plane where is perpendicular. A line F intersects this plane with the above-mentioned Q mounting surface (when the height B from the tape center is equal) appears.

This line F is called a guard line. This guard line F
``includes ``heat theory'' and ``points''.

An inclined post 9 is arranged near the guard line, and the angle at which it is wrapped is 2S because if the angle S between the guard line F and the tape T1 is S, the angle between the guard line F and the tape T is also S. .

As shown above, if you can see the guard line, you can fully evaluate the tape pass.

Next, with reference to FIG. 4, changes in the guard line will be explained.

First, let F and E be guard lines in the case of the conventional M path shown in FIG. In this case, as mentioned above,
Since the throat drum is tilted toward rotation in the negative axis direction, the center axis of the tilt is the Y axis, which is θ2−V2θ1. Next, Yl rotated slightly counterclockwise from the Y axis,
When the inclination angle of the rotary head drum 11 is the same as the inclination central axis, the guard lines are F and E. In the conventional M path, since L and N were at symmetrical positions with respect to the Y axis, guard lines E and F are still symmetrical with respect to the Y axis. If you think about Y+rtl+center, the L point will get closer, so the tape height will be higher than the L point in the case of the Y axis,
Accordingly, the gart line F1 becomes closer to the L point. Since the N point is reversed, the guard line of El is also farther away than the N point.

Guard line F2. F2 is the case of F2 in which the central axis of inclination has rotated further counterclockwise than Yl.

These six guard lines F, F,, F2.
L.E.

Focusing on F2, tape T2 and guard lines E, E,
.

Angle α with F2, α1. α2 has the relationship F2>F1>α. On the contrary, guard line F, F,, F
, and the angle formed by the tape T1, β, β1. β2 is F2〈β
,〈β.

α24-F2. α1+β1. Each of α+β is equal to so.

From this tendency, it can be seen that the winding force applied to the inclined post 12 on the tape exit side can be reduced.

However, in this situation, unfortunately, the gart line E2°F
Not only is position 2 extremely difficult in actual design, but F
2 is too far from point N, resulting in a large tape path for the device. A means for solving this problem will be explained with reference to FIG.

As explained in FIG. 3, the guard line is the intersection line between the reference plane where the tape T exists and the reference plane where the tape T1 or F2 exists.
Alternatively, if we change the height relative to F2, we can see that guard lines E and F move in parallel.

- As an example, if the height of the tape T is increased by Q, then the tape T, .
If you attack F2, the guard line will change as follows. If the inclination of the reference plane of the tape T1 with respect to the base plane of the tape T is F2, the guard line F2 moves in parallel to F3 by changing the height Q. The same goes for the tape T2; by changing the height Q, a parallel movement equivalent to the inclination angle γ1 occurs, and the guard line E
2 changes to E3. Due to this change in guard line,
First, the arrangement of the inclined post 12-3 is easy to design and suitable for a small path. Heat theory, guard line E3 is E
Since the angle α2 with the tape T2 is the same, the wrapping angle of the tape wrapped around the inclined boss) 12-3 can be significantly reduced compared to the conventional M path. Ta.

Conversely, since the angle β2 between the tape T1 and the guard line F3 is larger than the conventional β, the guide roller 1Q is used in this pass to reduce the angle between the guard line F3 and the tape T1. It was decreased from B2 to δ. For the purpose of the present invention, the angle of winding around the inclined post 12 on the tape exit side is reduced until the end. Even if the wrapping angle increases by wrapping the tape directly around an inclined post without using the guide roller 10 on the tape entrance side, the tape tension on the tape entrance side is originally several steps higher than that on the tape exit side. is small, so T2
2e"θxT, (T2 is the inclined post exit tension, T
If the tension is evaluated as an absolute value as shown in the equation (l is the inlet tension, μ is the friction coefficient, and θ is the wrapping angle), this does not contradict the purpose of the present invention.

Specifically, the height Q due to the parallel movement of the guard lines F and H described above can be changed by keeping the rotary head drum 11 as it is and increasing the height of the tape cassette 1 by Q compared to the conventional one. be. This means that the tape height at point P2 has now become lower than the internal height of tape cassette 1 by Q.

A specific tape loading mechanism will be explained in FIG. There are two rings A24 and B26 supported by three ring holders 23 on the outer periphery of the rotary head drum 11. Ring A24. Both ring B25 has a driving body (
(not shown) to which the driving force is transmitted, gears having the same diameter are formed, and a boat pin A26. A boat pin B27 is integrally provided. The long hole 282L of the boat lever 28 engages with the boat pin A26, and the boat spring A29 engages with the boat pin A26.
A left boat 31, which can be freely moved together with a boat lever 28 by a rotation pin 30, is elastically biased by a force τ1 against a stopper A32. A guide roller 5 is provided at one end of the boat lever 28, and a boat spring B 33 for biasing the left boat 31 counterclockwise is provided near the guide roller 5. The boat 31 has guide rollers 8, 10 . An inclined post 9 is provided, and the roller holder 34 of the guide roller 5c6T portion engages with seven surfaces of the stopper A32, and the end surface 31a of the boat 31 at the lower end of the guide roller 10 comes into contact with the stopper A32. position. The tip of the cam plate 36 is rotated counterclockwise around the cam shaft 36 by a boat pin A26. This cam plate 36 is provided with a slide pin 37, and the slide plate 36 is provided with a slide pin 37.
8 against the slide pin 39, and insert the guide pins 40, 4
1 and move in parallel from left to right. This slide board 3
8 includes a full width erasing head 6 and an impedance roller shaft 42 . Impedance roller 7 is fixed.

FIG. 7 shows a state in the middle of loading. The left boat 31 has a left boat guide 4 centered around the rotation pin 3o.
3, since the roller holder 34 at the bottom of the guide roller 8 comes into contact with it, it is held and loaded as shown in the figure. This is to improve the device area and the efficiency of post arrangement within the cassette.

Next, the light boat 44 will be explained. A post 12 and a guide roller 13 are fixed to the light boat 44, a light boat guide 45 having a U groove is sandwiched therebetween, and a boat plate 46 is fixed with screws using boat support pins 47. The light boat 44 has a threaded part 442 of the guide roller 13 and the boat support pin 47 in the U groove of the light boat guide 45.
L is engaged and guided. One end of a boat arm 49 is engaged with the boat support pin 4Y, and the other ends of the four boat arms are engaged with a boat pin B27 provided on the boat support pin 4Y, and the light boat 44 is loaded together with the ring 25. . At the loading end, shaft holder 4
B engages with the 7 sides of the stop spit B 50, and the left boat 4
4 is positioned by abutting on the convex portion 50a of the Strozopa B50.

FIG. 8 shows the state of the light boat 44 at the loading start position.

In FIG. 6, reference numeral 51 indicates several plates of the audio control head 16 and the audio erasing head 14, 62 a capstan motor, 53 a capstan bolt, 64 a flywheel, and 56 a capstan nozzle.

The light boat 44 is guided by the light boat guide 45 and loaded until it engages with the stopper B50.

The left boat 31 is regulated by the left boat guide 43 from inside the cassette until just before the end of loading, and is loaded in the attitude shown in FIG. , and then positioned by stopper A32. The slide 38 moves with the movement of the boat pin A26,
Full width erase Hesdro? The seven impedance rollers are set in their proper positions. This completes the loading operation.

With the above configuration, the following effects can be obtained.

(1) By reducing the angle at which the tape from the rotating head drum wraps around the inclined post 12, the occurrence of stick-slip→jitter, which was conventionally thought, can be suppressed.

Next, changes in the wrapping angle obtained through specific design are shown.

■Conventional type: Wrapping angle: 76 degrees ■Main tape pass: Wrapping angle: 36 degrees (2) Conventional M pass:
The area from point P to point H on the outer circumferential surface of the rotating head drum was located at a higher position than the tape inside the cassette, so if parallel loading was performed, the tape would be damaged by the lead of the rotating head drum when loading the tape from P to N. There was a problem with being exposed. This becomes even more of a problem when using thinner tapes. On the other hand, in this tape bus, the point P is
By moving to 2, the length from P2 to H became shorter, and
Since the tape height at point P2 is lower than the internal height of the cassette (Q), the length of the tape at a position higher than the internal tape of the cassette is greatly reduced compared to the past. The chance of damage to the tape is reduced accordingly, and it can be said that the tape path is less difficult for the tape.

[Effects of the Invention] As described above, according to the present invention, the tension of the tape after passing through the rotating head drum can be reduced.

[Brief explanation of the drawing]

FIG. 1 is a plan view of a conventional magnetic recording/reproducing apparatus, FIG. 2 is a plan view of a magnetic recording/reproducing apparatus according to an embodiment of the present invention, and FIGS. 3, 4, and 6 are illustrations of the same apparatus. 6 to 10 are a plan view and a side view of the device. 1... Kasezoto, 9, 12... Inclined post, 11... Rotating head drum, 17...
... Capstan, 31 ... Left boat, 4
4...Light boat. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2 Figure 8 Figure 4 Figure 2 Figure 5

Claims (2)

[Claims] (1) A tape loading device configured to pull out the tape from the tape cassette only in a plane parallel to the mounting surface of the tape cassette and wind it around a rotating head drum at a predetermined angle; Radodra to rotation. The tangential direction at the point where the remaining winding angle is wound around the rotary head drum and the inclination direction of the rotary head drum with respect to the plane are set to different directions, and the point that becomes the tangent to the rotary head drum is set to A magnetic recording/reproducing apparatus characterized in that the tape is set at a point exceeding a winding angle A from a winding start point. (2) The magnetic recording and reproduction according to claim 1, wherein the inclination direction of the rotary head drum is set such that the height of the tape existing at a point that is tangent to the rotary head drum is different from the height of the tape in the cassette. Device.