JPS5813478Y2 - Tape tension device in magnetic recording and reproducing equipment - Google Patents

Description

[Detailed Description of the Invention] The present invention is a magnetic recording/reproducing device such as a video tape recorder (VTR), in particular, a magnetic recording/reproducing device that can automatically determine the size of an inserted tape cassette and vary the span length of the tape cassette. This invention relates to improvements in tape tension devices in recording and reproducing devices.

In order to be able to use tape cassettes of different sizes in magnetic recording and reproducing devices, such as VTRs, devices have been proposed that can distinguish between the sizes of large and small cassettes and automatically vary the reel stand span length. ing.

However, conventional devices of this type have disadvantages in that the rotation of the reel stand is not smooth and the engagement of the cassette with the cassette guide shaft is not very good.

Another problem is that the reel is difficult to fit into the reel stand when inserting the cassette.

The present invention was devised to improve the drawbacks of such conventional devices, and will be described below with reference to embodiments shown in the drawings.

In the embodiment shown in FIGS. 1 to 3, 1 on the upper side of the drawing
A to 1c are reel stands, and helical gears are formed on the outer peripheral surface of each reel stand.

(However, a helical gear is not formed in a portion of the reel stand 1c.

) Reference numeral 26a at the bottom of the drawing is a reel stand corresponding to the reel stand 1a, and those corresponding to the reel stands 1b and lc are symmetrical, so illustration thereof is omitted.

2゜2' is a reel lever that can rotate around axis 01.

Reel stands 1a and 26a are placed thereon.

3, 4, and 5 are connected to the reel switching plate 12 by connecting levers.

Reference numeral 6 denotes an S tension operating lever, one end of which is connected to the levers 4 and 5, and one end of an operating rod 7 is connected to the other end.

The other end of the operating rod 7 is connected to one end of an S tension operating lever 8.

This lever 8vC is designed to come into contact with a stopper 9, and a tension spring 10 is attached to the other end of the lever.
One end of the spring is coupled, and the other end of the spring is engaged with one end of the rotatable tension regulator arm 11 via a predetermined member.

The reel levers 2, 2' are spring-loaded to the member 13.

The members 14a, 14b, 15a, 15b are the detection lever 1
It is provided between the S-tension actuating lever 8a and the S-tension operating lever 6, and is adapted to be interlocked when a cassette is detected.

A spring 16 applies a biasing force to the one member 14a.

17 is a tension band, one end of which is attached to the reel stand 1c [
the other end is the tension regulator arm 11
is combined with

The detection lever 18a is rotatably supported at a fulcrum 18b, and as will be described later, when a cassette is inserted, a member 18c attached to the upper end of the lever 18a comes into contact with the side end surface of the cassette depending on the size of the cassette. It is designed to rotate in contact with each other.

Reference numeral 21 denotes a cassette up plate, which is normally biased by a spring 25, and one end of which is provided with a stopper projection 21' for the lever 18a.

Reference numeral 22 denotes a lock lever for locking the reel lever 2 by engaging with a lock pin 22' in conjunction with a VTR loading ring (not shown).

23 is a board, and 24 is a reel hub.

In the mechanism configured as described above, the reel stand 1a placed on the reel lever 2 is rotated from the axis O to the axis 04' position depending on the size of the cassette to be inserted, and the reel base 1a placed on the reel lever 2 is rotated from the axis O to the axis 04' position. This is automatically set to the platform span length, but its operation will be explained first.

It goes without saying that the operation of the reel stand 26a placed on the reel lever 2' on the opposite side is the same as that for the reel stand 1a.

Now, as shown in FIG. 2, when a large cassette 20, for example, is inserted and the cassette setup plate 21 is pushed in, the reel switching plate 12 is moved to the member 1 depending on the position of the cassette detection lever 18a.
The support shaft 13a on 3 moves to the right with respect to VC.

As a result, the lever 4 connected to the reel switching plate 12
, 5.3 are operated to rotate about their respective axes as shown in FIG. 1, causing the reel lever 2 to rotate counterclockwise.

The reel stand 1a moves from the axis O to a position 04'.

At this time, it should be noted that, as shown in FIG. 2, only the biasing force of the spring 25 is acting on the cassette, and the cassette detection lever 18a is completely separated from the cassette. No lateral pressure is applied to the cassette.

As shown in FIG. 3, the lever 2 is interlocked with a loading ring (not shown), and the lever 22 engages with a lock pin 22' to be locked in a predetermined position.

In this case, even if the cassette is slightly eccentric to the reel stand position, both reel and reel stands can move a little until tape loading is complete, so that the reel and reel stand engage five times when the cassette is inserted, but as soon as loading is complete, Both reel stands are perfectly positioned.

FIG. 4 shows an example of the locking mechanism of the reel lever 2.

In the figure, 27 is a loading ring. 28 is a rotatable lever having a rolling wheel 29 at one end that moves while contacting the outer periphery of the loading ring 27; 30 is a rod that connects the lever 31 to the lever 28; 32 is the lever 3;
1 to one end of a rotatable lock operating lever 33.

A protrusion 34 that can engage with the lock lever 22 is provided at the tip of the lock operating lever 33, and the lock lever 22 is rotatable, with a central protrusion 35 that engages with the lock pin 22'. A recess 38 is formed therein, and a spring 36 with a relatively weak biasing force is coupled to the end.

When loading of the tape is completed, there is a protrusion 37 on the outer periphery of the loading ring 27 at a position immediately before loading is completed, and the rolling wheel 29 is placed on the protrusion 37, so that the lock operating lever 33 is moved in the direction of the arrow. rotated in the direction of
The protrusion 34 engages with the lock lever 22 to rotate it.

Therefore, the recess 38 of the lever 22 fits into the lock pin 2' to lock the reel lever 2.

Note that the reel lever 2 may be configured to be locked by a mechanism linked to the cassette setup mechanism immediately after the cassette is completely accommodated in the guide shaft.

Next, the automatic adjustment function of the tape back tension in the above embodiment will be explained.

In a VTR that can use large and small cassettes as described above, it is necessary to maintain the back tensions on both supply reel sides at appropriate values, especially when the tape runs in FWD.

Needless to say, this tension has a serious effect on the stability of head contact, tape running, etc.

Therefore, it is desirable that this tape back tension be constant regardless of the size of the reel diameter.

Therefore, in this invention, in consideration of such reasons, (a) the winding angles of large and small cassette tapes to the guides (guides from the guide around which the tape coming out of the S reel is wound to the S tension regulator guide side) are made the same. The guides are arranged so that the tape winding diameter ratio (the ratio of the diameter of the large diameter reel to the diameter of the small diameter reel) is the same for large and small cassettes.
The diameter of each reel is set so that (b) the strength of the S tension regulator spring 10 is automatically adjusted depending on the size of the cast.

That is, in FIG. 1, in the case of the small cassette 19, the tape passage first passes through the fixed guides G, G...
...It is designed to lead to the S-tension, regulation 3, arm, and guide G4.

Further, in the case of the large cassette 20, the tape path is such that the tape coming out from the small diameter reel hub 24c or the large diameter reel hub 24d passes through fixed guides G, G, . . . and reaches G43.

In this case, fixed guide G1. G3. G4... The wrapping angle of the tape and the fixed guide G2. G3. G
Each guide shaft and the S reel shaft are arranged so that the winding angle of the tape with respect to 4 is approximately equal in position.

Next, the strength of the spring 10 is automatically adjusted as described below.

For example, when the small cassette 19 is inserted into the cassette setup plate 21 and pushed in the C direction as shown in FIG. and 15a do not operate.

Therefore, since the S-tension operating lever 6, the operating rod 7, and the S-tension operating lever 8 connected to the lever 15a are not interlocked, the biasing force of the spring 10 is kept constant by the stopper 9, and the tension regulator arm 11. A load force is applied to the reel stand 1c via the tension band 17.

On the other hand, when the large cassette 20 is inserted as shown in FIG. 2, the detection lever 18a moves to the position indicated by the two-dot chain line.
When the cassette setup plate 21 is pushed in the C direction in this state, unlike when inserting a small cassette, each lever 15b, 1
5a, 14at 14bt6, 7, 8 and the spring 10 are interlocked, and the force applied to the tension band 17 is made stronger by the spring 10.

Thus, according to the present invention, as described above, the magnetic recording and reproducing apparatus which can discriminate the sizes of large and small cassettes and automatically vary the span length of the reel stand is improved, and the following effects can be obtained.

(a) Even if cassettes of different sizes are used, the S-side bank tensions can be made to have the same tendency.

(b) As a result, tape running, head contact, etc. can be stabilized regardless of the size of the cassette.

[Brief explanation of the drawing]

Fig. 1 is a schematic configuration diagram of one embodiment of the present invention, and Fig. 2 is a schematic diagram of an embodiment of the present invention.
3 is a sectional view taken along the line AA' in the figure, FIG. 3 is a view taken from direction B in FIG. 1, and FIG. 4 is a view showing an example of a locking mechanism used in the present invention. 1a-1c...Reel stand, 18a...
Cassette detection lever, 10...Tension spring.

Claims (1)

[Scope of utility model registration request] A pair of rotatable reel levers, a pair of reel stands placed on the reel levers, a reel switching plate that moves according to the size of the cassette when a cassette is inserted, and this reel switching plate and a means for interlockingly rotating the reel lever in a predetermined direction, and configured to determine the size of a large or small cassette and automatically vary the span length of the reel stand, with the cassette inserted. a cassette detection lever attached to the cassette amplifier board; and a cassette detection lever attached to the cassette amplifier board; and the reel switching plate, rotate the reel lever, and
The reel switching plate includes a tension spring that applies a load force to the reel stand, and a tension arm that works together with the tension spring to detect the tension of the magnetic tape and detects the load force applied to the reel stand. 1. A tape tension device for a magnetic recording/reproducing apparatus, characterized in that the load force of the tension spring is changed in conjunction with the above, so that tape tensions in large and small cassettes are approximately the same.