JPH0544094B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a magnetic recording and reproducing device, and in particular, during a loading operation in which a magnetic tape pulled out from a cassette is wound onto a cylinder equipped with a video head, an audio control head is The present invention also relates to a magnetic recording/reproducing device for a VTR which performs a loading operation.

[Background of the Invention] Conventionally, in an ordinary VTR magnetic recording/reproducing device that uses a standard diameter cylinder and has a winding angle of 180°, the audio control head does not move and remains at a fixed position during loading operation. Adjustment of the length of the magnetic tape from the video head of the cylinder to the audio control head (hereinafter referred to as the X value) is
By biasing the audio control head mounting plate against the tapered screw with a spring and moving the tapered screw forward or backward,
This was accomplished by moving the audio control head mounting plate using the tapered portion.

However, the VTR, which was designed to be smaller and lighter in weight, also had the audio control head in a loading operation.
Especially for VTRs with small cylinders and large wrap angles,
Since many tape guides are required to change the tape posture, there are many space constraints around the cylinder. Therefore, it is difficult to adjust the X value using the conventional tapered screw described above.

One way to adjust the X value without using a tapered screw is to drill two adjustment holes in the audio control head mounting plate and move the mounting plate back and forth. Since the mounting plate slides, there are problems in that not only is it difficult to align the position during adjustment, but also fine adjustments cannot be made.

Regarding the X value adjustment mechanism, the
There is a publication number 39523.

[Purpose of the invention]

The present invention eliminates the above-mentioned problems of the prior art and provides accurate X-value in a magnetic recording/reproducing device for a small and lightweight VTR, especially a VTR with a small cylinder and a large winding angle, in which the audio control head also performs a loading operation. The object of the present invention is to provide a magnetic recording/reproducing device equipped with an X value adjustment mechanism that can be easily adjusted.

[Summary of the invention]

The configuration of the magnetic recording and reproducing device according to the present invention is that it is attached to an audio control head mounting plate, and
It has an audio control head whose winding angle is secured by an inlet tape guide member provided on the audio control head mounting plate and an outlet tape guide member provided on the audio control head loading arm, and the tape can be pulled out from the cassette. In a magnetic recording and reproducing device for a VTR, the audio control head is also loaded during a loading operation in which a magnetic tape is wound onto a cylinder equipped with a video head. A rotation fulcrum is provided in a direction approximately 90 degrees from the point of contact with the entrance tape guide member with respect to the direction in which the magnetic tape enters the guide member, and the audio control head mounting plate is rotatably attached to this rotation fulcrum. This is how it was done.

[Embodiments of the invention]

Before entering into the description of the embodiments, basic matters related to the present invention will be explained.

When a small cylinder is used to reduce the size and weight of a VTR, the winding angle of the cylinder becomes large and the number of tape guides for controlling the attitude of the magnetic tape increases by one or more. The range and the tape running position of the audio control head overlap. Therefore, it is necessary to also perform a loading operation on the audio control head and move it to the tape running position after the tape running member has passed. However, due to space constraints, it is no longer possible to mount the tapered screws conventionally used to adjust the X value.

The above-mentioned X value is the length of the magnetic tape from the control head to the position where the magnetic head attached to the cylinder starts to come into contact with the magnetic tape.
In other words, in FIG.
0 corresponds to the length of the magnetic tape up to the position where the magnetic tape 9 starts contacting the cylinder 33 via the output side guide roller 8 and the output side inclined pin 7. Compatibility of cassette tapes can be achieved by specifying this X value to a predetermined length; therefore, for example, the VHS standard specifies this X value as 79.24 mm.

Further, when VTRs are manufactured, they are assembled so that this X value falls within an error range of about the track width of a magnetic tape. Therefore, after assembly, an adjustment reference tape is attached and played back, and the position of the audio control head 12 is adjusted so that the playback output is maximized to optimally set the X value.

The present invention relates to improving the efficiency of the X value adjustment, and as shown in FIG. The length of the magnetic tape between the members 11 is adjusted.

Therefore, in the present invention, as shown in FIG.
An audio control head mounting plate 25 is provided which can rotate about the mounting shaft 13a of the head. Note that FIG. 1 shows the loading state of the audio control head 12.

The magnetic tape 9 enters from the third inclined pin 10 side, is bent by the inlet tape guide member 11 provided on the audio control head mounting plate 25, and comes into contact with the audio control head 12, and then reaches the outlet tape guide member 13. It flows out from the side.

In the present invention, the magnetic tape direction between the third inclined pin 10 and the entrance tape guide member 11 (in FIG.
The angle θ formed by the straight line connecting the inlet tape guide member 11 and the outlet tape guide member 13 is set to be about 90 degrees.

The X value (tape length between the cylinder and the audio control head) is determined by adjusting the adjustment screw 22 provided on the loading arm 18 to adjust the audio control head mounting plate 25 to the output side tape guide member 13.
Use this as a fulcrum to rotate and adjust. That is, by adjusting the X value, the length of the magnetic tape between the third inclined pin 10 and the inlet tape guide member 11 is changed, so that the audio signal of the audio control head can be synchronized with the video signal.

Also, since the adjustment range of the above X value is small, the above is omitted.
The 90 degree angle θ hardly changes. As a result, the third
Since the winding angle of the magnetic tape around the inclined pin 10 hardly changes, the X value can be adjusted while keeping the running and guiding properties of the tape stable. In addition,
If the audio control head mounting plate is biased by a torsion spring so that it comes into contact with the adjustment screw installed on the audio control head loading arm, the audio control head can be installed by moving the adjustment screw forward and backward. The X value can be adjusted by rotating the plate, and the X value can also be finely adjusted by adjusting the rotation angle of the adjustment screw appropriately.

Hereinafter, the present invention will be explained with reference to Examples.

FIG. 1 is a plan view showing details of the X-value adjusting mechanism in a magnetic recording/reproducing apparatus according to an embodiment of the present invention, FIG. 2 is a side view of the X-value adjusting mechanism according to FIG. 1, and FIG. 4 is a schematic plan view showing a magnetic recording and reproducing apparatus equipped with the X value adjustment mechanism according to FIG. 1; FIG. 4 is a plan view showing a state in which the FIG. 5 is a plan view showing a state where the X value is shortened by δ from the state shown in FIG.

First, the outline of this magnetic recording/reproducing device will be explained using the drawings.

The tape is attached to the audio control head mounting plate 25, and the wrapping angle is determined by the entrance tape guide member 11 provided on the audio control head mounting plate 25 and the exit tape guide member 13 provided on the audio control head loading arm 18. The magnetic tape 9 pulled out from the cassette 1 is transferred to the cylinder 33 equipped with the video head.
During the loading operation for winding the magnetic tape 9 on the tape, the audio control head 12 is also loaded, and the magnetic tape 9 is moved in the direction in which the magnetic tape 9 enters the entrance tape guide member 11 on the audio control head loading arm 18. On the other hand, a mounting shaft 3a of the exit tape guide member 13 is provided in a direction approximately 90° from the contact point with the entry tape guide member 11, and the audio control head mounting plate 2 is attached to the mounting shaft 13a.
5 is rotatably attached, and an adjusting screw 22 that can move forward and backward is attached to the audio control head loading arm 18.
This is a magnetic recording/reproducing device in which an audio control head mounting plate 25 urged by a torsion spring 21 is brought into contact with the head.

Next, details of the X value adjustment mechanism of this magnetic recording/reproducing apparatus will be explained using FIGS. 1 and 2.

Reference numeral 20 denotes an arm rotation fulcrum installed in the chassis 34. A compression spring 30 is attached to the lower outer peripheral side of the arm rotation fulcrum 20, and the audio control head loading arm 18 is mounted on the compression spring 30.
A cylindrical attachment portion 18a is fitted thereinto, and a nut 19 is further assembled via a retainer 31. Therefore, the audio control head loading arm 18 is biased upward by the compression spring 30, and by rotating the nut 19,
Its height can be adjusted. Also,
An adjustment screw 22 is attached to the audio control head loading arm 18.

The entrance tape guide member 11 is assembled into a mounting shaft 11a provided on the audio control head mounting plate 25, is pressed from below by a compression spring (not shown), and is tightened from above by a nut 27b. It is being

The output tape guide member 13 is assembled into a mounting shaft 13a related to a rotation fulcrum provided on the audio control head loading arm 18, is pressed from below by a compression spring 28, and is tightened from above by a nut 27a. It is being

The mounting shaft 13a is fitted into a hole drilled in the audio control head mounting plate 25, and the audio control head mounting plate 25 is fitted with the mounting shaft 13a.
5 is rotatable around the mounting shaft 13a, is biased clockwise by a torsion spring 21 attached to the base of the cylindrical mounting portion 18a, and is brought into contact with the adjustment screw 22. . Further, the audio control head mounting plate 25 has arc-shaped long holes 25a and 25b with setscrews 23a and 23b, which are centered around the rotational fulcrum, that is, the mounting shaft 13a. By tightening the screws 23a and 23b, the audio control head mounting plate 2
5 can be fixed to the audio control head loading arm 18. in this case,
Magnetic tape 9 wrapped around third inclined pin 10
, that is, the direction in which the tape guide member 11 on the entrance side advances.
The position of the mounting shaft 13a is at an angle θ=approximately 90° with respect to the direction in which the magnetic tape 9 enters.

The audio control head 12 is fixed to an audio control head mounting plate 25.

A tape running system of a magnetic recording/reproducing apparatus equipped with the above-mentioned X value adjustment mechanism will be explained with reference to FIG.

The magnetic tape 9 pulled out from the cassette 1 is connected to the tension pin 2, impedance roller 3, FE
Head 4, entrance guide roller, entrance inclined pin 6,
The tape runs through the cylinder 33, the output side inclined pin 7, the output side guide roller 8, the third inclined pin 10, the input side tape guide member 11, the audio control head 12, and the output side tape guide member 13, and connects the capstan 15 and the pinch roller. The running system is driven by 14. The magnetic tape 9 is wound around the cylinder 33 by approximately 270°+α, and the third inclined pin 1 is used as a member for tape attitude control, compared to a running system using a standard cylinder of the VHS system.
There are more and more 0's. Furthermore, since the position of the audio control head 12 when the tape is running is within the loading operation range of the output guide roller 8, the output guide roller 8 is loaded and, after passing, the audio control head 12 is loaded to the position when the tape is running. It's getting old.

The operation of the X value adjusting mechanism of the magnetic recording/reproducing apparatus constructed as above will be explained using FIGS. 4 and 5.

When the two set screws 23a and 23b are loosened and the adjustment screw 22 is rotated and moved forward,
The audio control head mounting plate 25 that is in contact with this rotates by +δ against the force of the torsion spring 21 (the state shown in Figure 4), and the X value becomes longer by δ, which is shorter than the normal X value. Adjustments can be made depending on the situation. Audio control head mounting plate 2
The mounting shaft 13a, which serves as a pivot point for the magnetic tape 9, is oriented so that the angle θ=approximately 90° with respect to the direction in which the magnetic tape 9 enters the entrance tape guide member 11. Therefore, even if the audio control head mounting plate 25 rotates and the position of the entrance tape guide member 11 changes, the change is a nearly linear movement, and the angle of the entrance direction of the magnetic tape 9 does not change. Therefore, the third inclined pin 10
There is almost no change in the winding angle of the magnetic tape 9, and there is no problem in maintaining the tape posture.

After adjusting the X value, tighten the setscrews 23a and 23b and attach the audio control head mounting plate 25 to the audio control head loading arm 1.
By fixing it to 8, the X value does not go out of order and is always kept in a stable state.

On the other hand, when the adjustment screw 22 is rotated and moved backward,
The audio control head mounting plate 25 that is in contact with this rotates by -δ (the state shown in Fig. 5),
Adjustment can be made when the X value is shorter by δ and is larger than the normal X value.

According to the embodiment described above, the X value can be adjusted by rotating the audio control head mounting plate 25 around the mounting shaft 13a, which is a pivot point provided on the audio control head loading arm 18. It can be carried out reliably and easily. Since the output side tape guide member is located on the mounting shaft 13a, which is a rotational fulcrum, when the input side tape guide member 11 on the audio control head mounting plate 25 rotates, the magnetic tape 9 is not attached to the audio control head 12. This has the effect that the X value can be adjusted while maintaining the wrapping angle.

Further, since the attachment shaft 13a of the output tape guide member 13 is shared as a rotational fulcrum, there is an advantage that the cost can be reduced.

Furthermore, the audio control head mounting plate 25 is biased by the torsion spring 21 and brought into contact with the adjustment screw 22 attached to the audio control head loading arm 18, and the X value is adjusted by moving the adjustment screw 22 forward and backward. Since this is done, there is an effect that the X value can be easily finely adjusted using the X value adjustment mechanism with a simple structure.

In this embodiment, the pivot point of the audio control head mounting plate 25 is shared with the mounting shaft 13a of the output tape guide member 13; It may be located anywhere as long as it is approximately 90° from the point of contact with the entrance tape guide member 11 with respect to the direction in which the magnetic tape 9 enters the entrance tape guide member 11 above.
However, if they are shared, the number of parts and assembly man-hours will not increase, resulting in lower costs.

In the above embodiment, the audio control head loading arm 18 is used to rotate the audio control head mounting plate 25.
Although the adjusting screw 22 attached to the housing is rotated, other means may be used.

An example of another means for rotating the audio control head mounting plate will be described below.

FIG. 6 is a plan view showing the main parts of the X value adjustment mechanism in a magnetic recording/reproducing apparatus according to another embodiment of the present invention, and FIG. 7 is a plan view of the main parts of the audio control head mounting plate in FIG. , FIG. 8 is a plan view of a main part of the audio control head loading arm in FIG. 6. In each figure, parts given the same numbers as in FIG. 1 are the same parts.

In this embodiment, instead of the adjustment screw 22, a stopper 35 that comes into contact with the audio control head mounting plate 25A is installed, an external recess 25c is provided in the audio control head mounting plate 25A, and the audio control head loading arm 1
8A, a notch hole 18b is bored at a position facing the external recess 25c.

In this configuration, the external recess 2
5c and the notch hole 18b, and by inserting a flat head screwdriver 36 and prying it, the audio control head mounting plate 25A is rotated relative to the audio control head loading arm 18A. Then, with the set screw 23 rotated by the amount of deviation from the set X value,
a, 23b to fix the audio control head mounting plate 25A to the audio control head loading arm 18A.

〔Effect of the invention〕

As described in detail above, according to the present invention, it is possible to accurately and easily set the X value in a magnetic recording/reproducing device for a small and lightweight VTR in which the audio control head also performs a loading operation, particularly for a VTR with a small cylinder and a large winding angle. It is possible to provide a magnetic recording/reproducing device equipped with an X value adjustment mechanism that can adjust the X value.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing details of the X-value adjusting mechanism in a magnetic recording/reproducing apparatus according to an embodiment of the present invention, FIG. 2 is a side view of the X-value adjusting mechanism according to FIG. 1, and FIG. 4 is a schematic plan view showing a magnetic recording and reproducing apparatus equipped with the X value adjustment mechanism according to FIG. 1; FIG. 4 is a plan view showing a state in which the Figure 5 is a plan view showing a state in which the X value is shortened by δ from the state in Figure 1, and Figure 6 is
FIG. 7 is a plan view showing the main part of the X value adjustment mechanism in a magnetic recording/reproducing apparatus according to another embodiment of the present invention, FIG. 7 is a plan view of the main part of the audio control head mounting plate in FIG. 6, and FIG. FIG. 7 is a plan view of a main part of the audio control head loading arm in FIG. 6; 1...cassette, 9...magnetic tape, 11...
Inlet tape guide member, 12... Audio control head, 13... Outlet tape guide member, 13a... Mounting shaft, 18, 18A...
Audio control head loading arm, 18b... Notch hole, 21... Torsion spring, 22... Adjustment screw, 25, 25A... Audio control head mounting plate, 25c... External recess, 33... Cylinder, 35... ...Stotsupa.

Claims (1)

[Claims] 1. During tape loading in which a magnetic tape is attached and wound around a cylinder, the loading arm of the audio control head is rotated around a first fulcrum to rotate the audio control head on the loading arm. In a magnetic recording/reproducing device for video signals which is brought into contact with a magnetic tape, an inlet tape guide member and an audio control head are mounted and are rotatable around a second fulcrum provided on the loading arm. a head mounting plate;
means for adjusting the rotation angle around the second fulcrum; further, the rotation angle adjustment means around the second fulcrum includes rotation angle setting means around the second fulcrum; the angle between the direction connecting the entrance tape guide member and the second fulcrum and the direction in which the magnetic tape enters the entrance tape guide is set to about 90 degrees, and the rotation The angle setting means rotates the head mounting plate around the second fulcrum to adjust the position where the video head starts contacting the magnetic tape and the X value, which is the length of the magnetic tape up to the control head. A magnetic recording/reproducing device characterized in that a head mounting plate is fixed to a loading arm. 2. The magnetic recording and reproducing apparatus according to claim 1, wherein the second fulcrum is an attachment member for attaching the output tape guide member to the loading arm. 3. In claim 1 or 2, the rotation angle setting means of the head mounting plate about the second fulcrum is attached to the loading arm and applies a biasing force to the head mounting plate about the second fulcrum. 1. A magnetic recording and reproducing device comprising: a spring that provides a biasing force; and an adjustment screw that rotates a head mounting plate against the biasing force of the spring.