JPS5823668B2 - Tape cassette - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic tape cassette, and more particularly to a pad constant pressure maintaining device that maintains a constant contact pressure of a magnetic tape against a magnetic head when loaded into a recording/reproducing device.

Generally, when a magnetic tape stored in a cassette is loaded into a recording/reproducing device, it is pushed by a magnetic head and is sandwiched between a pad built into the cassette and the head surface of the magnetic head.

Conventionally, as shown in Fig. 1, the above structure is such that a leaf spring 2 with both ends supported is provided inside a cassette 1, a pad 3 is attached to this leaf spring 2, and when the cassette 1 is loaded into a recording/playback device, the magnetic The pad 3 is pressed by the head 4, and at this time, the pad 3 is pressed against the magnetic head 4 via the magnetic tape 5 by the pushing back action of the leaf spring 2.

However, in the conventional mechanism described above, the relative position between the pad 3 and the magnetic head 4 changes depending on the loaded state of the cassette 1, and as the magnetic head 4 is placed in the direction of the arrow in the figure with respect to the position of the cassette 1, the leaf spring The amount of deflection of pad 2 increases, and as a result, the contact pressure of pad 3 with tape 5 fluctuates (see FIG. 2).

The pressure fluctuations of the pad 3 have a great effect on the quality of the recorded sound, so conventionally this problem has been solved by strictly determining the relative position of the cassette 1 with respect to the magnetic head 4. It was extremely difficult to obtain the desired precision during manufacturing and assembly.

In view of this, it is an object of the present invention to provide a constant pressure maintaining device for a pad that can always keep the pressing force of the pad applied to the magnetic head constant even if the relative positional relationship between the cassette and the magnetic head is out of order. It was done for a purpose.

In order to achieve the above object, the present invention provides a support member in a cassette that can be freely displaced by being pressed by tentacles that protrude in a certain relationship with the head surface of a magnetic head of a recording/reproducing device. The member supports a spring piece that maintains a constant spring pressure regardless of the displacement of the member, and a pad facing the magnetic head is attached to this spring piece, and when loading a cassette, the supporting member is used to maintain a constant spring pressure. The pad pressure is always pressed against the magnetic head by a predetermined spring pressure of the spring member.

The present invention will be explained below with reference to embodiments shown in the drawings.

In FIG. 3, the tape cassette 10 has a reel 1 inside.
1 and 12 are arranged in parallel, and one end face of the cassette 10 is provided with a window hole 14 into which the magnetic head 13 enters when being loaded into a recording/reproducing apparatus.

A magnetic tape 5 is positioned inside the window hole 14 and runs between the reels 11.12 along guide rollers 15.16.

A pad support mechanism 17 installed in the cassette 10 corresponding to the window hole 14 has pins 18 at both ends inside the cassette 10.
, 18 and 19, 19. A spring piece 21 is provided on this support member 20, one end of which is fixed and the other end of which is movable.The pad 3 is attached to this spring piece 21. Being ignored.

The support piece 20 has a contact surface portion 20a on which a tentacle that protrudes from the device side with a certain relationship to the head surface 13a of the magnetic head 13 comes into contact when the support piece 20 is loaded into the recording/playback device.
, 20a.

The tentacles 22.22 in this actual estimation consist of protrusions that protrude by a certain length from the head surface 13a on the upper and lower sides of the magnetic head 13, and when the cassette is loaded, the tentacles 22.22 touch the contact surfaces 20a, 20a of the support member 200. It is configured to suppress and displace this when it hits.

Since the present invention has the above-mentioned configuration, when the cassette 10 is loaded into the recording/playback device, the tentacles 22, 22 first move toward the support member 20.
0 contact surface portions 20a, 20a, and this support member 20 is retreated.

At the same time, the head surface 13a of the magnetic head 13 hits the pad 3 of the spring piece 21 with the magnetic tape 5 sandwiched therebetween, and the tape 5 is sandwiched between the pad 3 and the magnetic head 13.

In this case, the reaction force of the support piece 200 does not act on the head surface 13a of the magnetic head 13, but is received by the tentacles 22, 22, and only the reaction force of the spring piece 210 acts on the head surface 13a through the pad 3. .

Therefore, a constant pressure due to the initial set pressure of the spring piece 21 applies a reaction force to the pad 3, and therefore the magnetic tape 5
The contact pressure between the magnetic head 13 and the head surface 13a of the magnetic head 13 is always kept constant.

As is well known, the magnetic head 13 has the function of exchanging magnetic force into current, and at this time, because it converts extremely weak magnetic force into current, it may pick up magnetic force from sources other than the tape 5, which causes noise. However, in the present invention, the magnetic head 13 is hidden by the support member 20, so by using a highly permeable material such as permalloy for the support member 20, its shielding effect causes the above-mentioned problems. The negative effects will be resolved all at once.

As explained above, in the present invention, the spring piece that supports the pad is supported by the support member, and the support member is provided with a tentacle installed on the side of the recording/playback device in a certain relationship with the head surface of the magnetic head during loading. Since the positional shift is absorbed and the tape is pressed against the head surface of the magnetic head by the predetermined pressure of the spring piece at that position, even if there is a change in the positional relationship between the cassette and the magnetic head when loading the cassette, the tape will not be removed. Therefore, deterioration of sound quality is prevented due to fluctuations in pad pressure, and good recording can always be performed.

Further, as mentioned above, there are various effects such as the ability to prevent the generation of noise due to the shielding effect of the support member.

[Brief explanation of the drawing]

Figure 1 is a schematic plan view showing a conventional pad support mechanism;
The figure shows the pad pressure characteristic diagram, Figure 3 is a cross-sectional plan view of the main part of the tape cassette equipped with the device of the present invention, Figure 4 is an enlarged front view of the device of the present invention, and Figure 5 is the device of the present invention. FIG. 6 is an explanatory diagram showing the operational status during loading of a cassette, and FIG. 7 is a pressure characteristic diagram of the pad according to the apparatus of the present invention. 3...Pad, 10...Cassette, 1
3... Magnetic head, 20... Supporting member, 21... Spring piece.

Claims (1)

[Claims] 1. A supporting member is provided in the cassette and can be freely displaced by being pressed by tentacles that protrude in a fixed relationship with the head surface of the magnetic head of the recording/reproducing device. A device for maintaining a constant pad pressure in a tape cassette, which supports a spring piece designed to maintain a constant spring pressure, and a pad facing the magnetic head is attached to the spring piece.