JPS6358688A - Structure of guide pin - Google Patents

Abstract

PURPOSE:To stabilize the drive of a magnetic tape and at the same time to improve the rubbing characteristics of a magnetic tape, by fitting externally a sleeve made of a nonmagnetic matter having a low frictional coefficiency and high wear resistance to the magnetic tape to a guide pin. CONSTITUTION:A sleeve 13 made of nonmagnetic stainless of tungsten carbide, etc. and having its well-polished outer surface is fitted and fixed with pressure to guide pins 5 and 5' set at positions near an opening part for magnetic head of a tape cassette main body 1. A magnetic tape 2 rubs a magnetic head 7 with prescribed contact pressure in its drive mode and is held between a pressure pad 10 and the head 7 to produce tension F. In this case, the tape 2 rubs the outer circumference surface of the sleeve 13 fitted externally to pins 5 and 5' with prescribed contact pressure and at a fixed winding angle. Here the sleeve 13 is made of a nonmagnetic matter having a low frictional coefficient and high wear resistance to the tape 2 and therefore no electrification of the tape 2 is caused together with no deformation of both pins 5 and 5' due to their own friction. Thus the stable drive is secured with the tape 2.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to the structure of a guide pin for a tape cassette loaded into a magnetic recording/reproducing device.

Background of the Invention In recent years, there has been a demand for higher quality recording and playback functions, particularly in magnetic recording and playback devices in the audio field. It is desired to improve the precision of the positional relationship between the tape running system of the magnetic tape and the magnetic head. This requirement is particularly strong in fields that require high recording density, such as digital audio tape recorders (DAT).In other words, cassette-type digital audio chips generally have an order of magnitude more recording trunks than conventional analog cassette-type tapes. This is because the track width has become narrower, on the order of several tens of crm.

Furthermore, improvement of the sliding characteristics, which affects the deviation (sinter) in the time axis direction during tape running, is also an important issue in achieving higher recording densities.

If the functions related to these requirements are not improved or if the functions deteriorate, the short wavelength information will deteriorate due to azimuth fluctuation or track misalignment between the magnetic tape and the magnetic helad, 1 phase shift, etc. This causes problems and the audio playback waveform becomes unstable.

As mentioned above, the reasons why the tape running system of magnetic tape becomes unstable and the sliding characteristics of magnetic tape deteriorate are as follows.
This is largely due to friction between a guy pin provided inside the tape cassette, which will be described later, and the magnetic tape guided by the guide pin, and wear of the guide pin.

Hereinafter, the above cause will be explained in detail based on FIGS. 4 to 6, which show the internal conditions of a conventional tape cassette A used in a magnetic recording/reproducing apparatus.

The magnetic tape 2 stored in the tape cassette main body 1 has a guide roller 3.3' and guide pins 4, 4', 5.5'.
Both ends are respectively wound onto cassette reels 6 and 6' via the cassette reels 6 and 6'. The guide pins are often integrally molded together with the tape cassette main body 1, and are made of synthetic resin.

In the vicinity of the guide pins 5, 5' of the tape cassette body 1, when the tape cassette A is loaded into a magnetic recording/reproducing device, there is a magnetic An opening 8 for the head 7 (see FIGS. 5 and 6) to emerge and retract is provided.

A pressure pad 10 supported by a magnetic shield plate 9 is provided on the back side of the magnetic tape 2 running through the opening 8. The pressure pad 10 is generated when the magnetic head 7 presses the pressure pad 10 through the magnetic tape 2 when the magnetic head door enters the tape cassette body 1 through the opening 8 (see FIG. 6). The elastic force of the pressure band 10 is used to bring the magnetic tape 2 into sliding contact with the magnetic tape 7 at a predetermined contact pressure (see FIG. 6).

In the tape cassette A configured as described above,
When the magnetic tape 2 is driven to run in the direction of the arrow 11 by a drive mechanism (not shown), and the magnetic head 7 presses the pressure band 10 through the magnetic tape 2 in order to come into sliding contact with the magnetic tape 2 with a predetermined contact pressure. (See FIG. 6) The magnetic tee 12 is subject to vibration due to the frictional force generated by being held between the pressure band 10 and the magnetic head 7.

A tension F(
(see Figure 6) occurs.

At this time, as shown in FIG. 6, the magnetic tape 2 comes into sliding contact with the guide pin 5.5' with a constant contact pressure and the winding is at a corner.

Since the tape cassette A is constructed as described above, the guide pins 5 and 5', which are made of synthetic resin material and are provided near the magnetic head 7, are pushed against the magnetic tape 2 by friction with the magnetic tape 2. This causes problems such as charging and deformation of the guide pin 5.5' itself due to wear.

The charging of the magnetic tape 2 and the deformation of the guide pins 5, 5' themselves cause chattering of the magnetic tape 2 and cause of fluctuation (waving) of the magnetic tape 2 in the width direction. The tape running system becomes unstable and the sliding characteristics of the magnetic tape 2 deteriorate.

Purpose of the Invention The present invention was devised in view of the above circumstances, and aims at stabilizing the tape running system of the magnetic tape and reducing the sliding characteristics of the magnetic tape by improving the structure of the guide pin. The purpose of this invention is to provide a guide pin structure that will not cause problems.

Structure of the Invention In order to achieve the above-mentioned object, the main means adopted by the present invention is that the tape cassette loaded in the magnetic recording/reproducing apparatus is provided in the vicinity of the magnetic head exit/exit opening; In the structure of the guide pin that guides the magnetic tape in the cassette by sliding it on the surface, a sleeve made of a non-magnetic material that has a low coefficient of friction and high wear resistance against the magnetic tape is fitted onto the guide pin. This is the structure of the guide pin according to the following points.

EXAMPLES Hereinafter, examples embodying the present invention will be described with reference to the accompanying drawings to provide an understanding of the present invention.

It should be noted that the following examples are examples embodying the present invention, and are not intended to limit the technical scope of the present invention.

Here, FIG. 1 is an explanatory diagram of the structure of a guide pin according to an embodiment of the present invention, and FIG. 2 is an illustration of the structure near the magnetic head when a tape cassette having the above guide pin structure is loaded in a magnetic recording/reproducing apparatus. The plan view and FIG. 3 are explanatory diagrams of the structure of a guide pin according to another embodiment of the present invention.

Further, the same reference numerals will be used for the same elements as in the conventional tape force center having guide pins shown in FIGS. 4 to 6.

The structure of the guide pin according to this embodiment is shown in FIGS. 1 and 2.
As shown in the figure, the guide pin 5 (5') of the conventional tape cassette body 1 (see Figs. 4 to 6) has a low friction coefficient and high durability against the magnetic tape 2 (see Fig. 2). A sleeve 13 made of a thin cylinder made of highly abrasive non-magnetic material (for example, non-magnetic stainless steel or tungsten carbide with a sufficiently polished outer surface) is fitted onto the outside.

In this embodiment, the sleeve 13 is fixed to the guide pin 5 (5') by press fitting.

In the tape cassette having the guide pin structure as described above, the magnetic tape 2 is driven to run in the direction of the arrow 11 by a drive mechanism of a magnetic recording/reproducing device (not shown), and the magnetic tape 7 is When the pressure pad 10 is pressed through the magnetic tape 2 to make sliding contact with the magnetic tape 2 with a predetermined contact pressure, the outer magnetic tape 2 is held between the pressure pad 10 and the magnetic pad 7. Due to the frictional force generated by this, tension F (see FIG. 2) is generated between the pressure pad 10 and a drive mechanism (not shown).

At this time, as shown in FIG. 2, the magnetic tape 2 comes into sliding contact with the outer circumferential surface of the sleeve 13 fitted around the guide pins 5, 5' with a certain contact pressure and the angle of the winding. As described above, since the sleeve 13 is made of a non-magnetic material with a low coefficient of friction and high wear resistance, the magnetic tape 2 due to friction with the magnetic tape 2 as in the conventional guide pin 5.5'. There are no problems such as charging of the guide pin 5.5' or deformation of the guide pin 5.5' itself due to wear.

As a result, smooth tape running can be ensured over a long period of time without damaging the magnetic tape.
Accurate and stable tracking can be performed.

In the above embodiment, the sleeve 13 is externally fitted onto the guide pin 5.5' provided near the magnetic head 7, but other guide pins 4.4' (
It goes without saying that the same effect can be obtained even if the sleeve 13 is externally fitted onto the sleeve (see FIG. 4).

Furthermore, as shown in FIG. 3, the structure of the guide pin is changed by removing the sleeve 14 in which the guide pin 5 (5') is formed with a split 14' parallel to the axis of the guide pin 5 (5'). It may also be constructed by fitting.

In this case, the inner diameter of the sleeve 14 is the same as that of the guide pin 5.
(5'), and when the sleeve 14 is fitted onto the guide pin 5 (5'), an elastic force acting in the radial direction of the sleeve 14 causes the sleeve 14 to be attached to the guide pin 5 (5'). (5').

Therefore, even if there is some variation in the external dimensions of the guide pin 5 (5"), the sleeve 14 can be easily attached to the guide pin 5.
(5').

It goes without saying that when the sleeve 14 is fitted onto the guide pin 5 (5'), the split 14' of the sleeve 14 should not be located in the sliding contact area with the magnetic tape 2.

Effects of the Invention As described above, the present invention provides a tape cassette installed in a magnetic recording/reproducing apparatus near an opening for the emergence and retrieval of a magnetic head, and guides the magnetic tape in the tape cassette by slidingly contacting the surface thereof. The structure of the guide pin is characterized in that the guide pin is fitted with a sleeve made of a non-magnetic material having a low coefficient of friction and high wear resistance against the magnetic tape. Therefore, it is possible to provide a guide pin structure that stabilizes the tape running system of the magnetic tape and does not deteriorate the sliding characteristics of the magnetic tape.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of the structure of a guide pin according to an embodiment of the present invention, and FIG. 2 is a plan view of the vicinity of the magnetic head when a tape cassette having the above guide pin structure is loaded in a magnetic recording/reproducing device. , FIG. 3 is an explanatory diagram of the structure of a guide pin according to another embodiment of the present invention, FIG. 4 is a perspective view of the inside of a conventional tape force center commonly used, and FIG. FIG. 2 is a plan view of the vicinity of a magnetic head when a tape cassette having a conventional guide pin structure is loaded into a recording/reproducing apparatus. (Explanation of symbols) 4.4', 5.5'...Guide pin 13.14...Sleeve

Claims (1)

[Claims] In the structure of a guide pin that is provided in the vicinity of a magnetic head exit/exit opening of a tape cassette loaded in a magnetic recording/reproducing device and guides the magnetic tape in the tape cassette by slidingly contacting the surface thereof, the guide pin is provided with the above-mentioned A structure of a guide pin characterized in that a sleeve made of a non-magnetic material having a low coefficient of friction and high wear resistance is fitted around a magnetic tape.