JPS5840256B2 - film film - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a suppression device for pressing a film-like magnetic recording medium against a magnetic head during recording and reproduction.

Generally, when recording and playing back magnetic tape (hereinafter, magnetic tape will be described as a specific example of a film-like magnetic recording medium), it is necessary to slide the magnetic tape over a magnetic head in order to improve its recording and playback characteristics. It is necessary to bring the tape into close contact with the moving surface, and conventionally, a tape suppression device as described below has been used for this purpose.

1A and 1B are a side view and a top view, respectively, of the cassette tape as seen from the magnetic head side. In this case, a pressing device having the following structure is used.

That is, in this figure, 1 is an elastic member 1 in which a pad 13 made of velvet, rasher, felt, etc. is attached to a holding member 15 at a position corresponding to a recording/reproducing magnetic head 11;
4, and when the tape 12 is running, the pad 13 presses the tape 12 against the sliding surface of the magnetic head 11 across the peak of the pad 13, as shown in FIG. Bats with such a structure have been commonly used in conventional quantities.

However, with a tape bat of this structure, when the tape is running, the tape is pressed against the magnetic head across the butt gold mine, so when the tape is run repeatedly for a long time, the magnetic head slides as shown in Figure 3. The moving surface 11' is worn and the surface becomes uneven. At the same time, the magnetic powder attached to the magnetic surface of the tape 12 is scraped off due to the abrasion caused by the magnetic head and becomes attached near the magnetic head gap. This will cause a significant negative impact on performance.

Therefore, in order to devise a tape bat that eliminates the above-mentioned drawbacks, the present inventor conducted various experiments regarding the wear of the magnetic head, and obtained the following results.

(1) The life of a magnetic head is mainly determined by the amount of wear in the head gap and its vicinity.

(2) The amount of wear on the magnetic head depends on the pressing force between the tape and the magnetic head.

(3) The role of the tape bat is to use its pressure to create a frictional force between the magnetic head and the tape, and use that frictional force to create tape back tension, which also causes a component of the tape tension to be applied to the tape. It has become clear that this causes pressure contact force.

(4) The pressure generated by the bat is highly uneven, which is particularly unfavorable in terms of head wear.

(5) Due to the above-mentioned non-uniform and irregular pressure unevenness, a pressure of about 30 to 100 times the required contact force is applied in the high-pressure areas, which significantly accelerates head wear.

(6) The tape contact force is at least 0.05 fl/
I found out that ma is fine.

Based on the above results, the present inventors have found that by devising the pad structure, wear near the magnetic head gap can be significantly reduced, and high performance recording and playback can be achieved even after long-term use. and the outer part of the butt pressure is made different, and the pressure of the outer part is increased,
We found that the above-mentioned drawbacks can be eliminated by adopting a pad structure in which the pressure near the gap part is low, preferably O, and we conducted a more detailed experimental study on this point. (1) Gap A desirable value for the pressure difference between the inner part and the outside thereof should be several times or more, preferably 10 times or more.

Specifically, it is usually 50 to 10 in areas of the pad that are under high pressure.
Since it is approximately 0 g/crIL, the weak portion, that is, the gap portion and its vicinity, is preferably 5 to 1 ogycyt or less.

(2) In (1), the vicinity of the gap refers to a range of 0.1 to several inches from the tape sliding surface of the magnetic head, especially an appropriate width of about 0.2 to about 5 inches, centered around the gap. is selected depending on, for example, the tape material, the bat material, the shape of the magnetic head, etc.

Obtaining the above results, and taking these into consideration, the suppression according to the present invention adds improvements to the conventional tape suppression device to prevent uneven wear of the gap portion of the magnetic head caused by the pad and its vicinity. At times, the tape sliding surface mainly upstream of the gap portion is pressed against the tape running direction.

The term "bat" used here refers not only to conventional felt, but also to anything that has the purpose of minimizing the spacing cross between tape heads, stabilizing tape running, and applying appropriate back tension to the tape. It includes rigid bodies and isoelectric elements.

Hereinafter, the present invention will be explained in detail with reference to examples and the like.

Figure 4A shows an embodiment in which the present invention is applied to an open-reel type recording/playback device.The reel section, casing, and other parts other than the tape pressing device are completely unchanged from the conventional device, so the overall view is not shown. It is a top view when only a pressing device portion is picked up and enlarged.

Further, FIG. 4B is a side view thereof. Reference numeral 21 denotes a magnetic head, and when the tape feeding is stopped, the head 21 is normally located at the position indicated by the dashed line in the figure, but when the tape is running for recording/playback, etc., the head 21 is located at the position indicated by the dashed line in the figure. The head 21 moves in the direction of the arrow P to the point drawn by the solid line in the figure, and starts contacting the magnetic tape 22 with the tape sliding surface of the head 21.

Here, to explain the other coded parts, the part 23 indicated by a dotted line is the core 28 which is built in the magnetic head 21.
The gap 24 is a plate member 25 and 2 made of plastic etc. which is rotatably attached around the support column 21.
5' is a bat glued to one end of the plate; 26;
26' is a stopper for preventing rotation of the plate 24 beyond a certain angle, and the plate 24 and para) 25, 25' are the fourth stopper.
It has a shape as shown in the perspective view of Figure C.

Now, to explain the operation of this embodiment, when the tape 22 is at rest, the plate body 24 is in a state as shown by the dotted line in the figure, but when the tape 22 starts running in the direction of the arrow Q in the figure, The butt 25' located upstream of the gap 28 in the running direction of the tape 22 starts moving toward the gap 28 while pressing the tape against the tape sliding surface of the magnetic head 21 due to friction with the tape 22. do.

On the other hand, the plate 24 holding the bat also begins to rotate in the direction of arrow Q around the support post 27 due to the movement of the bat, but stops when the side end of the plate 26 hits the stopper 26.
Correspondingly, the bat 25' also stops moving, and presses the tape against the head sliding surface at the stopped position.

In this case, the stopper 26, 26' is provided at a predetermined position so that the bat 25' stops at a predetermined position on the tape sliding surface on the upstream side of the gap portion 28 with respect to the tape feeding direction. be.

Also, when the tape is fed in the opposite direction, the other bat 25 presses a predetermined position on the tape sliding surface in exactly the same manner as described above, so that the tape can be moved in either reversible direction. This device also works effectively.

By using a tape pressing device with such a structure, wear in and around the head gap, which has the most serious negative impact on the life and characteristics of the magnetic head, can be greatly reduced. All of the drawbacks of the device can be eliminated, and the longevity and characteristics of the head can be dramatically improved.

Further, the shapes of the plate body 24 and the pads 25, 25' are not limited to those shown in the above embodiment, but may be as shown in FIGS. 5A and 6A.

That is, FIG. 5A shows an example in which rotating bodies 29 and 29' such as pinch rollers made of an elastic material such as rubber are provided instead of bonding the pads 25 and 25' to the plate body 24 of the above embodiment. It is a top view, and Figure 5B is a side view at that time, and Figure 5B is a side view at that time.
Figure C is a perspective view.

Further, as shown in FIG. 6A, a thin metal plate 31 with spring properties is bonded to one end of the arm 30, and pads 25- and 25' are bonded to the metal plate, as shown in the side view of FIG. FIG. B1 A perspective view thereof is shown in FIG. 6C.

The tape suppression device according to the present invention as described above can be used not only in reel-to-reel type recording and reproducing devices, but also in all kinds of recording and reproducing devices that use magnetic tape.

By the way, if the embodiment of the present invention shown in Fig. 4 is applied to a tape cassette, it will become as shown in Fig. 7A, with almost no changes to the internal shape of the conventional cassette L housing (in this embodiment, the upper and lower lids are (A part of the inner wall 32 of the housing is ground to attach this device to a support 33 for joining the body) It is extremely small and can be easily installed.

FIG. 7B is an enlarged top view of the part related to the device of the present invention in FIG. 7A, and except for the inner wall 32 serving as the stopper in FIG. 4A, the other structures and operations are the same as in FIG. 4A. The case is exactly the same.

FIG. 8 is a schematic top view showing the outline of the second suppression device according to the present invention.

34 is a movable member for attaching a pad made of an elastic material such as phosphor bronze; 35 is a concave-shaped pad adhered to the movable member 34; 36 is a stopper for regulating the left and right movement of the movable member 34; 37 is a movable member for attaching the movable member 34; It is a holding member for holding the pad 35, and when the tape 22 is fed in the direction of the arrow W, the pad 35 moves horizontally to the left due to friction with the tape 22.
When the key-shaped part 38 provided at the side end of the movable member 34 that is integrated with the pad engages the stopper 36, the pad 35 stops, and the pad 35 stops at the stopped position (the outside of the head gap and its vicinity). (predetermined in advance so that the tape is at a predetermined position) is pressed against the magnetic head sliding surface.

FIG. 9 is a top view schematically showing a third tape suppressing device according to the present invention. To explain this structure, 40 is a seal plate 41 attached to one end of a pad holding member 39 having a shape as shown in the figure. Pads 7 and 42 provided at intervals are limiters for preventing the pad holding member 39 from moving left and right by more than a certain amount, and reference numeral 45 is a limiter to which this pressing device is fixed to a housing (not shown). As shown in the figure, in the pad holding member guide, a protrusion 46 that protrudes inward of the pad holding member 39 is slidably attached to the guide wall, and a coil spring support member 44 is provided at the bottom of the guide. The coil spring support member 44 and the pad holding member 39 are connected to each other by a coil spring 43 so as to constantly press the butt holding member 39 toward the magnetic head 21, as shown in the figure.

The operation of this pressing device is the same as that shown in FIG. While sliding, the pad 40 moves along the tape sliding surface of the magnetic head 21, and since the pad 40 constantly presses the magnetic head 21 by the coil spring 43, the tape 2
Even when the two cars were running in reverse, they always acted quickly and properly.

10A and 10B are top views schematically showing a fourth tape pressing device according to the present invention. To explain the structure of FIG. 10A, 40 is a pad, 41 is a shield plate to which the pad 40 is attached, 47 4 is a pad holding member having a shield plate 41 on the bottom, 42 is a pad holding member movement limiter, and a pad holding member guide shaft 4 is provided on the upper part of the pad holding member 47.
8, a gap is provided as shown in the figure so that the pad holding member 47 can slide up and down, and the upper head of the pad holding member 47 is always held at both ends by supports 50. It is pressed by a leaf spring 49.

The operation of this device is similar to that shown in FIG. 9, except that a pad holding member guide shaft 48 is provided within the pad holding member 47, and the pad holding member 47 slides with respect to the guide shaft 48. It is.

FIG. 10B is almost the same as FIG. 10A in that the limiter 52 is provided inside the bat support 51, and the pressure transmitting body on the upper part of the bat support 51 is arranged along the transmitting body guide 54. The structure operates in the same manner as in FIG. 10A, except that it slides vertically, horizontally, and horizontally.

Although various pressing devices for achieving the object of the present invention have been described above, the present invention is not limited to these methods, and the point is that the butt provided on the holding member etc. is pressed against the tape feeding direction during tape feeding. The gist of the present invention can be achieved with any device in which the holding member is movable so that a predetermined position upstream of the magnetic head gap portion can be pressed by the bat, and
The present invention can be used in any device that records and reproduces data using magnetic tape, and is extremely useful in practice.

All parts with the same numbers in the drawings are made of the same parts.

[Brief explanation of drawings]

FIG. 1A is a side view of a conventional cassette tape as seen from the magnetic head side, FIG. 1B is a top view of the cassette tape shown in FIG. A top view showing the tape suppression mounting used in conventional cassette tapes, FIG. 3 is an explanatory diagram showing the wear relationship between the magnetic head sliding surface, the tape, and the tape butt, and FIG. 4A is the one according to the present invention. FIG. 4B is a top view for explaining the operation between the tape pressing device and the magnetic head, and FIG. 4C is a side view of the relationship between the tape pressing device and the magnetic head in FIG. 4A when viewed from the side. is a perspective view showing the shape of the tape pressing device of FIG. 4A, FIG. 5A1 is a top view of the tape pressing device of the present invention, and FIG. Figure A1 Figure 6 A
5C and 6C are respectively perspective views of the tape suppression device shown in FIGS. 5A and 6A, and FIG. 7A is a side view of the tape suppression device shown in FIG. FIG. 7B is an enlarged top view when the tape suppression device portion of FIG. 7A is picked up and enlarged. FIG. 8 is a schematic diagram of the second suppression device according to the present invention. FIG. 9 is a top view schematically showing a third suppressing device according to the present invention, and FIGS. 10A and 10B are top views schematically showing a fourth pressing device according to the present invention. DESCRIPTION OF SYMBOLS 11... Magnetic head, 12... Tape, 13... Bat, 14... Elastic member, 15... Holding member, 21... ... Magnetic head, 22 ... Tape, 23 ... Core, 24 ... Plate body, 25, 25' ... Bat, 26 , 26'... Stopper, 27.
...Strut, 28 ...Core gap, 29
, 29'...Roller, 30...Arm, 31...Elastic body, 32...Inner wall,
33... Support column, 34... Movable member, 3
5... Bat, 36... Stopper,
37... Holding member, 38... Key shaped portion, 39...
... Bat holding member, 40 ... Pad 4
1...: Shield plate, 42... Limiter, 43... Coil spring, 44... Coil spring support member, 45... Pad holding member guide , 46... Protrusion, 47... Pad holding member, 48... Pad holding part 7 material guide shaft, 49... Leaf spring, 50... ...Plate spring support body, 51... Bat support body, 52...
...Limiter, 53...Pressure force transmitter, 54.
...transmission body guide.

Claims (1)

[Claims] 1 A plurality of suppressing members provided facing the magnetic head at the upstream and downstream sides of the running direction of the film magnetic recording medium with respect to the gap of the magnetic head, a supporting member supporting the plurality of pressing members, and a supporting member supporting the plurality of pressing members; A shaft member defining a rotation center and a limiting member restricting a rotation range of the support member about the shaft member as the rotation center are provided, and the rotation of the support member causes the plurality of pressing members to move one side or the other of the film. A film-like magnetic recording medium pressing device that presses a film-like magnetic recording medium against a magnetic head.