JPH0235657A - Circular sheet type recording medium guiding device - Google Patents

Abstract

PURPOSE:To always keep the stable and satisfactory head touch of a magnetic head for a magnetic sheet by displacing the regulation applying member of an auxiliary regulation means corresponding to the rotating angular velocity of a circular sheet type recording medium. CONSTITUTION:The title device is equipped with a main regulation means 2 to regulate the sliding state of the circular sheet type recording medium 1 for the head, the auxiliary regulation means 3 to supplement the regulation of the circular sheet type recording medium 1 by the main regulation means 2, and a displacement means 4 to displace the regulation applying member of the auxiliary regulation means 3 corresponding to the rotating angular velocity of the circular sheet type recording medium 1. Thereby, it is possible to displace the height position of the auxiliary regulation means 3 by the displacement means 4 corresponding to the rotating angular velocity of the circular sheet type recording medium 1. In such a way, an appropriate regulation (guide) function by the main regulation means 2 can be maintained even when the angle of rotation changes.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a circular sheet-shaped recording medium guiding device, more specifically, a circular sheet-shaped recording medium guiding device that rotates a circular sheet-shaped recording medium at high speed and slides a recording/reproducing head on the recording medium. The present invention relates to a guide device for a circular sheet-shaped recording medium when recording information or reproducing recorded information.

[Prior Art] As is well known, in a magnetic recording and reproducing device that records and reproduces image information using a circular sheet-like recording medium (hereinafter referred to as a magnetic sheet), high-quality recorded images and reproduced images are produced. To achieve this, the magnetic sheet is rotated at high speed relative to the magnetic head, and the magnetic head is brought into sliding contact with the magnetic surface of the magnetic sheet that is rotating at high speed (for example, 3600 rpm). This allows for high-quality recording and playback operations. In addition, as a means of sliding the magnetic sheet onto the head at a constant pressure to obtain a stable head touch, conventionally, a hard air pad is placed on the opposite side of the magnetic head at a portion of the magnetic sheet facing the magnetic head. Positive pressure is generated by the airflow generated between the sheets,
There is a method in which the sheet is brought into contact with the head using this positive pressure (hereinafter referred to as the positive pressure method), and a ring-shaped recess is provided around the magnetic head, and when the magnetic sheet rotates at high speed on the top surface of the head. There is a method (hereinafter referred to as a negative pressure method) in which a negative pressure is generated by the flow of air generated in this suction ring, and the magnetic sheet is brought into pressure contact with the magnetic head by this negative and positive pressure.

Considering both of these types, if the rotation of the magnetic sheet stops for some reason, in the case of a positive pressure type, the head top protrudes against the recess of the hard air pad, so the magnetic sheet There is a risk of plastic deformation of the magnetic sheet, whereas in the case of the negative-positive method, there is no negative pressure itself and the sheet and head are separated, so there is no risk of the magnetic sheet being plastically deformed. However, considering the case where the rotation of the magnetic sheet is decelerated, in the case of the positive pressure method, the magnetic sheet is sandwiched between the pad and the head, so the sliding contact is relatively stable. In the negative pressure method, as the number of rotations of the magnetic sheet decreases, the generated negative pressure also decreases, making the sliding contact state unstable.

FIGS. 5(A) and 5(B) show an example of a conventional magnetic sheet guiding device in which the magnetic sheet 1 is brought into sliding contact with the magnetic head 9 by a negative pressure method using a suction ring.
The suction ring 2 constitutes a main regulating means for regulating the state of sliding contact of the sheet with the head. The magnetic head 9 is fixed by adhesive or the like to the center upper part of the suction ring 2 formed of a bottomed negative pressure generating member having a donut-shaped concave portion 2c at the top. The magnetic surfaces are disposed all the way and are adapted to move in the radial direction of the seat 1. magnetic sheet 1
is, for example, 3 per minute by a spindle motor (not shown).
It is designed to rotate at a high speed of 600 revolutions, and the above-mentioned suction ring 2 is arranged so as to be in sliding contact with the lower magnetic surface, and the suppressing pad 3, which is an auxiliary regulating means, is in sliding contact with the upper surface. has been done. Bad 3 as an auxiliary regulatory measure
is attached to the tip of a support arm 8 that extends perpendicularly from the top of the support column 7 that is erected on the chassis board 6, and is pressed against the upper surface of the seat. The suction ring 2 has a concave portion 2C formed between an outer ring 2a and an inner ring 2b, and a magnetic head 9 is embedded in the center of the inner ring 2b.

In the magnetic sheet guide device configured in this way, when the magnetic sheet 1 is driven by a spindle motor (not shown) and rotates at high speed in the circumferential direction, the magnetic sheet 1 is rotated at high speed in the circumferential direction. A negative pressure is generated between the concave portion 2c of the suction ring 2 and the magnetic sheet 1 due to the airflow generated. Then, the surfaces 1a and lc of the magnetic sheet 1 facing the concave portion 2C of the suction ring 2 are attracted to the concave portion 2C, so that the magnetic sheet surface 1b at the inner center comes into pressure contact with the magnetic head 9. Therefore, it is possible to record or reproduce desired image information on the magnetic sheet 1 by obtaining a stable head touch.

In this way, the contact between the magnetic sheet 1 and the magnetic head 9 is basically caused by the negative and positive forces generated between the magnetic sheet 1 and the suction ring 2 as the magnetic sheet 1 rotates at high speed, so that the magnetic sheet 1 is attracted to the suction ring 2. However, in order to provide a starting point for the attraction, and to suppress the influence of curling of the sheet and regulate the height of the sheet flowing into the ring, there is a The above-mentioned pad 3 is provided as an auxiliary regulating means for regulating the upper surface of the magnetic sheet 1 on the opposite side to the magnetic surface.

The pad 3 is normally arranged so that the magnetic head 9 and the magnetic sheet 1 are in an optimal sliding contact state when the magnetic sheet 1 is rotating at a constant speed of a predetermined rotation speed, for example, 3600 rpm. The height from the chassis board 6 is fixed.

[Problems to be Solved by the Invention] However, since the negative pressure generated between the magnetic sheet 1 and the attraction ring 2 is proportional to the relative speed of the magnetic sheet 1 to the attraction ring 2, it is necessary to change the rotation speed of the magnetic sheet. For example, when the rotation speed is lowered, the negative pressure generated also decreases, and the state of sliding contact between the magnetic sheet 1 and the magnetic head 9 changes accordingly.
In other words, there is a drawback that stable head touch cannot be obtained.

That is, even when erasing is performed by reducing the rotational angular velocity of the magnetic sheet 1 and supplying an erasing signal to the magnetic head 9 in order to perform high-frequency erasing, the contact state between the pressing pad 3 and the magnetic sheet 1 is Since the recording is performed with the optimum value set for recording and reproducing at the normal rotational angular velocity of the sheet 1, a stable head touch corresponding to the magnetic sheet 1 of the magnetic helad 9 cannot be obtained, and reliable erasing cannot be performed. There is a problem.

Furthermore, this problem also becomes a drawback in the following cases. That is, in a 5VF (still video floppy), which is a magnetic sheet, there is usually one track per magnetic sheet.
The image information for one frame is recorded and reproduced again. For example, the rotational angular speed of the magnetic sheet 1 is reduced by half, and the image information for one frame is recorded on one track. There are cases where In such a case, if recording and reproducing are performed at a rotational angular velocity that is half of the normal rotational angular velocity, a drawback arises in that the magnetic head 9 cannot stably touch the magnetic sheet 1 for the above-mentioned reason.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to solve the above-mentioned problems by providing a magnetic head 9 even when the rotational angular velocity of the magnetic sheet 1 changes.
To provide a circular sheet-shaped recording medium guiding device in which the edges, grooves, and notches of a magnetic sheet 1 can always be maintained in a stable and good condition.

[Means and effects for solving the problems] The circular sheet-shaped recording medium guide device of the present invention includes a main regulating means for regulating the sliding contact state of the circular sheet-shaped recording medium with respect to the head, and a circular sheet-shaped recording medium guided by the main regulating means. The apparatus is characterized by comprising: an auxiliary regulating means that assists in regulating the recording medium; and a displacement means that displaces the regulating member of the auxiliary regulating means in accordance with the rotational angular velocity of the circular sheet-shaped recording medium. It is.

[Example] The present invention will be specifically described below with reference to the drawings. In addition, in the embodiment of the circular sheet-shaped recording medium guiding device described below, the same reference numerals are given to the constituent members that are exactly the same as those in the conventional example explained in FIG. 5, and the explanation thereof will be repeated. To avoid this, omit this.

1 and 2 show a first embodiment of the present invention, in which a suppressing pad 3 as an auxiliary regulating means is supported by the tip of a bimorph piezoelectric actuator 4 as a displacement means. It is attached to 7. As is well known, this bimorph type piezoelectric actuator 4 is made by arranging piezoelectric ceramics 4a and 4b symmetrically in the polarization direction, which have an inverse piezoelectric effect that causes distortion when a voltage is applied to both sides of a thin metal plate 4C. Each piezoelectric ceramic 4a.

When a voltage is applied between the bimorph piezoelectric actuators 4 and 4b, the distal end of the bimorph piezoelectric actuator 4 bends in the vertical direction in the figure, using the base end fixed to the column 7 as a fulcrum, so that the height of the suppression pad 3 changes. And with this, the suppression bad 3
Magnetic sheet 1 or success/failure ring 2 which is the main regulating means
The relative position to changes. The output end of a driver operational amplifier 5 is connected to the piezoelectric ceramics 4a and 4b that constitute the actuator 4.

On the other hand, as shown in FIG. 2, the disc-shaped magnetic sheet 1 is loaded into the recording medium guide device by the center hub 21 disposed at the center being chucked by the spindle shaft 23a of the spindle motor 23. The spindle motor 23 is driven to rotate clockwise. A carriage 22 is disposed below the magnetic sheet 1 and parallel to the magnetic sheet 1 so as to face the lower surface of the magnetic sheet 1. In the magnetic sheet 1, an adsorption ring 2, which also serves as a main regulating means, is attached to the magnetic sheet 1 in sliding contact with the magnetic sheet 1. Further, in the carriage 22, a guide member 24 fixed to the lower surface of the negative side edge thereof is inserted through a guide shaft 25, and an oval long hole 22a is bored in the center thereof to expose the spindle motor 23. It is set up. The carriage 22 is moved on a chassis board (not shown) in the radial direction of the magnetic track 1 by an access morph or the like, along the guide shaft 25, and thereby the magnetic head 9 embedded in the suction ring 2 is moved. Any track on the magnetic surface of the lower surface of the magnetic sheet 1 is accessed. The suppressing pad 3, which is the auxiliary regulating means, is disposed on the upstream side of the upper surface of the sheet portion facing the magnetic pad 9 that is in sliding contact with the magnetic sheet.

FIG. 3 is a block diagram of an electric circuit showing the drive system of the circular sheet-shaped recording body guiding device of this embodiment. Third
In the figure, the spindle servo circuit 32 and the pad height conversion actuator drive circuit 33 are placed inside the guide device, but the system controller 31 does not necessarily need to be installed inside the guide device, and the system controller 31 is not necessarily installed in the guide device, but rather the It may be arranged in a part of the interior of the machine. The motor is turned on and off from the output terminal TI of the system controller 31.
An off signal and a rotation speed switching signal are output from the output terminal T2. The motor on/off signal is supplied to the spindle servo circuit 32 to control starting and stopping of the spindle motor 23, and the rotation speed switching signal is
The H# level or "L" level binary signal is supplied to the spindle servo circuit 32 and the pad height conversion actuator drive circuit 33, but even if this signal is an analog switching signal, good.

The drive circuit 33 includes the driver operational amplifier 5 shown in FIG. 1 above.

In addition, the suction ring 2 constituting the main regulating means needs to be made of a fairly hard material and a non-magnetic material.For example, it is possible to use a special f14sUs304, but in the case of 5US304, the child is Since it is magnetic, there is a risk that recorded tracks may be erased. Therefore, it is preferable to use a ceramic material such as tungsten carbide, which is completely non-magnetic.

On the other hand, the suppressing pad 3 constituting the auxiliary regulating means must also be made of a non-magnetic material, but since there is no requirement that the material be particularly hard, a material such as brass plated with nickel is used.

In this embodiment configured in this way, when a motor on/off signal is supplied from the system controller 31 shown in FIG. 3 to the spindle servo circuit 32, the servo circuit 32 is activated, and as shown in FIG. The spindle motor 23 shown in FIG. 1 is driven, and the magnetic sheet 1 chucked on the motor shaft 23a begins to rotate. At this time, the rotation angular velocity of the magnetic sheet 1 is determined according to the H/L level of the rotation speed signal supplied from the system controller 31.

This rotational speed signal is also supplied to the suppression pad height conversion actuator drive circuit 33, and a positive or negative DC voltage is applied from the driver operational amplifier 5 (see Fig. 1) of the same drive circuit 33 to the height conversion actuator drive circuit 33 of the suppression pad. As shown, the voltage is applied to the bimorph piezoelectric actuator 4. Then, the piezoelectric actuator 4 is displaced in the vertical direction in the figure, and as a result, the height position of the pressing pad 3 attached to the tip of the piezoelectric actuator 4 is adjusted to the rotation of the spindle motor 23 (see FIG. 2). In other words, the displacement corresponds to the rotational angular velocity of the magnetic sheet 1. Therefore, even if the rotational angular velocity of the magnetic sheet 1 changes, the head can stably touch the magnetic head 9 of the sheet 1.

FIG. 4 is a side view of a main part of a circular sheet-shaped recording medium guide device showing a second embodiment of the present invention. In this embodiment, mechanical displacement means using an eccentric cam 11 is used to displace the height position of the suppressing pad 3, which is an auxiliary regulating means. Other than this point, the other configurations are the same as those of the above embodiment. Therefore, there is no difference in their effectiveness.

In this second embodiment, the suppressing pad 3 is fixed to one end of a support lever 14 that is disposed horizontally and is brought into contact with the upper surface of the magnetic sheet 1.

The support lever 14 is supported at its middle fulcrum by a support shaft 13, and an eccentric cam 11 is attached to the other end of the lever 14.
are in contact with each other. This eccentric cam 11 is fixed to a rotating shaft 12, and the lower surface of the other end of the support lever 14 comes into pressure contact with the operating peripheral surface of the eccentric cam 11.

In the second embodiment configured in this way, if the eccentric cam 11 is rotated according to the rotational speed of the magnetic sheet 1 by an actuator such as a motor or a solenoid, the height of the suppression pad 3 can be adjusted. Since the position is displaced, the pressing force of the pad 3 against the magnetic sheet 1 changes, and good head contact of the magnetic head 9 with the magnetic surface of the sheet 1 can be obtained.

In addition, in the description of each of the above embodiments, the butt 3, which is the auxiliary regulating means, has been described as being disposed upstream of the suction ring 2, which is the main regulating means, but it may be disposed downstream. Alternatively, it may be arranged separately on the upstream side and the downstream side, and it goes without saying that the arrangement position is not limited to that of the above embodiment.

Furthermore, although the adsorption ring 2 as the main regulating means has been explained as being ring-shaped, it is also arranged in the vicinity of the magnetic sheet 1 and the sheet 1 rotates at high speed to generate negative pressure. It goes without saying that the structure is not limited to this, and may be formed into a plate shape, for example.

[Effects of the Invention] As described above, according to the present invention, the height position of the auxiliary regulating means is displaced by the displacement means in accordance with the rotational angular velocity of the circular sheet-like recording medium, so that Even if the rotational angular velocity changes, the main regulation means can maintain appropriate regulation (
(Guidance) A remarkable effect is achieved in that the action is maintained.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of main parts of a circular sheet-shaped recording medium guide device showing a first embodiment of the present invention. FIG. 2 is a perspective view of main parts showing the arrangement of each component in the circular sheet-like recording medium guide device. 3 are block diagrams of the drive electric circuit in the guide device of the first embodiment, and FIG. 4 is a block diagram of main parts of the circular sheet-shaped recording medium guide device of the second embodiment of the present invention. , FIG. 5(A) is a main part configuration diagram showing an example of a conventional circular sheet-shaped recording medium guide device, and FIG. 5(B) is a plan view of a suction ring which is the main regulating means. 1......Circular sheet-like recording medium 2...
...Main regulating means 3... Auxiliary regulating means 4... Bimorph piezoelectric actuator (displacement means) 11... Eccentric cam ( displacement means) 14...
・Support lever (displacement means) Horse 1 Figure

Claims (1)

[Claims] (1) A main regulating means for regulating the sliding state of the circular sheet-like recording medium with respect to the head; an auxiliary regulating means for assisting the main regulating means in regulating the circular sheet-like recording medium; and rotation of the circular sheet-like recording medium. A circular sheet-shaped recording medium guiding device comprising: a displacement means for displacing a regulating member of the auxiliary regulating means according to an angular velocity.