JPH0626078B2 - Disk device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic recording / reproducing apparatus using a flexible disk, and more particularly to a head contact mechanism suitable for an electronic still camera.

[Background of the Invention]

Discs used in electronic still cameras are 13th to 1st.
As shown in FIG. 4, it is housed in a plastic case 9 for protection and dust prevention. The case 9 is provided with windows 9a and 9b, and the head and the disk can contact each other only within this range.

A method of contacting the head and the disk in the electronic still camera will be described with reference to FIGS. A pad plate 3 having a concave portion is arranged behind the contact portion between the head 1 and the disk 2, the head 1 is projected into the concave portion, and the flexibility of the disk 2 is used to press the head 1 and the disk 2 together. . By forming the concave portion of the pad plate 3 in a groove shape in the moving direction of the head 1, it is possible to select a track on the disk 2 surface of the head 1.

In this contact method, the disk 2 is bent and brought into contact with the head 1, so that the contact state between the head 1 and the disk 2 is kept constant in order to obtain good recording / reproducing characteristics (hereinafter simply referred to as characteristics). In order to do so, a high setting accuracy is required for the relative positional relationship among the head 1, the disk 2, and the pad plate 3. In particular, regarding the set positional relationship of the disc 2 in the direction of the rotation axis, the characteristics tend to be significantly deteriorated even if a slight error or fluctuation occurs.

As shown in FIGS. 13 to 14, the disc 2 is detachably and replaceably fitted to the rotary shaft 5a of the disc drive motor 5 in the central hole 4a of the central portion reinforcing member 4. Rotating shaft 5
Reference numeral a denotes a stepped shape as shown in the drawing, the disk 2 is oriented in the direction of the rotation axis thereof, and the bottom surface of the center portion reinforcing member 4 (hereinafter referred to as the disk side reference surface) is provided on the upper surface (hereinafter referred to as the rotation shaft side reference surface) 5b of the step. The surface 4b is positioned in contact with the surface 4b.

Here, the following may be considered as the main error factors of the setting position of the disk 2 in the rotation axis direction.

1) The rotating shaft side reference surface 5b and the disk side reference surface 4b
B) Insufficient flatness, b) Insufficient squareness with respect to the rotating shaft 5a, C) Scratches, adhesion of dust, etc .; error due to change in relative position around the rotating shaft 5a of the disc 2 for each mounting. Cause This causes a problem in reproducibility for each mounting.

2) Variation in thickness from the bottom surface 4b of the central reinforcing member 4 to the mounting surface 4d of the disk 2 depending on each disk 2; compatibility with a plurality of disks becomes a problem.

3) The vicinity 2a of the mounting portion of the disc 2 to the central reinforcing member 4
Distortion, warpage, etc. generated on the disk; since the disk 2 is flexible, such defects are likely to occur near the mounting portion.
As a result, the set position changes during one rotation of the disk 2.

Considering the mass production of electronic still cameras, these error factors are unavoidable even if they occur to some extent. Further, as one means for making the characteristics less susceptible to the influence of these error factors, by shortening the relative distance between the head 1 and the pad plate 3 in the rotational axis direction of the disk 2, the pressure bonding force between the head 1 and the disk 2 is increased. However, considering the reliability of the apparatus such as the wear of the head 1 and the damage of the disk 2, there is a limit value for the pressure bonding force.

Here, as shown in FIGS. 13 to 14, the pad plate used in the conventional device has a cutout portion of the groove 3a only on the outer peripheral side end portion of the disk 2 (hereinafter, the outer peripheral end cutout portion). 3) is provided. For example, it is described in JP-A-57-113460. However, when the pad plates having the same shape are used, the allowable setting range in the rotation axis direction of the disk 2 that can secure good characteristics with respect to the total sum of the error factors even in the limit pressing force of the head 1 and the disk 2 However, there is a problem in that the performance of the device tends to deteriorate.

[Object of the Invention]

The object of the present invention is to reduce fluctuations in the mounting position of the disk in the direction of the rotation axis of the disk and to mount the disk to the central reinforcing member of the disk even with a small head-disk pressing force in which head wear and disk damage are not a practical problem. An object of the present invention is to provide a highly reliable magnetic disk device in which characteristic deterioration is unlikely to occur due to the generated distortion, warpage, and the like.

[Outline of Invention]

In the case of the conventionally used pad plate shape, in the cross section shown in FIG. 14, when the disk 2 is viewed in the radial direction, the abutment portion between the head 1 and the disk 2 from the rotation center portion where the above-mentioned error factor occurs. There is no other component between 2b and it is directly connected. Therefore, it is considered that the situation was susceptible to the above-mentioned error factors.

In the present invention, by adding a new means for restricting the disk 2 in the direction of the rotation axis between the center of the rotation axis of the disk 2 and the head contact portion 2b, an error factor that occurs in the center of the disk Is affected by the head contact portion 2b
It is intended to reduce the transmission.

Further, in the present invention, when the above-mentioned regulating means is provided, even if the head moves in the radial direction, the contact surface between the regulating means and the disk is brought into contact with the pad plate so that the head contact is uniform. It is arranged so as to be slightly displaced from the surface on the pad plate side in the rotation axis direction.

Example of Invention

The first embodiment of the present invention will be described below with reference to FIGS. The structure and shape of the head abutting portion are almost the same as those of the conventional one shown in FIGS. 13 to 15, but the groove portion 3a of the pad plate 3 is left uncut at the inner peripheral side end portion with respect to the disk 2. The difference is that a portion 3c (hereinafter referred to as an inner peripheral end uncut portion) is provided. When using the pad plate of this shape,
As shown in the figure, the disc 2 is always in contact with the uncut end portion 3c of the inner peripheral edge of the pad plate 3 at the point 2c. Therefore, the position of the disk 2 in the direction of the rotation axis is always constant at the point 2c even if the rotation center portion fluctuates. Therefore, the contact portion 2 between the head 1 and the disk 2
The degree of influence on b becomes small, and good characteristics can be stably maintained.

Here, the head 1 moves on the surface of the disk 2 in the radial direction of the magnetic disk 2 in a section corresponding to the recording range of the disk 2 for track selection. Therefore, in order to maintain good characteristics, the contact state between the head 1 and the disk 2 must be kept good and constant in the moving section. However, in this embodiment, as described above, the uncut portions 3c and 3b of the groove 3a are provided on the inner side and the outer side of the disk 2 of the pad plate 3.

Therefore, when the head 1 is located closer to the inner circumference of the disk 2 (hereinafter referred to as the inner circumference track) in the moving section, the influence of the inner peripheral end uncut portion 3c of the pad plate 3 is affected as shown in FIG. As the head 1 becomes stronger, the head 1 comes into a so-called one-side contact state in which the head 1 strongly abuts the disk 2 at the end portion 1a on the inner peripheral side with respect to the disk 2, and the characteristics deteriorate. On the contrary, when the head 1 is located near the outer circumference of the disk 2 (hereinafter referred to as the outer circumference track) in the moving section, the influence of the outer peripheral end uncut portion 3b of the pad plate 3 is strong as shown in FIG. Then, the head 1 comes into a one-sided contact state in which the head 1 strongly abuts the disk 2 at the outer peripheral side end portion 1b with respect to the disk 2, and the characteristics also deteriorate. This characteristic deterioration is the 4th and 5th.
Deflection angle 2 in the radial direction at the contact portion 2b of the disk 2 with the head 1 shown in the figure (hereinafter simply referred to as deflection angle) 2
Due to the variation of c. Now, as shown in FIG. 5, in the contact portion 2b of the disk 2 with the head 1, the direction of the deflection angle when the disk 2 is bent in the clockwise direction from the horizontal state in the drawing is defined as the plus direction. Then, based on the deflection angle when the head 1 in FIG. 4 is located on the inner track, the deflection angle when the head 1 in FIG. 5 is located on the outer track fluctuates in the plus direction. It turns out that.

In order to prevent this characteristic deterioration, in this embodiment, as shown in FIGS. 1 and 3, the vicinity of the inner peripheral side end portion 3c of the pad plate 3 is
The pad plate 3 is recessed from the other surface facing the other disk 2 by a predetermined amount to form a step 3d. FIG. 1 is a view of the pad plate 3 viewed from the head 1 side. Now, in the vicinity of the inner peripheral end 3c of the pad plate 3, the disk 2 of the peripheral portion
When the concave surface is gradually dented from the surface opposite to and the step difference is increased, the deflection angle increases in both the inner and outer tracks. (Transition to the plus direction) Then, the increase amount at this time tends to increase as it goes to the inner track due to the distance difference from the inner end 3c of the pad plate 3 in the radial direction of the disk 2. Therefore, by utilizing this tendency, it becomes possible to correct the difference in the deflection angle in the outer peripheral track among the above. FIG. 6 shows the correlation between the radial track position of the head 1 on the disk 2 and the deflection angle at the contact portion 2a of the disk 2 with the head 1. A indicates the track position on the innermost circumference of the disk 2 in the moving section of the head 1 and B indicates the track position on the outermost circumference. Further, P, Q, R, and S respectively show the actual measurement results when the step difference of the pad plate 3 = 0, a, 2a, 3a. From the figure, when the step amount = 2a (R in FIG. 9), the deflection angle of the disk 2 is constant in all the movement sections of the head 1, and good characteristics are maintained even when the head 1 selects a track. It becomes possible to do.

Here, since the inner peripheral side end 3c of the pad plate 3 is recessed, the inner peripheral side end 3c does not come into contact with the disc 2 and the influence of the positional fluctuation of the disc 2 in the rotation axis direction is caused. Although there is concern that the effect of reducing the degree may not be obtained, the desired amount of effect can be ensured because the amount of bending of the disk 2 at the time of contact with the head 1 is sufficiently larger than the amount of step difference of the pad plate 3.

Further, since the inner peripheral side of the disc 2 is close to the fixed end to the central portion reinforcing member 4, the bending rigidity is larger than the outer peripheral side,
By providing the disc sandwiching portion on the inner peripheral side, it is feared that the pad plate 3 and the disc 2 may slide with a large pressure bonding force and the disc 2 may be easily damaged. By forming the side end portion 3c in a concave shape, the pressure bonding force can be reduced, and an effect of suppressing damage can be obtained.

Further, in the present embodiment, the pad plate structure in which the vicinity of the inner peripheral side end portion 3c of the pad plate 3 is also depressed from the peripheral portion is adopted. However, according to the same concept, as shown in FIG. 7, the outer peripheral side end portion of the pad plate 3 is formed. 3b can also be formed by denting the vicinity of the inner peripheral side end 3c and the outer peripheral side end 3b of the pad plate 3 as shown in FIG. Similarly, it becomes possible to maintain good characteristics for the track selection of the head 1.

In addition, in this embodiment, by simply changing the pad plate shape,
It is possible to obtain a desired effect while maintaining good characteristics for head track selection, which is an extremely economical method.

Next, a second embodiment of the present invention will be described with reference to FIGS. Although the structure and shape of the head contact portion are almost the same as those of the conventional one shown in FIGS. 13 to 15, the disk 2 is located inward of the contact portion 2b with the head 1 of the disk 2 in the rotation axis direction of the disk 2. 2 is different in that a fixing surface 6 for positioning and a second pad plate 7 for pressing the panel-supported disk 2 against the fixing surface 6 are provided. Also in this embodiment, as in the first embodiment, the position of the disk 2 in the direction of the rotation axis is always constant at the contact portion 2d with the fixed surface 6, so that the head contact is stable and good characteristics are stable. It becomes possible to hold.

Further, in the present embodiment, according to the same idea as in the first embodiment, the fixed surface 6 regulates the rotation axis direction of the disk 2 by a predetermined amount 6a from the surface of the pad plate 3 facing the disk 2. By shifting to the pad plate 3 side in the rotation axis direction, it is possible to maintain good characteristics for track selection of the head 1.

Further, in this embodiment, the fixed surface 6 and the second pad plate 7 have a width in the radial direction of the disk 2,
Since the point 2d sandwiched between the two is in a state close to fixed support, the contact portion 2b between the head 1 and the disk 2 is almost not affected by the position variation in the rotation center direction of the disk 2 at the rotation center thereof. It becomes possible to maintain good characteristics extremely stably.

Furthermore, in this embodiment, if the pad plate having the shape of the first embodiment is used, the inner peripheral side end portion 3c of the pad plate 3 is used as a substitute for the fixing surface 6, and the disc 2 is moved to the first position as shown in FIG. Two
The same effect can be obtained by adopting a structure in which the pad plate 7 is pressed against the inner peripheral side end portion 3c.

FIG. 12 shows the variation of the height of the disc mounting surface (the variation of the position of the disc 2 in the rotation axis direction) when the conventional pad plate and the pad plate of the first embodiment of the present invention are used.
The following shows the actual measurement results of the recording / playback output for. A shows the output when a conventional pad plate is used, and B shows the first output of the present invention.
7 shows an output when the pad plate having the shape of the example is used.
The output is 0 dB when the peak output is obtained.
In the same figure, considering that the output is within -1db from the peak state as the allowable deterioration amount, the fluctuation amount of the disk mounting surface height that satisfies this is L ₁ in the case of the conventional pad plate 3, and the first embodiment of the present invention. L ₂ = 7.8L ₁ where L ₂ is the case of the pad plate having the shape in the above example. Therefore, when the pad plate having the shape according to the first embodiment of the present invention is used, compared with the case where the pad plate having the conventional shape is used, the disc mounting surface height variation is about 8
It is possible to maintain good characteristics with double stability.

〔The invention's effect〕

According to the present invention, the wear of the head and the damage to the disk are not a practical problem. Even when the head-disk pressing force is changed, the mounting position of the disk varies in the rotation axis direction and the disk is mounted on the reinforcing member in the central portion. Since it is possible to prevent the deterioration of the characteristics due to the distortion, warpage, etc. generated in the part, it is possible to improve the reliability of the device.

[Brief description of drawings]

FIG. 1 is a perspective view showing a pad plate shape in the first embodiment of the present invention, FIG. 2 is a plan view showing a head contact portion of the first embodiment, and FIG. 3 is an A- in FIG. A'sectional view, FIG. 4 is a sectional view showing the flexure shape of the disk on the inner track, FIG. 5 is a cross-sectional view showing the flexure shape of the disk on the outer track, and FIG. 6 is the relationship between the track position and the flexure angle of the disk. 7 is a perspective view showing an alternative shape of the pad plate of the first embodiment, and FIG. 9 is a plan view showing the head contact portion of the second embodiment. FIG. 11 is a sectional view taken along the line AA 'in FIG. 9, FIG. 11 is a sectional view showing a head contact portion of an alternative method of the second embodiment, and FIG. 12 shows the relationship between the disk mounting surface height and the head output. FIG. 13 is a correlation diagram, FIG. 13 is a plan view showing a head contact portion in a conventional electronic still camera, and FIG. A-A 'cross-sectional view, FIG. 15 B-B of FIG. 13' of Figure 3 is a cross-sectional view. 1 ... Head, 2 ... Disc, 3 ... Pad plate, 4 ...
... Center reinforcement, 5 ... Disk drive motor, 6 ... Fixing surface, 7 ... Second pad plate.

Claims (1)

[Claims] 1. A flexible disk as a recording medium, a head for recording / reproducing a signal on / from the disk, and a recess on the surface facing the head, and the disk on the side of the recess. A disk support member that supports the disk surface in a flexed state, the first, second, third, and fourth support portions in which the disk support member supports a disk surface around the recess. The first and second support portions are arranged on both sides of the recess in the circumferential direction of the disc, and the third support portion is formed on the disc inner peripheral side of the recess, and the fourth support portion The supporting portion is arranged on the outer peripheral side of the disc in the recess, and the first, second and fourth disc supporting portions are arranged such that their respective supporting surfaces are in the same plane substantially perpendicular to the disc rotation axis, and the third disc supporting portion is provided. The support surface of the part is the above-mentioned first, second and fourth support surface positions. Disk apparatus characterized by being formed in a lower position in the depth direction of the recess than.