JPS59186169A - Head touch adjusting device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a head touch adjustment device for adjusting the contact of a signal read head with respect to a record carrier, and an object of the present invention is to provide a means for always maintaining a good head touch.

Prior Art In an apparatus for reading signals recorded on a record carrier such as a rotating magnetic sheet using a signal reading head such as a magnetic head, contact between the record carrier and the head (an air layer of approximately 0.5 μm between the record carrier and the head) is used. (including the state in which they are in contact with each other across the two sides (the same shall apply hereinafter)) is important. If this contact condition is not good, spacing loss will occur and the reproduction output level will be reduced.

In order to prevent such poor contact, it has been proposed to dispose a stabilizing plate at a position that sandwiches the recording carrier and faces the head. FIG. 1 shows a rotating magnetic sheet device equipped with this type of stabilizing plate, and FIG. 2 shows its AA cross section. In these figures, reference numeral 1 denotes a rotating magnetic sheet, which rotates in the direction of the arrow in the figures during operation. 2 is dust from the magnetic head,
The signals recorded on the sheet 1 are read out and supplied to a playback device (not shown). Reference numerals 3 and 4 denote upper and lower stabilizers, respectively, which are placed in positions sandwiching the seat 10 when it rotates, and stabilize the flow of air between the stabilizers 6 and 4 to stabilize the seat. It functions to maintain constant contact between the head 1 and the head 2.

The position of the upper stabilizer 3 relative to the seat 1 and therefore the head 2 has an important influence on the properties of the device;
The contact state between the sheet 1 and the head 2 changes slightly depending on the distance between the stabilizer plate 3 and the sheet 1 and the head 2, and the reproduction output level also changes. Furthermore, when moving the head 2 in the radial direction of the sheet 1 to change the track, the state of contact between the sheet 1 and the head 2 may change due to mechanical errors in the head moving device or the rigidity of the sheet 1 itself. , this may cause a decrease in playback output. In addition, if there is a difference in the thickness of the sheet 1, the contact state with the head 2 will change, and the reason for using a thick sheet for the key is not only that the contact state deteriorates as described above, but also that the head 2 This causes wear and tear.

Purpose of the Invention The present invention prevents a reduction in reproduction output due to the deterioration of the contact condition between the record carrier and the signal read head due to the causes mentioned above, and maintains the contact between the two in a good condition to always ensure good reproduction. An object of the present invention is to provide a head touch adjustment device that can maintain an output level.

Structure of the Invention The main point of the invention is to slightly move the above-mentioned stabilizing plate according to the magnitude of the reproduction output, so that the contact between the record carrier and the signal read head is always maintained in a good state. The structure includes a stabilizing plate (in a specific example described later, for example, the upper stabilizing plate 13 in FIG. 3) provided at a position facing the signal reading head while sandwiching the record carrier; The present invention is characterized by a head touch adjustment device comprising: means for moving the stabilizing plate relative to the recording carrier 1 (means for moving the stabilizing plate 13 in response to the output of the head 12 shown in FIG. 6);

In the above, the citation of the specific examples described later does not limit the scope of the present invention, and the embodiments of the present invention can be modified as appropriate within the scope of the claims.

heads, and the record carrier is defined by these heads.
A rotating disc-shaped record carrier from which signals are to be read.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the drawings, a detailed description will be given below of the overall structure of a specific example of the helad touch adjustment device of the present invention, a specific example of a stabilizing plate drive unit, and the robustness of a modification thereof. The following description will be made regarding an example in which the recording carrier is a rotating magnetic sheet and the signal reading head is a magnetic head.

Overall configuration of a specific example of the head touch adjustment device of this invention (
(Fig. 3) Fig. 3 shows an example of a head touch adjustment device embodying the present invention. In the figure, 11 to 14 denote a rotating magnetic sheet, a magnetic head, and an upper side, respectively, similar to 1 to 4 in Fig. 1. The stabilizer and lower stabilizer are shown. In this example, magnetic sheet 1
It is assumed that information corresponding to one field or one frame of a video signal is recorded in one track of FM.

15 is a preamplifier whose output is supplied to a video signal processing circuit and processed to reproduce a video signal, and is also branched to an envelope detection circuit 16, where the envelope component in the output is detected. be done. The detection output of the envelope detection circuit 16 is integrated by the integration circuit 17, and the output is sent to the f41 memory 18 and the first memory 18.
The data is input to the second memory 19 via the . The integrating circuit 17 and the first and second memories 18 and 19 are controlled by a predetermined timing, for example, a vertical synchronization signal T of a reproduced video signal. In other words, at the timing of gl, the integration circuit 1
7 is input to the memory 18, at the second timing, the signal accumulated in the memory 18 at the first timing is transferred to the memory 19, and the second output of the integrating circuit 17 is input to the memory 18. is input. After the sixth timing, the same operation is repeated. Memories 18 and 19
The stored values of are compared in a comparator circuit 20, and the moving direction of the stabilizer plate 13 is determined in a direction determining circuit 21 according to the output thereof,
The stabilizer drive circuit 22 drives and controls the stabilizer 13 so that it approaches or moves away from the magnetic sheet 11 as shown by arrow B in the figure.

In the above configuration, the magnetic head 12 and the magnetic sheet 11
The output of the head 12 is affected by the contact state with the third
As shown at 5 on the input side of the preamplifier 15 in the figure, an amplitude modulation component is included. This output passes through a preamplifier 15, an envelope detection circuit 16 detects its envelope component, that is, an amplitude modulation component due to the influence of the contact state, and integrates it in an integration circuit 17. Since the integrating circuit 17 and the first and second memories 18 and 19 are controlled by, for example, the vertical synchronizing signal T at the timing described above, the comparison output of the comparator circuit 20 corresponds to the period of the current vertical synchronizing signal. Since it indicates the magnitude of the output of the head 12 in the previous cycle, the direction determining circuit 21 determines the moving direction of the stabilizer plate 13 according to this comparison output, and the stabilizer drive circuit 22 determines the moving direction of the stabilizer plate 16. control the drive in that direction. For example, when the stabilizer 13 is moved in a direction closer to the magnetic sheet 11 and therefore the magnetic head 12, if an increase in output is observed at the next timing, the stabilizer 16 is further moved in the same direction, and conversely the output decreases. If you see this, move it in the opposite direction. In this way, the playback output can always be kept at the best level.

Specific example of stabilizer plate drive unit (Fig. 4) Fig. 4 shows an example of the drive unit of the stabilizer plate 16 in the control system etc. of Fig. 6. In this example, the drive unit of the stabilizer plate 13 is driven by piezoelectric ceramics. This is done using a laminated plate 30 consisting of 31 to 33. Piezoelectric ceramics undergoes deformation in the thickness direction when a voltage is applied in the thickness direction, and if it is made into a laminated structure, the amount of deformation in response to the voltage increases as a whole. The plate '50 is fixed to the stabilizer plate 13, and the piezoelectric ceramic 6
If the upper surface 31a of 1 is fixed to a fixing member such as a housing of the device, and a voltage is applied to the piezoelectric ceramics 31 to 33,
The stabilizer plate 13 moves in the direction B in the figure. Note that the stabilizing plate 13 itself can also be made of piezoelectric ceramics.

Modified Example of Stabilizer Plate Drive (FIG. 5) In FIG.
~33, for example, the stabilizing plate 16 is attached to the three bins 64 to 36 provided on the laminated plate 30 fixed to the casing (not shown).
It supports this by bringing it into contact. In this example,
Similar to the device shown in FIG. 4, the stabilizer plate 16 moves in the direction B in the figure in response to the voltage applied to the piezoelectric ceramics 51-36. In this example, even if the leaf spring 67 is attached to the insertion cover of the magnetic sheet 11, it is possible to prevent slight movement of the stabilizer plate 13 due to external factors.

Instead of the above-described specific example, the slight movement of the stabilizer plate 13 can also be performed by an electromagnetic drive system such as a voice coil. In the present invention, the stabilizer plate 16 is moved instead of the head 12, so a structure that avoids magnetic influence on the head 12 can be easily realized.

Effects of the Invention As described in detail above, according to the present invention, the stabilizing plate, which is provided at a position facing the signal readout head while sandwiching the record carrier, is moved relative to the record carrier in accordance with the output of the signal readout head. As a result, the contact state between the record carrier and the signal reading head can be maintained in a good state at all times, and a decrease in the head output due to deterioration of the contact state between the two can be prevented.

That is, it is possible to cope with changes in the contact state between the two due to the head feeding mechanism or the like, or changes in the contact state due to the thickness, rigidity, etc. of the recording medium, and a good reproduction output level can always be obtained.

In addition, the adjustment is not made by slightly moving the signal read head (but by slightly moving the stabilizing plate), so the configuration is extremely simple, and even if an electromagnetic drive source is used, for example, there is no magnetic influence on the head. This has the advantage of increasing the degree of freedom in selecting a driving source.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a conventional rotating magnetic sheet device using a stabilizing plate, FIG. 2 is a cross-sectional view M1M3 taken along the line A-A in FIG. The figure is a perspective view of a specific example of the stabilizing plate drive unit in the device shown in FIG.
Figure @5 is an exploded perspective view of another specific example. In the figure, 11 is a magnetic sheet that is a recording carrier, 12 is a magnetic head that is a signal read head, 13 is an upper stabilizer plate, and 14
1 is a lower stabilizer plate, 16 is an envelope detection circuit, 17 is an integration circuit, 18.19 is a memory, 20 is a comparison circuit, 21 is a direction determining circuit, 22 is a stabilizer plate ear 5h circuit, 30 is a piezoelectric ceramic dipping plate, 67 indicates a leaf spring. L1 muscle? mouth

Claims (1)

[Scope of Claims] A stabilizing plate provided at a position facing a signal read head while sandwiching the record carrier; 1) means for moving the stabilizer with respect to the record carrier in response to an output of the signal read head; Equipped with a head touch adjustment device.