JPS58115664A - Magnetic recording and reproducing mechanism - Google Patents

Abstract

PURPOSE:To increase track density scarcely different from the conventional instructure, by providing a single slider with two magnetic recording and reproducing heads, and performing track servocontrol by one head while the other head performs magnetic recording. CONSTITUTION:A head 31 is an external head for servomechanism and is a general magnetic recordihg and reproducing head. A head 30 picks up a signal recorded on a track in the form of an electric signal, which is inputted to a comparing circuit 33 through an amplifying circuit 31 and through the circuit 31 and a delay circuit 22 respectively. Thus, the difference of the head before and after its movement is detected on the basis of the difference, a motor control circuit 34 is operated to drive a driving motor 35. Similarly, when an external head 11 performs magnetic recording, an internal head 10 performs track servocontrol. This control system allow the centers of the heads to follow up tracks within some range from the centers of the tracks over undulations. The extent of the undulations is determined by the time constant of the delay circuit 32 and that of the motor control circuit 34 and under proper control, the undulations are suppressed to <=1mum.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic recording and reproducing mechanism that performs magnetic recording on a rotating magnetic recording medium.

Conventionally, the mechanism for performing magnetic recording on a rotating magnetic recording medium is as shown in Fig. 1, in which a head block with a head 1 fixed to a slider 2 is fixed to an arm 5. Recording is performed by sandwiching the magnetic recording medium 3. Arm 5 is operated in drive mode 4. The amount of change in the drive motor 4 is determined from the outside. For example, if the drive motor 4 is a pulse motor, a pulse corresponding to the amount of movement of the arm 5 is applied. Since the amount of movement is a predetermined length, tracking errors occur due to changes in temperature due to thermal expansion of the arm 5 and the magnetic recording medium 3. Track density is generally determined by including temperature expansion of the materials of each component.

Therefore, in order to increase the track density, K selects materials with small temperature expansion for the component parts, but it is inevitably designed without taking temperature expansion into consideration, and if it is not made larger than the nine track density, it will overlap with the adjacent track. .

The present invention has been made to eliminate such drawbacks.

An embodiment of the present invention will be described with reference to FIGS. 2 and 5. FIG. 2 is a partially enlarged view of the head block 13 of FIG. 5 in which the head 10.11 is attached to the slider 12. Heads 10 and 11 can perform magnetic recording and reproduction independently and have the same track width.

The head block 13 is connected to a drive motor 15 by an arm 14, and is configured to sandwich a 6-press recording medium 16 with a presser foot 17.

From the above configuration, the relationship between the magnetically recorded signal and the reproduced signal due to track deviation is as shown in Figure 4.Since recording and reproduction are performed using heads 10° and 11 having the same track width, the track width and the gap Maximum output is obtained when the widths are equal and the gap center is located at the center of the track. Furthermore, if the gap center is equal to or deviates from the gap width, no reproduction output can be obtained.

Therefore, since the maximum output is obtained when the gap center is located at the center of the track, the drive motor 15 is controlled so as to obtain the maximum output.

For example, when performing magnetic recording with the inner head 10, the signal magnetically recorded by the outer head 11 is used as a track servo signal, and the reproduced signal having the relationship as shown in FIG.
The drive motor 15 is controlled as a servo mechanism so that the reproduction signal 1 is maximized. FIG. 5 shows a block diagram of the control section. The head 51 is an outer head that performs a servo mechanism, and is a general magnetic recording/reproducing head. The head 30 extracts the signal recorded in the trunk as an electrical signal,
The signal passed through the amplifier circuit 51 and the signal further passed through the delay circuit 52 are input to a comparison circuit 53. The difference between before and after the movement K is detected, and based on this amount, the motor control circuit 34 is operated to move the drive motor 55. Similarly, when the outer head 11 performs magnetic recording, the inner head 10 can perform track servo.

In this control method, the head center follows the track center while undulating within a certain range. The amount of this fluctuation is determined by the time constant of the delay circuit 52 and the motor control circuit! It is determined by a time constant of 140, and if proper control is performed, the fluctuation can be made to be less than 1 #m.

In the above description, the magnetic recording sickle is sandwiched between the head block and the presser foot, but the head may be used instead of the presser foot.

As described above, according to the present invention, when one head performs recording, the other head is used to perform track servo, so that it is possible to correct track deviation due to temperature expansion of one recording medium, arm, and drive motor. The structure is almost the same as the conventional one, and the track density can be increased.

[Brief explanation of drawings]

Figure 1 is a diagram for explaining a conventional magnetic recording and reproducing mechanism. FIG. 2 is an enlarged view of the head block for explaining the present invention. FIG. 3 is a diagram for explaining the present invention. FIG. 4 is a diagram for explaining the positional relationship between the track center and the gap center of the reproduced output, and is a diagram where the track width is 1. FIG. 5 is a block diagram 1.10 for explaining the present invention.
jl...Head 2.12...Slider 5.16.
・・・・・・・・・・・・Recording medium 4.15・・・・・・
・・・・・・Drive motor 5.14・・・・・・・・・・
・・Arm 6.17・・・・・・・・・・Presser foot 13
・・・・・・・・・・・・・・・・・・Head flock 30・・・・・・・・・・・・・・・・・・Head 51
・・・・・・・・・・・・・・・・・・Amplification circuit 32・
・・・・・・・・・・・・・・・・・・Delay circuit 55...
・・・・・・・・・・・・・・・Comparison circuit 54...
......Motor control circuit 35.
・・・・・・・・・・・・・・・・Drive motors and above Applicant: Hosei Kogyo Co., Ltd. Patent attorney Mogami

Claims (1)

[Claims] 1. A single slider has two magnetic recording media heads,
9. A magnetic recording and reproducing mechanism characterized in that when one head is performing magnetic recording, the other head performs track servo.9.