JPH01224983A - Memory - Google Patents

Abstract

PURPOSE:To stably contact and slide a head on the surface of a storage medium with a minute load and minute frictional force by detecting the frictional force when the head is contacted and slid, adjusting the pressing force of the head to the storage medium according to the detected frictional force, and controlling the frictional force within a constant range. CONSTITUTION:When a head 1 is contacted and traveled on a storage medium 3, a parallel spring 5 is bent by the frictional force generated by the contact and the slide of both of them. The displacement is detected by a displacement detecting mechanism 6 and adjusted by a frictional displacement control circuit 8 and a deflection adjusting electromagnet 7 so that the deflection can be zero all the time. A frictional force control circuit 9 makes the suction force of the electromagnet 7 into its input and controls the pressing force of the head 1 to the storage medium 3 so that constant frictional force can be generated all the time by decreasing the current of a load adjusting electromagnet 4 when the frictional force is excessive and increasing the current when the frictional force is too small. Thus, the head 1 can be stably contacted and slid on the surface of the storage medium 3 with the minute load and the minute frictional force.

Description

[Detailed Description of the Invention] (Industrial Application Field) Storage devices, including magnetic storage devices, in which a recording/reproducing head slides in contact with a storage medium to record and read information are in widespread practical use. . The biggest problem with this type of storage device is wear. Furthermore, if the contact is unstable, the head may "jump" and recording/reproduction may not be performed. The present invention relates to a storage device that reduces wear and prevents head "jumping."

(Prior Art and Problems to be Solved by the Invention) A floppy device is a contact sliding type magnetic storage device. This is a device in which a magnetic head is pressed against a flexible magnetic disk coated with magnetic powder and performs recording and reproduction while in contact. The load of pressing is more than 10 grams, and the life span due to wear occurs after several hundred blades to tens of millions of passes. When a metal thin film storage medium, which is expected to be a future high-density storage medium, is used, the wear is even more severe, making it difficult to put it into practical use.

Furthermore, in a magnetic disk device in which the magnetic head floats without contact, the head slides in contact during startup and shutdown, causing wear.

Magnetic disks using thin metal film storage media have several hundred angstroms of hard protective film, such as carbon, attached to them to reduce wear, but even so, the lifespan of the disks is limited to several tens of thousands of cycles.

If the recording density i is to be further increased in the future, the thickness of the protective film will have to be made thinner, which will shorten the lifespan.

VHD is a type of video disc that reads information by changing capacitance. In this method, a capacitance detection head slides in contact with the disk surface.

This also has a problem in terms of lifespan compared to optical recording type video discs, which have no contact at all.

The conventional storage devices exemplified above reach the end of their service life quickly due to severe wear due to high loads and localized severe wear when coming into contact with minute protrusions scattered on the storage medium. If the pressing load is reduced to reduce wear, the head will bounce over the storage medium, making normal recording and reproduction impossible.

The present invention was proposed in order to improve the above-mentioned drawbacks, and its purpose is to realize a storage device with a long life and high storage density by applying an extremely light load and non-jumping head to the storage device. To achieve this, a mechanism is used to detect the frictional force between the head and the storage medium and control the load.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a storage device in which a recording/reproducing head slides in contact with a storage medium to record and read information. The gist of the invention is to provide a storage device comprising a mechanism that detects the frictional force and controls the frictional force within a certain range by adjusting the pressing force of the head against the storage medium according to the detected frictional force. It is something to do.

(Function) In the present invention, in a storage device in which a recording/reproducing head contacts and slides on a storage medium to record and read information, the frictional force at the time of contacting and sliding of the head is detected, and the detected frictional force is applied to the storage medium. By providing a mechanism that controls the frictional force within a certain range by adjusting the pressing force of the head against the storage medium accordingly, the head can stably slide in contact with the surface of the storage medium with an extremely small load and frictional force. As a result, a long-life storage device can be realized. In addition, stable contact can virtually eliminate the effective gap between the head and the storage medium, allowing high-density recording and reading. .

It is something.

(Example) Next, examples of the present invention will be described.

It should be noted that the embodiments are merely illustrative, and it goes without saying that various changes and improvements may be made without departing from the spirit of the present invention.

FIG. 1 shows a side view and control circuit of an embodiment of the invention.

In the figure, 1 is a head, 2 is a leaf spring, and the head 1 is fixed to the tip of this leaf spring 2. 3 is a storage medium, on which the head 1 slides in contact.

4 is a load adjustment electromagnet that attracts the leaf spring 2 and adjusts the load. 5 is a parallel spring. The parallel spring 5 is deflected by the frictional force generated by the sliding contact of the head 1 with the storage medium 3. Reference numeral 6 denotes a displacement detection mechanism for detecting the displacement of the parallel spring 5, which is composed of a capacitance sensor, a light sensor, a tunnel current sensor for detecting tunnel current, and the like. 7 is a deflection adjusting electromagnet that attracts the parallel spring 5 and always makes the deflection of the parallel spring 5 zero. Reference numeral 8 denotes a frictional displacement control circuit which receives the displacement signal from the displacement detection mechanism 6 and controls the current of the deflection adjusting electromagnet 7 to make the deflection of the parallel spring zero. The attraction force of the deflection adjustment electromagnet 7 generated by the operation of the frictional displacement control circuit 8 becomes equal to the frictional force between the head 1 and the storage medium 3. 9 inputs the output of the frictional force control circuit 8, that is, the attractive force of the deflection adjustment electromagnet 7, and when the frictional force is excessive, the current of the load adjustment electromagnet 4 is reduced, and when it is too small, the current is increased to maintain a constant constant. This is a friction force control circuit that controls the generation of friction force. 10 is a signal processing circuit that processes read signals from the head 1 and write signals to the head 1.

To operate this, first the head 1 is caused to run in contact with the storage medium 3. At this time, the pressing force of the head 1 against the storage medium 3 is extremely small, for example, less than a milligram. When the storage medium 3 runs, a frictional force is generated on the head 1, but the deflection of the parallel spring 5 is adjusted by the frictional displacement control circuit 8 and the deflection adjustment electromagnet 7 so that it always becomes zero. This reduces the jitter of write and read information. Frictional force changes depending on the properties of the storage medium. In particular, if there is a p1-adsorbing substance with large step convexities on its surface, the frictional force will be extremely large. In addition, the head jumps easily. This phenomenon causes rapid wear in that area,
The generated wear particles are attracted to the head and the storage medium, further accelerating wear. The load adjustment electromagnet 4 is controlled to avoid this, and has the effect of reducing the pressing force of the head 1 when the frictional force increases. However, since the frictional force is generated only in a contact state, the head 1 will not be completely separated from the storage medium 3. In this way head 1
The head 1 smoothly contacts and slides on the storage medium 3 with a constant minute frictional force, and the head 1 stably writes and reads information.

FIG. 2 is a diagram showing another embodiment of the present invention.

In the figure, 1 is a head, 3 is a storage medium, 414 is a load adjustment electromagnet, 6 is a displacement detection mechanism, 7 is a deflection adjustment electromagnet, 8
9 is a frictional displacement control circuit, 9 is a frictional force control circuit, 10 is a signal processing circuit, and 11 is an L-shaped spring. In this embodiment, the leaf spring 2 and parallel spring 5 of the embodiment shown in FIG.
A simple structure is realized by replacing the spring 11 with a shaped spring 11.

Note that even if a bar spring is used in place of the plate spring in the embodiment of the present invention, the effects of the present invention will not be lost. Also, in place of the electromagnet, other mechanisms for generating attractive or repulsive force such as electrostatic force may be used. Even if it is used, the effects of the present invention are not lost.

The device of the invention can be realized as a storage device with various recording and reading principles.

If a storage medium that stores information in the form of magnetization is used, it becomes a device that records with a magnetic head that generates a magnetic field and reads out with a magnetic sensor such as an inductive type or magnetoresistive type.

If a storage medium that stores information in the form of electric charge is used, the device can perform recording and reading using simple electrodes.

If information is recorded on a storage medium using irregularities on the surface of a conductor or changes in the dielectric constant of the surface, the device can read out changes in capacitance using simple electrodes. Furthermore, by applying a higher voltage to the electrodes than during reading to create irregularities and changes in the crystal structure of the storage medium, the device can also record data.

If the storage medium is a conductor and information is recorded using the irregularities on the surface of the conductor or changes in electrical resistance, the device can be used to read out changes in contact resistance or tunnel current using electrodes. Furthermore, by applying a higher voltage to the electrodes than during reading to create irregularities and changes in the crystal structure of the storage medium, the device can also record data.

If information is recorded as changes in reflectance on a storage medium,
This is a device that reads data using a light sensor such as a thin optical fiber. Furthermore, by irradiating a storage medium with strong light from the tip of this optical sensor and causing a change in the reflectance of the storage medium, the device can also record data.

By recording information on a storage medium as unevenness and detecting the unevenness as displacement using a stylus, the device becomes a device that reads surface roughness as information. Furthermore, the device can record data by applying voltage to the stylus and creating unevenness on the storage medium.

The embodiments of the present invention can be summarized as follows.

(a) If the storage medium stores information in the form of magnetization, the head is a magnetic sensor. (b) If the storage medium stores information in the form of electric charge, the head is an electrode. (If the storage medium stores information in the form of capacitance with the head, the head is an electrode.) The storage medium stores information in the form of contact resistance or tunnel current resistance. (e) If the storage medium stores information in the form of light reflectance, the head must be an optical sensor. (f) The storage medium stores information in the form of unevenness. For example, the head may be a stylus.

(Effects of the Invention) As described above, according to the present invention, in a storage device in which a recording/reproducing head slides in contact with a storage medium to record and read information, the frictional force at the time of contact and sliding of the head is detected, In addition, by providing a mechanism that controls the frictional force within a certain range by adjusting the pressing force of the head against the storage medium according to the detected frictional force, the head can be pressed against the storage medium surface with an extremely small load and frictional force. Since it is possible to stably contact and slide on the surface, a long-life storage device can be realized. In addition, stable contact can virtually eliminate the effective gap between the head and the storage medium, which has the effect of enabling high-density recording and reading.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a side view and a control circuit of an embodiment of a storage device according to the invention, and FIG. 2 shows another embodiment of the invention. 1... Head, 2... Leaf spring, 3... Storage medium,
4... Load adjustment electromagnet, 5... Parallel spring, 6...
Displacement detection mechanism, 7... Deflection adjustment electromagnet, 8... Frictional displacement control circuit, 9... Frictional force control circuit, 10...
Signal processing circuit, 11... L-shaped spring patent applicant Nippon Telegraph and Telephone Corporation Figure 2

Claims (1)

[Claims] In a recording device in which a recording/reproducing head contacts and slides on a storage medium to record and read information, the frictional force at the time of contacting and sliding of the head is detected, and the head is applied to the recording medium according to the detected frictional force. A storage device characterized by having a mechanism that controls frictional force within a certain range by adjusting pressing force.