JPS6079544A - Recording by large capacity disk - Google Patents

Abstract

PURPOSE:To realize a superlarge capacity disk whose track density and line density are both high by combining a magnetic performance and an optical performance, or each performance such as the magnetic performance, the optical performance and a lubricating performance of a projecting groove surface layer, etc. CONSTITUTION:One track is constituted of a pair of grooves A and B, in which one is recessed and the other is projecting. An interval of other track corresponding to one groove to said A or B. On the surface of the A and B grooves, a layer to which magnetization and an optical performance have been given is formed by its base material itself or a coating film. Basing on an optical performance difference and a focal difference of these one and the other grooves, a track control of a disk is executed by means of tracking by a laser, and also, information is recorded on adjacent groove or the same groove basing on the magnetizing performance or the optical performance which the groove has. In this way, an extremely high line recording density, for instance, 150 to 450kbP, and a high track density, for instance, 10,000 to 25,000TPI are obtained. A superlarger capacity disk is realized by an effect of both of them.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ultra-high capacity disk. Conventionally,
Even though optical disks had a high track density, the recording linear density was not high. On the other hand, magnetic disks such as perpendicular magnetic disks can have a high recording linear density, but do not have a high track density. The present invention realizes an ultra-large capacity disk with high track density and linear density.

FIG. 1 shows an example of the structure of a disk according to the present invention. In order to take advantage of both the high track density and tracking performance of the optical system and the high linear density of perpendicular magnetic recording, the
A pair of grooves, one of which is concave and the other convex, constitute one track. The distance from other trucks corresponds to one of these grooves. A layer with magnetization and optical performance is formed on the surface of the groove, either by the base material itself or by a coating. Track control of the disk is performed by laser tracking based on the optical performance difference and focus difference between one of these grooves and the other, and information recording is performed using the other adjacent groove or the same groove based on the magnetization performance or optical performance of the groove. The key is to do it on top of the groove. This allows extremely high linear recording densities, e.g. 150 to 450 km bPI.
and a high track density, for example 10,000 to 25,000 TPI.

The effects of both make it possible to realize an ultra-high capacity disk. moreover,
Capacity can be increased by applying magnetic or optical recording to the grooves that serve as track spacing.

Possible combinations of magnetic and optical performance are shown below.

In the above, A is vertical magnetization in A and non-magnetization or horizontal magnetization in B; B1 is the same optical property for both A and B; B2 is low light reflectance or high light absorption in A, and high light reflectance in B; B3 teeth,
A has high light reflectance, and B has low light reflectance or high light absorption. However, the expression "high and low" above refers to the comparison between A and B. Multiplex magnetic recording is also possible by adding horizontal magnetic recording performance to the above A, B, which has a strong track spacing factor. At this time, problems such as crosstalk with the adjacent perpendicular magnetic recording device are dealt with by changing the recording frequency band. High b of perpendicular magnetic recording
Even when PI requires a wide recording groove width on the first side due to read energy, a high TPI can be achieved by designing the first side sufficiently wide and the second side sufficiently narrow. It is also effective to perform optical recording (optical or photothermal magnetic recording) on either A or B of B1, B2 of B2, or A of B3.

In addition, by bringing the head into contact with the convex surface and utilizing the depth of the adjacent concave grooves, non-contact recording and reproduction of the concave magnetized film can be achieved, achieving an effect equal to or greater than that of submicrometer or less floating heads.

Furthermore, by imparting lubricating performance to the surface layer of the convex grooves, it is possible to ensure the wear interface effect of the head.

This can be done, for example, by reacting the resin end groups, impregnating with molybdenum disulfide, blending, etc.

The provided lubrication performance is conveniently referred to as C. A super-large storage capacity disk is made possible by each performance A (magnetic performance) and B (optical performance), or a combination of A, B, and C.

To manufacture a disk, for example, a perpendicularly magnetized film is deposited on the surface of a raw substrate, then a photoresist is coated, grooves are formed by etching after exposure to a groove pattern, and then the resist on the convex grooves is removed.

Another effective method is to reactively process the groove surface with an electron beam that can be finely controlled while tracing the groove.

The transducer consists of a hybrid head that incorporates a magnetic head and a laser head while taking into consideration the groove spacing.

bPI…Bit part punch TPI…Truck per inch

[Brief explanation of drawings]

Figure 1 shows the groove configuration of the disk. 1... Convex groove (equivalent to A or B) 2... Concave groove (equivalent to B or A) 3... Convex groove surface layer 4... Concave groove surface layer Patent applicant: Hikaru Yokoegawa

Claims (1)

[Claims] A and B1, A and B2, A and B3, A, B1 and C in the sentence,
A magneto-optical recording disk having a configuration of a combination of A, B2 and C, and A, B3 and C.