JPS59101044A - Recording and reproducing device - Google Patents

Abstract

PURPOSE:To effectively increase the recording capacity of a recording medium and, at the same time, to perform the tracking under an excellent condition, by forming a spiral groove or concentric grooves in the recording medium and moving a recording electrode or reproducing electrode along the grooves. CONSTITUTION:A recording medium 101 shown in the figure is formed in such a way that a spiral groove or concentric grooves having a V-shaped cross section is formed in a semiconductor layer 102 by etching after patterning and the 1st insulating film 103, such as silicon oxide (SiO2) film of about 20Angstrom in thickness, is formed on the surface of the semiconductor layer 102, in which the grooves are formed, and then, the 2nd insulating film 104 having an electric charge storing function made of Si3N4, etc., of about 500Angstrom or less in thickness is formed on the 1st insulating layer 103. On the surface of the product, grooves 106 are formed correspondingly to the surface shape of the semiconductor layer 102. When the angle of the V of the grooves 106 is represented as alpha and the width of the facing wall surfaces of the grooves 106 is as (l) and recording is performed by using the (l) as the track width, the recording capacity can be increased by 1/sin (alpha/2) times when compared with the recording made on a flat surface.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention is based on a semiconductor layer. The present invention relates to an apparatus for recording signals in the form of electrostatic charges and electrically reproducing them using a disk-shaped recording medium composed of a V film and a V film.

[Technical background of the invention and its problems]

Conventional so-called dynamic memory devices other than IC memory are broadly classified into magnetic disks or tapes, optical disks, and capacitance disks.Magnetic disks can be easily recorded, played back, and erased. However, it has the disadvantage of low recording density. On the other hand, in optical discs and capacitive discs, signals such as video signals, audio signals, or data signals are recorded in the form of full concave and convex shapes on a disc-shaped recording medium such as vinyl chloride, and then reproduced optically or electrostatically. Since this method is adopted, it is possible to record and reproduce signals at high density, but there is a drawback that erasing and re-recording are practically impossible. Many proposals have been made for rewritable optical discs, but most of them are still in the experimental stage.

In contrast, recently, recording media have been constructed by forming an insulating film with a charge storage function on a semiconductor layer such as silicon to form a recording/reproducing line that has a high recording density and is capable of re-recording. By applying a recording signal voltage to a recording electrode that moves relatively, charges are accumulated in the insulating film and signals are recorded.On the other hand, for reproduction, the reproducing electrode is similarly moved over the recording medium and the insulating film A method has been proposed in which the presence or absence of a depletion layer that occurs in a semiconductor layer corresponding to the charge accumulation state in the semiconductor layer is detected as a change in capacitance.According to this method, the recording electrode contacts the recording medium. By reducing the surface area, the recording density and recording capacity can be increased.0 However, in reality, the dimensions of the recording electrodes are small both in the direction of movement relative to the recording medium and in the track width direction. There is a limit to the size of the recording electrode, and it cannot be made too small from the viewpoint of electrode life.Furthermore, if the dimension of the recording electrode in the track width direction is reduced to make the trunk narrower, there is the problem that tracking becomes difficult. be.

[Purpose of the invention]

An object of the present invention is to provide a signal recording and reproducing device that can effectively increase the recording capacity and perform good tracking in a device that performs all signal recording and reproducing using a recording medium using a semiconductor. be.

[Summary of the invention]

In this invention, a spiral or concentric groove is formed on the surface of a recording medium formed entirely of an insulating film having a charge storage function on a semiconductor layer, and a recording electrode and a reproducing electrode are arranged relative to each other along the groove. It is characterized by recording and reproducing signals by moving the device.

〔Effect of the invention〕

According to this invention, by forming grooves in the recording medium, the surface area of the recording medium can be increased and the recording capacity can be increased, and as a result, the contact area between the recording electrode and the recording medium can be reduced and the recording density can be increased. The same effect can be obtained as increasing the recording capacity by increasing the recording capacity.

In this case, there is no need to use an extremely narrow-shaped recording electrode, which is advantageous in manufacturing, and the life of the recording electrode can be extended. Furthermore, since this groove can be used as it is as a tracking groove for recording and reproduction, accurate tracking is facilitated even if the track is extremely narrow.

[Embodiments of the invention]

FIG. 1 shows a part of a radial cross section of a recording medium in an embodiment of the present invention.

5 in the figure, the recording medium 101 is formed by patterning the semiconductor layer 102 and then forming V-shaped grooves in a spiral or concentric shape by etching, and then forming a V-shaped groove in a spiral or concentric pattern on the semiconductor layer 102.
An insulating film 1o3, for example, a silicon oxide (Sin2) layer of about 20yS- is formed, and a second insulating film 104 having a charge storage function, such as Si3N4, with a thickness of about 5oox or less is formed thereon. The surface thereof has grooves 106 corresponding to the surface shape of the semiconductor layer 102.
A conductive layer 105 is deposited on the back surface of the semiconductor layer 102.

FIG. 2 is for explaining the effect of increasing the recording capacity by forming 106 grooves on the surface of the recording medium 101. If the width of 106b is l, and if recording is performed with t as the track width, the recording capacity will be 1/sin (α /2) It can be seen that it is doubled.

For example, if ct-90 degrees, the recording capacity is 5 times, ct-
If you set it to 60 degrees, it will double. Furthermore, as shown in FIG. 1, by narrowing the flat portions 107 between the grooves 106, the recording capacity can be further increased. Further, as shown in FIG. 3, the cross-sectional shape of the groove 106 does not have to be completely V-shaped, but may be an inverted trapezoid shape with a flat bottom of the figure 7.

Signal recording and reproduction are performed using a recording electrode and a reproducing electrode, each of which has an electrode film coated on the side surface of a needle-shaped substrate, and FIG. 4 shows the situation. The configuration of the recording medium 101 is similar to that shown in FIG. Recording electrode 401
The tip of the needle-like base 402 is located at both opposing wall surfaces 106a of a V-shaped groove 106 formed on the recording medium 101.

It is V-shaped so as to contact 106b.

Then, both wall surfaces 106PL, 1
Independent electrode films 403 and 404 facing 06b
is covered. An advantage of forming the electrode 401f in the above-described shape is that the groove 106 on the recording medium 101 can also be used as a tracking groove. Signal recording is performed by applying a full recording signal voltage to the electrode films 403 and 404 of the recording electrode 401. Apply voltage to the recording electrode 401 and the entire recording medium 10
This is done by moving the groove 106 along the groove 106 relative to the groove 106. For example, if a spiral groove 106 is formed on the recording medium 101 as shown in FIG.
The entire recording medium 101 is rotated in a constant direction, and using a recording electrode 401 as shown in FIG. Groove 1 from the starting point 501 of the groove 106
Record all lines on one wall of 06, for example l0fyfL,
When the end point 502 of the groove 106 is reached, the recording electrode 401 is returned to the starting point 501 of the groove 106, and this time a recording signal voltage is applied to the other electrode film 404 to record on the other wall surface 106b of the groove 106. , can be recorded on the entire surface. Reproduction can also be performed using the same reproducing electrode as the recording electrode and following the same procedure as recording.

Similarly, on the recording medium 101 having a spiral groove 106 formed thereon, a recording electrode 601 as shown in FIG. , two wall surfaces 106a each having a groove 106 on the front side and the rear side in the moving direction of the needle-like base body 602.

The electrode film 603°6 is placed in contact with one side of each electrode 106b.
Recording chamber vi601 'ff: with 04 deposited,
First, the recording medium 101 is rotated in one direction, recording is performed from the starting point of the groove 106 to the end point of the groove 106 using, for example, the electrode film 603, and then the rotation direction of the recording medium 101 is reversed.
Even if recording is performed up to the starting point of the groove 106 using another electrode film 604, recording can be performed over the entire surface. Reproduction can be performed using the same procedure.

7. (In this invention, the cross-sectional shape of the groove formed on the recording medium is not limited to a V-shape, for example, as shown in FIG. 7(a)
, Even if the groove is U-shaped or semi-circular as shown in (b), the overall shape of the groove is not spiral.
It may be concentric.

[Brief explanation of drawings]

Fig. 1 is a radial cross-sectional view of a recording medium in one embodiment of the present invention, and Fig. 2 shows the effect of increasing recording capacity by forming all grooves with a V-shaped cross section on the recording medium in the same embodiment.・Diagrams for explanation, FIG. 3 is a diagram showing a deformation pattern of a groove with a V-shaped cross section, and FIGS. 4 and 5 are for the same example.
6 (a) z (b) t (c) are cross-sectional views and plan views showing how recording and reproduction are performed in the recording electrode (
7(a) and 7(b) are diagrams showing other examples of the cross-sectional shape of the grooves formed on the recording magnetic material. 101... Recording medium, 102... Semiconductor layer, IO2
...first insulating film, IO4...second insulating film, 10
5...4 electric layers, 106-...grooves, 106a, l06b
---Groove wall surface, 401,601...Recording electrode (reproduction electrode), 402.602...Acicular substrate, 403,40
4゜603.604...electrode film, 501...start point of groove, 502...end point of groove. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5

Claims (1)

[Claims] (1) A disk-shaped recording medium formed by forming an insulating film having a charge storage function on a semiconductor layer, and a recording electrode to which a recording signal voltage is applied on this recording medium are connected relative to each other. a recording means for recording a signal by moving a charge corresponding to a recording signal voltage on the insulating film; In a recording and reproducing apparatus that is fully equipped with a reproducing means that reproduces a signal by detecting a change in the electrical characteristics of a recording medium, a spiral or concentric groove is formed on the recording medium, and a spiral or concentric groove is formed on the recording medium. A recording/reproducing device characterized in that the recording electrode and the reproducing electrode are moved. The record according to claim 1, characterized in that independent electrode films are applied to the side surfaces of the groove in the direction of movement thereof, facing both opposing wall surfaces of the groove. playback device. (3) The recording/reproducing apparatus according to claim 1, wherein the cross-sectional shape of the groove formed on the recording medium is V-shaped.