JPS63279442A - Optical semiconductor recording medium and recording and reproducing method thereof - Google Patents

Abstract

PURPOSE:To enable optical recording and reproduction without contact by effectively utilizing the photoelectric conversion and electric charge holding effects by a nitrided film layer, insulating layer and semiconductor layer and the polarization effect generated according to the charge held in the electrooptic polarization layer. CONSTITUTION:This medium is constituted by laminating a transparent electrode layer 18 having light transparency and electrical conductivity, the electrooptic polarization layer 17 consisting of a liquid crystal or the like which generates a polarization effect in the prescribed direction according to the electric field, the nitrided film layer 16, the insulating layer 15 and the semiconductor layer 14 formed with a meshed isolation layer 14a successively, impressing a prescribed voltage between the transparent electrode layer 18 and the semiconductor layer 14 and entering a light signal to be recorded thereto. Recording is enabled by the depletion layer formed in the insulating layer 14 and the charges accumulated in the nitrided film 16 and the light polarized in the prescribed direction is entered to the electrooptic polarization layer 17 polarized in the prescribed direction. Reproduction is executed by detecting the indecent light of this time.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to an optical semiconductor recording medium using a semiconductor having photoelectric conversion characteristics and a recording/reproducing method therefor, and in particular to optically recording/reproducing and recording/reproducing. The present invention relates to an optical semiconductor recording medium capable of retaining a recorded signal for a long period of time and repeatedly reproducing the same, and a recording/reproducing method thereof.

[Prior Art] A recording medium using a conventional semiconductor element and a recording/reproducing method thereof will be explained with reference to figures. First, the configuration is shown in Figure 8.
Specifically, reference numeral 1 is a disc-shaped recording medium, on the surface of which recording materials for recording and reproduction, which will be described later, are laminated. The recording medium 1 is moved in a predetermined direction Y1 by the drive device 2.
The stylus 3 is rotated at a constant speed in the radial direction of the recording medium 1 x 1, and the stylus 3 scans the surface of the recording medium 1 . That is, by rotating the recording medium 1 and simultaneously moving the stylus 3 in the radial direction x1, the recording medium 1 is scanned in a spiral or concentric line.

The stylus 3 is connected to a write/read circuit 5 via a coil 4.
Connected to and covered by ;! To record the retraction signal, it is supplied to the stylus 3 via the coil 4 and the above scanning is performed. On the other hand, during reading, the stylus 3 detects a change in capacitance by performing the above scanning, and supplies this detection signal to the loading/reading circuit 5 via the coil 4.

Next, the structure of this recording medium 1 and the principles of recording and playback will be explained in the ninth section.
This will be explained based on the diagram. The figure shows the recording medium in Figure 8 at Z.
This is a top view taken along line -7, and is a top view of a silicon oxide film (S
A layer 7 of iO2) and a nitride film (Si3N4) are laminated, and a conductive layer 9 formed by aluminum vapor deposition or the like is formed on the back surface.

During recording and reproduction, the conductive layer 9 is set to earth potential,
The stylus 3 scans the upper surface of the nitride film 8. First, in the case of writing, since a voltage corresponding to the voltage level of the signal to be written is applied to the nitride film 8 via the stylus 3, a charge 10a is generated in the nitride film 8, and at the same time, a charge 10a is generated in the semiconductor substrate 8.
A depletion layer 10b having a depth corresponding to the amount of charge is generated inside.

Since this charge is accumulated and retained in the nitride film 8 even when the device is removed from the device, recorded data can be stored for a long period of time. On the other hand, in the case of playback, the recorded part (
When scanning the recording track) with the stylus 3, the depletion layer 1
It is possible to detect the presence or absence of 0b or a change in capacitance depending on the depth, and it is possible to reproduce the recorded signal based on this detection signal.

[Problems to be Solved by the Invention] However, according to such conventional technology, in order to perform recording and reproduction by scanning the stylus, the distance between the stylus and the nitride film of the recording medium must be at least several tens of degrees strong. If scanning was performed at this interval, the stylus and recording medium would actually come into contact with each other, causing mutual wear.

[Means for solving the problems] The present invention has been made in view of the above problems.
The purpose is to provide a new recording medium that allows contactless recording and playback.

In order to achieve this object, the present invention includes a transparent electrode layer having translucency and conductivity, an electro-optic polarizing layer such as a liquid crystal that generates a polarizing effect in a predetermined direction according to an electric field, a nitride film layer, an insulating layer, and a semiconductor. The layers are laminated at least one after another, and a predetermined voltage is applied between the transparent electrode layer and the semiconductor layer so that the optical signal to be recorded is incident on the transparent electrode layer and the semiconductor layer. In addition to making recording possible due to the electric charge generated by
Reproduction is performed by applying light polarized in a predetermined direction to the electro-optic polarizing layer, which is polarized in a predetermined direction by charges accumulated in the nitride film, and detecting the reflected light at that time. Make it a technical point.

[Example] An embodiment of the present invention will be described below with reference to the drawings.

Figure 1 is a perspective view of the newly developed recording medium.
A disk-shaped recording medium 11 has a recording area 12 formed by laminating recording materials, which will be described later, and is rotated around a central portion 13 during recording and reproduction.

The cross-sectional structure (Z-Z line cross-section) of the recording medium 11 will be explained based on FIG. 2(a). A layer 15 of silicon oxide film (SiO2), Nitride film (Si3N4) layer 16
, an electro-optic polarizing layer 17 made of liquid crystal, etc., In Sn
Transparent electrode layers 18 made of oxide or the like having translucency and conductivity are laminated in this order, and a conductive layer 19 made of aluminum evaporation or the like is laminated on the semiconductor substrate 14 . Furthermore, by forming a mesh-like isolation F514a as shown in FIG. 2(b) on the surface portion of the semiconductor substrate 14, single crystal n-type silicon isolated from each other is An array of fine parts 14b is formed. This isolation ffl 15a is formed of an insulator doped with a high concentration impurity, implanted with ions, or formed by LOCOS oxidation. Note that the cross-sectional shape and arrangement of the fine portions 14b are determined as appropriate depending on the application, design specifications, and the like.

Again in FIG. 2(a), the central portion C of the transparent electrode 18
A conductor 20 is formed on the upper surface of the conductor 20, thereby forming the central portion 13.

Next, the configuration and recording method of a recording apparatus using the recording medium 11 having such a structure will be explained based on FIGS. 3 and 4. First, to describe the configuration, in FIG. 3, when the recording medium 11 is mounted on a support mechanism (not shown), it is rotated at a constant speed in the circumferential direction Y2 around the center portion 13 by the drive shaft of the drive device 21. ing.

Further, a contact terminal (not shown) contacts the conductor 20 and the conductive layer 19, and by applying predetermined voltages V and v[E, VD is created between the transparent electrode layer 18 and the conductive layer 19.
O-■ [Mark the voltage of E. Note that in this embodiment, the voltage V
is set to a potential of 25 to 40 V, and the voltage (2) E1 is set to the earth potential (OV), and the potential of the conductive layer 19 is set to an appropriate potential that is relatively 25 to 40 V lower than that of the transparent electrode layer 18.

Reference numeral 22 denotes an optical system that directs an optical image from the subject A onto the recording area 12 of the recording medium 11 in a two-dimensional space.

The optical axis of the optical system 22 and the rotation axis C of the center portion 13 are designed to be shifted from each other by a predetermined interval, and the drive device 21 rotates the recording medium 11 in the circumferential direction Y by a predetermined rotation angle θ.
2, the area Vt can irradiate the recording area 12 with a plurality of optical images that do not overlap with each other.
12a, 12b, , , , are secured.

Reference numeral 23 denotes a control circuit that instructs the drive device 21 to perform drive control based on this rotation angle θ, which occurs when, for example, the release button of an electronic still camera designed based on the present invention is turned on (shooting). Control operation is performed in synchronization with signal Lb.

FIG. 4 is a sectional view showing the principle of the recording method according to the present invention, and is shown corresponding to FIG. 2(a).

That is, when an optical image is irradiated by the optical system 22 as described above, the light flux passes through the transparent electrode 18 and the electro-optic polarizing layer 17 and reaches the nitride film layer 16, and as a result, each minute portion 14b receives a different amount of light. At the same time, a depletion layer Nb with a depth corresponding to
Each depletion 11 is formed in the nitride film 16 via the silicon oxide film 15.
A charge distribution Ch corresponding to the depth of Nb is generated. The depletion layer Nb and charge distribution Cb generated in this way are
Remove it from the device and set the voltage to V. 8.Even if VE is not applied, it will be retained for a long time, and it will be possible to reproduce it repeatedly until erasing described later is performed.In this case, because of the isolation layer 14a, the charge and depletion layer Although the distribution is not continuous, since the fine portions 14b and the isolation layer 14a are formed extremely finely using semiconductor manufacturing technology, high-resolution recording is possible.

Next, a method for reproducing images from the recorded recording medium 11 will be explained. Figure 5 shows an outline of the playback device (showing the J4 configuration).
24 is a pickup device, - a light source device 24a that converges light (using a laser beam, etc.) polarized in a predetermined direction of the toe m and irradiates the recording area 12 of the recording medium 11 in a minute range; The light receiving device 24b photoelectrically converts the detected signal SV to generate a detection signal SV, and is configured to move in the radial direction Z-7 of the recording medium 11. 25 is a drive device that supports the mounted recording medium 11 around the center portion 13 and rotates it at a constant speed in a predetermined circumferential direction Y3. Reference numeral 26 denotes a synchronization signal generation circuit, which generates a synchronization control signal S1 for causing the drive device 25 to rotate the recording medium 11 at a constant speed, and a synchronization control signal S1 for causing the drive device 25 to rotate the recording medium 11 at a constant speed, and the pickup device 24 in the radial direction Z-7 at a constant speed or in steps at regular intervals. A synchronization control signal S2 is generated to cause the movement to occur. Therefore, the light beam from the pickup device 24 scans the recording area 12 as the recording medium 11 rotates, and scans the area where the latent image is formed in a spiral or concentric pattern based on the synchronization control signal S2. .

For example, the number of tracks to be scanned is set to a value equal to the standard television system, such as 525 tracks. Reference numeral 27 denotes a synchronous reproduction circuit, which inputs the detection signal S and reproduces the video signal Sv.

■ Form. That is, the synchronous regeneration circuit 27 receives the synchronous control signal S.
1. Clock signal S synchronized with S2. is supplied from the synchronization signal generation circuit 26, and it is determined based on the clock signal Sc which minute portion 14b is likely to be scanned to generate the detection signal S9, and the signal S of the image to be reproduced is determined.
V, is selectively generated. To be more specific, the detection signal S is a so-called line sequential signal, and for example, when reproducing the video recorded in the shaded area 12a in the same figure, the detection signal S is scanned over the square recording area (signal q). When the signal SVo is removed from the detection signal S and the signal SVo is applied to a monitor television, processing is performed such that image reproduction by well-known horizontal scanning and vertical scanning can be performed.

Next, the principle for reading signals from the recording medium 11 will be explained based on FIG. 6. When recording is performed on the recording medium 11, the depletion layer and charge distribution channel are maintained as described above. A polarization effect occurs, and only light polarized in a predetermined direction with respect to this polarization direction can pass through. The present invention utilizes this effect, and as described above, only light polarized in a predetermined direction (not limited to laser beams) is irradiated from the light source device 24a, and the polarization of each minute portion of the electro-optic polarizing layer 17 is changed. The light receiving device 24b detects the reflected light with an intensity corresponding to the intensity.

Therefore, the detection signal SV corresponding to each fine part of the recorded video pattern can be detected, and by processing this at a predetermined timing by the synchronous reproduction circuit 27, the subject image can be reproduced. And is the depletion layer and charge distribution a discharge? Since the recorded image is retained without any modification, the recorded image can be repeatedly reproduced.

Next, a method of erasing a so-called latent image (depletion layer and charge distribution) in a recording medium will be explained. For this purpose, the transparent electrode layer 18
A relatively high voltage with a polarity opposite to that shown in FIGS. 3 and 4 is applied between the conductive layer 19 and the conductive layer 19 to discharge the charges accumulated in the nitride film 16 and at the same time erase the depletion layer. let In addition, in the explanation of the image forming method (along with FIG. 3), there is no mention of erasing the latent image before image formation, but it is not possible to perform image formation after erasing by the above erasing method. It's no good.

As explained above, according to this embodiment, the photoelectric conversion and load retention effects of the nitride film layer 16, silicon oxide film layer 15, and semiconductor substrate 14, and the electro-optic polarization light 17 are applied to the retained charges. By making extremely effective use of the polarization effect that occurs in accordance with the
Since this is done without contacting the recording medium, it is possible to significantly reduce the damage to the recording medium that would occur in the conventional case.

Furthermore, since the optical image is directly recorded as a latent image, the signal processing circuit etc. can be greatly simplified compared to electronic cameras equipped with conventional solid-state image carriers and magnetic recording means.
It can be easily used like a camera using silver halide film. Another advantage is that the latent image can be easily erased simply by applying a predetermined voltage to the transparent conductive layer. Furthermore, although this embodiment describes a disc-shaped recording medium, a card-shaped recording medium or other shapes may also be considered.
Items with different shapes are also included in the present invention. Although it is not possible to explain all the effects due to space constraints, all the effects produced by the recording medium of this embodiment are related to the present invention.

Next, another embodiment according to the present invention will be described with reference to FIG. The first embodiment described above forms a so-called latent image directly on the recording medium 11, but the recording apparatus shown in FIG. It was designed so that it could be recorded. That is, in the figure, 28 is a light irradiation mechanism that modulates the recorded signal into an optical signal, converges this optical signal into an extremely fine beam, and irradiates the recording area 12 in a spot shape. The recording medium 11 is the third
Predetermined voltage V as in the figure. o, V[E are applied, the recording area 12 is rotated at a constant speed in a predetermined direction Y4 by the driving device 29, and at the same time the light irradiation mechanism 28 is moved stepwise in the radial direction Z4 at a constant speed or at a constant cycle, so that the recording area 12 is spirally rotated. It is designed to be scanned in a circular or concentric circular pattern.

For example, if the recorded signal is a digital signal of "1" or "0", scanning is performed synchronously so that each digital signal is sequentially recorded on each fine portion 14b of the recording medium 11. This makes it possible not only to record images as in the first embodiment, but also to record digital signal data. still,
If an image is captured by a conventional COD or MO8 type image sensor, and a signal read out by dot-sequential scanning of this hyperemia signal is optically modulated as a signal to be recorded, it becomes possible to record an image using the recording apparatus shown in FIG.

Note that reproduction and erasing are performed in the same manner as in the first embodiment, so their explanation will be omitted.

As described in the above two embodiments, these embodiments exhibit excellent effects not found in the prior art. Note that in these embodiments, for convenience of explanation, the recording device, playback device, and erasing device have been explained separately, but recording, playback, and erasing are performed by sharing common components. A functional integrated device can be easily constructed.

In the above embodiment, the isolation 14a is formed in the semiconductor substrate 14 to form a plurality of fine parts 14b, but this is because the depletion layers formed by recording in the mutually adjacent fine parts 14b are electrically This is to ensure complete separation between the two. However, in recording applications that do not particularly require high resolution, it is not necessary to provide this isolation. That is, isolation is not necessary if the depletion layers formed adjacent to each other can be separated to some extent even without isolation, and separated enough to record the characteristics of the recorded data.

[Effects of the Invention] As explained above, according to the present invention, photoelectric conversion and one-time retention effects by the nitride film layer, insulating layer, and semiconductor layer, and the electrical engineering polarizing layer are generated in response to the retained charges. By making effective use of the polarization effect, it is possible to perform repeated recording and reproduction, making it possible to provide a new optical semiconductor recording medium that has an extremely simple structure and is easy to absorb. Since recording and reproducing can be performed without contact, no damage occurs during recording and reproducing, and extremely excellent effects are exhibited.

[Brief explanation of drawings]

FIG. 1 is an external perspective view showing a schematic configuration of an embodiment of a recording medium based on the present invention, FIG. 2(a) is a cross-sectional view of a main part of the recording medium based on FIG. F-F in Figure 2(a)
A sectional view taken along the line, FIG. An explanatory diagram, FIG. 5 shows the configuration of an embodiment of a reproducing apparatus according to the present invention.A schematic configuration diagram, FIG. 6 is an explanatory diagram for clarifying the reproduction principle of a recording medium, and FIG. t1!!Abbreviated tiA diagram showing the conjunction of another embodiment of the recording apparatus according to the present invention, FIG. 8 shows the configuration of a conventional recording apparatus J-11'! 8 is a dimensional explanatory diagram illustrating the principle of the recording method using the apparatus shown in FIG. 8. 11: Recording medium 12: Recording area 13: Center part 14: Semiconductor substrate 15: Silicon oxide film layer 16: Nitride film layer 17: Electro-optic Polarizing layer 18: Transparent electrode layer 19: Conductive layer 14a: Einstein 14b: i-emission parts 21, 25, 29: Drive device 22: Optical system 23: Control circuit 24: Pick-up device 24.1, light source device 24b, light receiving Everyone's stomach 26: Domei Shinyumi generation circuit 27: Domei Saigyu circuit 28: Light irradiation machine (14th patent attorney (8107) Kiyotaka Sasaki,
``(3 others)''P4 Figure 3 Figure 4 Figure 5 Figure Oka Figure 6 Figure 7 Figure 8 Figure 9

Claims (5)

[Claims] (1) A transparent electrode layer having translucency and conductivity, an electro-optic polarizing layer that generates polarization in a predetermined direction depending on an electric field, a nitride film layer, an insulating layer, and a semiconductor layer are laminated in sequence. Features of optical semiconductor recording media. (2) The optical semiconductor recording medium according to claim 1, wherein the semiconductor layer is composed of a plurality of fine parts separated from each other. (3) An optical semiconductor comprising at least sequentially laminated a transparent electrode layer having translucency and conductivity, an electro-optic polarizing layer that generates a polarizing effect in a predetermined direction according to an electric field, a nitride film layer, an insulating layer, and a semiconductor layer. By applying an optical image from a subject to the transparent electrode layer while applying a predetermined voltage between the transparent electrode layer and the semiconductor layer of the recording medium, a depletion layer is created in a portion of the semiconductor layer.
A recording method for an optical semiconductor recording medium, characterized in that recording is performed by generating and retaining charges in the nitride film. (4) An optical semiconductor comprising at least sequentially laminated a transparent electrode layer having translucency and conductivity, an electro-optic polarizing layer that generates a polarizing effect in a predetermined direction according to an electric field, a nitride film layer, an insulating layer, and a semiconductor layer. By applying a predetermined voltage between the transparent electrode layer and the semiconductor layer of the recording medium and irradiating the transparent electrode layer with an optical signal modulated based on the recorded signal, a depletion layer is formed in the semiconductor layer. A recording method for an optical semiconductor recording medium, characterized in that recording is performed by generating and retaining charges in a nitride film. (5) An optical semiconductor comprising at least sequentially laminated a transparent electrode layer having translucency and conductivity, an electro-optic polarizing layer that generates a polarizing effect in a predetermined direction according to an electric field, a nitride film layer, an insulating layer, and a semiconductor layer. A method for reproducing an optical semiconductor recording medium, comprising reproducing a recorded signal by irradiating the transparent electrode layer of the recording medium with light polarized in a predetermined direction and detecting reflected light from the electro-optic polarizing layer.