JPS61194636A - Optical information recording device - Google Patents

Abstract

PURPOSE:To obtain an optical information recording device employing a highly stable recording medium by giving to the recording medium at least two types of crystal structures in the solid state, holding the crystal structure inherent to one temperature area in the other one, and/or forming the recording medium with metal or alloy causing different volume changes in the crystal state. CONSTITUTION:The recording medium has at least two types of crystal structures in the solid state, holds the crystal structure inherent to one temperature area in the other one, and/or compassed of the metal or alloy causing different volume changes in the crystal state. The titled device has said phase transformation type recording medium for changing optical characteristics such as light reflection, transmission and absorption due to a heat history formed on an insulating substrate and a means giving a current to some or overall of the medium. The heat history is added by the current to give to optical recording alloy an information change, and the information volume is detected by an optical characteristic detecting means. Thus a flawless device in terms of erasure of recording information can be economically obtained with the simple constitution.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to an optical information storage device that stores information by optical means, and particularly to an optical information storage device that can perform recording, reproduction, and erasing.

[Background of the invention]

In recent years, as information recording becomes more dense and digital, various information recording and reproducing methods are being developed. In particular, optical discs that use laser light energy to record, erase, and reproduce information are capable of higher recording densities than magnetic discs, as stated in Industrial Rare Metal & 80.1983 (Optical Disks and Materials), and are expected to become more promising in the future. It is a powerful method of recording information. Among these, laser playback devices have been put into practical use as compact discs (CDs).

On the other hand, recordable methods can be broadly divided into two types: write-once type and rewritable type. The former allows writing only once and cannot be erased, while the latter allows repeated recording and erasing. In the write-once type recording method, a laser beam is used to destroy or shape the recording portion of the medium to create unevenness, and for reproduction, a change in the amount of light reflected due to the interference of the laser beam at the uneven portion is used for reproduction. For this recording medium, it is generally known that Te or its alloy is used to form irregularities by melting and sublimating Te. This type of medium has some problems such as toxicity. ° As a rewritable recording medium
Magneto-optical materials are the mainstream. This method uses optical energy to invert and record the local magnetic anisotropy of the medium near the Curie point or the compensation point temperature, and the polarization plane of the polarized incident light at that part is caused by the magnetic Faraday effect and magnetic Kerr effect. Play with the amount of rotation. This method is considered to be the most promising method for rewriting, and active research and development is underway with the aim of putting it into practical use in the next few years. Other rewritable methods include amorphous and crystalline recording media (45) (1983).
) describes a material in which small amounts of Ge and Sn are added to TeOx.

[Purpose of the invention]

An object of the present invention is to provide an optical information recording device using a highly stable recording medium.

[Summary of the invention]

In the present invention, erasing is performed by heating at least a portion of the recording medium using a method other than laser light.

The recording medium is a metal or alloy that has at least two types of crystal structures in a solid state, maintains the crystal structure in one temperature range in the other temperature range, and/or causes different volume changes in the crystal state. It is characterized by consisting of.

Note that any alloy that causes a change in unevenness can be used even if no crystal change occurs.

Examples of alloys include Cu-A n alloy, Cu-Zn alloy, Cu-An-Znn alloy, Cu AQ Nx alloy, Cu-AQ-Mn alloy, Cu AQ Fe-Cr
Alloy, Cu-Ga alloy, Cu AQ Ga alloy, C
u-In alloy, Cu-Al-In alloy.

Cu-G e alloy, Cu-A Q-G e alloy,
Cu-Sn alloy, Cu-Te alloy, Cu-Ti alloy.

Cu-Aji-Sn alloy, (, u-Zn alloy, Cu-8i alloy, Cu-8b alloy, Cu-Be alloy.

Cu-Be alloy, Cu-Mn alloy, Cu-Pd alloy, C
u-Pt alloy sAg-Zn alloy *'g-A2 alloy w
Ag-Cd alloy, Ag-In alloy.

A g -G a alloy film A g A Q An
Alloy, Ag-AM-Cu alloy, Ag-Al1-Au-C
u alloy.

Ag-An-Cd alloy tAg-Pt alloy e A g -
8 alloy, Ag-8n alloy, Ag-Te alloy + Ag-T
n alloy, Ag-Zr alloy, Ag-As alloy.

A g -A u alloy, Ag-Be gold alloy A g
Mg alloy, Ag-Li alloy, Ag Mn alloy, AQ
-Fe alloy, AQ -Mg alloy, AQ Mn alloy.

AQ-Pd alloy, AQTe alloy, AQ
-T x alloy, AQ-Zn alloy, AjlZr alloy, Ni
-5 heavy alloy, Ni-8i alloy, Ni-8n alloy.

Ni-Gn alloy, Mn-Ge alloy, Ni-Ga alloy, Ni-Mn alloy, Ni-8 alloy, Ni-Ti alloy r
F s As alloy, AsS alloy p As -Z
n alloy, Fe-Ba alloy, Fe-Ni alloy.

Fa-Cr alloy, Fe-P alloy, Mn-Pd alloy.

Mn-P alloy, Mn-Sb alloy, Mn-8i alloy e Au Cn alloy, Au-An alloy,
Au-In alloy, A, u-Ga alloy, AuCd alloy.

Au-Cu gold alloy Au-Fe alloy, Au-Mn
alloy, AuZn alloy, Ba-Ca alloy, Bi-pb gold alloy Bi-TQ alloy, Ti-Ni alloy.

N1-V alloy, Ni-Zn alloy, Cd-Li alloy.

Cd-Mg alloy, Cd-Pb alloy, Cd-Sb alloy, 5
b-In alloy, 5b-In-8 heavy alloy.

Mg-Ce alloy, Go-Cr alloy, Go-Ge
Alloy, Go-Mn alloy, Go-Sb alloy* Co V
alloy, In-Mg alloy, In-Mn alloy, In-Ni alloy, In-5n alloy, In-TQ alloy.

Li-Zn alloy, Mn-Zn alloy, Pb-TQ alloy, p
b-s alloy, pb-sb gold alloy Pd-Zn alloy, 5n-
Sb alloy, T(1-Sb alloy, 5b-Zn alloy, Ti-
8n alloy, Tjl-8n alloy.

Zr-8n alloy, Zr-Th alloy, Ti-Zn alloy, T
Examples include i-Zr alloy.

As an example of the alloy, the following are preferred in terms of 1 weight composition.

Ag with 30-46% Zn, 6-10% Aa, 40-60
%Cd, 20-30% In, 13-23% Ga alone,
Cu with 10-20% AA, 20-30% Ga, 20-4
0% In, 20-30% Ge, 15-35% Sn, 10
~60% Zn.

5 to 10% Si, 4 to 15% Bs, 30 to 45% sb alone, 15 to 25% In to Au, 10 to 15% Ga, 5
~25% Zn, 20-55% Cd.

2.5-5% Aa alone, Ni 55-60% AQ
, alloy with 40-50% Ti added alone, In-25~
35% Ti alloy, Fe alloy with 55% or less pt added, Mn-5~50% Cu alloy, 8815~25%-In
30-40%-sb gold alloys
Ingredients, 4th ingredient.

The following elements other than the second component can be added as the fifth component and the like.

Ia, Ila, IVa, Va, Way■a,■.

Ib to vb, the total of one or more rare earth elements is 1
It is 5% by weight or less.

Specifically, the Ia group is Li, and the na group is Mg.

Ca, ■a fist is Ti, Zr, Hf, Va group is V.

Nb, Ta, VIa group is Cr, Mo, W, La group is M
The n and ■ groups are Go, Rh, Ir, Fa, and Ru.

○s, Ni, Pd, Pt, Ib group is Cu, Ag.

Au, nb group is Zn, Cd, Wb group is B, AQ.

Ga, In, and lVb groups include C, Si, Go, and Sn.

The pb and vb groups are P, Sb, and Bi, and the rare earth elements are Y.

La, Ce, Sm, Gd, Tb, Dy, and Lu are preferred, particularly preferably 0.1 to 5% by weight.

The above recording medium has a first temperature (high temperature) higher than room temperature in a solid state and a second temperature (low temperature) lower than the first temperature.
The alloy has an alloy composition in which at least a portion of its surface forms a crystal structure different from that obtained by non-quenching at the low temperature by quenching from the high temperature.

This alloy is heated and cooled in the same phase state.

It has at least two types of spectral reflectance at the same temperature and can reversibly change the spectral reflectance. That is, the alloy according to the present invention has phases with different crystal structures in at least two temperature ranges in a solid state, and among these, the high temperature phase is quenched and the low temperature phase is a non-quenched standard state. The spectral reflectance is different, and the spectral reflectance changes reversibly by heating and cooling in a high sum temperature region and heating and cooling in a low phase temperature region.

The principle of the change in reversible reflectance of this recording alloy will be explained with reference to FIG. 1. FIG. 8 is a phase diagram of an X-Y binary alloy in which a solid solution exists and c an intermetallic compound. A
Taking an alloy with a Bx composition as an example, this alloy has a b single phase, a (b+c) phase, and an (a+c) phase in the same phase state. The crystal structure is a.

Each of b and c is different in a single phase state, and the optical properties, such as spectral reflectance, are different in each of these single phase and mixed phase. In such alloys, the (a+o) phase is stable at T temperature, generally room temperature. When this is heated and rapidly cooled to T4 temperature, the b phase is rapidly cooled to T1 temperature. This b
The phase may transform into a new phase (for example b') during quenching, and since this state is different from the (a+c) phase, the spectral reflectance will also be different. When this rapidly cooled phase (or b' phase) alloy is heated to T2 temperature below Te temperature and cooled, (a +
c) It transforms into a phase, and the spectral reflectance returns to its initial state. By repeating such two heating and cooling processes, it is possible to reversibly change the spectral reflectance.

(Alloy Composition) The recording alloy must have different crystal structures at high and low temperatures, and the rapidly cooled crystal structure must be formed by rapid cooling from a high temperature. Furthermore, the phase formed by this rapid cooling must change to the crystal structure at a low temperature by heating at a predetermined temperature.In this way, rapid cooling from a high temperature creates a crystal structure that differs from the crystal structure at a low temperature. 1 as the cooling rate to obtain the structure
It is preferable that such a change in crystal structure occurs at a temperature of 02°C/sec or more or 10''/'Csec or more.

The recording alloy is preferably made of an alloy of at least one element selected from Group Ib elements of the periodic table and at least one element selected from Group NB, Group MB, Group TVb, and Group VB.

(Manufacturing method) In order to obtain reflectance variability, the recording alloy must be capable of forming a supercooled phase by heating and rapidly cooling the material. In order to create and store information at high speed, it is desirable to use a non-bulk material with a high rapid heating and cooling effect and a small heat capacity.In other words, the energy applied to a desired minute area allows the depth of only the desired area to be reduced. It is desirable to have a non-bulk material that has a volume that can change to a crystal structure different from the standard crystal structure throughout.Therefore, in order to produce high-density information in a desired micro area, non-bulk foils and films with small heat capacities are required. , thin wire or powder is preferable. For producing information in a micro area with a recording density of 20 megabits/d or more, a film thickness of 0.01 to 0.2 μm is generally recommended. In general, intermetallic compounds are used. It is difficult to plastically process the material, therefore, it is effective to directly rapidly cool and solidify the material from the gas phase or liquid phase to form it into a predetermined shape as a method to make fi, film, thin wire, or powder. These methods include PVD methods (vapor deposition, sputtering methods, etc.).

There are CVD methods, molten metal quenching methods in which molten metal is rotated at high speed and made of a member having high thermal conductivity, especially by pouring the molten metal onto the circumferential surface of a metal roll and rapidly solidifying it, electroplating, and chemical plating methods. When using a film or powder material, it is effective to form it directly on the substrate or to apply it and adhere it to the substrate. When coating, it is best to use a binder that does not cause a reaction even when the powder is heated.Also, to prevent oxidation of the material due to heating, it is also possible to coat the surface of the material, the film formed on the substrate, or the surface of the coating layer. It is valid.

The foil or thin wire is preferably formed by a molten metal quenching method, and preferably has a thickness or diameter of 0.1 mm or less.

In particular, in order to produce foil or thin wire with a crystal grain size of 0.1 μm or less, a thickness or diameter of 0.05 m or less is preferable.

The powder is preferably formed by an atomization method in which molten metal is jetted together with a gaseous or liquid refrigerant and then poured into water to be rapidly cooled. The particle size is preferably 0.1 μm or less, and ultrafine powder with a particle size of 1 μm or less is particularly preferable.

The film can be formed by vapor deposition, sputtering, CVD electroplating, chemical plating, etc., as described above.

In particular, sputtering is preferable to form a film with a thickness of 0.1 μm or less, and sputtering allows easy control of the target alloy composition.

(Structure) The recording alloy must have a different crystal structure at high and low temperatures, and must have a supercooled phase composition in which the crystal structure at high temperatures is maintained at low temperatures by rapid cooling from high temperatures; Although the intermetallic compound has a lattice crystal structure, the supercooled phase is preferably an intermetallic compound having a Cs-CQ type or DO3 type ordered lattice, for example. The alloy of the present invention is preferably an alloy that mainly forms this intermetallic compound, since the optical properties can be greatly changed.

In particular, a composition in which the entire alloy forms an intermetallic compound is preferred; this intermetallic compound is called an electronic compound.

In particular, alloy compositions near 3/2 electron compounds (average outer shell electron concentration a/a of 3/2) are good.

Further, the recording alloy preferably has an alloy composition having an in-phase transformation, for example, an eutectoid transformation or an enclosing transformation, and an alloy having a large difference in spectral reflectance can be obtained by quenching from a high temperature and non-quenching.

The optical recording alloy is preferably an alloy having ultrafine crystal grains, and the crystal grain size is particularly preferably 0.1 μm or less.

That is, the crystal grains are preferably smaller than the wavelength of visible light, but may be smaller than the wavelength of semiconductor laser light.

(Characteristics) The recording material can be formed to have at least two types of spectral reflectance in the visible light region at the same temperature. That is, it is necessary that the spectral reflectance of a material having a crystal structure (structure) formed by rapid cooling from a high temperature is different from that of a material having a crystal structure (structure) formed by non-quenching.

In addition, the difference in spectral reflectance obtained by quenching and non-quenching is preferably 5% or more, particularly preferably 10% or more.0 If the difference in spectral reflectance is large, it is easy to visually identify the color, It has remarkable effects in various applications described later.

As a light source for spectrally reflecting, electromagnetic waves other than visible light can be used, and infrared rays, ultraviolet rays, etc. can also be used.

Other properties of recording alloys include electrical resistivity.

The refractive index of light, the polarization rate of light, the transmittance of light, etc. can be changed reversibly in the same way as the spectral reflectance, making it possible to record various information,
It can be used to reproduce recorded information.

Since the spectral reflectance is related to the surface roughness of the alloy, it is preferable that at least the intended portion has a mirror surface so as to have 10% or more in the visible light region as described above.

When a recording alloy is heated and rapidly cooled, its physical or electrical properties such as spectral reflectance of electromagnetic waves, electrical resistivity, refractive index, polarization ratio, transmittance, etc. are changed by partially or entirely changing the crystal structure, and these properties are It can be used as an information recording element by utilizing the change in .

As a means of recording information, electrical energy in the form of voltage and current, electromagnetic waves (visible light, radiant heat, infrared 2. ultraviolet light, light from photographic flashlights, electron beams, proton beams, argon lasers, semiconductor lasers, etc.) are used. (laser beam, high-voltage spark discharge, etc.), and is preferably used as an optical recording medium by taking advantage of the change in spectral reflectance caused by the irradiation.The use of a recording alloy in an optical disk recording medium. Therefore, it can be used in read-only type, additional recording type, and rewritable type disc devices, and is particularly effective in rewritable type disc devices. The recording method may be either a method of continuously applying energy in a pulsed manner or a method of applying energy continuously; in the former case, it is possible to record as a digital signal.

An example of the principle of recording and reproduction when the recording alloy is used in the recording medium of an optical disk is as follows.

First, the recording medium is locally heated and then rapidly cooled to maintain the crystal structure in the high temperature region in the low temperature region to record predetermined information, or the recording medium is locally heated using the high temperature phase as a pace. recorded locally by a low temperature phase during the high temperature phase,
Information can be reproduced by irradiating the recorded portion with light and detecting the difference in optical characteristics between the heated portion and the non-heated portion. Furthermore, the recorded information can be erased by heating the portion recorded as information at a temperature lower than the heating temperature at the time of recording.

If the light is a laser beam, a short wavelength laser is preferable.6 Since the reflectance of the heated part and non-heated part of the present invention is large at wavelengths around 500 nm or 800 nm, it is preferable to use a laser beam having such a wavelength for reproduction. is preferred. The same laser source is used for recording and reproduction, and another laser beam with a lower energy density than that for recording is used for erasing.

Current energy heating, which will be described later, is preferred for erasing information over a wider area.

Further, a disk using a recording alloy as a recording medium has a great advantage in that it can be visually determined whether information is recorded or not.

That is, this recording alloy is formed in a thin film state on the substrate 11 as shown in FIG. By applying relatively long low thermal energy with a pulse width τ, the first phase transforms into the second phase and the reflectance changes from ■ to ■ as shown in Figure 3. At this time, the reflectance changes from ■ to ■. This reflectance change is sensed by a well-known optical head device that irradiates the alloy material 1 with a light beam of low thermal energy P1 that does not contribute to phase transformation as shown in FIG. 2(A) and electrically detects the reflected light. can do. The optical head records a second temperature profile for a short period of time, which is a high temperature profile necessary to cause a phase change to the second phase. One temperature profile is distributed as light energy for erasing, and a temperature profile resulting from irradiation with thermal energy that does not directly contribute to phase change is distributed as optical energy for reading.

[Embodiments of the invention]

It has become clear that the recording properties of phase transformation type recording alloys allow writing with a pulse width on the order of 0.1 μs.
Compared to the conventional method, (1) it has a rewriting function that the conventional PID method does not have. (2) It is promising as a high-density recording material because it has a longer recording life than amorphous/crystalline modified types that have a rewriting function.

Phase change recording alloys have higher mechanical strength and elongation than conventional materials, so they are highly flexible and can be used by vapor deposition or sputtering on thin-walled disks, tapes, cards, etc. This is especially convenient. The method for recording and erasing information on such various information carriers must be determined based on the amount of information required, the image of the device, etc., and in particular, it is necessary to adopt a method based on the characteristics of the material.

In this regard, since recording alloys have high thermal conductivity, it is effective to input a pulse of high thermal energy for a short period of time to record on a minute area when recording I3, and this makes it possible to achieve high-speed writing. .

When erasing, the conventionally used oscillation wavelength of 830n
When light energy of m is applied to a semiconductor laser with a pulse width shown in FIG. 2(A), the reflectance decreases from the recording state (■) to the erasing state (2). At this moment, the amount of heat input to the optical recording alloy film 1 increases, so if the temperature rises to the second temperature profile, there is a risk of rewriting. Therefore, such an erasing method using light energy is not necessarily optimal.

In this regard, when using an Ar'' laser with a wavelength of around 358 nm, the above problem can be avoided because the reflectance increases when changing from the recording state (■) to the erasing state (■).However, the Ar'' laser is a semiconductor laser. It is larger and more expensive than , and is disadvantageous in terms of equipment.

The present invention was devised in view of this point, and the erased state is obtained by passing an electric current through the recording alloy and utilizing the generated energy. The method of applying current must be appropriately selected depending on the various information carriers, and the principle thereof will be explained below in FIG.

In FIG. 4, probes 31 and 33 of a current probe type head 33 are brought into contact with an information recording carrier in which a thin film of recording alloy 1 is formed on an insulating substrate 11, and electrical energy from a power source 4 is applied to the information recording carrier by a switch means 5. It is supplied to a part of the recording alloy 1, and the Joule heat generated in this area causes the recording alloy to generate heat.

The specific resistance of the alloy is 10-s to 10"' Ω. Therefore, the resistance value R of the alloy between the electrodes with a thickness of 0.1 μm, a width of 1 μm, and a length of 1 μm is Experimentally, approximately 3 mW of power is required to heat the phase to the first phase transformation temperature (erasure temperature) of 150°C, so the required current is .To increase the amount of information to be processed, see Figure 4. .

A multi-probe as shown in (B) is effective.

Further, as shown in FIG. 4(C), a plurality of protective films 10 and conductive films 11 having excellent abrasion resistance and transparency can be formed on the surface of the actual information recording carrier in an array. . In this case, since the information recording area is limited by the pitch of the electrodes 101 to 123, microfabrication such as a photolithography is used to process the information to a micrometer order. This structure is suitable as an example in which an optical recording alloy is coated on a card.

Figure 5 shows recording alloy 1 coated with a transparent conductive protective film 11°11'.
This structure generates heat by passing current through the thickness of the alloy using probes that contact the upper and lower surfaces of the alloy. A recording carrier having such a structure can have an extremely thin overall thickness on the order of microns, making it possible to realize a recording alloy tape. In this way, optical recording alloy 1
It is possible to generate heat and perform the above-described transformation between the first phase and the second phase.

FIG. 6 shows a structure in which a recording alloy 1 is formed on a reinforcing material 12, and the material of the reinforcing material 12 is made of a material having a higher resistivity than the optical recording alloy 1 so that it also functions as a heat generating element. This material is preferably a nichrome-based material, which is a general heating resistance material.A transparent conductor 11°11' is coated on the upper and lower surfaces where the probe 3.3' comes into contact, which increases the durability of the recording alloy tape. improve. The total thickness of these is not only the strength but also the required current and voltage between 1 μm and 10 μm.

It is necessary to design with consideration to heat generation efficiency, etc.

FIG. 7 is a schematic diagram of the entire recording, continuous recording, and erasing system for an optical recording alloy tape.
2, 23 rollers are provided, recording probes 3, 3'
A current is applied to the top and bottom surfaces of the tape to provide the optical recording alloy formed on the tape with the thermal energy necessary for its phase transformation. Depending on a given temperature profile, the optical recording alloy 1 on the tape will have an increased reflectance, for example, and this will be reflected in the light source 7. Beam splitter 6, objective lens 5. Photodiode 1
It is detected as a voltage signal change by a readout system consisting of:

The dimensions of the objective lens 5 and its focal aperture are adjusted in advance so that when its tip presses against the tape 1, the beam spot of the optical system is narrowed down. 31 and 31' are erasing probes, and when necessary, recording probes 3 and 3 are used.
By applying less heat energy than ′ for a long time,
The optical recording alloy 1 is transformed into a first phase, the reflectance is lowered, and information is erased. The detailed function of the information succession system will become clearer in the embodiments described later.

FIG. 8 shows a temperature profile that generates Joule heat by passing an eddy current through the recording alloy and causes phase transformation of the first phase and the second phase.

A high frequency current of approximately MHz is transmitted from the high frequency oscillator 4 to the coil C.
When the alloy film 1 is brought close at right angles to the magnetic flux H generated in the coil, eddy currents are generated concentrically on the alloy film.

The magnitude of the eddy current is determined by the distance d between the coil 3 and the alloy film 1.
, so it must always be kept constant. Figure 8 (
B) is one method to achieve this, in which a transparent insulating film 10 with a thickness of d' is formed between the coil 3 and the alloy film 1, and the lower end of the coil 3 is always in contact with the film surface. ing. Therefore, the tension between the two is always maintained at d', a constant eddy current always flows through the alloy film 1, and a predetermined temperature profile can be obtained with good reproducibility. In this example, the insulating film 10 is provided on the alloy film 1, but if the invention is applied to the optical alloy tape described above, a spacer having a thickness of d' may be provided between the two.

FIG. 9 shows a recording alloy 1 configured as a disk image, transported onto a motor 10 by a movable holder 100, and rotated once while the coil 3 is moved in the radial direction to generate an eddy current on the alloy 1 and generate heat. This is an example of a device that erases information recorded by.

This device can be manufactured compactly and at low cost as an information eraser. Also.

Conventional bit-type (write-once) type optical recording.

By unifying the readout device and data processing method, an erasable optical recording device using optical recording alloy can be realized by simply adding this erasing device, and the customer only needs to install a new inexpensive erasing device. Extremely convenient.

It is the 10th dedicated device that only erases recorded information.
As shown in the figure, a heat capacitor 2 previously maintained at a predetermined temperature is brought into contact with the recording alloy 1 to obtain a predetermined temperature profile. Further, an optical recording alloy 1 is placed in an oven 2 as shown in FIG. 11, and a microwave is sent from a high frequency coil 3 to generate a current in the optical recording alloy 1, which is operated in conjunction with a switch, a timer, etc. 5 to maintain a predetermined temperature. Devices for obtaining profiles are available. These devices can be manufactured extremely simply and at low cost.

Next, FIG. 12 shows the overall structure of an optical head for an optical recording alloy disk having recording, reading, and erasing functions.

The signals and operations of each part in the figure will be explained below.

1 is a laser diode serving as a light source.

A collimation lens 2 converts the light beam from the laser diode 1 into parallel light. 3 is a polarizing beam splitter (hereinafter P
BS) transmits the output light of the collimation lens and refracts the returning light from the λ/4 plate as shown in Record 4 described below. The λ/4 plate 4 is used for phase polarization of light in order to facilitate discrimination between incident light and reflected light in the PBS 3.

5 is an objective lens, which is used to condense incident light. A coupling lens 6 receives the light beam from the PH 10 and condenses it. The coupling lens 6 is composed of two semicylindrical lenses orthogonally crossed. 7
is a photodetector. The photodetector 7 is a coupling lens 6
By detecting the shape of the light spot of the incident light L6 from the objective lens 5, the shape of the light spot of the output light L5 from the objective lens 5 is indirectly detected. 8 is an actuator, and the actuator 8 adjusts the focal position of the output light L5 of the objective lens 5 according to the output of the photodetector 7. Reference numeral 81 denotes a lens drive section, and the lens drive section 82 adjusts the position of the objective lens 5 based on the drive control output from the actuator 8.

Reference numeral 9 denotes a disk on which information can be optically recorded, reproduced, erased, etc., and a part of the disk is shown.
The above-mentioned recording and reproduction are made possible by irradiating a desired light spot on the disk surface with the output light L5 from the disk. 10 is the motor, and disk 9 is the motor 10.
Driven by Reference numeral 30 denotes a high-frequency coil placed in close proximity to the disk 9, which generates an eddy current in the optical recording alloy film formed on the disk 9 to apply the aforementioned predetermined temperature profile to a relatively wide area for recording. Erase information. 30' is a high frequency coil having the same function as 30, and is installed in a case where it is more convenient to heat the disk 9 from the back side. A detailed view of this example is shown in FIG. 13 below.6 That is, in order to prevent the influence of dirt on the surface of the disk 9, a recording alloy film 91 is formed on the lower surface, and recording and reproduction are performed from the upper surface into the transparent substrate 9. The light beam that has passed is focused on the alloy film 91 and recorded with the maximum energy density, and read out with increased resolution.

However, when erasing is performed, the temperature is lower than the temperature profile during recording and a long period of irradiation is required, as described above. To achieve this, methods to spread the light beam have been proposed, such as irradiating a long oval beam in the track direction of the disk 9 and creating multiple beam spots using an AO modulator. This method cannot be said to be the most ideal for information carriers using alloys.The reason is that it is contradictory to narrowing down the light beam to the limit required during recording and reading, and expanding the light beam sufficiently during erasing is contradictory. This is because it is difficult to do this with a single optical system. Therefore, as shown in FIG. 13, by bringing the high frequency coil 30' close to the optical recording alloy film 91 to generate eddy current in the alloy film, a desired temperature profile that is uniform over a relatively wide area is created. Is possible.

Therefore, even when the disk 9 is rotating at high speed, the desired information area can be heated for a long time, and the information can be completely erased. Of course, when erasing information in a small area, there is also a mode in which the light beam irradiated from the top surface of the disk 9 is enlarged and heated for a longer time at a lower temperature than during recording to erase local information. It is possible.

FIG. 14 shows an example in which the erasing coil 50 includes a sensor function for detecting the gap d with the recording alloy 1, and is equipped with a force motor 81 that uses this signal to keep the force d constant. . Namely.

As shown in FIG. 8, a voltage E0 depending on the gap d is induced in the coil 50, so this is amplified by 8 and fed back to the force motor 81, so that the coil 50 and the photoalloy film 91 are constantly connected to each other. It has the function of keeping the gap between the two parts at a desired value. Therefore, a temperature profile can be generated in the alloy film 91 with good reproducibility. Note that the high frequency coil 5° can also be configured to be divided into two coils: one for displacement detection and one for heating the alloy film. Records of this information.

It is preferable that the frequencies of the amounts of electricity used for reading and erasing are set to different values from the viewpoint of reducing the influence on other modes.

FIG. 15 shows Will! on the substrate 11! An example is shown in which the alloy film is formed in one area.This is useful for preventing crosstalk with adjacent information, and when a high-frequency coil is used to send eddy current to the alloy film, the current will not flow outside of this area. Information in this area can be completely erased.

This structure may be formed by depositing a recording alloy film on the substrate by vapor deposition or sputtering, and then microfabricating it using photolithography technology. If the alloy film is deposited on the protrusion, since the thickness is thin, the alloy film will not adhere to the uneven side surfaces, and the upper surface of the protrusion and the other regions will be insulated, and the same discrete structure as described above can be realized.

An optical disk was prepared by forming an Ag-40 wt % Zn alloy film on a glass substrate by sputtering. In order to prevent the 0 alloy film from being oxidized by heating during recording and erasing, and to prevent it from peeling off from the substrate, Si
A protective film (thickness: 30 nm) of O, was formed by vapor deposition. A DC-magnetron sputtering method was used to deposit the alloy film on the glass plate, and an RF sputtering method was used to form the SiO film. Sputtering output is 140~200w,
The substrate temperature was set at 200°C. Inside the container 10-
'After evacuation to about Torr, Ar gas is
A thin film was prepared by introducing m Torr. The film thickness is S i
O, film thickness is about 30 nm, 1 alloy film thickness is 0.05 ~
The thickness was varied within a range of 10 μm. Using the optical disk thus manufactured, recording and erasing were performed, and these operations were repeated.

The Ar gas laser was continuously oscillated. The sample was placed on a manual movement stage, the sample was moved, and the 200 mW laser beam was focused and scanned on the film surface of the sample. The part irradiated with the laser light turned pink.The 1-alloy film was heat-treated together with the substrate to become silvery white.The focus of the 0-order laser light was slightly shifted from the film surface, and the laser output density was lowered. It was scanned in the direction intersecting the pink part (up and down in the figure). As a result, the original pink color was erased and the color changed to silvery white. It was confirmed that concave or convex portions were formed on the base surface at the same time as these color changes were recorded, and that the original flat surface was restored by erasing.

From the above results, it was confirmed that recording and erasing using the alloy in the ll film state is possible. This writing.

It was confirmed that erasing can be repeated any number of times.

〔Effect of the invention〕

The alloy type information recording device using the present invention can realize successive recording and erasing functions, and in particular, it is possible to economically provide a device that can completely erase recorded information with a simple structure.

By using the present invention, not only optical discs but also
It is possible to provide a rewritable tape and card information recording device using an alloy.

[Brief explanation of drawings]

Figure 1 is a state diagram of the recording alloy, Figure 2 is a diagram of heat input energy to the recording alloy, Figure 3 is an example of the spectral reflection characteristics of the recording alloy, and Figure 4 is a diagram of the recording alloy.
Figure 5 is a diagram of the heating principle of recording alloys, Figure 5.6 is another heating method for recording alloys, Figure 7 is an optical recording tape recorder using recording alloys, Figure 8 is the principle of eddy current heating of recording alloys, and Figure 8 is a diagram of the heating principle of recording alloys. Fig. 9 shows an eddy current heating type recorded information erasing device, Fig. 10 shows a recorded information erasing device using a heat capacitor, Fig. 11 shows a recorded information erasing device using a microwave oven, and Fig. 12 shows erasing using a high-frequency heating coil. FIG. 13 shows a detailed view of the same as above, FIG. 14 shows the configuration of a high-frequency erasing heating coil having a position control function, and FIG. 15 shows an optical recording alloy information carrier having a discrete structure. 1.91... Recording alloy film, 2... Heat capacity body, 11.
9... Board, 3.3', 31.32... Current probe. 4...Power supply, 5...Switch means. $1 Donkey AF5x
δ￥12-mouth (Ha) ttsesu (B) 5A30 (Ha) Deputy Chief (Minoha Fang-3rZTL (30g'C) (δ): I!L, Choken Asahi) 勺-4+7Z7L (325+Su 30th (C) Shira % Czp) CLL-l Cow AfL-Conflict N1 (72ff°C) No. Φ mouth <A) Mouth Yu mouth decoy bite -0 ri] Mouth mouth S + 圀(C) Collection 13 圀t+- 5 ¥31 taro

Claims (1)

[Claims] 1. A phase change type recording medium formed on an insulating substrate that changes optical properties such as reflection, transmission, and absorption of light due to different thermal histories, and a part or all of the recording medium to which an electric current is applied. The apparatus has a means for applying thermal history to an optical recording alloy by applying a thermal history using an electric current, and detects the amount of information using an optical property detecting means, wherein the recording medium is in a solid state and has at least two types of information. An optical information recording device characterized by being made of a metal or alloy that has a crystal structure in one temperature range and maintains the crystal structure in another temperature range and/or exhibits different volume changes in the crystal state. Device. 2. The optical information recording device according to claim 1, wherein the recording medium is made of a metal or an alloy whose crystal structure at high temperatures in a solid state is maintained by supercooling from high temperatures. 3. The recording medium is made of a metal or alloy in a crystalline state that undergoes phase transformation, and has phases with different crystal structures in at least two temperature ranges in a solid state, and there are recesses caused by the transformation between the phases. Or, by forming a convex part to change the state of light reflection with the base surface, it can be used as information such as signals, characters, figures, etc.
2. The optical information recording device according to claim 1, further comprising a heating means for memorizing a symbol so that it can be identified or for erasing the concave or convex portion to its original state, and a means for reproducing the information. 4. The recording medium contains elements from groups I, b to VII, of the periodic table.
Claims 1 to 3 consist of a metal or alloy whose main component is a transition metal element of Group B or Group VIII metal element.
The optical information recording device according to any one of Items. 5. In the apparatus according to claim 1, at least two electrodes are provided on a part of the recording medium, and a current is applied to a desired area to apply predetermined heating and cooling to record and erase information on the recording medium. optical information recording device. 6. In the apparatus according to claim 1, a coil is brought close to a desired region of the recording medium, and eddy current is applied to provide a predetermined heating and cooling profile to record and erase information on the optical recording medium. optical information recording device. 7. A recording medium whose crystal structure is changed by applying a thermal change is brought into contact with the recording medium, and a part or all of the medium is heated and cooled in a prescribed manner by passing an electric current through the medium, and this is used to apply a phase change to the optical recording alloy. , the information recorded on the optical recording alloy is detected by means for detecting changes in light reflection, transmittance or absorption rate, wherein the recording medium has at least two types of crystal structures in a solid state; 1. An optical information recording device characterized by being made of a metal or alloy that maintains a crystal structure in one temperature range in another temperature range and/or exhibits different volume changes in the crystal state. 8. In the apparatus according to claim 4, a part or all of the optical recording alloy is heated and cooled in a predetermined manner by a heat capacity body having another heat source and a contact means, thereby causing a phase change; An optical information recording device that records and erases information on a recording medium. 9. In the device according to any one of claims 1 to 5, the first temperature profile defining the first phase is
An optical information recording device that is maintained at a lower temperature for a longer time than a second temperature profile that defines a phase, and that erases recorded information by applying the first temperature profile by a current flowing through the recording medium. 10. In the device according to any one of claims 1 to 6, the first temperature profile that defines the first phase causes a third temperature profile that does not contribute to a phase change to occur at a lower temperature and for a longer period of time.
An optical information recording device that is pre-maintained to a temperature profile of 11. An optical information recording apparatus according to claim 6 or 7, which is provided with a light irradiation means and uses the light irradiation means to heat the recording medium and provide a second temperature profile to record information. 12. An optical information recording device according to any one of claims 1 to 8, in which the frequency of the current flowing through the recording heating means differs depending on each temperature profile. 13. An optical information recording device according to any one of claims 1 to 9, wherein the phase change material is adhered to one or both surfaces of an insulating substrate. 14. An optical information recording device according to claim 10, in which a plurality of phase change materials are formed separately in specific regions. 15. An optical information recording device according to claim 14, having a stepped structure for separation. 16. A recording medium is formed on an insulating substrate, a transparent insulating film is deposited on the transparent insulating film, a part of which is removed to provide a plurality of electrode pads that are electrically connected to the recording medium, and the recording medium is in a solid state. It is characterized by being made of a metal or alloy that has at least two types of crystal structures, maintains the crystal structure in one temperature range in the other temperature range, and/or causes different volume changes in the crystal state. Optical information recording device. 17. A recording medium tape having a transparent conductive film formed on the upper and lower sides of the recording medium film, and a plurality of current probes for information recording and erasing brought into contact with the upper and lower surfaces of the recording medium tape, the recording medium being in a solid state and having at least two Optical information characterized by being made of a metal or alloy that has a different type of crystal structure, maintains the crystal structure in one temperature range in another temperature range, and/or causes different volume changes in the crystal state. Recording device. 18. The recording medium according to claim 16 is in the form of a flexible tape, and information is recorded and erased using a heating temperature profile using an electric current flowing through an optical recording alloy or an adjacent heating element. An optical information recording device that performs reading by detecting the reflected light of the light irradiated onto the optical recording alloy. 19. In the apparatus according to claim 3, an insulating film of a predetermined thickness is formed on the optical recording alloy film, and a high-frequency coil for heating the optical recording alloy film is brought into contact thereon. Recording device. 20. A recording medium formed on an insulating substrate, a high-frequency heating coil for erasing information recorded on the recording medium, a moving means for changing the relative position of the two in two directions, and a driving/cutting means for the high-frequency coil; The recording medium is made of a metal or alloy that has at least two types of crystal structures in a solid state, retains the crystal structure in one temperature range in the other temperature range, and/or causes different volume changes in the crystal state. An optical information recording device characterized by: 21. In the information recording device according to claim 19, the recording medium formed on the transparent substrate is irradiated with light from the substrate side to give a second temperature profile to record, read, and record information. An optical information recording device that erases recorded information by bringing a high-frequency heating coil close to the medium side. 22. An optical information recording device according to claim 20, comprising means for maintaining the tension between the high-frequency heating coil and the optical recording alloy film at a constant value.