JPH08153343A - Production of optical information recording medium and production apparatus - Google Patents

Abstract

PURPOSE: To provide a flash initialization device with which arbitrary setting of discharge light emission time (irradiation time) and discharge light emission power (irradiation light power) is possible and an initialization method which uses the device and decreases thermal damages. CONSTITUTION: An optical information recording medium 3 of a phase transition type having a thin film 1 of a material which induces a reversible change of its optical characteristics by irradiation with an energy beam, such as laser beam, on a substrate 2 is formed. The initialization device is provided with a means (shielding circuit part 10) which instantaneously lowers light emission intensity to a substantially zero level after light emission for a prescribed time at the time of executing an initial crystallization stage with rays 4 emitted from a flash light source 7, by which the large irradiation power is made compatible with the short irradiation time and the various thermal damages are decreased. Since useless electric energy is not consumed, the charging completion time of the electric energy for the next discharge light emission is shortened.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a manufacturing process of an optical information recording medium having a recording thin film layer on a substrate which causes a phase change between crystal and amorphous upon irradiation with a laser beam or the like, and a manufacturing apparatus applied to the manufacturing process. It is a thing.

[0002]

2. Description of the Related Art For example, Ge-Sb-T is mounted on a disk-shaped, card-shaped, sheet-shaped or film-shaped substrate.
Te, such as e and In-Se, and a chalcogenide thin film based on Se, or a semi-metal thin film such as In-Sb as an information recording layer are already known as phase change optical recording media. In phase change optical recording, for example, a recording thin film layer made of the above phase change material is instantly irradiated with a laser beam focused on a light spot of submicron order size,
By locally heating the irradiation unit to a predetermined temperature, a change in the atomic bond state is caused in the irradiation unit. If the reached temperature of the irradiated portion is equal to or higher than the crystallization temperature, only the minute portion can be converted into a crystalline state, and if it is equal to or higher than the melting point, only the minute portion can be made amorphous. If either the amorphous phase or the crystalline phase is defined as a recorded state or an erased state (or an unrecorded state), reversible recording or erasing of information will be performed. In such a recording thin film layer, since the optical characteristics differ between the crystalline phase and the amorphous phase, it is possible to reproduce the signal by optically detecting this characteristic difference.

In addition to utilizing such a phase change between an amorphous phase and a crystalline phase, a phase change between a high temperature phase and a low temperature phase in a crystalline state is used to apply the phase change of a substance to information recording. Some do. It is known that it is possible to treat the high temperature phase as an amorphous phase and the low temperature phase as a crystalline phase in almost the same manner.

Usually, in the above-mentioned amorphous-crystal phase change optical recording medium, the recording direction is changed from crystal to amorphous. Therefore, the recording thin film should be converted into a crystalline state in advance as a precondition for recording. Is performed. This is called initialization.

As an initialization method, a method which is put into practical use at present is a sequential processing method using a laser beam as described in, for example, JP-A-60-106031. In other words, using a laser with a much higher output than the laser diode used for recording and reproduction,
A light spot with a width of 00 μm is formed. By irradiating this light spot while feeding the medium at a constant speed, a large number of tracks can be crystallized at one time by one operation. In the case of this method, since the area to be heated at one time is small, the heat load is small and cracks are unlikely to occur, but there is a disadvantage that initialization takes time.

On the other hand, there is a method of collectively crystallizing the entire disk surface by using flash light. This is proposed, for example, in JP-A-62-250533. In the publication, a recording film (for example, Te ₉₀ Ge ₁₀ having a thickness of 70 nm sandwiched between SiO ₂ layers having a thickness of 100 nm) that causes a phase change between crystalline and amorphous is formed on a substrate (acrylic resin) made of an organic material. There is disclosed a method in which a recording layer) is provided and the recording film is subjected to flash exposure for initial crystallization. In this publication, a xenon flash is used as a light source, a reflecting mirror is used, an exposure time is 1 μs to 1 ms, and an output of 1 MW is 500 μm.
It is described that the irradiation was performed for s (the energy is 500 J), but there is no disclosure about a specific example of an accurate light emission waveform of flash light, a method of controlling the light emission waveform, a configuration of a power supply, or the like. Further, in all the examples disclosed in the publication, flash irradiation is performed from the recording film side, and there is no disclosure about flash exposure from the substrate side.

Another prior art is Japanese Patent Laid-Open No. 63-2615.
JP-A-53-53 discloses that there is a possibility of initialization using flash light even in the middle of forming an optical disc. In the specification of the publication, a recording film (Sb-having a thickness of 120 nm) is formed on a substrate (polycarbonate).
Initial stage in three cases: the step of forming a Se-Bi film), the step of forming a protective film (ultraviolet curable resin or a SiO ₂ film having a thickness of 50 nm to 1 μm), and the step of adhering two disks with an adhesive. The results of the chemical experiments are shown. At the same time, here, the experimental results regarding the difference between the case where the irradiation is performed from the substrate side and the case where the irradiation is performed from the protective layer side are shown. That is, when irradiation is performed from the substrate side, on the substrate surface (the side on which the recording film is formed on the side opposite to the irradiation side),
It is disclosed that minute unevenness is likely to occur due to heat damage. Further, as a means for solving this, the same specification discloses a method of covering the inner peripheral portion and the outer peripheral portion of the disk with a mask when irradiating with flash light. However, in the case of this prior example, the disclosed flash light irradiation condition is only the emission time of the flash lamp of 0.5 ms to 2 ms, and the variation example of the emission waveform of the flash light or the emission waveform is optimized. No mention is made of how to control the waveform.

As a prior art relating to controlling the irradiation waveform of flash light, for example, Japanese Patent Laid-Open No. 3-35424 is known.
Publication. In Example 5 in the specification of the publication, the relationship between the time Δt3 from the start of light emission to the peak of the emission intensity and the time Δt4 from the peak to the stop of the light emission is such that Δt4 ≦ Δt3. It is disclosed that crystallization with small heat damage can be performed by emitting light, and as a means for that, a circuit is shown in the drawing (FIG. 11) attached to the specification. However, the above circuit is a general circuit for discharging and emitting a flash lamp, and in this case, the light emission time (discharge time) is uniquely determined by the time constant of the circuit. That is, in the circuit disclosed in this prior art, it is difficult to arbitrarily set t3 and t4 independently. That is, unlike the invention of the present invention which will be described in detail later, after the discharge for a certain period of time, the discharge is instantaneously and forcibly stopped.

Further, the publication describes that various changing speeds (rising and falling) of the light emission power can be selected, but whether the changing speed is steeper or smoother is better. As for, no judgment has been given. Rather, in the specification of the publication, page 4, upper left column, first
In the second line, taking the drawing (FIG. 3) attached to the publication as an example, it is stated that the rising and falling changing shapes have no special meaning. Especially, in order to make the fall sharp like the light emission waveform of FIG. 3 (or FIG. 1, FIG. 6, FIG. 6) attached to the publication, some special device is considered necessary. There is no description of means for realizing the above.

Generally, the simplest means for obtaining a sharp fall as shown in FIG. 3 in a normal discharge circuit is to reduce the time constant of the circuit. In that case, energy is stored. It is usually necessary to reduce the capacity of the condenser to be placed, and the light emission energy is also reduced accordingly. There is no prior document that discloses a method of keeping a large amount of emission energy and realizing a steep fall, and the effect thereof.

As described in each of the above-mentioned prior documents, the problem of the flash initialization method is that when a resin substrate is used, the substrate is susceptible to thermal damage (shrinkage, distortion, warpage, etc.). Therefore, some proposals have been made in the past to solve this problem. However, what can be said in common with any of the conventional methods is that the absolute value of the discharge time is uniquely determined depending on the time constant of the circuit, that is, the light emission time, the rising speed, and the falling speed. It has not been carried out to easily and arbitrarily set the light emission waveforms such as that according to the recording medium.

In general, since the time constant of the discharge circuit is inversely proportional to the capacitance of the capacitor, increasing the energy of light emission and shortening the discharge time are contradictory. Until now, the irradiation power and the irradiation time have been increased. There was the inconvenience that could not be arbitrarily selected as an independent variable. In other words, for media with various characteristics, that is, for various media with different crystallization temperatures and crystallization rates,
It was not easy to give optimum conditions to each, and the versatility of the device was low.

The structure of the phase change recording medium is, for example, as shown in FIG. 10A, a dielectric layer 41, 4 on a substrate 40.
The most general structure is that the recording thin film layer 42 sandwiched by 3 is formed, and then the reflective layer 44 and the protective layer 45 are sequentially formed. As the protective layer 45, for example, a material in which an ultraviolet curable resin is applied to a thickness of several tens of μm by a method such as spin coating and is irradiated with an ultraviolet ray and cured is often used. Usually, the case where only one side of the disk surface is used in this shape is called a single plate structure. Further, for example, as shown in FIG. 10B, a case where two mediums having a single plate structure are stuck together with the film surface inside is called a double-sided structure. This double-sided structure
A first dielectric layer 41, a recording thin film layer 42,
The two dielectric layers 43, the reflective layer 44, and the protective layer 45 are used as two laminated bodies, and the protective layers 45 and 45 are integrated with an adhesive (for example, hot melt adhesive) 49. That is, in the case of a double-sided medium, a method is used in which two single plate substrates having a protective layer made of an ultraviolet curable resin layer formed by the above method are bonded to each other with their protective layer surfaces facing inward with a hot melt adhesive. Has been. When this bonding step is disassembled, at least 1) a step of applying an ultraviolet curable resin layer on each single-plate medium, 2) a step of irradiating this with ultraviolet rays to cure and form a protective layer, and 3) a liquid on each protective layer surface. Compared with the production of a single-plate structure, four steps are required: a step of applying the hot melt adhesive in a state of 4), a step of bonding the adhesive-coated surface to the surface and cooling, and fixing the adhesive surface. There were many processes.

In the case of a double-sided medium, a method of forming a medium by laminating an ultraviolet curable resin layer as an adhesive layer is disclosed in JP-A-63-275057. However, the method disclosed here is to accelerate the curing by irradiating the disc surface with ultraviolet rays from the horizontal direction as much as possible. This method is different from the method of the present invention in which the adhesive can be applied only by irradiating from the outside. In the above-mentioned conventional technology, since the ultraviolet irradiation is performed from the end face portion where the resin layer is exposed, there are problems that the irradiation efficiency is difficult to increase and that a plurality of ultraviolet irradiation light sources are required.

The reason why the UV curable resin is not used as an adhesive in the case of the double-sided type is as follows. That is, in the case of a phase-change type optical disk (similarly to a magneto-optical disk), the ultraviolet light for curing the ultraviolet curable resin is hardly transmitted from the substrate side because the metal reflective layer is used. Is. In other words, it is difficult to cure the UV curable resin layer because the light does not reach the adhesive layer when irradiated with UV light from either side. The above-mentioned prior art does not show a solution to this fundamental problem.

By the way, in a medium having a single plate structure, since the upper and lower structures are asymmetrical, there is a tendency that a warp is likely to occur in either direction. That is, the protective layer 45 is
For example, in order to protect a layer directly related to recording of an optical information recording medium such as an optical disc from being affected by dust, humidity, external force, etc., it is a layer usually installed in this field, From the viewpoint of workability, strength, adhesiveness, etc., an ultraviolet curable resin is exclusively used. However, current UV curable resins shrink when polymerized and cured, which causes warping and / or distortion of the optical information recording medium. Another cause of the warp and strain is a change in volume of the recording thin film layer. As described above, in the phase change optical recording medium, the recording thin film is converted into a crystalline state in advance, but the recording thin film layer also tends to contract during crystallization, which causes warpage. Regardless of the cause, for example, in the single-plate configuration of FIG. 10A, there was a tendency that the protective layer side contracted and became a concave surface, and the substrate side became convex.

At the time of initialization by flash irradiation, heat is applied to the entire surface of the medium all at once. Therefore, in addition to the stress due to the above-mentioned crystallization, the stress due to the shrinkage of the ultraviolet curable resin also occurs at the same time. That is, there is a problem that it is difficult to relieve stress, and warpage and distortion are likely to occur remarkably.

As described above, in the disk having the single plate structure, some warpage as an result of the initialization work remains as an unavoidable tendency. As described in the examples, the warp or distortion generated in the recording medium is a great cause of servo defects such as focus defect and tracking defect when it is driven, which is not preferable. In the single-plate structure, as another problem, when the protective layer provided on the surface layer is not sufficiently cured, for example, when the optical information recording medium is exposed to high temperature and high humidity conditions, the recording thin film layer is There is also a problem that the function as a recording thin film layer is impaired due to deterioration or peeling.

For the purpose of recovering the adhesiveness at the interface between the recording layer and the dielectric layer, which is reduced by the stress due to heat generated from the recording layer at the time of initialization and the volume change of the recording layer due to the phase change, The recording medium 6 under the condition of 30 ℃ ~ 90 ℃
There is a prior art in which heat treatment is performed for 24 hours to 24 hours (JP-A-5-
No. 151623).

However, the purpose of this prior art is to provide an object of the present invention to perform heat treatment in order to correct the warp or distortion if the warp or distortion actually occurs due to the heat generated during the initialization work. Is different from. Further, in order to achieve the object of the present invention, as will be described later, the manner of holding the medium at the time of heat treatment, the point of how to apply an external force, etc. become important. Not touched at all. Further, in the prior art, only the example by laser initialization is shown, and no problem due to the temperature rise of the adhesive layer, which is a problem in the case of the flash method, is considered.

A device for flashing a flash lamp generally has an electric circuit configuration as shown in FIG. That is, the main capacitor 32 that stores the electric energy necessary for flashing the flash lamp 31, the power source 33 that charges the main capacitor 32 with the electric energy, and the flash lamp 3
1. A trigger coil 34 for generating a trigger voltage to start the flashing of No. 1, a discharge switch 35, a changeover switch 36 for switching between charging and discharging of the main capacitor 32, and a current value control for charging. It is based on a circuit including a resistor 37. The following method is generally used to initialize an optical recording medium using the initialization device of the electric circuit configuration of FIG. That is, the changeover switch 36 is switched to charging, and the output of the power supply 33 is set to the same voltage value as the voltage value required to determine the flash intensity of the flash lamp 31. This voltage setting is mainly determined by the withstand voltage of the main capacitor 32, and if set above the withstand voltage, the withstand voltage of the main capacitor 32 will be exceeded and the main capacitor 32 will be destroyed at the time of full charge. Is common. Power supply 33
Since a potential difference is generated between the main capacitor 32 and the terminal of the main capacitor 32, electric energy is supplied from the power source 33 to the main capacitor 32 through the resistor 37. The terminal voltage of the main capacitor 32 increases with the supply of electric energy, and finally the electric energy is supplied until the output voltage of the power supply 33 and the terminal voltage of the main capacitor 32 become the same (that is, until the potential difference disappears). To be done. In this way, after charging the main capacitor 32, the changeover switch 36 is turned off. After that, when the discharge switch 35 is turned on, a pulsed voltage is generated on the primary side of the trigger coil 34. As a result, a voltage of about 10 kV is generated on the secondary side of the trigger coil, and the flash lamp 31 flashes. By the light emitted by this flash,
The optical recording medium 38 is initialized.

Generally, the initialization process is carried out by the above method, but in the initialization by the flash light, the entire surface of the optical recording medium is initialized in a lump, so the initialization (crystallization) itself. Is performed in 1 to 2 ms or less. Therefore, the time required for initialization is almost determined by the charging time of the main capacitor 32.

Conventionally, there has been a problem that the time required for this charging is considerably long. In case of initialization by flash,
Most of the time required is the time required to charge the capacitor, and shortening this time makes it possible to further increase the advantage of the flash method. When the present inventors actually measured the charging time for the main capacitor 32, the results were as follows. For example, flash lamp 3
It is assumed that 12 flash lamps 1 are simultaneously flashed, and the flashing voltage of both electrodes of the flash lamp 31 is 700V. The power supply voltage is set to 700V, and the main capacitor 32 has a capacity of 36 because it flashes 12 simultaneously.
The capacitance is 000 μF. When the main capacitor 32 was charged under this condition, the charging time required about 5 minutes.

Here, when the relationship between the charging time of the main capacitor 32 and the ultimate voltage is measured, it becomes as shown by the solid line in FIG. That is, immediately after the start of charging, the main capacitor 3
Since almost no electric charge is stored in 2, the terminal voltage of the main capacitor 32 is as low as around 0V. For this reason,
Since the potential difference between the power supply voltage and the terminals of the main capacitor 32 is large and the flowing current is also large, the main capacitor 32
Is charged rapidly. However, the terminal voltage of the main capacitor 32 also rises in the process of continuing charging, and the potential difference from the power supply voltage decreases, so that the flowing current also decreases.
This phenomenon has a great influence as the charging progresses, and as a result, it takes a considerable time for the terminal voltage of the main capacitor 32 to reach the flash voltage of the flash lamp 31.

On the other hand, in the manufacture of today's optical recording media,
A takt time of about 1 minute is often required. Therefore, in order to shorten the initialization time by the flash light, it is necessary to shorten the charging time of the main capacitor as shown by the broken line in FIG.

[0026]

As described above, the prior art requires heating for initialization, and there is a problem that the heating causes damage and the product is likely to be broken.

In order to solve the above conventional problems, the present invention provides a flash initialization device capable of arbitrarily setting discharge light emission time (irradiation time) and discharge light emission power (irradiation light power). A first object of the present invention is to provide an initialization method that uses the device and has a small thermal damage.

A second problem to be solved by the present invention is to shorten the total time required for initialization in carrying out the flash initialization method as compared with the conventional method. It is an object of the present invention to provide a method for increasing the charging speed and a device for realizing the same, paying attention to the fact that most of the time required for the initialization is the charging time for the storage unit which is the energy source of flash light.

The third problem to be solved by the present invention is as follows.
In particular, in the manufacturing process of an optical information recording medium including a flash initialization process, and particularly in the manufacturing process of a medium having a single-plate structure, it is intended to reduce warpage and / or distortion of the medium, which is a protective layer manufacturing process. It is an object of the present invention to provide a manufacturing method for reducing warpage and / or strain through an initializing step and the like.

A fourth problem to be solved by the present invention is that the manufacturing process of the double-sided medium suitable for the flash initialization method is more complicated than that of the single plate type medium. It is an object of the present invention to provide a medium structure for reducing the number and a method for manufacturing the double-sided medium.

[0031]

In order to achieve the first object, the manufacturing method of the present invention controls the waveform of the flash light irradiated for initialization, and when crystallization occurs,
A method of instantaneously stopping light emission is used. Then, in order to realize the above method, the manufacturing apparatus of the present invention comprises a support for supporting an optical information recording medium having a recording thin film layer for causing a phase change between crystal and amorphous on a substrate, and a flash for discharging. A light source that emits light, a storage circuit unit that stores electric energy supplied to the light source, a trigger circuit unit that starts discharge of the light source, and the discharge is forcibly interrupted after a predetermined light emission time. The flash exposure apparatus is provided with a cutoff circuit section that instantly reduces the intensity of light emission from a predetermined intensity to a zero level effectively. When the initial crystallization of the optical information recording medium is performed, the storage circuit unit is charged with a predetermined applied voltage, the trigger circuit unit is operated to start discharging, and flash light is emitted in advance. After the elapse of the predetermined discharge time, the above-mentioned cutoff circuit section is operated to forcibly stop the discharge.

In order to perform initialization by crystallization without applying a thermal load to the resin substrate, the recording thin film layer and the protective layer as much as possible, the time for the heat generated in the recording thin film layer to diffuse to the surroundings is shortened as much as possible. It is necessary to. Since the actual crystallization time is on the order of several μs at most, it is important to raise the temperature of the recording thin film layer to the crystallization temperature instantaneously and cool it as soon as possible after the recording thin film layer is crystallized. . In other words, it is necessary to increase the temperature rising rate and the cooling rate as much as possible, and to keep the recording thin film layer in a high temperature state for the time required for crystallization of the recording thin film layer. However, normally, when flash exposure is performed, the tail portion of the light emission continues for a long time even after the peak value of the light emission intensity is exceeded, which is considered to cause thermal damage to the recording thin film and the substrate.

Therefore, according to the configuration including the interruption circuit of the present invention, the flash irradiation to the optical information recording medium is performed,
Since the light emission can be stopped within the minimum time required for crystallization and the light emission can be forcibly stopped at any time, the influence of the tail portion of light emission can be eliminated, and the heat during initialization can be eliminated. It is possible to greatly reduce damage.

Further, at this time, by stopping the discharge itself, unused electric charge remains in the capacitor without being discharged, and the time required for the next charge can be made much shorter than the first time. That is, when the initialization is repeated, the total time can be shortened and the production speed can be increased.

Preferably, in the present invention, the discharge time is up to 2
mS. Further, in the present invention, preferably, the composition of the recording thin film used for the optical information recording medium is a Ge-Sb-Te alloy as a main component.

In order to achieve the second object of the present invention, a manufacturing apparatus according to the present invention flashes an optical recording medium having a recording thin film on a substrate, which causes a phase change between a crystalline state and an amorphous state. In a device for irradiating light and collectively converting a predetermined region of the recording thin film into a crystalline state which is an initial state, means for supporting the optical recording medium, a light source for emitting flash light by discharge, Storage means for storing energy to be supplied to the light source, supply means for sending energy to the storage means, discharge starting means for starting discharge of the light source, and energy amount stored in the storage means. The accumulated amount detecting means for detecting and the supply amount setting means for setting the amount of energy to be supplied to the supplying means are provided, and according to the detected amount detected by the accumulated amount detecting means, The supply means is controlled so that the supply quantity set by the supply quantity setting means is larger than the reached quantity of the energy of the storage means or a specified value of the reached quantity, and the energy quantity of the storage means reaches a predetermined value. At the same time, it comprises a control means for interrupting the supply of energy from the supplying means to the accumulating means by means of a switching means, and controlling the discharge starting means to cause the light source to emit light. This shortens the charging time of the main capacitor and allows the discharge power to be set arbitrarily.

Since the supply amount of the supply means is made larger than the specified value of the amount of energy reached by the storage means, even if the amount of energy stored in the storage means becomes large, there is always a predetermined difference in the amount of energy between the supply means and the storage means. Is secured. Therefore, the degree of decrease in the amount of energy supplied is reduced and the energy supply time to the storage means is shortened, so that the initialization time of the optical recording medium is greatly shortened.

In the present invention, preferably, the energy supply amount of the supply means and the energy storage amount of the storage means are detected by a voltage amount, and the voltage value of the supply means is more than the voltage value at the time of completion of the storage of the storage means. Raise one higher.

Further, in the present invention, preferably, the energy supply amount of the supply means and the energy storage amount of the storage means are detected by a voltage amount, and the difference between the voltage value of the supply means and the reached voltage value of the storage means is detected. It is almost constant.

In order to achieve the third object of the present invention, a recording thin film layer which causes a phase change between crystal and amorphous is provided on a substrate, and a curable resin containing an ultraviolet curable resin is cured on the uppermost layer. In an optical information recording medium having a protective layer, a method is used in which after the initial crystallization step is completed, an annealing step is performed to completely cure the protective layer.

At the stage until the initialization, the ultraviolet curable resin applied as the material for the protective layer has not been completely polymerized, so that it has a certain degree of structural flexibility. Therefore, by performing the annealing step, the ultraviolet curable resin of the protective layer is completely cured, and the film formation of the protective layer as the optical information recording medium can be completed. At this time, the annealing process is performed while maintaining a state in which a force is applied in the direction to correct the warp or while actively applying an external force to correct the warp. As a result, the warpage that occurs in each of the steps can be corrected, and the state after annealing is fixed with the warpage corrected.

As a result, the reliability of the protective layer of the optical information recording medium can be improved, and at the same time, the number of defects caused by the warp in the initialization process can be reduced and the manufacturing yield can be improved.

Preferably, as the optical information recording medium,
A structure in which a first dielectric layer, a recording thin film layer, a second dielectric layer, and a reflective layer are laminated on a substrate and a protective layer is provided on the uppermost layer is used.

Preferably, the recording thin film layer is made of Ge-S.
An alloy thin film containing b-Te as a main component is used. Further, preferably, the annealing step also serves as a correction process for correcting the optical information recording medium to a warp-free state or for applying an external force in a direction of correcting the warp.

Further, preferably, in the annealing step, the optical information recording medium is placed on a table having a hole having a diameter slightly smaller than the outer diameter of the optical information recording medium having a disk shape, and the optical information recording medium The optical information recording medium is held so that the center of the optical information recording medium is aligned with the center of the hole and the convex surface of the optical information recording medium faces upward. Then, the optical information recording medium is weighted or fixed to the center portion of the optical information recording medium so that the optical information recording medium becomes convex or flat in the opposite direction.

Further, preferably, the annealing process also serves as a correction process, and the annealing process is performed while leaving at least one of the substrate surface and the protective layer surface flat on a flat surface.

Preferably, the annealing step also serves as a straightening step, and at least one of the innermost peripheral portion and the outermost peripheral portion of the substrate surface and the protective layer surface is pressed against an object having a flat surface while the annealing step is performed. Do.

Further, preferably, the flat surface is one surface of an object having heat resistance equal to or higher than the temperature of the annealing step, and the optical information is recorded on the flat surface of the object obtained by previously heating the object to a predetermined temperature. The annealing process is performed with the medium placed.

Further, preferably, the annealing step also serves as a straightening treatment, and the annealing step is performed while applying a force from both sides in a state where a plurality of optical information recording media having a single plate structure are stacked.

Further, preferably, the temperature of the annealing step is set to a temperature at which the phase change of the recording thin film layer occurs or less. Also,
Preferably, the annealing temperature is 100 ° C. or lower. The lower limit is about 60 ° C.

Further, preferably, the initial crystallization step is performed by flash exposure. As another method for achieving the above object, a recording layer having a multi-layered structure including a recording thin film layer that causes a phase change between crystal and amorphous is provided on a substrate, and an ultraviolet curable resin is contained in the upper layer of the recording layer. In the process of manufacturing an optical recording member having a structure including a protective layer of a cured coating, the manufacturing method of the present invention provides the recording layer and the protective layer of the optical recording member after providing the ultraviolet curable resin layer. The step of irradiating an ultraviolet ray while applying a correction force to the surface of the substrate opposite to the surface of the substrate provided with the step of irradiating ultraviolet rays and the step of initial crystallization after the step of irradiating the ultraviolet rays are included.

Usually, in a single-plate optical information recording medium (hereinafter referred to as an optical disc), the warp direction due to the formation of the protective layer and the warp direction due to the initialization are the same.
Amplify the warp of the optical disk after adding these processes,
The flatness of the layers involved in recording on the optical disc is impaired. Therefore, the warp after the initialization step can be suppressed by forming the protective layer while applying the correction force in the direction opposite to the direction in which the warp occurs at least during the protective layer curing step.

Preferably, the initializing step is performed in a state in which the correction force is applied. Further, preferably, an annealing step of heating the optical recording medium is performed between the ultraviolet light irradiation step and the initialization step.

Further, preferably, the annealing process is performed in a state where a correction force is applied. Further, preferably, the heat source of the annealing step is irradiation of an infrared light lamp. Further, preferably, the initialization step is performed by flash light irradiation.

According to the present invention, the warp and / or the strain after the initialization of the phase-change type optical disk medium between the amorphous phase and the crystalline phase is reduced, and the servo characteristics can be improved. A fourth object of the present invention is to provide a structure of an optical information recording medium for reducing the number of manufacturing steps of a double-sided medium which is a medium structure suitable for a flash initialization method, and a method of manufacturing the optical information recording medium. To provide.

In order to achieve the above-mentioned object, the present invention comprises two sheets having a multilayer structure film including a recording thin film layer and a metal reflection layer which produce a change optically detectable by irradiation of a laser beam on a transparent substrate. The above optical recording member is laminated with a resin containing an ultraviolet-sensitive curing component so that the multilayer structure film sides are inside each other, and the above two optical recording members are used. At least one of them has a transmittance of about 3% or more in the ultraviolet sensitive wavelength range of the resin. With the above structure, it becomes possible to cure the adhesive layer by irradiating ultraviolet rays from the outside through the substrate.

Here, it is preferable that the recording thin film layer applies a change in optical characteristics associated with a phase change phenomenon between an amorphous phase and a crystalline phase, and at least one of the recording members of the optical recording member. When the thin film layer is in an amorphous state, it has a transmittance of approximately 3% or more in the ultraviolet sensitive wavelength range of the resin.

Preferably, Au is used as the metal reflection layer.
Alloy containing _100% as a main component Au _100-x M _x (M is Cr, Al, A
g, Cu, Ni, Si, Pt and other metal elements, 100> x
≧ 0) is used.

Such an optical information recording medium has the above-mentioned 2
A film forming step of forming a film so that the multilayer structure film of at least one of the optical recording members has a transmittance of about 3% or more in the ultraviolet sensitive wavelength range of the resin; Step of arranging the physical recording members so that the surfaces on which the multilayer structure film is formed face each other, a filling step of filling the space between the facing multilayer structure films with the resin, and the resin by exposure to ultraviolet light. It can be obtained by a manufacturing method including an exposure step of curing.

In general, the influence of the ultraviolet-sensitive curing component on the curing rate depends on the wavelength of the ultraviolet rays to be irradiated, the quantum yield of the sensitive component (proportional to the ultraviolet irradiation intensity), and the like. However, according to the experiments by the present inventors, the rate-determining rate for curing by ultraviolet irradiation (although the curing rate slightly changes depending on the irradiation intensity) is mainly determined by the wavelength of ultraviolet rays. That is, if there is a specific wavelength that sensitizes the component that initiates polymerization upon irradiation with ultraviolet light, it is at least about 3%.
It was found that even with a transmittance of about a certain degree, the irradiation intensity itself to the sensitive component that initiates polymerization by ultraviolet irradiation is sufficient, and does not affect the curing rate so much. Therefore, according to the above configuration, a double-sided optical information recording medium can be formed only by filling the ultraviolet curable resin between the adhesive surfaces of the two discs and irradiating with ultraviolet rays. The number of manufacturing steps can be greatly reduced.

Here, exposure is preferably performed from both sides of the optical recording member. Further, preferably, after the exposure step, the optical information recording medium is irradiated with an energy ray for initialization.

A laser beam is preferably used as the energy ray. Further, preferably, flash light is used as the energy ray. Further, preferably, at least one of the two optical recording members is a read-only type.

[0063]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. First, a first object of the present invention is to provide a flash initialization device capable of arbitrarily setting discharge light emission time (irradiation time) and discharge light emission power (irradiation light power), and the device. An embodiment of the invention for achieving the provision of the initialization method with small thermal damage by using is described.

FIG. 1 is a diagram showing a main configuration of an embodiment of a flash initialization device capable of arbitrarily setting discharge light emission time (irradiation time) and discharge light emission power (irradiation light power). By using this apparatus, initialization with small heat damage can be performed as described below.

At the time of initialization, first, the optical information recording medium 3 having the recording thin film 1 (initially in an amorphous state) composed of the phase change material on the resin substrate 2 is placed on the support base with the substrate surface facing upward. Place on top of 6. Here, the substrate surface is on the top, but the substrate surface may be on the bottom, and a free form can be taken according to the device configuration.

A flash light source 7 is connected to a storage circuit section 8 for storing electric energy. In this embodiment, as the light source 7, 24 xenon flash lamps having a length of 35 cm are arranged on a plane with a space of 1 mm.

The storage circuit 8 is composed of a resistor and a capacitor, is connected to a power source 12, and is charged by the power source 12 to a predetermined voltage. Reference numeral 9 denotes a trigger circuit, which is activated after the capacitor of the storage circuit section is charged to a predetermined voltage to change the inside of the flash light source to a state in which it can be energized and stored in the storage circuit. The generated electric charges are made to flow into the discharge circuit at once. As a result, a strong flash light beam 4 is emitted from the flash light source 7. Reference numeral 11 denotes a reflector, which serves to enhance the efficiency of irradiation of the medium, but is not an essential element for completing the present invention.

The recording thin film 1 absorbs the flash light 4 and rises in temperature to undergo crystallization transition. Further, a discharge interruption circuit section 10 is attached to the discharge circuit, and after discharging for a predetermined time, the discharge is forcibly stopped, and the intensity of light emission can be instantaneously and effectively reduced to 0 level. it can.

Referring to FIG. 2, the operation principle of the cutoff circuit section 10 used in the initialization device of the present invention will be described. First, in the case of discharging, as a premise of causing discharging, first, the capacitor C1 of the storage circuit unit 8 is charged to a predetermined voltage. Next, the switch circuit 5 causes the trigger circuit 9
The ON signal is applied to the gate terminal of the SCR (hereinafter referred to as thyristor) S1 and the voltage is applied to both ends of the trigger transformer of the trigger circuit 9.

The above voltage is boosted, a high voltage is applied to the trigger electrode of the flash light source 7, and the cutoff circuit 1
The thyristor S2 of 0 is turned on. As a result, the electric resistance inside the flash tube sharply decreases, and the voltage across the main capacitor C1 is applied to both ends of the flash tube, so that discharge is started between the cathode and anode of the lamp and light emission is obtained.

Then, when the discharge is forcibly interrupted, an ON signal is applied to the gate terminal of the thyristor S3 in the cutoff circuit. At this time, a circuit (not shown) that outputs an ON signal is equipped with a timer, and after switching on the discharge start,
The ON signal is set to be output when a predetermined time has elapsed.

In the breaking circuit, a capacitor C2 for generating a breaking current is connected in a charged state. When the thyristor S3 is turned on, the voltage across C2 is applied to the thyristor S2 in the opposite direction, and a reverse current is generated, so that S2 is instantly turned off. As a result, the discharge from the main capacitor can be stopped. That is, it is possible to set an arbitrary light emission time regardless of the time constant of the circuit.

As the breaking circuit, for example, a varicut device (VARICUT24) manufactured by Sunstar Strobe Co., Ltd.
It is also possible to use. In this case, the effective light emission time can be arbitrarily controlled within the range of 0.1 to 10 msec.

FIGS. 3A to 3D show an example of a light emission pattern in which the pin diode receives light emitted from a xenon lamp which is discharged by using this circuit. The horizontal axis of each figure is a time axis, and for each of FIGS. 3A to 3C, one scale is 0.5 ms, and FIG.
Is 0.2 ms per scale. The vertical axis represents the emission intensity converted into the output voltage of the photo detector.
The capacitor capacity of the storage unit in the circuit is 6000μ.
F, the charging voltage is 800V.

FIG. 3A shows the case where the discharge interruption circuit 10 is not operated, and FIGS. 3B to 3D show the case where the interruption circuit 10 is operated respectively, and the light emission time is 2 mS, 1 mS and 0.5 mS, respectively.
This is equivalent to setting.

From these figures, it can be seen that after the lapse of the set time, the light emission is completely stopped and the level is rapidly lowered to 0 level. In FIGS. 3B, 3C and 3D, the light emission intensity increases momentarily immediately before the stop because the current from the capacitor C2 momentarily flows toward the flash tube.

FIG. 4A is a sectional view showing an example of the structure of an optical disk medium which is subjected to the initial crystallization process by applying the initialization method of the present invention. It is usually called a slow cooling configuration. Substrate 2 made of polycarbonate with a diameter of 200 mm and a thickness of 1.2 mm
ZnS-SiO ₂ having a thickness of 90nm on (SiO _2: 20 mol%) film (undercoat dielectric layer 14), having a thickness of 30 nm Ge
₂ Sb ₂ Te ₅ alloy thin film layer (recording thin film layer 1), thickness 154
nm of _{ZnS-SiO 2 (SiO 2:} 20 mol%) film (upper coating dielectric layer 15), Au thin film layer having a thickness of 10nm (reflection layer 16) was laminated by sputtering.

In the as-formed state, the recording film was in an amorphous state. Next, an ultraviolet curable resin was spin-coated on the uppermost layer to form a layer having a thickness of 20 μm, which was then irradiated with a mercury lamp and cured to form a protective layer 17.

Table 1 shows the results obtained by performing the flash irradiation shown in FIG. 3 on the medium having the structure shown in FIG. 4A. The distance between the lamp and the medium is 10 mm, the charging voltage is 650, 675, 700, 75
Five conditions of 0 and 800 V were set.

[0080]

[Table 1]

In Table 1, under the condition of "OK", it was possible to crystallize the entire surface of the disk without exhibiting thermal damage such as cracks and peeling, and "damage" was wrinkled regardless of whether it was crystallized or not. Occurs, some kind of damage such as cracks occurs, "partial residue" is a part where the emission intensity is comparatively weak and a part that remains without crystallization is found, and "impossible" means no crystallization at all. It shows that there was nothing. Crystallization can be easily judged with the naked eye because the optical density is high, but it was also confirmed by X-ray diffractometry as a precaution.

As is clear from Table 1, in the case of irradiation A without activating the cutoff circuit, it was found that thermal damage occurs before sufficient crystallization occurs. . In addition, by operating the cutoff circuit to cut the tail portion of light emission, it is possible to reduce excessive heating, and it is possible to achieve crystallization without heat damage.

Although not shown in Table 1 above, the light emission time was also tried under conditions of longer than 2 mS and shorter than 0.5 mS. As a result, there was a condition under which initialization was possible when the time until the cutoff circuit was activated was set to 3 mS, but when it exceeded 3 mS, damage was noticeable, which was not preferable. Below 2 mS, there were a wide range of conditions under which a beautiful initialized state was obtained. Further, even under the condition that the time was shorter than 0.5 mS, for example, the irradiation time of 0.2 mS and 0.1 mS, the initialization without any damage was possible.
However, in this case, the required charging voltage is 2kV, 4kV
Therefore, a large power supply is required.

Recording and reproduction were carried out by mounting the above-mentioned initially crystallized disk on an evaluation deck. Disk speed 27
Driven at m / s, a 780 nm wavelength laser (numerical aperture: NA = 0.55) is binary-modulated (peak power 24 m
W, bias power 10 mW), and recording frequency f1 = 1
The 8 MHz signal and the f2 = 6,75 MHz signal were alternately recorded by overwrite recording. When the C / N and erasing rate of f1 were measured, a C / N of 52 dB and an erasing rate of 26 dB were obtained, and it was found that the initialization was performed without problems.

Next, the initial crystallization method of the present invention was carried out by using an optical disk having another structure, which is usually called a quenching structure. As shown in FIG. 4B, in this embodiment, φ1
A 3 cm polycarbonate resin substrate was used, on which a 170 nm thick ZnS—SiO ₂ (SiO ₂ : 20 mol%) film, a 25 nm thick GeBi ₂ Te ₄ alloy thin film, and a 45 nm thick ZnS—SiO ₂ ( SiO ₂ : 20 mol%)
A film and 90 nm thick AlCr (Cr: 3 atomic%) were sequentially formed by a sputtering method. The recording film was in an amorphous state as it was formed.

Next, an ultraviolet curable resin was spin-coated on the uppermost layer to form a layer having a thickness of 20 μm, which was then irradiated with a mercury lamp and cured to form a protective layer. Initialization experiments were performed on the optical disc of this configuration as in the previous embodiment. At this time, the voltages are 625, 650, 675, 7
There are five levels, 00 and 750.

[0087]

[Table 2]

Also in this example in which the medium composition was changed, as is apparent from Table 2, when irradiation was performed without activating the interruption circuit, thermal damage was caused before sufficient crystallization occurred. It turns out that it will happen. Further, it was confirmed that when the cutoff circuit was operated, there was an appropriate charging voltage according to the light emission time, and under that condition, crystallization without heat damage could be performed.

In this case, as in the case of the slow cooling structure,
Conditions longer than 2 mS and shorter than 0.5 mS were tried, but the trends were the same. Recording / reproduction was performed by mounting the above-mentioned initially crystallized disc on an evaluation deck. Drive a disk at a linear velocity of 10 m / s and a wavelength of 78
Binary modulation of 0 nm laser (numerical aperture: NA = 0.50) (peak power 14 mW, bias power 7 mW)
The recording frequency f1 = 6.66 MHz signal and f2 =
Overwrite recording was performed with a signal of 2.5 MHz alternately. f
When the C / N of 1 and the erasing rate were measured, the C / N of 55 dB was obtained.
An erasing rate of N and 26 dB was obtained, and it was found that the initialization was performed without problems.

As can be seen from the above two examples, the initialization method and the initialization device of the present invention do not depend on the structure of the medium.
This is applicable even if the material and film thickness of each layer constituting the medium is changed.

As the substrate material, a transparent polymer material such as PMMA or polyolefin, a transparent inorganic material such as glass, or a metal such as Cu or aluminum can be used. Examples of the dielectric material include Zr-O, Ta-O,
An oxide such as Ge-O, Ti-O, Al-O, for example, Al
-N, Zr-N, Si-N, Ti-N, etc. nitrides, such as Si-C, Ti-C, etc. carbides, such as Ca-F, L
Fluorides such as aF can be used.

The recording thin film layer is, for example, Ge-S.
b-Te system and Co, Bi, Pd, O, N, Se in this system
Etc. (or a system in which some of these are substituted), Sb-Te system, In-Sb-Te system, Ga-Sb
System, Ge-Te system, Ag-Sb-In-Te system, Ge-
Bi-Te system, Ge-Sn-Te system, Ge-Bi-Te
-Se system, Ge-Te-Sn-Au, etc., or a system in which additives such as oxygen, nitrogen, etc. are added to these systems, as represented by phase change recording thin films, etc. Can be used.

Further, as the reflective layer material, Au, Al,
Metals such as Ni and Cr, or alloys based on these are used. In addition, as a medium configuration, for example, FIG.
Alternatively, the same medium as shown in B can be applied to a double-sided medium in which two sheets are laminated. That is, the present invention does not depend on the medium configuration.

The irradiation power required for the initial crystallization can be changed by selecting the distance between the medium and the light source. That is, if they are close to each other, the irradiation time can be shortened or the charging voltage can be lowered. On the contrary, if the distance increases, it is necessary to lengthen the irradiation time or increase the charging voltage. How to choose the above distance is a design matter of the device.

The next example is the time required for charging.
Corresponding to FIGS. 3A, 3B, 3C, and 3D described above, the charging time when initially charging to 750V and the time required to recharge to the voltage before discharging after discharging once were examined. The charging time was measured while the voltage was kept at 750V. The results are shown in Table 3.

[0096]

[Table 3]

As shown in Table 3, it took 4 minutes for the first charging, but there is a difference in the charging time corresponding to the discharging time at the time of the next charging after discharging once. That is, when the discharge time is 2 mS, the next charge is completed in 2 minutes, which is half of the initial time. Similarly, discharge time is 1 mS, 0.5
It can be seen that under the mS condition, the next charging time is shortened to 1 minute and 30 seconds. That is, it was confirmed that the time required for the initial crystallization was significantly shortened by using the discharge interruption circuit and performing only the minimum necessary discharge light emission during the initial crystallization.

Next, an embodiment for shortening the time required for the flash initialization method which is the second object of the present invention will be described. In this embodiment, it is noted that most of the time required for the flash initialization method is the charging time for the storage unit that is the energy source of the flash light, and a method for increasing this charging speed and a device for realizing the method are provided. To do.

FIG. 5 is a configuration diagram for explaining an example of the configuration of the initialization device in which the initialization time is shortened. At the time of initialization, the optical recording medium 18 is placed on the support base 19. A flash lamp 20 (hereinafter, simply referred to as “lamp”) is arranged facing the optical recording medium 18. Although only one lamp 20 is shown in this figure, a plurality of linear lamps may be arranged in parallel according to the shape and surface area of the medium, and a spiral lamp is arranged. You may.

The main capacitor 21 for accumulating the electric energy required to make the lamp 20 flash is
It is connected in parallel with the terminal of
A voltmeter 22 for detecting the amount of charge as the terminal voltage of the main capacitor 21 is connected in parallel. The voltmeter 22 is provided with a measurement value output terminal for outputting the measured voltage to another circuit.

Reference numeral 23 is a power source for charging the main capacitor 21. The power supply 23 is provided with a voltage setting circuit 24 capable of automatically controlling the output terminal voltage of the power supply. Reference numeral 25 denotes a changeover switch, which is provided to change over the charging and blocking of the main capacitor 21 and the discharging of the excessive charge amount.

The relay 26, the trigger coil 27, and the trigger capacitor 28 are provided to make the lamp 20 flash. The trigger capacitor 28 is charged to the voltage Vt through the resistor 30 in advance. When the relay 26 is closed in this state, the energy stored in the trigger capacitor 28 is converted into high frequency / high voltage energy by the trigger coil 27 and applied to the trigger electrode of the lamp 20.

Due to this high frequency and high voltage, the xenon gas inside the lamp 20 is dielectrically broken down, and a rapid discharge is started between the cathode and anode. As a result, the energy stored in the main capacitor 21 becomes light energy and instantaneously emits light.

The control means 29 controls to take in the measured value signal of the voltmeter 22, control to send a signal for determining the set voltage of the setting circuit 24, control to send a signal for changing the position of the changeover switch 25, and It is provided to control the sending of a signal to close the relay 26.

Next, the flow of control for initializing the optical recording medium 18 using the above apparatus will be described below. The light emission intensity of the lamp 20 is determined by the amount of charge of the main capacitor 21 that stores the electrical energy required to make the lamp 20 flash, but if the capacitor capacity is constant, the terminal voltage of the main capacitor 21 (that is, the terminal of the lamp). Voltage). Although the maximum allowable value of the applied voltage and the lower limit value of the light emission limit depend on the design of the lamp 20, an example using a lamp rated at 700 V will be described here.

In order to apply the 700V between the lamp terminals, it is necessary to charge the main capacitor 21 so that the voltage also becomes 700V. Therefore, 1) When the charging completion voltage of the main capacitor 21 is set to 700 V by the control means 29, a signal is sent from the control means 29 so that the changeover switch 25 is on the charging side.
Charging starts.

2) At the same time, the setting circuit 2 from the control means 29
4 is sent to set the output voltage of the power supply 23. 3) Since the terminal voltage of the main capacitor 21 rises as the charging is continued, this terminal voltage is detected by the voltmeter 22 and the measured value is sent to the control means 29.

4) The control means 29 sends a signal to the setting circuit 24 so that the potential difference between the output voltage from the power source 23 and the terminal voltage of the main capacitor 21 is always 700 V, and the setting circuit 24 outputs the output voltage of the power source 23. Is controlled to be 700 V higher than the voltage measured by the voltmeter 22.

5) At the same time when the voltmeter 22 detects 700V (or a value exceeding it), the control means 29 sends a signal so that the changeover switch 25 is in the cutoff position,
The charging of the main capacitor 21 is completed.

6) After charging is completed, the control means 29 controls the relay 2
The lamp 20 emits light when the signal is sent to 6 and the relay 26 is closed, and the optical recording medium 18 is irradiated with flash light for initialization.

FIG. 6 shows the charging time and the main condenser 21.
It represents the relationship of. In the figure, the straight line shown by the solid line shows the case where the potential difference is always kept at 700 V, which is shown in the above embodiment, and the terminal voltage of the main capacitor 21 is linearly boosted to the charging end voltage. Comparing this with the case where the applied voltage is set to a constant value (the curve of the broken line in the figure), it can be seen that the charging can be completed in a much shorter time when the method of the present embodiment is used. . In the case of this method, since the time until completion of charging and the amount of increase in the terminal voltage of the main capacitor 21 are constant, the charging completion time can be easily obtained, which is convenient.

The method of setting the output voltage of the power supply 23 is not limited to the above. More simply, the output voltage can be fixed to the upper limit of the set voltage of the power supply 23. For example, if the maximum rated voltage of the power supply 23 is 1 kV, the power supply 2
The setting circuit 24 is controlled through the control means 29 so that the output voltage of 3 becomes 1 kV. In this case, the potential difference immediately after the start of charging is 1 kV, and the potential difference at the end of charging is the charging completion voltage of the main capacitor 21 being 700V,
Since it is 300V, the terminal voltage of the main capacitor 21 changes as shown by the alternate long and short dash line in FIG. 6, and is shorter than charging by setting the voltage of the power supply 23 to 700V which is the voltage at the time of completion of charging. Can be charged with.

In any case, in the present invention, the output voltage of the power supply 23 is kept higher than the charging end voltage of the main capacitor 21 so that the potential difference between the two is made as high as possible and the current value flowing into the main capacitor 21 is increased. To do. As a result, the charging time can be shortened and the time required for initialization can be shortened.

As described above, one of the features of the initialization device of the present invention is that the supply amount setting means provided in the energy supply means, the stored amount detection means for detecting the amount of energy stored in the energy storage means, and the supply The point is that a control means for outputting a signal to the supply means, the switching means and the discharge starting means based on the outputs from the setting means and the accumulation detecting means is provided.

The targets to be detected by the supply amount setting means and the accumulated amount detecting means are the amount of electric charge for directly detecting energy,
Although there is a voltage converted from energy, etc., it is desirable to manage with voltage from the viewpoint of emitting flash light.

Further, in accordance with the detected amount detected by the accumulated amount detecting device, the supply amount set by the supply amount setting device is set to be larger than a predetermined reaching amount of the accumulating device or a set value of the reaching amount. It is also one of the features of the initialization device of the present invention that it is provided with a control means for controlling. Here, the predetermined reaching amount of the accumulating means means an energy amount or a voltage value required for the flash to emit light, and can be the same as a set value, or for example, a predetermined amount in order to start the discharge more smoothly. It is possible to set the set value slightly higher than the value. However, it goes without saying that any of the set values of the storage means described above is set lower than the saturated storage amount of the storage means.

In principle, the effect of the present invention is exerted when the supply amount is larger than either the predetermined reaching value of the accumulating means or the specified value of the reaching amount. Also, the greater the difference between the two, the more remarkable the effect. However, for example, in the case of detecting with a voltage, it is usually necessary to consider the voltage fluctuation of the supply means, so if it is 1.1 times or more of a predetermined reaching amount of the accumulating means or a specified value of the reaching amount, When the actual production is taken into consideration, an effect of about 1.3 times or more is preferable.
The upper limit is generally limited by the capacity of the supply means, and a supply means having a capacity of about 5 times or less is easily available, which is preferable. It should be noted that the ratio between the supply amount and the attainment amount of the accumulating means or the attainment amount regulation value does not change whether the energy is targeted or the voltage is targeted. is there.

Further, another feature of the present invention is that the supply means is controlled so that the supply quantity set by the supply setting means is larger than either the reaching quantity of the accumulating means or the specified value of the reaching quantity. The point is that the control means controls the switching means, cuts off the supply from the supply means to the storage means, and sends a signal to the discharge start means when the storage amount of the storage means reaches a predetermined value. That is, since the switching means is controlled via the signal of the detection means for detecting the amount of accumulation accumulated in the accumulation means (for example, the voltage between terminals), there is no fear of overcharging the main capacitor, etc. It also has a feature that charging can be completed and the discharge emission can be started.

The structure of the optical recording medium 18 applicable to the present invention is as described above with reference to FIGS. 4A and 4B. For example, on a substrate made of resin such as PMMA or polycarbonate, or glass, etc., a crystalline state and an amorphous state composed of a dielectric layer made of ZnS—SiO ₂ material, Ge—Sb—Te system, etc. can be reversibly changed. Phase change recording layer,
A thin film such as a reflective layer made of a metal element such as Au, Al or Cr or an alloy thereof is laminated.

The form of the optical recording medium 18 may be a structure in which a resin is spin-coated on the laminated thin films. It is also possible to bond the same resin plate and glass plate as the substrate using an adhesive. It is also possible to bond two sets of recording members using an intermediate substrate. Alternatively, it is also possible to make a structure in which recording, reproduction and erasing can be performed from both sides by adhering the film side inside with an adhesive.

The optical recording medium 1 may be manufactured by any method as long as it can record, reproduce and erase data. Also,
It may have a disk shape, a card shape, a sheet shape, or a film shape, and the invention is not limited to the shape of the optical recording medium 18.

Next, an embodiment for reducing the warp and strain of the medium generated through the step of forming the protective layer and the initial crystallization step, which is the third object of the present invention, will be described.
FIG. 9 shows a step of manufacturing a single-plate optical information recording medium (hereinafter referred to as an optical disk medium) 39 as one embodiment of the method for manufacturing an optical information recording medium according to the present invention. Although omitted in FIG. 9, the optical disc medium 39 includes a recording thin film layer that causes a phase change on the substrate and a protective layer.

Step (a) in FIG. 9 is a step of forming a recording thin film layer and the like on the substrate. When an organic resin substrate is used as the substrate material, a resin such as polycarbonate, polymethylmethacrylate (PMMA), or polyolefin is used. When an inorganic substrate is used, for example, a glass plate, copper, aluminum, or the like is used. A metal plate can also be used. Grooves or pit rows for guiding light are engraved on a concentric circle or a spiral line on the surface of the disk substrate, and a center hole is formed. When an inorganic substrate material such as a glass plate or a metal plate such as copper or aluminum is used as the substrate material, the guide groove or pit row is formed by a stamping transfer method (2P method) or the like.

On this substrate, a film forming step (a) is carried out by a method such as sputtering or vacuum evaporation to form a multilayer film having the required number of layers. For example, as shown in FIG. 10A, the first dielectric layer 41 and the recording thin film layer 4 are formed on the substrate 40.
A typical structure is one in which four layers of 2, the second dielectric layer 43, and the reflective layer 44 are stacked and the protective layer 45 is formed thereon, and each layer may be composed of a plurality of material layers. First, a first reflective layer (not shown) is provided, and then the first dielectric layer 41, the recording thin film layer 42, the second dielectric layer 43, and the second dielectric layer 41.
The reflective layer (not shown) may be formed in this order. Further, a configuration without any or both of the reflection layers, and a configuration without any or both of the dielectric layers can also be adopted.

The material for the dielectric layers 41 and 43 is Zn.
A typical S-SiO ₂ mixed film is Zr-O, Ta.
-O, Ge-O, Ti-O, Al-O and other oxides, Al
-N, Zr-N, Si-N, Ti-N and other nitrides, Si
Carbides such as -C and Ti-C, fluorides such as Ca-F and La-F, or a mixture thereof can be used.

The material of the recording thin film layer 42 is, for example, a phase change recording thin film to which a phase change is applied, typically Ge-Sb-.
Te, Co, Bi, Pd, O, N, Cr, I
n, Sn, Se, etc., or a part thereof is substituted, Sb-Te system, In-Sb-Te system, Ga-Sb
System, Ge-Te system, Ag-Sb-In-Te system, Ge-
Bi-Te system, Ge-Sn-Te system, Ge-Bi-Te
A system such as —Se system, Ge—Te—Sn—Au, or a system obtained by adding an additive such as oxygen or nitrogen to these systems can be used.

The material of the reflective layer 44 is Au,
Metals such as Al, Ni, Ag, Ti and Cr, or alloys based on them, such as Ag-Cr, Al-Cr,
Al-Ti, Ni-Cr, Au-Cr, etc. are used.

The disk-shaped medium which has completed the film forming step is transferred to the protective layer forming step of step (b) of FIG. Here, first, an ultraviolet curable resin is applied to the surface by a method such as spin coating, and then exposed to ultraviolet rays to be cured to be hardened.
(FIG. 10A).

After forming the protective layer, the process proceeds to the initialization step of step (c) in FIG. The initialization process may be either a laser method or a flash method. The disk-shaped medium that has undergone the initialization process is normally subjected to the above-mentioned two reasons, that is, the contraction due to the polymerization of the ultraviolet curable resin and the contraction due to the crystallization of the recording thin film. Warpage occurs in the direction in which the substrate surface side on which is not formed is convex. In this embodiment, a method for reducing this warp will be described.

After the initialization, the annealing step of step (d) of FIG. 9 is performed. This step is a feature of the present invention. In this embodiment, a copper plate 5 having a flat surface 50 with screw holes
1, the optical disk medium 52 is placed with the convex surface (here, the substrate surface 47 in FIG. 10A) facing upward, the optical disk center portion is fixed with the screw 53, and the disk medium 52 is pressed against the flat surface 50 so that there is no warp. keep. In this state, the whole is placed in a dry oven heated to a predetermined temperature and annealed. After annealing, if the whole is cooled and the screw is removed when the cooling is stopped, a disk medium with less warpage can be obtained.

There are various methods of correcting the warp other than the method of fixing the screw 53 to the screw hole of the copper plate 51 via the optical disk center portion.
This variation will be described below with reference to specific examples.

Example 1 Diameter 130 mm, Thickness 1.2
170mm thick Z on a polycarbonate substrate of mm
nS-SiO ₂ film, 25 nm Ge ₂ Sb ₂ Te ₅ film, 40 nm thick ZnS-SiO ₂ (SiO ₂ : 20 mol%)
Film and 80nm thick AlCr (Cr: 3 atom%) film are sequentially formed by the sputtering method, and an acrylic ultraviolet curable resin is applied to the uppermost layer to a thickness of about 20 μm by spin coating, followed by irradiation with a mercury lamp. And cured.

Next, twelve xenon flash lamps each having a length of 35 cm were lined up and the discharge light emission was carried out at the same time to crystallize the above-mentioned disk medium at once. When the warp angle was measured in this state, a large value of 10 milliradians was obtained.

Therefore, only the innermost peripheral portion 54 is fixed on the flat surface of the copper jig shown in FIG. 11A with the substrate surface 47 (convex surface) of the disk substrate 40 facing upward, and the disc substrate 40 is placed in an oven at 100 ° C. for 1 hour. Left for hours.

After natural cooling, it was confirmed that the protective layer was completely cured, and the warp angle was measured again.
It turned out to be as small as 5 milliradians. The warp angle is defined in FIG.

Example 2 The warped medium formed exactly as in Example 1 was annealed this time with the protective layer surface 48 facing up. One is the outer peripheral portion 55 as shown in FIG. 11B.
Only one of them was fixed, and the other one was fixed under the same conditions by fixing both the outer peripheral portion 55 and the inner peripheral portion 54 as shown in FIG. 11C.

When the protective layer was released after natural cooling, it was confirmed that all the protective layers were completely cured.
In the medium with only the fixed one, the center portion of the disk medium floated up, and random warpage occurred in the opposite direction. On the other hand, in the disk medium in which the inner peripheral portion 54 and the outer peripheral portion 55 were fixed at the same time and annealed, the warp angle was as small as 5 milliradian.

That is, when annealing is performed with the substrate surface facing upward, only the inner peripheral portion needs to be fixed, but the protective layer surface 4
It was found that when 8 was turned up, it was necessary to fix both the inner peripheral portion and the outer peripheral portion.

(Embodiment 3) A warped medium formed in the same manner as in Embodiment 1 is fixed to a stand 56 shown in FIG. 11D, and the central portion is tightened with a screw 57 so as to warp about 3 milliradians in the opposite direction. Annealing was performed as in Example 2.

After natural cooling, it was confirmed that the protective layer was completely cured, and when the warp angle was measured, the warp angle was significantly reduced and it was 1 milliradian or less in the convex direction of the substrate surface. .

(Embodiment 4) Thirty sheets of warped media formed in the same manner as in Embodiment 1 were prepared, stacked in the same direction, and the center portion was fixed on the base 58 with a weight 59 as shown in FIG. . In this state, it was placed in an oven at 100 ° C. and left for 3 hours.

After natural cooling, it was confirmed that the protective layer was completely hardened, and when the warp angle of each medium was measured, all were reduced to 5 milliradians or less. (Example 5) The medium of Example 1 was crystallized by a laser method. Rotate the disk at a speed of 5 m / s and set the wavelength of 830
A semiconductor laser having a wavelength of 1 nm and an output of 1 W was shaped to have a half width of 20 μm, and the entire surface was crystallized while sending a laser beam at a pitch of 10 μm. When the warp angle was measured in this state, it was 7 milliradian, which was a small value as compared with the flash method.

As in Example 1, with the substrate surface (convex surface) 47 facing upward, only the innermost peripheral portion 54 was fixed and left in an oven at 100 ° C. for 1 hour. After the natural cooling, it was confirmed that the protective layer was completely cured, and when the warp angle was measured again, it was found that it was as small as 5 milliradian.

A comparison between Example 5 and Example 1 shows that
It was found that a more remarkable effect can be obtained in the case of flash initialization when the annealing process also serves as the warp correction process.

(Example 6) Ten warped media formed in the same manner as in Example 1 were preheated to 100 ° C on the respective flat surfaces of three flat plates made of aluminum, alumina and glass. The substrate surface 40 was placed on top of the plate, allowed to stand for 30 minutes, and then naturally cooled.

It was confirmed that the protective layer was completely crystallized, and when the warp angle was measured, the warp angle after annealing was in the range of 5 to 7 milliradians regardless of which plate was used.

When the flat plate was changed to alumina or glass, the same effect was obtained. (Embodiment 7) The annealing temperature in Embodiment 1 is 60 to 120.
The measurement was performed in the range of 0 ° C in steps of 10 ° C. As a result, the higher the annealing temperature, the greater the effect of correcting the warp.
When the temperature exceeds 10 ° C., a slight abnormality was observed in the groove shape because polycarbonate was used as the substrate material.

In each of the above-mentioned embodiments, the polycarbonate material having low heat resistance is used as the substrate material, but it is also possible to use an inorganic material having high heat resistance, such as glass, as the substrate material. In this case, the hardening and warping of the protective layer before and after annealing were almost the same, but no abnormality was found in the groove shape even when the annealing temperature was 110 ° C. or higher. That is, the annealing treatment effect was sufficiently exhibited, and the high-temperature treatment also had the effect of shortening the treatment time.

Further, in each of the above-mentioned embodiments, the form provided with the dielectric film is exemplified, but the manufacturing method of the present invention is effective regardless of the presence or absence of the dielectric film. Further, the manufacturing method of the present invention enhances the reliability of the optical information recording medium by completely curing the protective layer, and at the same time, it is unavoidably caused through the steps of forming and / or initializing the recording thin film layer and the protective layer. Since it is a technology that can reduce warpage and distortion, it does not matter whether the material such as the recording thin film layer, the dielectric layer or the substrate is
Of course, there is no change in the effect.

Next, another embodiment for reducing the warpage and distortion of the medium generated through the step of forming the protective layer and the initial crystallization step, which is the third object of the present invention, will be described.

In this example, on a polycarbonate substrate having a diameter of 130 mm and a thickness of 1.2 mm, a ZnS-SiO ₂ film having a thickness of 170 nm was used as a subbing dielectric layer, and a Ge ₂ Sb ₂ Te ₅ film having a thickness of 25 nm was used as a recording thin film layer. A 40 nm-thick ZnS—SiO ₂ (SiO ₂ :
20 mol%) film, AlCr with a thickness of 80 nm as a reflective layer
(Cr: 3 atom%) films were sequentially formed by a sputtering method, and a plurality of disk media prepared by spin-coating an acrylic ultraviolet curable resin with a thickness of about 20 μm on the uppermost layer were prepared. Was done.

The disk medium A was irradiated with a mercury lamp as it was (in the state where no correction force was applied) to cure the ultraviolet curable resin, and was initialized by the flash method.
Incidentally. For initialization by flash, the discharge circuit shown in FIG. 14 was used, and exposure irradiation was performed by causing a xenon discharge tube to discharge and emit light.

The disk medium B was irradiated with ultraviolet rays to cure the resin layer, and then flash initialization was carried out while applying a correction force 61 to the state where the substrate surface 47 became concave as shown in FIG. .

After the disk medium C was irradiated with the ultraviolet ray 60, it was placed in an oven at 100 ° C. while being applied with a correction force 61 as in the case of the disk medium B and annealed for 1 hour. Was removed and flash initialization was performed.

The disk medium D was irradiated with the ultraviolet ray 60 and then subjected to annealing and flash initialization by applying the correction force 61 similarly to the disk medium C. The disc medium E was irradiated with a mercury lamp while applying the correction force 61 from the beginning to cure the ultraviolet curable resin. After that, without performing annealing, flash initialization was performed with the correction force 61 removed.

The disk medium F was irradiated with ultraviolet rays as in the case of the disk medium B, and then placed in an oven at 100 ° C. with the above-mentioned correction force 61 applied thereto and annealed for 1 hour. Flash initialization was performed in the removed state.

The disk medium G was subjected to ultraviolet irradiation and flash initialization under the condition that the above-mentioned correction force 61 was applied. The warp amounts of the respective disk media A to G were compared and evaluated by the warp angle shown in FIG. The results are shown in Table 4. In the table,
The “warp amount” is defined by the warp angle, which is the size of the warp applied by the correction force, and the “warp” indicates the result of measuring the actual warp angle after each step. Also, "No"
Means that each step is simplified or omitted as shown in the table. Further, in the table, mathematical signs of "+" indicate that the substrate surface is convex, and signs of "-" indicate that it is concave. Some of the tests were performed multiple times, but this is because the magnitude of the applied force was adjusted and the amount of warpage was adjusted. Considering the ease of manufacturing,
The maximum amount of warpage was 5 milliradians. However, finally, if it is about 7 milliradians or less, it is a practical level.

[0158]

[Table 4]

From the results shown in Table 4, in the case of A, B, and E in which the annealing process after curing the ultraviolet curable resin was omitted, the ultraviolet curable resin was not initialized after initialization regardless of the condition of the ultraviolet light irradiation. A large warp that the layer became concave occurred.

On the other hand, when ultraviolet rays are irradiated, no particular correction is made,
In the case of C and D where a force is applied so that the substrate surface becomes concave during annealing, and in the case of F where a correction force is applied during the ultraviolet irradiation process and the annealing process, the correction force is applied through the ultraviolet irradiation process, the annealing process, and the initialization process. In any of the cases of added G, the warp amount became extremely small, and it was found that it is very effective to perform the annealing treatment while applying the correction force.

Servo characteristics were examined by actually mounting each of the above disks on a deck. Disk rotation speed is 1800 rpm
And When the laser wavelength was 780 nm and the NA of the objective lens was 0.55, focusing and tracking were good for C, D, F, and G disks, but
Focusing was difficult with A, B, and E.

As a method of annealing, there is a method of putting the whole disk medium in an oven, but as shown in FIG. 16, a method of heating with an infrared ray 63 using an infrared lamp 62 can heat at high speed. It was convenient in terms. Regarding C, D, F, and G of the above-mentioned embodiment, the annealing by the infrared lamp 62 was tried, but the same result was obtained.

Since the gist of the present invention is a manufacturing method in which a correction force is applied at least in the ultraviolet curing step and the initialization step of the protective layer in a direction for correcting the warp, a phase change that requires initial crystallization. If it is an optical recording medium, it is already shown in FIG.
Any of the media described in 0 can be applied.

A fourth example of the present invention, which is a fourth example of the structure of a double-sided medium in which the number of manufacturing steps is reduced, and an example showing the manufacturing steps will be described. FIG. 17 is a sectional view showing the structure of one embodiment of the double-sided optical information recording medium of the present invention. In this embodiment, a ZnS—SiO ₂ film having a thickness of 90 nm is used as the first dielectric layer 65 and a Ge ₂ Sb film having a thickness of 30 nm is used as the recording thin film layer 66 on a transparent substrate 64 made of polycarbonate and having a thickness of 1.2 mm. ₂ Te ₅ alloy thin film layer, Z having a thickness of 154 nm as the second dielectric layer 67
nS-SiO ₂ film, metal reflection layer 68 having a thickness of 10 nm
Of two single-plate optical recording members 70 each of which is formed by laminating Au thin film layers by sputtering, and a resin containing an ultraviolet-sensitive component (hereinafter, referred to as “ultraviolet curable resin”) with the film sides inside each other. To form the adhesive layer 69,
Pasted together

The transmittance through the single plate optical recording member was about 5% in the vicinity of the wavelength (250 to 350 nm) of the mercury lamp used for curing the ultraviolet curable resin. However, the material of the transparent substrate 64 may be PMMA or glass, for example, in addition to the above polycarbonate. The materials for the first dielectric layer and the second dielectric layer include, for example, SiO ₂ and Ta in addition to the above ZnS-SiO _2.
It may be an oxide-based dielectric such as ₂ O ₅ or a nitride such as SiN or AlN. Further, as the material of the recording thin film layer 66, for example, an In-Sb-Te based phase change material may be used. In any case, the material constituting the double-sided optical information recording medium of the present invention is not limited.

FIG. 18 is a process chart showing a bonding process of the double-sided optical information recording medium in the embodiment of the present invention. On the transparent substrates 71 and 72 made of polycarbonate, thin films 73 and 74 that form recording layers are formed in multiple layers to form an optical recording member 70.

First, as shown in step (a), the substrates 71 and 72 are opposed to each other with the surfaces having the thin films 73 and 74 formed inside. The space between the thin films 73 and 74 may be appropriate, but about 3 mm is appropriate. Next, as shown in step (b), an ultraviolet curable resin 75 is injected into this space. After the injection, when the substrate 71 and the substrate 72 are brought into close contact with each other and integrated, the ultraviolet curable resin 75 spreads over the entire surfaces of the thin films 73 and 74 as shown in step (c). In addition to the above-mentioned adhesion method, for example, the substrates 71, 7
If 2 is rotated, uniform application of the ultraviolet curable resin is promoted, which is preferable. UV curable resin 7 as in step (c)
When 5 is uniformly applied and then the ultraviolet rays 76 are irradiated from the substrate 72 side, about 5% of the irradiated ultraviolet rays 76 reach the ultraviolet curable resin 75 as shown in step (d), and the ultraviolet curable resin is cured. To do. Through the above steps, the substrate 71 and the substrate 72 are integrated, and the double-sided optical information recording medium can be manufactured.

Although FIG. 18 shows the case where ultraviolet rays are radiated only from one side (substrate 72 side) of the transparent substrate of the optical information recording medium, this irradiation is performed on each transparent substrate 7.
It may be performed simultaneously from both sides of Nos. 1 and 72. In this case, since the curing of the ultraviolet curable resin 75 is promoted from both sides, the double-sided optical information recording medium can be bonded in a shorter time.

The ultraviolet transmittance of the optical recording member of the optical information recording medium of the present invention is shown in FIG. 17 even when it is composed of only the recording thin film layer and the metal reflection layer. Even when the recording layer is sandwiched between two dielectric layers and the metal reflection layer is provided on one of the dielectric layers, the material and the film thickness of the metal reflection layer are both determined. Dependent. Therefore, in order to control the ultraviolet ray transmittance in the sensitive wavelength region of the present invention, the ultraviolet ray transmittance is set mainly by controlling the material of the metal reflective layer and the film formation of the reflective layer.

As the material of the metal reflection layer, Al,
In addition to pure metal materials such as Cr, Ag, Cu, Ni, and Au, alloy materials with other metal materials, etc. can be applied. It can be achieved if it is in the range of up to 50 nm, but Au _100-x M _x (where M is a metal element forming the alloy) is particularly preferable when Au or an alloy containing Au as a main component, that is, 199> x ≧ 0. It is preferable because it is easy to satisfy both the reflectance, the ultraviolet ray and the transmittance.

Although the material and / or the film thickness of the metal reflective layer is the main factor as described above, there is also a contribution from the film thickness of the transparent substrate, the recording thin film layer or the dielectric layer,
It may occur that the film thickness needs to be appropriately selected depending on the materials used for these. Generally, 3% in the UV wavelength range
If it is above the above level, it is satisfactory.

However, in the case where the recording thin film layer is applied with the change in the optical characteristics caused by the phase transition between the amorphous phase and the crystalline phase, it is generally in the amorphous state when the recording thin film layer is formed. It is necessary that the ultraviolet transmittance of the recording thin film layer in the amorphous state is approximately 3% or more.

Therefore, the transmittance of the double-sided optical information recording medium bonded in the above process and the degree of curing of the ultraviolet curable resin were evaluated. The ultraviolet transmittance of the double-sided optical information recording medium was set to 0%, 1%, 2%, 3% and 5% by changing the film constitution of the thin films 73 and 74.

The thin films 73 and 74 of the double-sided optical information recording medium having a transmittance of 0% are composed of a ZnS—SiO ₂ (SiO ₂ : 20 mol%) film having a thickness of 70 nm on the transparent substrates 71 and 72. , A 25 nm thick Ge ₂ Sb ₂ Te ₅ alloy thin film, a 45 nm thick ZnS—SiO ₂ (Si 0 ₂ : 20 mol%) film, and a 90 nm thick AlCr (Cr: 3 atom%) structure. .

Further, the transmittance is 1%, 2%, 3%, and 5
%, The thin films 73 and 74 of the double-sided optical information recording medium are composed of transparent substrates 71 and 72 on which ZnS- having a thickness of 92 nm is formed.
Si0 ₂ (SiO _2: 20 mol%) film thickness 20~40n
Ge ₂ Sb ₂ Te ₅ alloy thin film of about m, ZnS—SiO ₂ (SiO ₂ : 20 mol%) film of 160 nm in thickness, thickness 5 to 5
The structure was such that an Au film of about 30 nm was formed, and the transmittance was adjusted by changing the film thickness of the alloy thin film and the Au reflective layer. The results are shown in Table 5.

[0176]

[Table 5]

As shown in Table 5, ultraviolet rays were radiated to try to bond the double-sided optical information recording medium having the above-mentioned transmittance of 0% to try to cure the ultraviolet-curing resin, but it could not be cured. Next, when the double-sided optical information recording medium having a transmittance of 1% was attached, an attempt was made to irradiate it with ultraviolet rays to cure the ultraviolet curable resin. Even if the ultraviolet rays were continuously irradiated as described above, the curing was not promoted and was insufficient. Also, the ultraviolet transmittance is 2
%, When the double-sided optical information recording medium was laminated, an attempt was made to irradiate it with ultraviolet rays to cure the ultraviolet-curable resin. The ultraviolet-curable resin was cured, but it took about 10 minutes for irradiation. This curing time was insufficient because a tact time of about 2 to 3 minutes was required to manufacture today's double-sided optical information recording medium.

On the other hand, when the double-sided type optical information recording medium having an ultraviolet transmittance of 3% was attached, an attempt was made to irradiate it with ultraviolet rays to cure the ultraviolet curable resin. Cured. Further, when UV irradiation was performed from both sides of the double-sided optical information recording medium, the UV curable resin was cured in about 2 minutes.

Finally, when a double-sided optical information recording medium having an ultraviolet transmittance of 5% was attached, ultraviolet rays were radiated from one side of the double-sided optical information recording medium to try to cure the ultraviolet curable resin. The UV curable resin cured in less than 1 minute.

From the above, when the double-sided optical information recording medium is bonded with the ultraviolet curable resin, the thin films 73, 7
The ultraviolet transmittance of 4 is recommended to be 3% or more in view of the relationship between the curing degree and the tact time.

The bonding strength of the double-sided optical information recording medium thus prepared was evaluated. The evaluation method was a drop test and high temperature and high humidity. In the drop test, the double-sided optical information recording medium is inserted into a cartridge used for recording / reproducing of this recording medium, and the height of the cartridge is set to 7
It dropped from 5 cm onto the concrete surface 6 times. As a result, in the double-sided optical information recording mediums with the transmittances of 3% and 5%, no abnormality was observed without peeling of the bonded and bonded portions. In addition, 2% of the products had no abnormality up to the fourth time, and a part was peeled off at the fifth time.

A double-sided optical information recording medium is
When left in an atmosphere of 80 ° C. and 80% RH for 300 hours and taken out, the double-sided optical information recording medium having transmittances of 3% and 5% did not show peeling of adhesion or cracks. Two
% Was normal for up to 100 hours, but 300
Some peeling was seen after a while.

Next, the prepared double-sided optical information recording medium was initialized. Initialization generally means that in the above-mentioned amorphous-crystal phase change optical information recording medium, the recording direction is changed from crystal to amorphous, so that the recording thin film is converted into a crystalline state in advance on the premise of recording. It means that things are stored.

As the initialization method, the two methods described above were tried. That is, for example, JP-A-60-1060
The method of sequential processing by a laser beam disclosed in Japanese Patent No. 31 is used. That is, using a laser with a much higher output than the laser diode used for recording and reproducing,
A light spot having a width of several 100 μm is formed. By irradiating this light spot while sending the medium at a constant speed,
It is possible to crystallize many tracks at once with one operation.

Further, for example, a method proposed in Japanese Patent Application No. 62-250533 and the like, in which flash light using a xenon lamp is used to collectively crystallize the entire disk surface in a short time, is used.

Initialization is carried out by the above two methods, and the double-sided optical information recording medium which has been pasted with a hot-melt adhesive, and the UV-curable resin shown in FIG. 17 of this embodiment are pasted. The initialization state of the combined double-sided optical information recording medium was compared.

When initialized by the laser beam, no abnormalities such as cracks, scratches or peeling were observed on both disks, and the initialization was excellent. In addition, when initialized with flash light, in the double-sided optical information recording medium bonded with a hot melt adhesive, slight peeling, wrinkles,
Or, there were cases where cracks were observed at several places, but in the double-sided optical information recording medium of the present invention as shown in, for example, FIG. 17, no abnormality such as scratches, cracks or peeling was observed.

Next, the initialized double-sided optical information recording medium of FIG. 17 was mounted in a recording / reproducing apparatus, and recording / reproducing evaluation of the disc was performed. A disk was driven at a linear velocity of 27 m / s and a laser having a wavelength of 780 nm (aperture ratio: NA = 0.5
5) was binary-modulated (peak power 24 mW, bias power 12 mW), and a signal with a recording frequency f1 = 18 MHz and a signal with a recording frequency f2 = 6.75 MHz were alternately recorded by overwrite.

The carrier-to-noise ratio of f1 (hereinafter referred to as "C
/ N ”), the erasing rate was measured, and it was found that a C / N of 52 dB and an erasing rate of 26 dB were obtained, and initialization was performed without problems. Also, overwriting was recorded repeatedly, but the initial signal quality was maintained,
No deterioration of C / N or erasing rate was observed.

As described above, in the optical information recording medium of the present invention, the ultraviolet curable resin is applied as the adhesive layer material, and the constitution of the recording layer having a multi-layered structure is devised so that it is approximately 3 in the sensitive light wavelength range of the ultraviolet curable resin. When the film thickness of each layer is selected so as to have a transmittance of at least%, and ultraviolet rays are irradiated, the ultraviolet curing resin is cured by the ultraviolet rays that have passed through the recording layer of the multi-layered structure, and the double-sided optical type is used in a short time and in a small number of steps. An information recording medium can be manufactured.

In the above embodiment, the case where the two bonded optical recording members have the same specifications has been described, but the essence of the present invention is that the ultraviolet transmittance of at least one of the optical recording members is approximately 3%. %, The optical recording member on one side of the double-sided optical information recording medium may be a read-only one represented by a CD or a CD-ROM. Further, for example, one of the optical recording members may be composed of only the recording thin film layer and the metal reflection layer, and the material of the dielectric layer, the recording thin film layer and the metal reflection layer of each of the two optical recording members. As a matter of course, the configuration may be changed and / or the film thickness may be changed.

Further, as the resin for adhering the optical recording member of the present invention, it is sufficient that it contains at least a UV-sensitive curing component, that is, even if it is mixed with a conventional hot melt adhesive or the like, Of course, the effect is exhibited.

[0193]

As described above, according to the present invention, a recording layer having a multi-layered structure including a recording thin film layer that causes a phase change between crystal and amorphous, and an ultraviolet curable resin on the recording layer are provided on a substrate. In the manufacturing process of the optical recording member having the structure including the protective layer of the cured film, the flash exposure device equipped with a shutoff circuit for forcibly stopping the flash emission is applied to the initialization process to obtain the amorphous phase. -The phase-change type optical information recording medium between crystal phases can be initialized at high speed, and at the same time, it is possible to reduce the thermal damage due to the initialization. At this time, it is possible to suppress wasteful discharge from the capacitor that accumulates the energy of flash emission, so that it is possible to shorten the time until the next charging is completed and shorten the tact of the initialization process by the flash method.

In the manufacturing process, a circuit for holding the difference between the voltage between the terminals of the main capacitor and the applied voltage at a predetermined value or more is introduced to complete the charging of the capacitor storing the energy of flash emission. It has become possible to shorten the time and further shorten the time required for the initialization process.

In addition, in the manufacturing process, after applying the resin containing the ultraviolet curable resin, a correction force is applied to the substrate surface of the optical recording member opposite to the substrate surface on which the recording layer and the protective layer are provided. By irradiating with ultraviolet rays while adding, it became possible to prevent warpage and distortion that occur in the flash initialization process in advance.

In the manufacturing process, after the flash initial crystallization process is completed, an annealing process that also serves as a warping or distortion correcting process is performed to significantly reduce the warping or distortion and to completely cure the protective layer. It has become possible to improve the servo characteristics, the reliability of the protective layer, and the manufacturing yield.

Further, in the above manufacturing process, by setting the ultraviolet transmittance of the optical recording medium to 3% or more, the number of manufacturing steps of the double-sided structure suitable for flash initialization is reduced, and the production efficiency is improved. It became possible to do.

[Brief description of drawings]

FIG. 1 is a diagram showing a main configuration in one embodiment of an initialization device having a cutoff circuit applied to an initialization method of the present invention.

FIG. 2 is a diagram for explaining the operation principle of the interruption circuit unit 10 used in the initialization device of the present invention.

FIG. 3 is a diagram showing a result of observing a light emission waveform of flash light with an oscilloscope in the flash initialization device of the present invention. A A light emission waveform diagram in the case of discharge light emission without using the interruption circuit of the present invention B The interruption of the present invention Light emission waveform diagram when the circuit is activated 2 ms after the start of light emission C Light emission waveform diagram when the circuit of the present invention is activated 1 ms after the start of light emission D The interruption circuit of the present invention is activated 0.5 ms after the start of light emission Waveform diagram of light emission

FIG. 4 is a cross-sectional view showing an example of the configuration of an optical disk medium which is subjected to an initial crystallization treatment by applying the initialization method of the present invention. A A cross-sectional view showing an example of a slow cooling configuration B B An example of a rapid cooling configuration Cross section

FIG. 5 is a configuration of an initialization device according to an embodiment of the present invention, in which a function for shortening charging time is added.

FIG. 6 is a diagram showing a relationship between a charging time and a charging voltage when the main capacitor for storing the light emission energy of the flash lamp is charged in one embodiment of the initialization device of the present invention.

FIG. 7 is a diagram for explaining a circuit configuration in a conventional initialization device.

FIG. 8 is a diagram for explaining a process of charging time and charging voltage to a main capacitor in a conventional initialization device.

FIG. 9 is a process drawing of an example of a method for manufacturing an optical information recording medium of the present invention.

FIG. 10 is a diagram showing a cross-sectional configuration of a configuration example of a phase-change recording medium. A A cross-sectional diagram in the case of a disc structure having a single-plate structure.

FIG. 11 is a first method of manufacturing an optical information recording medium of the present invention.
FIG. 4 is a diagram showing an example of a process of performing annealing using a disk fixing jig in the embodiment. (A) Configuration example in which the inner peripheral portion is fixed (B) Configuration example in which the outer peripheral portion is fixed (C) Inner peripheral portion And an example of the structure in which the outer peripheral portion is fixed separately (D) A structure in the case of fixing so as to have a warp in the opposite direction to that before the annealing step

FIG. 12 is a first method of manufacturing an optical information recording medium of the present invention.
Configuration diagram showing an example of a method for annealing a large number of discs at once using a disc fixing jig in Examples

FIG. 13 is a diagram for explaining a warp angle measuring method applied in the present invention.

FIG. 14 is a circuit diagram showing an embodiment of a discharge circuit used for flash initialization in the manufacturing process of the method for manufacturing an optical information recording medium of the present invention.

FIG. 15 is a process diagram of an example in which flash irradiation is performed while correcting the substrate surface to be a concave surface in the manufacturing process of the method for manufacturing an optical information recording medium of the present invention.

FIG. 16 is a schematic configuration diagram of an example in which an annealing step is performed using an infrared lamp in the manufacturing process of the method for manufacturing an optical information recording medium of the present invention.

FIG. 17 is a diagram in which an ultraviolet curable resin is used for the adhesive layer,
Sectional drawing which shows the structure of one Example of the double-sided optical information recording medium of this invention.

FIG. 18 is a schematic process diagram showing an embodiment of a process for manufacturing the double-sided optical information recording medium of the present invention (1) Process diagram of facing transparent substrates (2) Process diagram of injecting UV curable resin (3) Process drawing for uniformly applying UV curable resin (4) Process drawing for UV irradiation

[Explanation of reference numerals] 1 recording thin film layer 2 substrate 3 optical information recording medium 4 flash light beam 5 switch circuit section 6 support base 7 flash light source 8 storage circuit section 9 trigger circuit section 10 cutoff circuit section 11 reflector plate 12 power supply 13 trigger electrode 14 Undercoat Dielectric Layer 15 Overcoat Dielectric Layer 16 Reflective Layer 17 Protective Layer 18 Optical Recording Medium 19 Support 20 Flash Lamp 21 Main Capacitor 22 Voltmeter 23 Power Supply 24 Setting Circuit 25 Changeover Switch 26 Relay 27 Trigger Coil 28 Trigger Capacitor 29 control means 30 charging resistance 31 flash lamp 32 main condenser 33 power supply 34 trigger coil 35 discharge switch 36 changeover switch 37 resistance 38 optical information recording medium 39 optical information recording medium 40 substrate 41 first dielectric layer 42 recording thin film layer 43 second dielectric layer 44 reflection layer 45 protective layer 47 substrate surface 48 protective layer surface 49 adhesive (hot melt) 50 flat surface 51 copper plate 52 disk medium 53 screw 54 inner peripheral portion 55 outer peripheral portion 56 units 57 screws 58 units 59 weight 60 correction force 61 ultraviolet ray 62 infrared lamp 63 infrared ray 64 transparent substrate 65 first dielectric layer 66 recording thin film layer 67 second dielectric layer 68 metal reflective layer 69 adhesive layer (UV curing) Resin layer) 70 Optical recording member 71 Transparent substrate 72 Transparent substrate 73 Thin film 74 Thin film 75 UV curable resin 76 UV light

Continuation of front page (31) Priority claim number Japanese Patent Application No. 6-233830 (32) Priority date Hei 6 (1994) September 28 (33) Priority claiming country Japan (JP) (31) Priority claim number Special Heihei 6-236748 (32) Priority date Hei 6 (1994) September 30 (33) Priority claiming country Japan (JP)

Claims (36)

[Claims] 1. An optical information recording medium having a recording thin film layer that causes a phase change between crystal and amorphous on a substrate is irradiated with flash light, and a predetermined portion of the recording thin film is collectively in an initial state. A method of converting to a crystalline state, the step of supporting the optical information recording medium at a predetermined position, the step of charging the storage circuit section with electric energy supplied to the flash light source, and the trigger of the flash light source. Starting the light emission, and after continuing the light emission for a predetermined time, the cutoff circuit unit connected to the flash light source is activated to forcibly and instantaneously end the discharge to substantially reduce the light emission intensity. And a step of lowering the optical information recording medium to a zero level. 2. The discharge time is set to a maximum of 2 milliseconds.
The method for initializing the optical information recording medium according to 1. 3. The method for initializing an optical information recording medium according to claim 1, wherein the recording thin film layer is a thin film containing a Ge—Sb—Te alloy as a main component. 4. An optical information recording medium having a recording thin film layer that causes a phase change between crystal and amorphous on a substrate is irradiated with flash light, and a predetermined portion of the recording thin film is collectively in an initial state. An apparatus for converting to a crystalline state, comprising: a base portion for supporting the optical recording medium; a light source for emitting flash light by discharge; a storage circuit portion for storing electric energy supplied to the light source; A trigger circuit unit for starting discharge of the light source, and a shutoff circuit unit for forcibly interrupting the discharge after a predetermined light emission time and instantaneously reducing the intensity of light emission from the predetermined intensity to an effective zero level. A device for initializing an optical information recording medium, comprising: 5. An optical recording medium provided with a recording thin film which causes a phase change between a crystalline state and an amorphous state on a substrate is irradiated with flash light, and a predetermined region of the recording thin film is collectively initialized. Is a device for converting to the crystalline state, a means for supporting the optical recording medium, a light source for irradiating flash light by discharge, a storage means for storing energy to be supplied to the light source, and a storage means. Supplying means for sending energy to the storage means, discharge starting means for starting discharge of the light source, accumulated amount detecting means for detecting the amount of energy accumulated in the accumulating means, and supplying energy for the supplying means. The supply amount setting means for setting the amount, and the supply amount set by the supply amount setting means according to the detected amount detected by the accumulated amount detecting means reaches the energy of the accumulating means. Alternatively, the supply means is controlled so as to be larger than one of the specified values of the reached amount, and when the energy amount of the storage means reaches a predetermined value, the supply of energy from the supply means to the storage means is performed. An initialization device for an optical recording medium, comprising: a switching means for shutting off, and a control means for controlling the light source to emit light by a discharge starting means. 6. A voltage value of the energy supply amount of the supply means and an energy storage amount of the storage means is detected, and the voltage value of the supply means is made higher than the voltage value at the time of completion of the storage of the storage means. Item 6. An optical recording medium initialization device according to item 5. 7. The energy supply amount of the supply means and the energy storage amount of the storage means are detected by voltage values, and the difference between the voltage value of the supply means and the reached voltage value of the storage means is substantially constant. An optical recording medium initialization device according to item 1. 8. A structure including a recording layer having a multilayer structure including a recording thin film layer that causes a phase change between crystal and amorphous on a substrate, and a protective layer of a cured film containing an ultraviolet curing resin on the recording layer. A method of manufacturing an optical recording member of, wherein after providing the ultraviolet curing resin film, a correction force is applied to a substrate surface facing the substrate surface provided with the recording layer and the protective layer of the optical recording member. A method of manufacturing an optical information recording medium, which further comprises an ultraviolet irradiation step of irradiating an ultraviolet ray while additionally performing an initial crystallization step performed after the completion of the ultraviolet irradiation step. 9. Between the ultraviolet light irradiation step and the initialization step,
9. An annealing step of heating an optical recording medium is performed.
A method for manufacturing the optical information recording medium according to 1. 10. The method for manufacturing an optical information recording medium according to claim 9, wherein the annealing step is performed in a state where a correction force is applied. 11. The method for manufacturing an optical information recording medium according to claim 9, wherein the heat source in the annealing step is irradiation with an infrared lamp. 12. The method of manufacturing an optical information recording medium according to claim 8, wherein the initialization step is performed in a state where a correction force is applied. 13. The method for manufacturing an optical information recording medium according to claim 8, 9 or 12, wherein the initialization step is performed by flash light irradiation. 14. An optical information recording medium comprising a recording thin film layer for causing a phase change between crystal and amorphous on a substrate, and a protective layer formed by curing a curable resin containing an ultraviolet curable resin on the uppermost layer. The method for manufacturing an optical information recording medium, wherein the protective layer is completely cured by performing an annealing step after the completion of the initial crystallization step. 15. An optical information recording medium is constituted by laminating a first dielectric layer, a recording thin film layer, a second dielectric layer and a reflective layer on a substrate, and providing a protective layer on the uppermost layer. 15. The method for manufacturing an optical information recording medium according to claim 14, wherein. 16. The method for manufacturing an optical information recording medium according to claim 14, wherein the recording thin film layer is an alloy thin film containing Ge—Sb—Te as a main component. 17. The manufacturing of an optical information recording medium according to claim 14, wherein in the annealing step, a process of correcting the optical information recording medium to a warp-free state or a process of applying an external force in a direction of correcting the warp is performed. Method. 18. In the annealing step, the outer peripheral portion of the optical information recording medium is supported on a stand having a hole having a diameter slightly smaller than the outer diameter of the optical information recording medium having a disk shape, and In the state where the center of the optical information recording medium is aligned with the center of the hole, the optical information recording medium is held so that the convex surface of the optical information recording medium faces upward, and the optical information The recording medium is convex in the opposite direction,
Alternatively, the center portion of the optical information recording medium is weighted or fixed so as to be flat.
The method for manufacturing an optical information recording medium according to 4 or 17. 19. The optical information recording according to claim 14 or 17, wherein a straightening treatment is performed in the annealing step, and at least one of the substrate surface and the protective layer surface is left in a state of lying on a smooth surface. Medium manufacturing method. 20. A straightening process is performed in the annealing step, and at least one of the innermost peripheral portion and the outermost peripheral portion of the substrate surface or the protective layer surface is pressed against an object having a flat surface. Of manufacturing the optical information recording medium of. 21. The flat surface is one surface of an object having heat resistance equal to or higher than the temperature of the annealing step, and the optical information recording medium is placed on the flat surface of the object previously heated to a predetermined temperature. 21. A method for manufacturing an optical information recording medium according to item 19 or 20. 22. In a state where a plurality of optical information recording media having a single plate structure are stacked by performing a straightening process in an annealing process,
The method for manufacturing an optical information recording medium according to claim 14, 17 or 20, wherein a force is applied from both sides. 23. The annealing step is performed at a temperature not higher than a temperature at which a phase change of the recording thin film layer occurs.
Item 3. The method for producing an optical information recording medium according to any one of items 2. 24. The method for manufacturing an optical information recording medium according to claim 23, wherein the temperature of the annealing step is 100 ° C. or lower. 25. The method for manufacturing an optical information recording medium according to claim 14, wherein the initial crystallization step is performed by flash exposure. 26. An optical system in which two optical recording members each having a multi-layered film including a recording thin film layer and a metal reflection layer, which produce an optically detectable change upon irradiation with a laser beam, are attached on a transparent substrate. In the information recording medium, the two optical information recording members are made to face each other with the multilayer structure film inside, and the two optical information recording members are interposed via a resin containing a component that cures in response to ultraviolet rays. Optical information recording member, at least one of the two optical recording members has a transmittance of approximately 3% or more in the ultraviolet sensitive wavelength range of the resin. . 27. The recording thin film layer comprises an amorphous phase-
It utilizes the change in optical characteristics due to the phase change phenomenon between crystal phases, and when at least one recording thin film layer of the two optical recording members is in an amorphous state, the ultraviolet sensitive wavelength of the resin 27. The optical information recording medium according to claim 26, which has a transmittance of about 3% or more in the range. 28. The optical information recording medium according to claim 26, wherein the metal reflection layer is an alloy Au _100-x M _x (M is a metal element, 100> x ≧ 0) containing Au as a main component. 29. Two optical recording members comprising a transparent substrate and a multi-layer structure film including a recording thin film layer and a metal reflection layer which produce a change optically detectable by irradiation of a laser beam, A manufacturing method comprising a step of laminating using a resin containing a sensitive curing component, wherein the multilayer structure film of at least one of the two optical recording members is approximately 3% in an ultraviolet sensitive wavelength range of the resin. A film forming step of forming a film having the above-mentioned transmittance, an arranging step of arranging the two optical recording members so that surfaces on which the multilayer structure film is formed face each other, and the facing multilayer structure film. A method of manufacturing an optical information recording medium, comprising: a filling step of filling the space with the resin; and an exposure step of curing the resin by exposure to ultraviolet light. 30. The method for manufacturing an optical information recording medium according to claim 29, wherein the exposure is performed from both sides of the optical recording member. 31. The optical information recording medium is irradiated with energy rays for initialization after the exposure step.
0. The method for manufacturing the optical information recording medium described in 0. 32. The method for manufacturing an optical information recording medium according to claim 31, wherein the energy beam is a laser beam. 33. The method for manufacturing an optical information recording medium according to claim 31, wherein the energy beam is flash light. 34. The optical information recording medium according to claim 26, wherein at least one of the two optical recording members is a read-only type. 35. The method for manufacturing an optical information recording medium according to claim 29, wherein at least one of the two optical recording members is a read-only type. 36. The optical information recording medium according to claim 8, wherein the optical information recording medium is arranged in a direction such that the warp is corrected by its own weight and the ultraviolet ray is irradiated. Production method.