JPH11110816A - Optical recording medium and formation of image - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a utilizing method for a phase transition material which forms an image by irradiating the phase transition material with light. SOLUTION: A sticking type phase transition optical recording medium 10 has a structure in which laminated bodies 20, 20' respectively incorporating phase transition type recording layers 3, 3' are stuck to each other so that substrates 1, 1' are arranged outsides. The image is preliminarily plotted in the recording layer of either one of the laminated bodies by utilizing the phase transition of the recording layer which is a recording principle. The image can be directly transferred (exposed) by using a mask pattern, etc., or can be plotted by using a laser light source. The formed image can be discriminated in accordance with the change of a color.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a phase change type optical recording medium, and more particularly, an image such as a label or a decorative figure is recorded in advance in at least one of the phase change type recording layers. And a method for recording an image on a phase change material by irradiating an optical recording medium on which a user can record text information on another recording layer.

[0002]

2. Description of the Related Art In recent years, optical recording media have become widespread as media for recording multimedia data such as moving images or audio. Among them, rewritable optical recording media capable of rewriting data have attracted attention. Rewritable optical recording media include magneto-optical recording media and phase-change optical recording media. Among them, the phase-change optical recording medium can use the same optical system as a CD-ROM, and unlike a magneto-optical disk, a magnetic head Therefore, there is an advantage that the drive structure can be simplified since recording can be performed without the need for a drive. The phase change optical recording medium is characterized in that a phase change material is used as a recording layer, and recording and erasing are performed by thermally reversibly changing a crystalline state and an amorphous state of the phase change material. Recently, in order to realize large capacity and high density, the thickness of the substrate has been reduced,
A phase change optical recording medium of a type in which a laminate including a recording layer is bonded is being put to practical use.

[0003]

However, a general method of using an optical recording medium using a phase-change material as a recording layer is to irradiate the recording layer with a laser beam to irradiate multimedia data such as audio and moving images. Or a way to record code information such as data on a database,
The difference between the reflectivity in the crystalline state and the reflectivity in the amorphous state, which is one of the characteristics of the phase change material, is merely used for recording and reproducing bit signals.

[0004] Further, in a laminated optical recording medium, a title label, a warning label, a maker logo, and the like are printed by screen printing or offset printing on a surface on which no recording is performed.

[0005] Also, a laminated optical recording medium in which information is recorded on only one side is known. This medium has a structure in which a laminated body in which a recording layer and a dielectric layer are laminated on a substrate and a dummy body composed of a single substrate are bonded. Here, since the dummy substrate is subjected to residual stress or the like at the time of injection molding, the substrate tends to warp vertically and horizontally. On the other hand, in a laminate formed by a sputtering method or the like, in addition to such a warp of the substrate, a warp due to a stress of a laminated film or a rise in temperature during sputtering occurs. For this reason, since the laminated body and the dummy body have different warpages at the bonding surface, even if the laminated body and the dummy body are bonded, the warpage cannot be corrected mutually.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an optical recording medium having at least one recording layer in which an image is formed in advance. Another object of the present invention is to provide a method of using a novel phase change material, which forms an image by irradiating the phase change material with light having a predetermined wavelength.

[0007]

According to a first aspect of the present invention, there is provided an optical recording medium having at least two phase-change recording layers, wherein at least one of the at least two recording layers is provided. An optical recording medium characterized in that an image is formed in advance by a change in the atomic arrangement of a recording layer due to light irradiation.

[0008] The optical recording medium according to the first aspect of the present invention comprises:
It has at least two phase-change recording layers, and at least one recording layer has an image that can be visually recognized or distinguished based on a change in hue, for example, characters, numerals, pictures, Marks, symbols, designs, decorative figures, patterns, patterns, serial numbers, lot numbers, labels, and the like are recorded in advance by changes in the atomic arrangement caused by light irradiation. Further, code information such as multimedia data such as sound and moving image and data of a database, which are usually recorded, can be recorded in at least one other recording layer.
That is, in the optical recording medium of the present invention, since the image is drawn in advance using the phase change of the recording layer, which is a recording principle, the process of forming an image such as a label becomes extremely simple. Further, the image formed by the phase change has a unique gloss and gives a novel impression to users and consumers.

The optical recording medium of the present invention is a bonded type phase change formed by laminating a pair of laminates including at least one phase change type recording layer on a substrate such that the substrate is on the outside. It can be an optical recording medium. In order to be suitable for a bonding type high-density optical recording medium, the thickness of each substrate is preferably 1 mm or less. In the case of forming a laminated type phase change optical recording medium, since an image is formed in advance on the recording layer of either one of the laminates, by using the other laminate as a layer on which information is recorded, The optical recording medium of the present invention can be used as a bonded type phase change optical recording medium in which information is recorded on only one side. Further, a single-sided bonded type phase change optical recording medium using a single transparent substrate as a dummy laminate that does not perform recording,
Comparing the warp of the medium with the laminated optical recording medium of the present invention, the warp of the optical recording medium of the present invention has been corrected because two identical laminates are laminated.

The optical recording medium of the present invention has a structure in which at least a phase-change recording layer, a dielectric layer, and a reflective layer are provided on a light-transmitting substrate, and the thickness of at least one of these layers is adjusted. By the color of the surface or image of the optical recording medium,
The hue, hue or hue can be changed. Any material can be used as the material of the recording layer as long as it is a phase change material. For example, Ge-Sb-Te system and Ag
-In-Sb-Te-based or Ge-Sb-Te-Co-based phase change materials can be used as the recording layer.

According to a second aspect of the present invention, there is provided a method for recording an image by irradiating a phase change material with light of a predetermined wavelength to change the atomic arrangement of the phase change material.

When the method according to the second aspect of the present invention is used, an optical recording medium using a phase change material as a recording layer is irradiated with a laser beam to change the atomic arrangement of the recording layer, that is, change the crystalline state and the amorphous state. By producing a phase change between the quality state and the image state, an image can be formed.

When an optical recording medium using a phase change material as a recording layer is irradiated with a laser beam to the recording layer in an amorphous state at such an intensity that the recording layer becomes higher than the crystallization temperature.
The portion of the recording layer irradiated with the laser beam changes phase to a crystalline state. Therefore, by irradiating the recording layer with laser light in accordance with images of characters, pictures, symbols, marks, patterns, designs, patterns, and the like, these images can be formed on the recording layer in a crystalline state. Since the light reflectance differs between the crystalline state and the amorphous state, a color change or light contrast occurs between the image-recorded portion and the unrecorded portion of the recording layer, and the recorded information is determined as visual information. Or can be recognized. Therefore, by using the above-described method, it is possible to easily form an image such as a label or a decorative figure on the disk surface, which has been conventionally applied to the disk surface by screen printing or the like.

In the present invention, an image is not a code information itself such as multimedia data such as a sound or a moving image or data on a database, but a character which can be visually distinguished or identified based on a change in hue. It is a concept that includes numbers, pictures, marks, symbols, designs, decorative figures, patterns, patterns, serial numbers, lot numbers, labels, and the like. Such an image can be formed by direct transfer (exposure) as an image using a mask pattern or the like, or by drawing using a laser light source. Alternatively, it may be formed by performing light irradiation using code information.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments and examples of the present invention will be specifically described with reference to the drawings.

Embodiment 1 FIG. 1 shows a schematic configuration diagram of an optical recording medium 10 according to the present invention. The optical recording medium 10 has a structure in which laminates 20 and 20 ′ including the phase change recording layers 3 and 3 ′ are bonded together via an epoxy resin adhesive 7. Hereinafter, a method for manufacturing the optical recording medium 10 having this structure will be described.

First, the laminate 20 shown in FIG. 2 was manufactured in the following procedure. Transparent substrate 2 made of polycarbonate resin
1 on a ZnS—SiO 2 first using a sputtering apparatus.
Dielectric layer 22, AgGeSbTe recording layer 23, ZnS-
The SiO2 second dielectric layer 24 and the AlTi reflection layer 25 were sequentially laminated. Next, the ultraviolet curable resin 2 is formed on the reflective layer 25.
6 was applied by spin coating. The transparent substrate 20 is a polycarbonate resin substrate molded by an injection molding method, the thickness of the substrate is 0.6 mm, the outer diameter is 120 mm,
The inner diameter was 15 mm, and the track pitch was 0.74 μm.

[0018] One set (2
0, 20 ′), and an epoxy resin-based adhesive (adhesive) 7 was applied on the ultraviolet curable resin film 6 of one of the laminates 20 by a printing method. The adhesive is applied in a donut shape concentric with the substrate 1, and its inner diameter is 0.1 m larger than the inner diameter of the substrate 1.
m, and the outer diameter is smaller than the outer diameter of the substrate 1 by 0.1 mm. Then, as shown in FIG. 1, the laminates 20 and 20 'are bonded to each other via the epoxy resin-based adhesive 7 such that the substrates 1 and 1' are disposed outside, thereby forming a phase change of a close bonding type. An optical recording medium 10 was manufactured.

[Measurement of Warpage of Optical Recording Medium] In order to measure the degree of warpage of the phase-change optical recording medium 10 thus obtained, the following measurement was performed. Phase change optical recording medium 10
Then, light was made incident from a direction perpendicular to the surface thereof, and an angle (optical tilt) formed between the incident light and the reflected light was measured.
The measurement result is 0.5 deg. , 0.2 deg. In the circumferential direction. It was below.

[Method of Forming Image] An image was drawn on the recording layer 3 by irradiating a laser beam from above the substrate 1 of the laminate 20 of the phase-change optical recording medium 10 obtained as described above. The method is described below.

First, the obtained phase change optical recording medium 10 is placed in an initialization device for initializing the phase change optical recording medium,
While rotating at a linear velocity of 12 m / s, the wavelength 810
Automatic focusing was performed using a semiconductor laser with a laser spot of about 2 × 48 μm in nm. In the automatic focusing, the intensity of the laser beam was kept to the extent that recording was not performed (about 150 mW), and the laser beam was focused on the recording film 3 by the lens in the initialization head. Adjustment was made so that the focal point came on the recording film 3 while detecting the reflected light from the recording film 3. While auto-focusing in this way, the laser beam is 520 m
The recording layer 3 was irradiated with the intensity modulated between W and 150 mW. The portion irradiated with the 520 mW laser light changed in reflectance and appeared to change in color. This is because the portion of the recording layer 3 irradiated with the laser beam having a laser beam intensity of 520 mW was heated to a temperature higher than the crystallization temperature, and the material constituting the recording layer changed its phase from an amorphous structure to a crystalline structure during the cooling process. It is considered to be. That is, when the 520 mW laser beam was irradiated to the optical recording medium which initially exhibited blue, the irradiated portion turned blue-white. By appropriately adjusting the modulation pattern of the laser light in accordance with the image, an image such as a desired character, picture, symbol, mark, pattern, figure, or pattern could be formed on the surface of the optical recording medium 10. .

Comparative Example 1 A phase-change optical recording medium was manufactured in the same manner as in Example 1, except that a transparent substrate having the same thickness as the laminate was used instead of the laminate 20 '. For this phase change optical recording medium, the warpage of the phase change optical recording medium was measured in the same manner as in Example 1. The measurement results show that the radial angle is 1.
0 deg. In the circumferential direction is 0.4 deg. Met. Comparing this result with the measurement result of the warpage of the phase change optical recording medium of Example 1, it is understood that the warpage of the phase change optical recording medium of Example 1 is corrected.

Embodiment 2 In Embodiment 1, an image is formed by a laser beam spot using a device used for initializing and recording / reproducing a phase change optical recording medium. A method of forming an image (bulk image) by irradiating light with a light source fixed to a light source will be described.

FIG. 3 shows an outline of the image forming method of this embodiment. The bonded type phase change optical recording medium 10 manufactured in the first embodiment is mounted on the mounting table 35, and the mask 33 and the light source 31 are disposed above the mounting table 35. In the mask 33, an opening pattern 33a corresponding to an image drawn on the phase-change optical recording medium 10 is formed in advance. A xenon lamp can be used as the light source 31. When the xenon lamp 31 is illuminated in the arrangement shown in FIG. 3, the phase change optical recording medium 10 is illuminated (exposed) by the light transmitted through the opening pattern 33a of the mask 33. The illumination time and the power of the xenon lamp 31 are adjusted such that the illuminated recording layer of the phase change optical recording medium is heated to a temperature exceeding the crystallization temperature. By irradiating light in this manner, the mask 33
An image 40 corresponding to the opening pattern 33a was formed on the phase change recording medium. Before the illumination (exposure), the surface of the phase change recording medium 10 exhibited a blue color, whereas the illuminated (exposed) portion of the image 40 turned blue-white.

In this embodiment, an optical element such as a lens is arranged between the phase change recording medium 10 on the mounting table 35 and the mask 33 to enlarge or reduce the opening pattern 33a. It can also be transcribed. Further, a pulse laser can be used as the light source 31 instead of the xenon lamp.

As described above, in the above embodiment, images such as characters, pictures, and marks are formed on the bonded type phase change optical recording medium by changing the atomic arrangement by light irradiation.
An image can also be formed in combination with screen printing or the like. For example, screen printing may be performed on a part of the film surface of the phase change optical recording medium, and an image may be formed on a part of the same or another film surface by an atomic arrangement change due to light irradiation. Also, screen printing using translucent ink or the like may be performed on the surface of the phase change optical recording medium on which an image is formed by the change in the atomic arrangement due to light irradiation.

In the above embodiment, an image is formed by irradiating the recording layer in the amorphous state with a laser beam to change the phase to a crystalline state. By irradiating a laser beam of power, an image can be formed by changing a phase to an amorphous state.

The method for forming an image is not particularly limited, and may be a method using ultraviolet irradiation and heating such as a xenon lamp or a mercury lamp, a method using light irradiation such as a flash lamp, a high power gas laser or a high power semiconductor laser. A method using irradiation with a light spot having a large diameter, a method using a combination of heating and laser light irradiation, and the like can be used.

Although the phase-change optical recording medium manufactured in this embodiment exhibited a blue color, the surface of the phase-change optical recording medium was adjusted by adjusting the thickness of the dielectric layer and the recording layer to take advantage of multiple interference of light. Color can be changed. For example, by setting the film thickness of the first dielectric layer to about 110 nm, the color of the surface of the disk can be made green. By doing so, the appearance of the phase change optical recording medium can be changed,
Further, the recorded image can be further decorated.

In this embodiment, a laminated type phase-change optical recording medium is manufactured by using a laminated body having the same laminated structure. However, as a dummy laminated body in which information is not recorded, the thickness and material of each layer are changed. A laminated type phase change optical recording medium may be manufactured by using different laminates.

[0031]

According to the optical recording medium of the present invention, since the image is drawn in advance by utilizing the phase change of the recording layer, which is the recording principle, the process of forming an image such as a label becomes extremely simple. Further, the image formed by the phase change has a unique gloss and gives a novel impression to users and consumers. In particular, if the optical recording medium of the present invention is applied to a laminated type phase change optical recording medium in which two laminates each having at least one phase change recording layer are laminated, the lamination on the side where an image is formed is obtained. It can be used as a bonded single-sided phase change optical recording medium with a body as a dummy body. Furthermore, the warp is reduced when comparing the bonded optical recording medium of the present invention, which is a bonded optical recording medium of a single-sided specification, in which a single transparent substrate is used as a dummy body, and a bonded optical recording medium. .

According to the present invention, an optical recording medium using a phase change material as a recording layer is irradiated with a laser beam to change the atomic arrangement of the recording layer, that is, the phase change between a crystalline state and an amorphous state. To form an image. The image formed on the recording layer causes a color difference or light contrast between the surface of the optical recording medium and the image recording portion from the difference in the reflectance between the crystalline state and the amorphous state,
The image can be determined or recognized as visual information.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a bonded type phase change optical recording medium according to the present invention manufactured in Example 1.

FIG. 2 is a cross-sectional view of a laminate constituting the phase-change optical recording medium of FIG.

FIG. 3 is a diagram illustrating an image forming method used in a second embodiment.

[Explanation of symbols]

 1, 1 ', 21 Substrate 2, 2', 22 First dielectric layer 3, 3 ', 23 Recording layer 4, 4', 24 Second dielectric layer 5, 5 ', 25 Reflective layer 6, 6', Reference Signs List 26 UV curable resin 7 Epoxy resin adhesive 10 Phase change optical recording medium 20, 20 'Laminate 31 Light source 33 Mask 33a Opening pattern 35 Mounting table 40 Image

Claims (7)

[Claims] 1. An optical recording medium having at least two phase-change recording layers, wherein an image is previously formed on at least one of the at least two recording layers by a change in the atomic arrangement of the recording layers due to light irradiation. An optical recording medium characterized by being performed. 2. The optical recording medium according to claim 1, wherein the image is an image visually recognizable based on a change in color of the phase change type recording layer. 3. A laminate comprising at least one layer of a phase-change recording layer on a transparent substrate having a thickness of 1 mm or less and being laminated to each other such that the substrate is on the outside. The optical recording medium according to claim 1. 4. An optical recording medium comprising at least one
The optical recording medium according to any one of claims 1 to 3, wherein the color of the image is changed by using a light interference effect by adjusting a film thickness of the layer. 5. A method of forming an image by irradiating a phase change material with light of a predetermined wavelength to change an atomic arrangement of the phase change material. 6. The method of claim 5, wherein the phase change material is irradiated with light of a predetermined wavelength through a mask on which the image pattern is formed. 7. The method according to claim 5, wherein the phase change material is a recording layer of a phase change type optical recording medium.