JPH0341642A - Production of optical recording medium - Google Patents

Abstract

PURPOSE:To produce the optical recording medium of a good dynamic balance with a simple stage without generating a recessed part in the outside shape by executing cutting by irradiation with light beams and increasing the cutting speed in the part where light beams intersect at the time when the optical recording medium is cut from an original plate. CONSTITUTION:Stuck substrates 1 are installed onto an X-Y stage 6 and cutting lines 3 intersect at an intersection point 5 like the cutting line 3 from a beginning point 7 to an end point 8 to cut the outside shape. Any outputs of the laser beams to be used for the cutting are usable if the outputs are in such a range where the end faces of the stuck substrates 1 are not melted by the cutting and adhesive agents do not melt and bleed to the outside. The cutting lines intersect at the intersection part and, therefore, the recessed part by the melting of the resin is liable to arise at the end part and since such recessed parts are generated more in the end part than in the non-intersection parts, the relative line speed is set higher than in the non-intersection part. The optical recording medium which is free from the recessed parts in the outside shape and has the good dynamic balance is produced by the simplified cutting stage in this way.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field 1] The present invention relates to a method for manufacturing an optical recording medium, and more particularly to a method for cutting a substrate of an optical recording medium for optically recording and reproducing information. BACKGROUND ART Conventionally, magnetic materials such as magnetic tapes and magnetic disks, various semiconductor memories, and the like have been mainly used to record various types of information. Such magnetic memories and semiconductor memories have the advantage that information can be easily written and read, but on the other hand, they have the problem that the information content can be easily tampered with and that high-density recording is not possible. Ta. In order to solve these problems, an optical information recording method using an optical recording medium has been proposed as a means to efficiently handle a wide variety of information, and an optical information recording carrier, a recording/reproducing method, and a recording/reproducing device for this purpose have been proposed. has been done. Such an optical recording medium as an information recording carrier is generally prepared by using a laser beam to evaporate a part of the optical recording layer on the information recording carrier, cause a change in reflectance, or cause deformation. Information is recorded or reproduced based on differences in optical reflectance and transmittance. In this case, the optical recording layer is a so-called DR, which does not require any development treatment after information is written, and can be "directly read after writing."
It is an AW (direct read after write) medium that allows high-density recording and additional writing, making it effective as an information recording and storage medium. FIG. 5 is a schematic cross-sectional view of a conventional optical recording medium. In the figure, 21 is a transparent substrate, 22 is a track groove, and 2
3 is an optical recording layer, 24 is a spacer/adhesive layer, and 25 is a protective substrate. In FIG. 5, information is recorded and read by optically writing and reading through a transparent substrate 21 and a track groove 22. At this time, tracking is performed using the phase difference of the laser beam using the fine irregularities of the track groove. I have made it possible for you to do so. In order to perform high-density recording and reproduction on write-once optical discs (WODs) such as those mentioned above, a predetermined pattern for tracking is molded when the substrate is molded, and alignment for recording and reproduction is performed. ing. Conventional methods for manufacturing optical discs have generally involved molding substrates in single sheets using methods such as injection and compression methods. On the other hand, molding the substrate by a method of forming a large number of patterns has the advantage that the time-consuming process of molding the substrate can be simplified. [Problems to be Solved by the Invention] However, when a board is molded using this large-sized multifaceted example, a process of cutting the outline of each pattern is required, and there is also the problem that the outside of each preformat pattern is distorted during molding. Therefore, it has become necessary to cut the pattern so that the distortion does not remain in the pattern. Conventionally used cutting methods include punching with a press and cutting with a cutter, but these methods tend to make the substrate thicker. With highly elastic resins such as polycarbonate, they bounce back, making it difficult to cut with precision. Therefore, cutting the substrate with a high-power laser beam is being practiced. However, with this laser cutting, more of the substrate melts at the point where the laser beams intersect, creating a depression, which deteriorates the processing accuracy of the external shape.As a result, the dynamic balance of the completed optical recording medium is insufficient. The problem is that it is difficult to obtain good media. Moreover, from a large substrate on which a multifaceted pattern is formed,
Since each cut pattern or disk falls off at the same time as cutting, each pattern must be clamped, resulting in a problem of poor workability. The present invention was made for the purpose of solving the above problems, and is an optical recording device that records and reproduces information by changing optical properties such as reflectance and transmission by irradiation with a light beam such as a laser beam. An object of the present invention is to provide a novel method for manufacturing an optical recording medium that solves the problems caused by cutting a substrate. [Means for Solving the Problems] The present invention provides an optical recording medium for recording and reproducing information by changing optical properties such as reflectance and transmittance by irradiation with a light beam such as a laser beam. In the manufacturing process by cutting, the cutting is performed by irradiation with a light beam, and when the optical recording medium is cut from the original,
This is a method for manufacturing an optical recording medium characterized by increasing the cutting speed at the parts where the light beams intersect, and by this method, no depressions or the like are created in the outer shape even in the parts where the light beams intersect and are cut. It becomes possible to manufacture an optical recording medium with good dynamic balance through a simple process. That is, in the process of the present invention, first, an original is made larger than the outer diameter of the intended optical recording medium, and then the outer shape is processed, such as edging, by irradiation with a cutting light beam such as a laser beam. When the cutting light beam cuts the original optical recording medium, when the light beams intersect and pass through the same point, the speed of the light beam is made faster than when the light beams do not intersect. Hereinafter, the present invention will be explained in detail with reference to the drawings. FIGS. 1 to 3 are schematic diagrams showing embodiments of the cutting process of the optical recording medium of the present invention, in which FIG. 1 is a large-format master with 20 individual surfaces, and FIG. 2 is a single-leaved master. It shows the cutting process. FIG. 3 is a partially enlarged view showing the cutting line of FIG. 1. FIG. As shown in FIGS. 1 and 2, the method for cutting an optical recording medium according to the present invention is to form each preformat pattern, form a recording layer, and protect it with or without a spacer. Transparent substrate 1 (
A master disc) is cut at a starting point 7 and an ending point 8 by continuous irradiation with laser light such as a carbon dioxide laser. In the figure, 2 is each pattern on the bonded substrate l, and 3 is the outer periphery of each pattern cut by laser beam irradiation. At this time, the cutting light beams intersect at the intersection shown at 5. As the cutting method that can be used in the present invention, any method can be used as long as it can cut with a light beam such as a laser beam, and for example, a carbon dioxide laser, a YAG laser, etc. can be used. As shown in FIGS. 1 and 2, the bonded substrate 1 is placed on the XY stage 6, and the cutting line 3 intersects at the intersection 5 from the starting point 7 to the ending point 8 like the cutting line 3. Cut the outline. The output of the laser beam used for cutting can be any output as long as the end face of the bonded substrates 1 is not melted by cutting or the adhesive is not melted, but it is 500~ A range of 2000W is particularly preferred. The moving speed of the XY stage becomes the relative linear velocity of the cutting light beam, and although this relative linear velocity depends on the intensity of the cutting laser beam and the diameter of the focused beam, it may cause the edge surface of the cut optical recording medium to become rough. , any speed can be used as long as it does not cause dents. Further, it is preferable that the cutting speed be constant at each of the non-intersecting portion 3 and the intersecting portion 5, since this results in a simpler configuration of the cutting device. Furthermore, the relative linear velocity of the non-intersecting portion can be any speed as long as it does not affect the properties of the resulting medium.
Cutting can be stably performed within the range of 3 to 50 m/min. If no practical problem arises, a speed range of 1 to 100 m/min outside this range can also be used. Since the cutting lines intersect at the intersection, depressions are likely to occur due to melting of the resin at the ends, and more depressions occur than at the non-intersection, so the relative linear velocity needs to be faster than at the non-intersection. In the present invention, the intersection is a part on the outer periphery of the target optical recording medium where the point where the light beam enters and the point where it exits overlap, and theoretically it is one point, but it depends on the diameter and intensity of the light beam. It becomes a large part. The size of this portion varies depending on the type of light beam used, the thickness of the substrate, the material, etc., but is usually 1 to 100 J in the direction of movement of the light beam.
It is LII. The relative linear velocity of the light beam is increased as it enters and exits this section. The change in speed when moving from a non-intersecting part to an intersecting part and from an intersecting part to a non-intersecting part should be done as smoothly as possible,
It is desirable to reach a constant speed at intersections. Any relative linear velocity at the intersection can be used as long as it is faster than the velocity at the non-intersection, but generally 1 to 200 m/min, particularly preferably 2 to L
It is in the range of oom/min. Incidentally, in FIG. 3, the portions where the light beams intersect other than the intersection 5 have little effect on the characteristics of the optical recording medium, and the linear velocity of the light beams is not particularly limited. Further, in the present invention, in order to prevent the medium cut from the master disk from falling away from the master disk after cutting, the center hole 4 of the medium can be inserted into the bin 9 before cutting, as shown in FIG. It is possible. Next, other configurations of the present invention will be explained. The structure of the optical recording medium produced according to the present invention may be the general structure shown in FIG. In FIG. 5, a transparent substrate 21 used as a bonded substrate (master) in the present invention
Any material can be used as long as it is transparent to recording/reproducing light, such as polycarbonate (PC), polystyrene (PST), polymethyl methacrylate (PMMA), and polyethylene terephthalate (PET). Plastics such as , nylon, polyvinyl chloride (PVC), and polymethylpentene (PMP) can be used. -The diameter of the disc pattern is 10~
You can choose from 300mm depending on the required capacity. In the optical recording medium manufacturing method of the present invention, the transparent substrate 21 can be used not only in a single sheet as shown in FIG. can. The thickness of the transparent substrate can be freely selected as required, but is preferably l, 20±0.05non. A track groove portion 22 is formed in the transparent substrate 21 . Track grooves 22 can be formed by injection method, compression method, injection/compression method, ultraviolet curing resin method (2P), if the unevenness can be created.
Any method such as , calender roll molding method, etc. can be used. After the uneven pattern is formed, the optical recording layer 23 is formed. Examples of materials that can be used include organic materials such as cyanine, naphthoquinone, and polymethine, organometallic materials such as phthalocyanine, and metal materials such as tellurium and bismuth. Any material that is generally used for optical recording can be used. The recording layer 23 can be manufactured by any commonly used film forming method, including dry methods such as sputtering and vacuum deposition, wet methods such as spin cord and roll coater, etc. can be used. The transparent substrate 21 on which the recording layer 23 is formed is bonded to the protective substrate 25 with or without a suitable spacer 24 interposed therebetween. The protective substrate 25 can be made of any material as long as it does not cause deformation such as warping or waviness even when used integrally with the transparent substrate 21. For example, it can be freely selected from plastic, paper, etc. can do. The protective substrate 25 can be made of the same material as the transparent substrate 21 or a different material. Similar to the transparent substrate 21, the protective substrate 25 can be used in any form, such as a single sheet, a large multi-sided sheet, or a continuous sheet. The thickness of the protective substrate 25 can also be freely selected depending on the configuration of the optical recording medium. A preferable thickness is the same thickness as the transparent substrate 21 or a thinner thickness. The spacer 24 can be freely selected from any form and material as long as it can be bonded to the transparent substrate 21 and the protective substrate 25. For example, it is also possible to use a ring-shaped plastic or a mixture of adhesive and plastic beads as a spacer. As the adhesive for bonding the spacer 24, the transparent substrate 21, and the protective substrate 25, any adhesive such as a thermoplastic adhesive, a thermosetting adhesive, a reactive adhesive, a pressure sensitive adhesive, etc. can be used. A preferable adhesive is one that does not cause the bonded substrates to melt due to the heat generated during cutting, causing misalignment or uneven thickness, and does not emit gas during cutting. (Example) Hereinafter, the present invention will be explained in more detail with reference to Examples. Example 1 As shown in Figure 1.2, a 550 x 40 piece with a thickness of 1.2 mm
20 (5×4) preformat patterns each having a diameter of 86 mm were formed on a 0 mm polycarbonate plate (Panlite 251, Yojin Kasei) using a pressing method to create a transparent substrate with multiple sides. Thereafter, an optical recording material represented by the following structural formula (I) was applied with a solvent. [13 0.3ms + thickness, l oox I 00mm (7
) Polycarbonate plate (Panlight 251. Yojin Kasei)
as a protective plate, and the outer diameter of the center part is φ2゜, the inner diameter is φ150111, and the outer diameter is φ86.0 for the outer periphery.
rnm, and a ring-shaped spacer with an inner diameter of φ83°0III+ was used for bonding. Spacer thickness is 0.3 mr
It is a. A hot melt adhesive (EVA7500EXP80, Hirodyne) was applied in advance to both sides of the spacer. 3.0 by heat press machine
) (g/cm2 pressure and heating at 100°C for 15 seconds to bond both substrates and the spacer. The bonded substrates were processed using a carbon dioxide laser processing machine (Mitsubishi Mellaser, ML806T2-25SRP) with a laser power of 1000W. The cutting stage was moved in the XYθ directions so that the cutting linear speed was constant at 10 m/min. Under these conditions, cutting was performed as shown in Figures 1 and 2. At intersection 5), the moving speed of the processing stage was increased so that the linear velocity of the cutting laser was 20 m/min.In addition, in order to prevent the cut optical disk from falling away from the large substrate,
As shown in FIG. 4, it is also possible to insert the center hole 4 into the bottle 9 and then cut it. You can also stack and stock the discs cut at that time. In this way, the speed of the cutting line was made faster at intersections than at non-intersections, and each section was cut. When the completed optical disc was measured, the roundness of the outer periphery was 0.1 mm at the maximum deviation, which was a good value. There were no dents or the like on the outer periphery of the disk. Also, the dynamic balance was good at 0.5N, and there was no effect on recording/playback at all. Example 2 One preformat pattern with a diameter of 86 mm was formed on a 10100×100 polycarbonate plate with a thickness of 1.2 mm using the same method as in Example 1. An optical recording material was applied with a solvent in the same manner as in Example 1. 0.3 as in Example 1
A polycarbonate protective substrate measuring 10,100×100 and having a thickness of 111,111 mm was adhered in the same manner as in Example 1 using the same spacer as in Example 1. The bonded substrates were cut using the same laser cutting machine as in Example 1, with the same laser power as in Example 1, and at a linear velocity of 15 m/min at non-intersecting portion 3 and 25 m/min at intersection 5. . When the completed optical disc was measured, the maximum deviation from a perfect circle at the outer periphery was less than 0.1 mm, which was a good value. There were no dents or the like on the outer periphery of the disk. Furthermore, the dynamic balance was also good at 0.5N. Example 3 In the same manner as in Example 1, 20 preformat patterns of 86 mm in diameter were formed on a 1.2 mm thick polycarbonate plate of 550 x 400 mm. An optical recording material was applied with a solvent in the same manner as in Example 1. 0 as in Example 1.
A polycarbonate protective substrate having a thickness of 311110 mm and a size of 550 x 400 mm was adhered in the same manner as in Example 1 using the same spacer as in Example 1. The bonded substrates were cut using the same laser cutting machine as in Example 1, and the laser power was s.
oow, the linear speed was 10 m/min at the non-intersecting part 3 and 20 m/min at the intersecting part 5. When the completed optical disc was measured, the maximum deviation from a perfect circle at the outer periphery was less than 0.1 mm, which was a good value. There were no dents or the like on the outer periphery of the disk. Furthermore, the dynamic balance was also good at 0.5N. Comparative Example A transparent substrate having a thickness of 1.2 mm and a diameter of 86 mm was prepared in the same manner as in Example 1. An optical recording material was applied with a solvent in the same manner as in Example 1. In the same manner as in Example 1, using a protective substrate with a thickness of 0.3 mto, the same ring-shaped spacers as in Example 1 were inserted into the inner and outer peripheral parts, and the materials were bonded together under the same conditions as in Example 1. The same laser cutting machine as in Example 1 was used to cut the outer shape. The laser power and linear speed during cutting were the same as in Example 1, the laser power was 1000 W, the linear speed of the cutting line was 10 m/min for both non-intersecting parts and intersecting parts, so that the cutting lines intersected at the outer periphery. Amputated. When we measured the completed optical disc, we found that the outer shape was recessed by 0.1 mm from the perfect circle at the intersection. At the intersection, the melting of the horse chestnut resin was large, and the surface area of the outer periphery was uneven and ±40-. Also, the dynamic balance is 1
．． 7N, which made recording and playback difficult. [Effects of the Invention] According to the present invention, there is no depression in the outer shape of the optical recording medium;
It has good dynamic balance, does not have any dents in its external shape, and can be manufactured using a simplified cutting process.
'It has the effect of providing a method for manufacturing an optical recording medium.

[Brief explanation of drawings]

FIG. 1 is a schematic plan view showing the chamfering of a master disc to be cut in the optical recording medium manufacturing method of the present invention, FIG. 2 is a schematic plan view showing the chamfering process shown in FIG. FIG. 4 is a schematic perspective view illustrating a method for storing a cut optical recording medium that can be used in the method of the present invention, and FIG. 5 is a diagram showing a general view of a general optical recording medium. FIG. 1... Bonded substrates 2... Each pattern on the substrate 3... Cutting lines (non-intersecting parts) 4... Center hole 5... Intersection of cutting lines 6... XY for laser cutting Stage 7.8...Laser cutting start point, end point 9...Bin lO...Cut disk 11...Base 1...Transparent substrate 2...Track groove 3...Optical recording medium 4... Spacer 5... Protective board

Claims (1)

[Claims] 1. In the process of manufacturing an optical recording medium by cutting from an original plate, the optical characteristics of which are changed by irradiation with a light beam to record and reproduce information, the cutting is performed by irradiation with a light beam, and optical recording is performed from the original plate. A method for manufacturing an optical recording medium, characterized in that when the medium is cut, the cutting speed is increased at a portion where light beams intersect.