MXPA06002264A - Method and tools for manufacturing a data supporting means having digital information and a hologram. - Google Patents

Abstract

The present invention refers to a method for manufacturing a disc-shaped optical data support and tools for manufacturing the same, which consists in attaching two discs, hereinafter known as disc means, by an adhesive coat. The image structure is located within the discs. The present invention therefore deters a pirate form reproducing an identical image structure, so that a customer may immediately recognize if the product is original or fake. The manufacture of the first and second discs may be simultaneously performed, so that the final disc has two metallic layers when both discs are attached together. The time for manufacturing de optical data support may be as short as that of a traditional data optical support having a single metal layer. Unlike the traditional method where the metallization steps are carried out one followed by the other, in the inventive method the metallization steps are parallely performed by two different machines, so that there is no delay in the product ion process. The process for manufacturing the present optical disc support includes a plurality of printing tools, such as male moulds; a pattern, a plurality of female pieces and a plurality of additional female pieces, the whole tools allow the pits to be recorded in the optical disc, which could be a DVD or compact discs.

Description

METHOD AND TOOLS FOR THE MANUFACTURE OF A MEDIA SUPPORTING DATA WITH DIGITAL INFORMATION AND A HOLOGRAM.

BACKGROUND OF THE INVENTION The manufacture of optical or compact discs, also called CD's, as well as the new Digital Versatile Discs, called DVD's is very complicated, which brings significant costs for the manufacturer. Once a compact disc is placed on the market, it is relatively easy to make copies of it to disseminate them legally. To protect against product piracy, CD and DVD discs have been d to image information that is difficult for those who illegally use the product to copy. Recently, we have tried to print holograms on CDs and DVDs. These holograms are almost impossible to copy, so that a buyer can immediately recognize if it is a merchandise produced under license or not.

In accordance with the current state of the art, it is known that a hologram can be d to digitally written data, such as for example US 4,967,286 of WO94 / 10684 and EP-A-0 611 472. The disadvantage of this method , is that when applying it there is little space on the surface of the information for the digital data or information and therefore its Storage capacity; p. eg, in the case of using them for audio or video, the playing time is reduced. Another disadvantage is the high costs in the manufacture of engraving tools, since different structures must be worked on; the height of the pit structure or digital information for the CD's is in the range of 0.12 μm, while the height of the structure of a hologram is in the range of 3 μm. Also in the manufacturing process of the discs by means of printing by injection of optical discs it is relatively difficult to give the shape of the different designs and to combine them with the different heights.

The technique describes in EP-A-0 608 358, a method for the production of an optical data support means according to which, on the metal layer of an injected disk, which contains the sample of pits or digital notches, an tional layer is placed, which is recorded and which contains the hologram, without this influencing the information of digital information pits contained in the layer below. When reading the digital information, only the information found on the metallic layer of the injected disk is perceived. The disadvantage is that the production method is complicated and takes a long time. That is why this method is not suitable for mass or series production.

OBJECTS OF THE INVENTION An object of the invention is to develop a method for the manufacture of a disc-shaped optical medium containing two metallic layers.

Where on one of the metallic layers the data are written in digital form. The other metal layer contains an image structure visible to the naked eye.

Another object of the invention is to develop a method for manufacturing an optical medium where manufacturing is quick and easy to make and which can also be manufactured in mass or in series.

Also, another object is to develop a method in which to form the disc are joined two discs called layers or layers joined by an adhesive lacquer where the union of the two half discs is made simultaneously.

It is also the object of the invention to develop a method for forming the disc where the metallization steps of both halves are performed in two different machines simultaneously avoiding the delay in the manufacture of the discs.

It is another object of the invention to create a series of printing tools necessary to be used in the manufacturing method of the optical disc (s) said tools are those that perform the pits formation, as well as the application of necessary holograms to prevent said discs from being falsified by its easy identification.

This will be evident in the following description and figures as an illustration of that indicated with numbers of the different parts in the figures shown.

BRIEF DESCRIPTION OF THE FIGURES Figure 1 shows the composition of a compact disc according to the current state of the art. Figure 2 shows the composition of a DVD according to the invention.

Figure 3 shows the schematic development of the method of manufacturing a DVD according to Figure 2. Figure 4 shows the steps necessary for the manufacture of the engraving tools to produce half of the disc with the hologram and half of the DVD .

DETAILED DESCRIPTION OF THE INVENTION Figure 1 shows the composition of a compact disc according to the current technique, consisting of a substrate (10), of polycarbonate with a typical thickness of 1.2 mm, a structure (12) is also represented , of pits formed by means of a stamper, the surface of that pit structure (12), is metallized by means of a process called "Sputter", or particle emission (enameling) for example. On this metallic layer (14), an additional layer (16) of thermoplastic material is applied. The surface that points upwards has a holographic structure, as shown in the figure with the number (18).

The surface of this holographic structure (18) also has a metallic layer (20). Above the layer (20), there is a layer of protective lacquer (22), whose surface (24) is generally partially printed. The hologram of the holographic structure (18) can be observed in the direction of the arrow (P1). The structure of pits or ridges (12), containing the digital data, can be read in the direction of the arrow (P2). As already mentioned, the production process of the compact disk shown in said figure is laborious, given that two engraving processes must be carried out on the same disc. Figure 2 shows the composition of a versatile digital disc (28), also called DVD. In a polycarbonate sheet of circular shape (30), the structure of the pits (32) is stamped, by means of a stamper and the piece or disk is passed to an injection-stamping process in an injection machine.

Subsequently the surface (34) is metallized on the pit structure (32), said metal layer is by means of "sputtering" or particle emission (enameling) for example. The support (30), and the metal layer (34), is called half disc (36). This half disc has a thickness of about 0.6 mm approximately in the case of a DVD. A second half disc (38) has a polycarbonate base (40), on which a holographic structure (42) is placed, and is applied by means of a stamper and an injection passage. It is then added to this holographic structure (42), and metallized by sputtering or emission of particles (enamel) for example (44). The two metallic layers of both halves of discs (36), (38), are facing each other, and are joined by means of an adhesive layer (46).

An ink-based print (48) is on the side containing the holographic structure (42) on which a design is printed. Figure 3 shows the manufacturing process for the DVD. In a first plastic injection machine (50), in said machine the first half disc (36) is produced, which is subsequently metallized, on the other hand, in a second injection machine (52), the second medium is produced disc (38), using a hologram stamper and metallized. On the first half disc (36), an adhesive (46) is applied, which catalyzes or sticks with ultraviolet light and the halves are glued together. Finally, both discs (36) and (38) are joined, in such a way that their metal sides are facing each other so that they can adhere or join one another, which have a thickness of 1.2 mm already joined, taking away out measurements to ensure quality. Both machines injection (50), (52), are arranged in parallel and share the same production rate. Figure 4 shows the stampers necessary for the production process of the optical disk for the holographic structure and the pits structure. In the upper line the production of the stamper (54), necessary to inject the hologram, can be seen. From a rectangular pattern (56), a hologram structure is created by means of laser beams, which is also called the male part (58). Generally, for the production of the male (58), the rectangular pattern (56) is destroyed. Typically, the pattern (56) has a dimension of 25.4 cm x 30.48 cm (10 inches x 12 inches). Normally, the male part (58) has a thickness of 300 μm. From the male part (58), a rectangular impression is formed by means of electroplating, which is known as a female part (60). Of this female part (60), at the same time, another copy (62) is produced by electroplating, but now it is circular. The female copy (62), usually has a diameter of 23 cm. From this female copy (62), an additional piece (54) is produced by electroplating modeling, and in addition to the female (62), several additional pieces (54) can be manufactured, which serve as stampers. By means of this tool for stamping the holographic structure on the disk by means of an injection process. It must be taken into account that the positive holographic structure of the pattern (56) also appears as a positive structure in the holographic structure. For a better understanding of the change of form from positive to negative, it is assumed for example, that there is an elevation as a holographic structure in the pattern (56). The male part (58) has a negative formation, i.e., a slit. The female piece (60), which has been formed from the pattern (58), has an elevation, so that the female copy (62) has a slit and the additional piece (54), at the same time has a elevation, which, in the engraving process, results in a slit in the middle disc. Since the observation of the structure of the hologram takes place from outside, that is, in Figure 2 from the printed side (48), this slit in the middle disc appears as an elevation from the point of view of the observer, ie, as a positive conformation. The step to produce the female copy (62) from the female (60) has a double function. On the one hand, the transition from rectangular to circular is achieved, which is necessary to be able to use it in the production process of the DVD. On the other hand, an additional copy step is carried out, which brings about a change of the structure from positive to negative, to obtain in the total of production steps a positive holographic structure on the second half disc (38). The bottom line shows the already known manufacture of the stamping tool (64), to produce the pits structure on the first half disc (36). From the circular pattern (66), the male part (68) is formed by means of electroplating modeling, from which the female part (70) is formed and from there again the piece or several additional pieces that serve as stamping tool for the process of production. The intermediate step of copying Further mentioned above is not necessary, since the information layer on the first disk means (36) may have a negative structure against the pattern (66). In this way, a large number of parts can be produced in mass production without a single disc having to go through several printing processes. DEVELOPED METHOD OF THE INVENTION According to the invention, two discs, which will be called discs, are joined by means of an adhesive layer. The image structure is inside the disc that is formed in this way. Because of this, it is difficult or rather impossible for a product pirate to reproduce the additional image structure identically, so that a buyer can immediately recognize if it is an original merchandise or an illegal copy. The manufacture of the first and second discs can be carried out simultaneously, in such a way that when joining both, the disc consists of two metallic layers. The time for the production of the optical data carrier can therefore be as short as the production of a traditional optical data carrier with a single layer of metal. Unlike the traditional method in which, the metallization steps are carried out one after the other, and in the method of the invention in which the metallization steps are carried out in two different machines in a parallel manner, in such a way that there is a delay in the production process.

It is preferable that the image structure be in the form of a hologram. A holographic structure is relatively difficult to produce and thus the degree of protection against clandestine copying is raised. In addition to that a hologram attracts more attention, in such a way that besides representing a warning constitutes a certain attraction for its acquisition. A preferred type of information support is the versatile digital disk (DVD), with a high data density. An information medium of this type can be used in a versatile manner as audio, video or computer data support. It has a greater storage capacity, which is achieved thanks to a greater density of pits, that is, of the pits in the metallic layer that contains the information. In the case of the DVD, these pits are flatter, narrower and shorter than on a compact disc and take up less space. In the most popular, single layer, only one layer of information is used, so the storage capacity used in a standard manner is 4.7 Gigabit. In this way, a large number of parts can be produced in mass production without a single disc having to go through several printing processes, then the manner in which the disc halves are glued is developed. The Glue Module. The halves of DVD layer 0 and layer 1 are placed one half on top of the other. To apply the glue a device separates the two parts, rotates them slowly and at the same time, injects the glue between them by means of needles and Dosing valves. When the needles are retracted, the distance between the halves will be reduced and the speed of rotation will be different. In this way the glue will be evenly distributed. The discs are centered on the table by four conical pins. The centering should be as shown in the following example: When the pins are incorrectly adjusted, the discs may come out with stripes or the heads deform the central holes of the discs, as shown in the following example: All other adjustments, such as amount of glue, revolutions and speeds must be made to obtain the correct alignment between the two layers or layers. Centrifuge Module The glue, once applied by the needles between the halves, should be distributed evenly. It is also necessary that the halves are centered before the glue is dried. That's why the centrifuge module consists of two centrifuges with conical pins and a pre-drier in the transfer, on top of them. When the transfer puts the disks of the table of glued spin the glue is still liquid. So the top half floats on the other and the conical pin can center the two. When using ultraviolet light from the pre-cutter to leave also glue by a change in its viscosity and use speed for the distribution of the glue and the adjustment of its thickness. The specifications allow 55microns +/- 15μm. To fix the halves of a DVD in a centered position you have to use large inner masks. In the metallizer of the layer 0. The centering pins of the centrifuges This line has conical pins in the centrifuges to center the discs, as shown below by way of example: Cross-section: Drying module The pre-dryer only fixes the two halves when they have been centered by the conical pins. It also dries the center of the DVD but always leaves liquid glue on the outside and especially on the edge of the discs. The function of the dryer is to dry this remaining liquid glue.

The transfer of the centrifuge module puts the pre-dried discs on the table of the drying module. The table rotates step by step and brings disk by disc under the dryer. When another disc arrives a diaphragm in the lamp opens and exposes the disc to ultraviolet light for a programmed time. The dried discs that come out of the dryer are transferred and put in the cooling module: The glue of the DVD consists of short molecules that can form a three-dimensional network as shown in the following example.

There is no solvent to evaporate from the glue. Small molecules form huge molecules. Metallic detail. When the disk halves are metallized, masks are used that cover different diameters in the centers of the halves. The half that carries the hologram has a smaller diameter than the other half. This fact provides an advantage to the next step of the process, where the glue between the reflective layers of the two halves. The advantage results when the half with the smaller diameter is shown downwards during the distribution of the glue between the halves. So it is possible for a low-intensity ultraviolet light to penetrate the non-reflecting polycarbonate in the center of the half that shows upwards, thus "curing" a part of the glue. With this pre-drying the risk of a displacement of the two halves with liquid glue during transport to the dryer is avoided, resulting in a more accurate central hole of the complete disc and likewise, the risk of contaminating the production line with glue is eliminated. .

Claims (14)

1. CLAIMS 1.- Method for manufacturing an optical data carrier in the form of a disk that comprises the combination of the following stages. The formation of a versatile digital disk (28), also called DVD, in a polycarbonate sheet of circular shape (30), on which the structure of the pits or grooves (32) is stamped, by means of a stamper and the piece or disk is passed to a second step of ejection by injection in a machine used for this purpose, as a third step is added a metal layer (34), on the structure of the pits or grooves (32), said layer of coating is by means of particle emission (enameling) for example, the support (30), together with the structure of the pits or grooves (32) and the metal layer (34), together form the disc medium (36), which is pressed in an injection machine and said disc is applied a layer of metal coating (44), this half disc (36), has a thickness of about 0.6 mm approximately in the case of a DVD, also also the The method comprises the formation of a second disk means (38), which has a support base. e (40), which is polycarbonate, on which a holographic structure (42) is placed or produced, said holographic structure is applied by means of a stamper and an injection step. Subsequently, a metallic coating layer (44) is added to this holographic structure (42), by metallization, the two metallic layers (34), (44), of both disc halves (36), (38), they meet facing each other, and are joined by means of an adhesive layer (46), CHARACTERIZED because in the formation step of the second half of the disc (38), an ink-based printing (48) is preferably applied on the side containing the holographic structure (42), on which a section design is engraved, in addition to the step of performing the printing of the holographic structure using the tool (54), which is formed in the following way, first a rectangular pattern (56) is constructed, in a photo-process machine, of the pattern (56), obtained by electroplating, a rectangular printing mold called male mold (58), of the male mold is obtained by electroplating a rectangular mold called female part (60), of the rectangular female part (60), a female copy of circular shape is obtained by electroplating (62) ), of said circular female copy (62), is obtained by electroplating at least one additional circular section (54), or several additional sections which are used to carry out the engraving or printing on the two halves of d iscos (36) and (38).
2. 2. Method for the manufacture of a disc-shaped optical data carrier according to clause 1, characterized in that the joining step of the two disc halves (36) and (38), is carried out by means of a liquid adhesive (46), which is a lacquer sensitive to ultraviolet rays, said adhesive (46), is applied on the metallic layer (34), of one of the two disk halves (36), (38), forming a unitary body both halves of disk.
3. 3. Method for manufacturing an optical disc-shaped data carrier according to clause 1, further characterized in that in the step of distributing the adhesive in both disk halves (36), (38), they are put in Contact Both sides of the two disc halves are subjected to a centrifugation step, subsequently subjecting both discs to a joint curing or drying process by means of ultraviolet rays.
4. 4. Method for the manufacture of a disk-shaped optical data carrier according to clause 1, further characterized in that in the stamping step for the formation of pits on the first half-disk (36), the disks are used a stamper (64), said stamper contains the pits.
5. 5.- Method for manufacturing an optical data carrier in the form of a disk according to clause 1, further characterized in that the second half disc (38), has a support (40), polycarbonate, on which a holographic structure (42) is applied, said structure (42), contains a hologram.
6. 6. Method for manufacturing an optical data carrier according to clause 1, characterized in that the stamper (54), which produces the second disk half (38), contains a holographic structure.
7. 7. Method for the manufacture of a disk-shaped optical data carrier according to clause 1, characterized in that the stampers (54), (64), are produced through a multi-step galvanic modeling with the aid of patterns (56), (66), to which a pits structure is recorded by means of ultraviolet rays.
8. 8. Method for the manufacture of a disc-shaped optical data carrier according to clause 1, characterized in that the data carrier, a compact disc, and especially a DVD (28), has a higher data storage capacity .
9. 9. - Tools for the manufacture of a disk-shaped optical data carrier comprising the combination of a one-shot-jet machine (50), which is responsible for printing the first disk section (36), by means of the stamper that contains the data in digital form and that is what leads the pits structure, said pits are made to the piece in the injection machine (50), the surface of the disc (36), is covered with a metallic layer ( 34), in a metallizing machine for emission of particles, a second injection machine (52), which is the one that prints the second half of the disc (38), using for this a stamper with a structure visible to the naked eye in which the different holograms are made and which are made to the tool in the second injection machine (52), covering the printed surface of the second disk (38), in a metallizing machine by emission of particles, characterized in that the faces of the halves of the discs (36) and (38), are facing each other to allow the application of an adhesive in the central part of both pieces uniting them and forming a unitary body, the adhesive is sensitive to ultraviolet rays in addition, the disc thus formed is subjected to a centrifugation process, subsequently subjecting said disc to a hardening process by means of ultraviolet rays.
10. 10. Tools for the manufacture of a disk-shaped optical data carrier according to clause 9, further characterized in that the injection machines (50), (52), are arranged in parallel and work with the same production cadence.
11. 11. - Tool for manufacturing an optical data carrier according to clause 9 further characterized in that the tool (54), which is formed by means of a rectangular pattern (56), in a photo-process machine, of the pattern (56), is obtained by electroplating, a rectangular printing mold called male mold (58), the male mold is obtained by electroplating a rectangular mold called female part (60), of the rectangular female part (60), is obtained by electroplating a female circular copy (62) of said circular female copy (62), is obtained by electroplating at least one additional circular section (54), or several additional sections which are used to perform the engraving or printing on the two disc halves (36) and (38).
12. 12.-Method for gluing and placing the holograms on the two halves of the discs consisting of the following stages using a glue module, to later go to the centrifuged stage in its respective centrifuge module, continuing with the step or drying step of the discs in the drying module and finally in the metallization stage of both discs characterized in that the step of gluing the DVD halves layer (0) and layer 1 are placed one half on top of the other. To apply the glue and a device separates the two parts, rotates them slowly and at the same time, injects the glue between them by means of needles and dosing valves. When the needles are retracted, the distance between the halves will be reduced and the speed of rotation will be different. In this way the glue will be evenly distributed; the discs are centered on the table by four conical pins; when the pins are incorrectly adjusted, the discs may come out with stripes or the heads deform the central holes of the discs, all other adjustments, such as amount of glue, revolutions and speeds, may be made to obtain the correct alignment between the discs. two layers of the discs achieving a suitable centering axis in said discs; also in the centrifugation stage the glue once applied by the needles between the halves, must be distributed evenly. It is also necessary that the halves are centered before the glue is dried. That is why the centrifuge module consists of two centrifuges with conical pins and a pre-drier in the transfer, on top of them. When the transfer puts the disks of the table of glued spin the glue is still liquid. So the top half floats on the other and the conical pin can center the two; by using ultraviolet light from the pre-drier to also leave glue by changing its viscosity and using speed for the distribution of the glue and the adjustment of its thickness. The specifications allow 55microns +/- 15μm .; Likewise, to fix the halves of a DVD in a centered position you have to use large inner masks. In the metallizer of the layer 0 and the pins of centering in the centrifuges are conical allowing to center the discs avoiding that said discs leave with stripes or the heads distort the central holes of the disks.
13. 13. - Method for gluing and placing the holograms on the two halves of the discs according to clause 12, where in the drying stage the pre-dryer only fixes the two halves when they have been centered by the conical pins. It also dries the center of the DVD but always leaves liquid glue on the outside and especially on the edge of the discs. The function of the dryer is to dry this remaining liquid glue; the transfer of the centrifuge module puts the pre-dried discs on the table of the drying module. The table rotates step by step and brings disk by disc under the dryer. When another disc arrives a diaphragm in the lamp opens and exposes the disc to ultraviolet light for a programmed time. It transfers the dried discs that come out of the dryer and puts them in the cooling module.
14. 14. Method for gluing and placing the holograms on the two halves of the discs according to clause 12, where the metallization stage is characterized because when the disc halves are metallized, masks are used that cover different diameters in the centers of the disc halves; where the half that carries the hologram has a diameter smaller than that of the other half, which allows applying the glue between the reflective layers of the two halves, in which when the half with the smaller diameter is shown down during the distribution of the glue between the halves, it is possible for a low-intensity ultraviolet light to penetrate the non-reflective polycarbonate in the middle of the half that shows upwards, thus "curing" a part of the glue, with this Pre-drying avoids the risk of a displacement of the two halves with liquid glue during transport to the dryer, resulting in a more accurate central hole of the complete disc and likewise, eliminates the risk of contaminating the production line with glue.