CA2206364A1 - Process for the manufacture of a master disk for the production of optical disk pressing matrices bearing a marking, particularly of the anti-pirate type, a master disk, a pressing matrix and the optical disk obtained - Google Patents
Process for the manufacture of a master disk for the production of optical disk pressing matrices bearing a marking, particularly of the anti-pirate type, a master disk, a pressing matrix and the optical disk obtainedInfo
- Publication number
- CA2206364A1 CA2206364A1 CA002206364A CA2206364A CA2206364A1 CA 2206364 A1 CA2206364 A1 CA 2206364A1 CA 002206364 A CA002206364 A CA 002206364A CA 2206364 A CA2206364 A CA 2206364A CA 2206364 A1 CA2206364 A1 CA 2206364A1
- Authority
- CA
- Canada
- Prior art keywords
- zones
- marking
- reflecting
- accordance
- bearing
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
- 238000000034 method Methods 0.000 title claims abstract description 54
- 230000003287 optical effect Effects 0.000 title claims abstract description 53
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 40
- 230000008569 process Effects 0.000 title claims abstract description 35
- 238000003825 pressing Methods 0.000 title claims abstract description 29
- 239000011159 matrix material Substances 0.000 title claims abstract description 22
- 239000011347 resin Substances 0.000 claims abstract description 52
- 229920005989 resin Polymers 0.000 claims abstract description 52
- 238000002310 reflectometry Methods 0.000 claims abstract description 13
- 239000000463 material Substances 0.000 claims description 48
- 238000000151 deposition Methods 0.000 claims description 6
- 239000011521 glass Substances 0.000 description 6
- 230000004048 modification Effects 0.000 description 4
- 238000012986 modification Methods 0.000 description 4
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000006870 function Effects 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- 239000004417 polycarbonate Substances 0.000 description 1
- 229920000515 polycarbonate Polymers 0.000 description 1
Classifications
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B23/00—Record carriers not specific to the method of recording or reproducing; Accessories, e.g. containers, specially adapted for co-operation with the recording or reproducing apparatus ; Intermediate mediums; Apparatus or processes specially adapted for their manufacture
- G11B23/28—Indicating or preventing prior or unauthorised use, e.g. cassettes with sealing or locking means, write-protect devices for discs
- G11B23/283—Security features, e.g. digital codes
- G11B23/284—Security features, e.g. digital codes on the record carrier
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
- G11B7/24—Record carriers characterised by shape, structure or physical properties, or by the selection of the material
- G11B7/26—Apparatus or processes specially adapted for the manufacture of record carriers
- G11B7/261—Preparing a master, e.g. exposing photoresist, electroforming
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B23/00—Record carriers not specific to the method of recording or reproducing; Accessories, e.g. containers, specially adapted for co-operation with the recording or reproducing apparatus ; Intermediate mediums; Apparatus or processes specially adapted for their manufacture
- G11B23/38—Visual features other than those contained in record tracks or represented by sprocket holes the visual signals being auxiliary signals
- G11B23/40—Identifying or analogous means applied to or incorporated in the record carrier and not intended for visual display simultaneously with the playing-back of the record carrier, e.g. label, leader, photograph
Landscapes
- Engineering & Computer Science (AREA)
- Computer Security & Cryptography (AREA)
- Manufacturing & Machinery (AREA)
- Manufacturing Optical Record Carriers (AREA)
- Optical Record Carriers And Manufacture Thereof (AREA)
Abstract
The invention concerns a manufacturing process for the creation of an optical disk pressing matrix bearing a marking, particularly of the anti-pirate type.
This process consists of interposing, between the turntable (3) of an information recording machine and a support (1) coated with a photosensitive resin (2), a layer (7) formed by zones of different reflectivity at the wavelengths of the light beam (4) used to record the information, and thus creating a marking.
The invention is suitable for application in particular in the area of production of optical disks bearing a marking.
This process consists of interposing, between the turntable (3) of an information recording machine and a support (1) coated with a photosensitive resin (2), a layer (7) formed by zones of different reflectivity at the wavelengths of the light beam (4) used to record the information, and thus creating a marking.
The invention is suitable for application in particular in the area of production of optical disks bearing a marking.
Description
CA 02206364 1997-08-2~
"Process for the manufacture of a master disk for the production of optical disk pressing matrices bearing a marking, particularly of the anti-pirate type, a master disk, a pressing matrix and the optical disk obtained"
The invention concerns a process for the manufacture o of a master disk for the production of optical disk pressing matrices bearing a marking, and in particular one of the anti-pirate type. It also concerns the process of manufacture of the pressing matrix and of the optical disk bearing a marking, particularly of the anti-pirate type, as well as the master disk, the pressing matrix and the optical disk obtained by these processes.
At the present time, in order to enable the consumer to identify the nature of the programme contained on an optical disk, a label is attached to one side of the optical disk, carrying this information in plain language.
This involves at least two additional steps in the manufacturing process of a master disk, consisting firstly of a part to produce these labels, and secondly of attaching them onto the disks.
CA 02206364 1997-08-2~
Furthermore, to distinguish an original from its unauthorised copy, various codes can be placed on the optical disk.
The most widespread practice is to place one or more codes in the identity band of the compact disk, either in plain language or in the form of a bar code. These codes can be the reference of the publisher, the reference of the company which made the master disk and/or the pressing matrix, and the reference of the company which executed o the pressing, depending on the space available on the identification band, and the agreements which exist between the various parties involved.
However, this information is very small in size, since it is located in the identification band and cannot under any circumstances encroach onto the area used for the programme material (from which the data is read by the optical reader).
This makes the information difficult to read and to interpret. The final consumer is therefore rarely able to ascertain at first glance the origin of the compact disks which he buys, because this information is not easily visible, or because the codes are too impenetrable.
The invention aims to get around these disadvantages by enabling an optical disk to be made which carries a marking which is visible to the human eye but which cannot be detected by the optical disk reader, meaning that it CA 02206364 1997-08-2~
does not affect the reading of the programme material, and which moreover cannot be copied. This marking is sufficiently large to allow the consumer to ascertain immediately when buying, the nature of the programme contained on the optical disk and/or to verify the authenticity of a compact disk.
In what now follows, the term "marking" will refer to any deliberate pattern which represents either information enabling the nature of the programme material to be o determined or enabling the authenticity of an optical disk to be determined. The term "marking" also covers the case in which the pattern created will simultaneously allow the nature of the programme contained on the optical disk to be identified the authenticity of the optical disk to be verified.
To this end, the invention proposes a manufacturing process for a master disk for the production of an optical disk pressing matrix which includes marking of a type consisting of:
20- depositing a layer of photosensitive resin on one side of the support.
- depositing this support, bearing the layer of photosensitive resin, onto the turntable of a recording machine.
- recording the information to be copied and to be read by an optical disk reader, in the form of a latent CA 02206364 1997 - 08 - 2~
image, in the layer of photosensitive resin, by the relative motion of an appropriate light beam;
- eliminating the zones of exposed photosensitive resin, this removal then leading to the creation of a succession of micro-slots which are representative of the information to be copied and to be read by an optical disk reader, with the following characteristics:
Before proceeding to the recording stage. of the information to be copied and to be read by the optical o disk reader, a layer formed of zones of a first material and zones of a second material, with different reflectivities at the wavelengths of the given recording light beam, where these zones of different reflectivity comprise the marking, is interposed between the turntable of the recording machine and the support bearing the photosensitive resin.
Accordance to a first method for implementation of the invention process, the said marking is made up by reflecting zones of a first reflecting material at the 20 wavelengths of a recording light beam, and of non-reflecting zones of a second material which is non-reflecting at the wavelengths of the recording light beam, the zones of the first reflecting material representing the marking as a positive.
According to another method for implementation of the ~ invention process, the marking is made up by reflecting CA 02206364 1997-08-2~
zones of a first reflecting material at the wavelengths of the recording light beam, and of non-reflecting zones of a second material which is non-reflecting for the recording light beam, the said zones of the second non-reflecting material for the recording light beam representing the marking as a positive.
According to a variant of the two preceding methods for implementation of the invention process, the said second non-reflecting material is absent, thus creating o the said non-reflecting zones.
According to yet another method for implementation of the invention process, the marking is made up from the zones of a first material which is more reflecting and the zones of a second material which is less reflecting for the recording light beam, with the zones of the first more reflecting material representing the marking as a positive.
According to still another method for implementation of the invention process, the marking is made up from the zones of a first material which is more reflecting and the zones of a second material which is less reflecting for the recording light beam, with the zones of the second less reflecting material representing the marking as a posltlve.
CA 02206364 1997-08-2~
According to a variant of the manufacturing process for a master disk of the invention, the layer forming the marking is formed on an independent support plate.
It can also be formed directly on the medium of the master disk, on the surface of this medium opposite to that bearing the resin layer.
Again, it can be formed directly on the turntable of the recording machine.
The different methods of production and the variants o of the manufacturing process for a master disk of the invention can furthermore include the following stages after the removal if the exposed resin zones:
- transfer to the medium of the micro-slots obtained by the said removal stage, and - removal of the zones of residual resin.
The master disk obtained by the various modes of the manufacturing process for a master disk according to the invention also forms part of the invention.
The invention also concerns a manufacturing process for an optical disk pressing matrix bearing a marking, characterised by the fact that that it includes the manufacture of a master disk according to the process of the invention and/or the use of the master disk obtained by the manufacturing process for a master disk of the invention.
The invention also covers the pressing matrix thus obtained.
The invention also covers a manufacturing process for an optical disk bearing a marking, characterised by the fact that that it includes the manufacture or the use of a master disk and/or the use of a pressing matrix according to the invention.
The master disk thus obtained also forms part of the invention.
Other objectives, details and advantages of this invention will appear more clearly on reading the detailed description which will now follow, with reference to the attached drawings in which:
- figure 1 shows, schematically, the manufacturing process for a master disk in accordance with the methods described above, and - figure 2 represents, schematically, the various stages of a variant of a manufacturing process for a master disk according to the invention.
In figure 1 attached, the process for ~he manufacture of a master disk according to the above method consists, in the stage marked (a), of depositing a layer of photosensitive resin of the positive type on support 1, generally made of glass.
CA 02206364 1997 - 08 - 2~
Then, as illustrated in the stage marked (b) in figure 1, this support (1) bearing the photosensitive resin is placed on the turntable (3) of the recording machine.
At the stage marked (c), the information to be copied and which will be read later by an optical disk reader (the programme material), are recorded in the form of a latent image into the layer (2) of photosensitive resin by the relative motion of an appropriate light beam, generally a laser beam. As illustrated in the stage o marked (c), this results in exposed resin zones (5).
During this recording process, and as illustrated by the dotted arrows in stage (c) of figure 1, laser beam 4 successively passes through the resin layer, changing its nature, to the focus point of the laser, and is absorbed by the turntable (3) of the recording machine.
Next, in the resin development stage, shown as (d) in figure 1, the exposed resin zones (5) are removed by any means known to professionals in this field. This leads to the creation, in the layer of photosensitive rèsin, of 20 micro-slots (6) representing the information to be copied and to be read by an optical disk reader.
This has now resulted in a master disk which bears on its surface a series of micro-slots representing a positive of the information to be copied (the programme material).
CA 02206364 1997-08-2~
From this master disk, a pressing matrix is created, generally in nickel, with on its surface a succession of micro-ridges which correspond to a negative of the micro-slots described previously.
This pressing matrix will then be used to press out the optical disks, generally on polycarbonate, bearing a succession of micro-slots which are a replica of micro-slots 6.
The optical disk is then covered with a thin metallic o reflecting layer which will allow a light beam emitted by the compact disk reader to read the recorded information.
As noted above, during the stage marked (c) in recording the information in the form of a latent image in photosensitive resin layer 2, laser beam 4 exposes the appropriate zone of the resin, passes through glass support 1, and is absorbed by the turntable of the machine.
The invention is based upon the following phenomenon.
If we interpose between the turntable (3) of the recording machine and the support (1) of the master disk, bearing its layer of photosensitive resin (2), a layer formed of at least two materials of different reflectivities, thus leading to the creation of at least two types of zones of different reflectivity representing a marking, the laser beam is reflected by these zones of different reflectivity, passes back through the support, and re-exposes the resin at the same place by virtue of the speed of the light emitted by the recording laser beam, which is naturally greater than the rotation speed of the turntable (3).
Therefore if we place, between support 1 and turntable 3, a layer formed of several zones of different reflectivity representing a marking, then the reflected laser beam re-exposes the resin, and this marking will be seen on developing the micro-slots. In fact the micro-slots which receive more light will be more open than theothers for the same development time (removal of exposed resin zones, as shown in stage (d)).
This phenomenon was used in the invention in order to create a marking on a master disk, and therefore on the pressing matrix obtained from this master disk and finally on the optical disk obtained from this pressing matrix.
In order to make it easier to understand the invention, we will now give several methods of implementation, purely as illustrative examples.
Firstly, if we refer to figure 2 attached, a method will be described for implementing the manufacturing process for a master disk for the creation of an optical disk pressing matrix bearing a marking in accordance with the invention.
The first stage, shown as (a) in figure 2, is identical to that of the process described above. On support 1, generally of glass, a positive-type layer of photosensitive resin is deposited.
Here, however, in contrast to the previously describe process illustrated in figure 1, and as illustrated in the stage shown as (a') in figure 2, this support (1), bearing the layer of photosensitive resin (2), is deposited on top of layer 7 formed by the reflecting zones shown as 8a and the non-reflecting zones shown as 8b. Zones 8a and 8b comprise the wanted marking.
o The marking can be a simple representation of the programme material contained on the optical disk. In this case however, the marking must be capable of being be viewed from the face of the optical disk, finally obtained because of the invention process, onto which is placed, using existing methods, the label performing the marking function of the invention, namely, presentation of the programme contained on the optical disk.
To this end, no label of any description must be placed on this side of the disk. In fact there is no further need here for any label on the optical disk of the invention.
This marking can equally well be a logo, a series of letters or numbers, a hologram, or any other graphic identifying the various participants, including the publisher, the company which manufactured the master disk and/or the pressing matrix, the company which did the pressing, and so on. In other words, it is an anti-pirate mark.
In this last case, it is possible to place a label on the optical disk, since the anti-pirate marking will be visible on the side of the optical disk opposite to that bearing the label, affixed by existing methods, intended to carry the nature of the programme contained on the optical disk. It is therefore possible to execute attachment of the label which has become necessary here.
o It should be noted, however, that in all of these cases, the marking is visible from both sides of the optical disk as long as no label is placed on it. The marking can simultaneously represent the programme contained on the disk and also a distinctive anti-pirate marking.
Moreover, in contrast to existing anti-pirate measures, the markings of the invention can cover the whole available area of the optical disk aimed at finally, without altering the thickness of the photosensitive resin layer and without affecting the unexposed areas of resin.
This is also true when the marking is used to represent the programme material contained on the optical disk.
This marking will therefore be large enough to be seen and clearly identified by the final consumer.
Then in the stage shown as (b) in figure 2, layer 7 and support 1 bearing resin layer 2 are deposited, using existing methods, onto the turntable (3) of an information recording machine.
Here layer 7 is formed on an independent support plate (not shown) in order to give it rigidity and the necessary mechanical properties.
There is no need to modify the conventional recording machine in any way whatsoever.
During the recording of information in the form of a latent image in resin layer 2, laser beam 4, modulated in o accordance with the information to be recorded and to be read by the optical disk reader, and as illustrated by the dotted arrows in stage (c) of figure 2, successively passes through photosensitive resin layer 2, exposing it in certain defined zones, thus leading to the formation of the zones marked 5 of exposed resin representing the information, and also support 1 in glass. The beam then reaches layer 7. If it encounters reflecting zone 8a of layer 7, the beam will be reflected, will pass again through the glass support, and will re-expose photosensitive resin 2 in the zones already exposed. This phenomenon is illustrated in figure 2 by dotted arrows which are slightly shifted to make the figure clearer.
Conversely to this, if the laser beam encounters non-reflecting zone 8b, it will be either absorbed by these non-reflecting zones 8b or it will pass through these non-reflecting zones to then be absorbed by turntable 3 of the recording machine.
Thus, as illustrated in figure 2, we get support 1, bearing resin layer 2, and having on its surface zones of resin, marked 5a, which have been exposed twice, representing the marking and the information to be copied, and zones 5 of resin which has been exposed only once, representing only the information to be copied.
The resin is then developed, meaning that the exposed resin zones are removed. As illustrated in stage (d), we then get a master disk made up of support 1 bearing in its o surface micro-slots 6 representing the information to be copied and micro-slots 8, corresponding to the double-exposed resin zones 5a, representing the marking and the information to be copied.
In figure 2, the modification of double-exposed micro-slots, shown as 5, has been deliberately exaggerated to better illustrate this phenomenon.
However the modifications made by the laser beam, reflected by the reflecting zones of layer 7, are very small, and are within the current tolerance standards 20 imposed on the size of the micro-slots 6, in order not to disrupt reading of the information of which these micro-slots are representative.
This means that an electronic reading device will not detect them, and the marking cannot be copied.
The professionals of the trade are familiar with the tolerance standards, which can vary with advances in the CA 02206364 1997 - 08 - 2~
manufacturing technology of the master disks. But these modifications, even though they are very small, of microscopic dimensions, are perfectly visible on the macroscopic scale.
In the above production method, layer 7 is formed by reflecting zones 8a composed of a first reflecting material, and then non-reflecting zones 8b composed of a second non-reflecting material. Reflecting zones 8a can be created by metallising through a mask of a support o plate which is non-reflecting to information recording light beam 4. This means that non-reflecting zones 8b can also be created by the absence of the second non-reflecting material. The reflecting zones can be representative of the marking as a positive or as a negative. In other words, the mask can allow the metallising to pass in order to represent the marking as a positive, or can represent it as a negative.
According to another method of implementation of the invention, layer 7 can be formed by more reflecting zones 8a and less reflecting zones 8b. Depending on the reflectivity of these zones, the laser beam, when it is recording the information, will be more or less reflected, and will therefore expose resin 2 to a greater or lesser degree.
The same micro-slot modification effect will thus be obtained, and the marking will also be visible.
CA 02206364 l997-08-2 In this case, in the same way as before, the more reflecting zones, 8a, can represent the marking as a positive or negative image.
According to yet another method of implementation of the invention, while in figure 2 zones 8a and 8b are represented as separate from support 1 and bearing photosensitive resin layer 2, and have been described previously as being deposited on an independent support plate, the marking composed of more reflecting zones 8a o and less reflecting zones 8b or of reflecting zones 8a and non-reflecting zones 8b can be formed directly on the surface of support 1, which is coated with the photosensitive resin.
The more reflecting zones 8a and less reflecting or non- reflecting zones 8b comprising the marking can also be formed directly on turntable 3 of the recording machine.
It should also be noted that another variant of the manufacturing process for the master disk of the invention, after the stage for removal of the exposed resin zones, consists of transferring the micro-slots into glass support 1, by plasma engraving for example, and then removing the zones of residual resin.
In this case the master disk is also composed of support 1, bearing on its surface a series of micro-slots engraved into the support itself.
CA 02206364 1997 - 08 - 2~
Also while the manufacturing process of a master disk, in accordance with the invention, was described using a layer of photosensitive resin of the positive type, it is also possible to use a photosensitive resin of the negative type, but in this case, it is the non-exposed resin zones which will be removed in the stage marked (d) in figure 2.
From this master disk, it is then possible to manufacture an optical disk pressing matrix and the o optical disks themselves.
The marking will be visible to the naked eye because of the diffraction of visible light induced by micro-slots 8, corresponding to deformed micro-slots 6, and representing the marking and the information to be read, which is different from the diffraction of visible light caused by micro-slots 6 when not deformed and representing only the information to be read.
In all of the variants and different methods of manufacture of the master disk described above, the 20 reflecting material or non-reflecting material or material reflecting to a greater or lesser degree will be reflecting or non-reflecting or reflecting to a greater or lesser degree for the light emitted by the recording laser beam.
To a professional in the trade, it will appear that any material allowing reflection of the light beam employed to record the information, will be appropriate.
He will also be able to determine the nature of these materials.
Also, while reference has been made to various materials n the above description of the process of the invention, it should be understood that what matters here is the different degrees of reflectivity between the various zones representing the marking.
The stages of the different variants of the process of o manufacture of the master disk of the invention can be incorporated into the manufacturing process of an optical disk pressing matrix and in the process for manufacture of optical disks, with no change to the equipment, and in all cases these processes will lead to the creation of optical disks bearing a marking visible to the naked eye but which cannot be read by an electronic device, and therefore cannot be copied.
Of course the invention is not limited in any way to the methods of implementation described above and illustrated. These have been provided only as examples.
Therefore although in the various methods of implementation previously described, layer 7 was described as being formed of two types of zone, 8a and 8b, with different reflectivities, it can also be formed, as desired, from a larger number of zone types of different reflectivities.
This means that it includes all techniques equivalent to the means described, and all their combinations, if these are effected in accordance with its spirit.
"Process for the manufacture of a master disk for the production of optical disk pressing matrices bearing a marking, particularly of the anti-pirate type, a master disk, a pressing matrix and the optical disk obtained"
The invention concerns a process for the manufacture o of a master disk for the production of optical disk pressing matrices bearing a marking, and in particular one of the anti-pirate type. It also concerns the process of manufacture of the pressing matrix and of the optical disk bearing a marking, particularly of the anti-pirate type, as well as the master disk, the pressing matrix and the optical disk obtained by these processes.
At the present time, in order to enable the consumer to identify the nature of the programme contained on an optical disk, a label is attached to one side of the optical disk, carrying this information in plain language.
This involves at least two additional steps in the manufacturing process of a master disk, consisting firstly of a part to produce these labels, and secondly of attaching them onto the disks.
CA 02206364 1997-08-2~
Furthermore, to distinguish an original from its unauthorised copy, various codes can be placed on the optical disk.
The most widespread practice is to place one or more codes in the identity band of the compact disk, either in plain language or in the form of a bar code. These codes can be the reference of the publisher, the reference of the company which made the master disk and/or the pressing matrix, and the reference of the company which executed o the pressing, depending on the space available on the identification band, and the agreements which exist between the various parties involved.
However, this information is very small in size, since it is located in the identification band and cannot under any circumstances encroach onto the area used for the programme material (from which the data is read by the optical reader).
This makes the information difficult to read and to interpret. The final consumer is therefore rarely able to ascertain at first glance the origin of the compact disks which he buys, because this information is not easily visible, or because the codes are too impenetrable.
The invention aims to get around these disadvantages by enabling an optical disk to be made which carries a marking which is visible to the human eye but which cannot be detected by the optical disk reader, meaning that it CA 02206364 1997-08-2~
does not affect the reading of the programme material, and which moreover cannot be copied. This marking is sufficiently large to allow the consumer to ascertain immediately when buying, the nature of the programme contained on the optical disk and/or to verify the authenticity of a compact disk.
In what now follows, the term "marking" will refer to any deliberate pattern which represents either information enabling the nature of the programme material to be o determined or enabling the authenticity of an optical disk to be determined. The term "marking" also covers the case in which the pattern created will simultaneously allow the nature of the programme contained on the optical disk to be identified the authenticity of the optical disk to be verified.
To this end, the invention proposes a manufacturing process for a master disk for the production of an optical disk pressing matrix which includes marking of a type consisting of:
20- depositing a layer of photosensitive resin on one side of the support.
- depositing this support, bearing the layer of photosensitive resin, onto the turntable of a recording machine.
- recording the information to be copied and to be read by an optical disk reader, in the form of a latent CA 02206364 1997 - 08 - 2~
image, in the layer of photosensitive resin, by the relative motion of an appropriate light beam;
- eliminating the zones of exposed photosensitive resin, this removal then leading to the creation of a succession of micro-slots which are representative of the information to be copied and to be read by an optical disk reader, with the following characteristics:
Before proceeding to the recording stage. of the information to be copied and to be read by the optical o disk reader, a layer formed of zones of a first material and zones of a second material, with different reflectivities at the wavelengths of the given recording light beam, where these zones of different reflectivity comprise the marking, is interposed between the turntable of the recording machine and the support bearing the photosensitive resin.
Accordance to a first method for implementation of the invention process, the said marking is made up by reflecting zones of a first reflecting material at the 20 wavelengths of a recording light beam, and of non-reflecting zones of a second material which is non-reflecting at the wavelengths of the recording light beam, the zones of the first reflecting material representing the marking as a positive.
According to another method for implementation of the ~ invention process, the marking is made up by reflecting CA 02206364 1997-08-2~
zones of a first reflecting material at the wavelengths of the recording light beam, and of non-reflecting zones of a second material which is non-reflecting for the recording light beam, the said zones of the second non-reflecting material for the recording light beam representing the marking as a positive.
According to a variant of the two preceding methods for implementation of the invention process, the said second non-reflecting material is absent, thus creating o the said non-reflecting zones.
According to yet another method for implementation of the invention process, the marking is made up from the zones of a first material which is more reflecting and the zones of a second material which is less reflecting for the recording light beam, with the zones of the first more reflecting material representing the marking as a positive.
According to still another method for implementation of the invention process, the marking is made up from the zones of a first material which is more reflecting and the zones of a second material which is less reflecting for the recording light beam, with the zones of the second less reflecting material representing the marking as a posltlve.
CA 02206364 1997-08-2~
According to a variant of the manufacturing process for a master disk of the invention, the layer forming the marking is formed on an independent support plate.
It can also be formed directly on the medium of the master disk, on the surface of this medium opposite to that bearing the resin layer.
Again, it can be formed directly on the turntable of the recording machine.
The different methods of production and the variants o of the manufacturing process for a master disk of the invention can furthermore include the following stages after the removal if the exposed resin zones:
- transfer to the medium of the micro-slots obtained by the said removal stage, and - removal of the zones of residual resin.
The master disk obtained by the various modes of the manufacturing process for a master disk according to the invention also forms part of the invention.
The invention also concerns a manufacturing process for an optical disk pressing matrix bearing a marking, characterised by the fact that that it includes the manufacture of a master disk according to the process of the invention and/or the use of the master disk obtained by the manufacturing process for a master disk of the invention.
The invention also covers the pressing matrix thus obtained.
The invention also covers a manufacturing process for an optical disk bearing a marking, characterised by the fact that that it includes the manufacture or the use of a master disk and/or the use of a pressing matrix according to the invention.
The master disk thus obtained also forms part of the invention.
Other objectives, details and advantages of this invention will appear more clearly on reading the detailed description which will now follow, with reference to the attached drawings in which:
- figure 1 shows, schematically, the manufacturing process for a master disk in accordance with the methods described above, and - figure 2 represents, schematically, the various stages of a variant of a manufacturing process for a master disk according to the invention.
In figure 1 attached, the process for ~he manufacture of a master disk according to the above method consists, in the stage marked (a), of depositing a layer of photosensitive resin of the positive type on support 1, generally made of glass.
CA 02206364 1997 - 08 - 2~
Then, as illustrated in the stage marked (b) in figure 1, this support (1) bearing the photosensitive resin is placed on the turntable (3) of the recording machine.
At the stage marked (c), the information to be copied and which will be read later by an optical disk reader (the programme material), are recorded in the form of a latent image into the layer (2) of photosensitive resin by the relative motion of an appropriate light beam, generally a laser beam. As illustrated in the stage o marked (c), this results in exposed resin zones (5).
During this recording process, and as illustrated by the dotted arrows in stage (c) of figure 1, laser beam 4 successively passes through the resin layer, changing its nature, to the focus point of the laser, and is absorbed by the turntable (3) of the recording machine.
Next, in the resin development stage, shown as (d) in figure 1, the exposed resin zones (5) are removed by any means known to professionals in this field. This leads to the creation, in the layer of photosensitive rèsin, of 20 micro-slots (6) representing the information to be copied and to be read by an optical disk reader.
This has now resulted in a master disk which bears on its surface a series of micro-slots representing a positive of the information to be copied (the programme material).
CA 02206364 1997-08-2~
From this master disk, a pressing matrix is created, generally in nickel, with on its surface a succession of micro-ridges which correspond to a negative of the micro-slots described previously.
This pressing matrix will then be used to press out the optical disks, generally on polycarbonate, bearing a succession of micro-slots which are a replica of micro-slots 6.
The optical disk is then covered with a thin metallic o reflecting layer which will allow a light beam emitted by the compact disk reader to read the recorded information.
As noted above, during the stage marked (c) in recording the information in the form of a latent image in photosensitive resin layer 2, laser beam 4 exposes the appropriate zone of the resin, passes through glass support 1, and is absorbed by the turntable of the machine.
The invention is based upon the following phenomenon.
If we interpose between the turntable (3) of the recording machine and the support (1) of the master disk, bearing its layer of photosensitive resin (2), a layer formed of at least two materials of different reflectivities, thus leading to the creation of at least two types of zones of different reflectivity representing a marking, the laser beam is reflected by these zones of different reflectivity, passes back through the support, and re-exposes the resin at the same place by virtue of the speed of the light emitted by the recording laser beam, which is naturally greater than the rotation speed of the turntable (3).
Therefore if we place, between support 1 and turntable 3, a layer formed of several zones of different reflectivity representing a marking, then the reflected laser beam re-exposes the resin, and this marking will be seen on developing the micro-slots. In fact the micro-slots which receive more light will be more open than theothers for the same development time (removal of exposed resin zones, as shown in stage (d)).
This phenomenon was used in the invention in order to create a marking on a master disk, and therefore on the pressing matrix obtained from this master disk and finally on the optical disk obtained from this pressing matrix.
In order to make it easier to understand the invention, we will now give several methods of implementation, purely as illustrative examples.
Firstly, if we refer to figure 2 attached, a method will be described for implementing the manufacturing process for a master disk for the creation of an optical disk pressing matrix bearing a marking in accordance with the invention.
The first stage, shown as (a) in figure 2, is identical to that of the process described above. On support 1, generally of glass, a positive-type layer of photosensitive resin is deposited.
Here, however, in contrast to the previously describe process illustrated in figure 1, and as illustrated in the stage shown as (a') in figure 2, this support (1), bearing the layer of photosensitive resin (2), is deposited on top of layer 7 formed by the reflecting zones shown as 8a and the non-reflecting zones shown as 8b. Zones 8a and 8b comprise the wanted marking.
o The marking can be a simple representation of the programme material contained on the optical disk. In this case however, the marking must be capable of being be viewed from the face of the optical disk, finally obtained because of the invention process, onto which is placed, using existing methods, the label performing the marking function of the invention, namely, presentation of the programme contained on the optical disk.
To this end, no label of any description must be placed on this side of the disk. In fact there is no further need here for any label on the optical disk of the invention.
This marking can equally well be a logo, a series of letters or numbers, a hologram, or any other graphic identifying the various participants, including the publisher, the company which manufactured the master disk and/or the pressing matrix, the company which did the pressing, and so on. In other words, it is an anti-pirate mark.
In this last case, it is possible to place a label on the optical disk, since the anti-pirate marking will be visible on the side of the optical disk opposite to that bearing the label, affixed by existing methods, intended to carry the nature of the programme contained on the optical disk. It is therefore possible to execute attachment of the label which has become necessary here.
o It should be noted, however, that in all of these cases, the marking is visible from both sides of the optical disk as long as no label is placed on it. The marking can simultaneously represent the programme contained on the disk and also a distinctive anti-pirate marking.
Moreover, in contrast to existing anti-pirate measures, the markings of the invention can cover the whole available area of the optical disk aimed at finally, without altering the thickness of the photosensitive resin layer and without affecting the unexposed areas of resin.
This is also true when the marking is used to represent the programme material contained on the optical disk.
This marking will therefore be large enough to be seen and clearly identified by the final consumer.
Then in the stage shown as (b) in figure 2, layer 7 and support 1 bearing resin layer 2 are deposited, using existing methods, onto the turntable (3) of an information recording machine.
Here layer 7 is formed on an independent support plate (not shown) in order to give it rigidity and the necessary mechanical properties.
There is no need to modify the conventional recording machine in any way whatsoever.
During the recording of information in the form of a latent image in resin layer 2, laser beam 4, modulated in o accordance with the information to be recorded and to be read by the optical disk reader, and as illustrated by the dotted arrows in stage (c) of figure 2, successively passes through photosensitive resin layer 2, exposing it in certain defined zones, thus leading to the formation of the zones marked 5 of exposed resin representing the information, and also support 1 in glass. The beam then reaches layer 7. If it encounters reflecting zone 8a of layer 7, the beam will be reflected, will pass again through the glass support, and will re-expose photosensitive resin 2 in the zones already exposed. This phenomenon is illustrated in figure 2 by dotted arrows which are slightly shifted to make the figure clearer.
Conversely to this, if the laser beam encounters non-reflecting zone 8b, it will be either absorbed by these non-reflecting zones 8b or it will pass through these non-reflecting zones to then be absorbed by turntable 3 of the recording machine.
Thus, as illustrated in figure 2, we get support 1, bearing resin layer 2, and having on its surface zones of resin, marked 5a, which have been exposed twice, representing the marking and the information to be copied, and zones 5 of resin which has been exposed only once, representing only the information to be copied.
The resin is then developed, meaning that the exposed resin zones are removed. As illustrated in stage (d), we then get a master disk made up of support 1 bearing in its o surface micro-slots 6 representing the information to be copied and micro-slots 8, corresponding to the double-exposed resin zones 5a, representing the marking and the information to be copied.
In figure 2, the modification of double-exposed micro-slots, shown as 5, has been deliberately exaggerated to better illustrate this phenomenon.
However the modifications made by the laser beam, reflected by the reflecting zones of layer 7, are very small, and are within the current tolerance standards 20 imposed on the size of the micro-slots 6, in order not to disrupt reading of the information of which these micro-slots are representative.
This means that an electronic reading device will not detect them, and the marking cannot be copied.
The professionals of the trade are familiar with the tolerance standards, which can vary with advances in the CA 02206364 1997 - 08 - 2~
manufacturing technology of the master disks. But these modifications, even though they are very small, of microscopic dimensions, are perfectly visible on the macroscopic scale.
In the above production method, layer 7 is formed by reflecting zones 8a composed of a first reflecting material, and then non-reflecting zones 8b composed of a second non-reflecting material. Reflecting zones 8a can be created by metallising through a mask of a support o plate which is non-reflecting to information recording light beam 4. This means that non-reflecting zones 8b can also be created by the absence of the second non-reflecting material. The reflecting zones can be representative of the marking as a positive or as a negative. In other words, the mask can allow the metallising to pass in order to represent the marking as a positive, or can represent it as a negative.
According to another method of implementation of the invention, layer 7 can be formed by more reflecting zones 8a and less reflecting zones 8b. Depending on the reflectivity of these zones, the laser beam, when it is recording the information, will be more or less reflected, and will therefore expose resin 2 to a greater or lesser degree.
The same micro-slot modification effect will thus be obtained, and the marking will also be visible.
CA 02206364 l997-08-2 In this case, in the same way as before, the more reflecting zones, 8a, can represent the marking as a positive or negative image.
According to yet another method of implementation of the invention, while in figure 2 zones 8a and 8b are represented as separate from support 1 and bearing photosensitive resin layer 2, and have been described previously as being deposited on an independent support plate, the marking composed of more reflecting zones 8a o and less reflecting zones 8b or of reflecting zones 8a and non-reflecting zones 8b can be formed directly on the surface of support 1, which is coated with the photosensitive resin.
The more reflecting zones 8a and less reflecting or non- reflecting zones 8b comprising the marking can also be formed directly on turntable 3 of the recording machine.
It should also be noted that another variant of the manufacturing process for the master disk of the invention, after the stage for removal of the exposed resin zones, consists of transferring the micro-slots into glass support 1, by plasma engraving for example, and then removing the zones of residual resin.
In this case the master disk is also composed of support 1, bearing on its surface a series of micro-slots engraved into the support itself.
CA 02206364 1997 - 08 - 2~
Also while the manufacturing process of a master disk, in accordance with the invention, was described using a layer of photosensitive resin of the positive type, it is also possible to use a photosensitive resin of the negative type, but in this case, it is the non-exposed resin zones which will be removed in the stage marked (d) in figure 2.
From this master disk, it is then possible to manufacture an optical disk pressing matrix and the o optical disks themselves.
The marking will be visible to the naked eye because of the diffraction of visible light induced by micro-slots 8, corresponding to deformed micro-slots 6, and representing the marking and the information to be read, which is different from the diffraction of visible light caused by micro-slots 6 when not deformed and representing only the information to be read.
In all of the variants and different methods of manufacture of the master disk described above, the 20 reflecting material or non-reflecting material or material reflecting to a greater or lesser degree will be reflecting or non-reflecting or reflecting to a greater or lesser degree for the light emitted by the recording laser beam.
To a professional in the trade, it will appear that any material allowing reflection of the light beam employed to record the information, will be appropriate.
He will also be able to determine the nature of these materials.
Also, while reference has been made to various materials n the above description of the process of the invention, it should be understood that what matters here is the different degrees of reflectivity between the various zones representing the marking.
The stages of the different variants of the process of o manufacture of the master disk of the invention can be incorporated into the manufacturing process of an optical disk pressing matrix and in the process for manufacture of optical disks, with no change to the equipment, and in all cases these processes will lead to the creation of optical disks bearing a marking visible to the naked eye but which cannot be read by an electronic device, and therefore cannot be copied.
Of course the invention is not limited in any way to the methods of implementation described above and illustrated. These have been provided only as examples.
Therefore although in the various methods of implementation previously described, layer 7 was described as being formed of two types of zone, 8a and 8b, with different reflectivities, it can also be formed, as desired, from a larger number of zone types of different reflectivities.
This means that it includes all techniques equivalent to the means described, and all their combinations, if these are effected in accordance with its spirit.
Claims (15)
1. A process for the manufacture of a master disk for the creation of optical disk pressing matrices bearing a marking, in particular of the anti-pirate type, consisting of:
(a) depositing a layer of photosensitive material (2) on one side of a support (1).
(b) depositing this support (1), bearing the layer of photosensitive resin (2) onto the turntable (3) of a master disk recording machine.
(c) recording the information to be copied and to be read later by an optical disk reader, in the form of a latent image, in the layer of photosensitive resin (2), by the relative motion of an appropriate light beam (4).
(d) removal of the zones of photosensitive resin in the zones (5) of exposed resin, this removal then leading to the creation of a series of microslots (6) which are representative of the information to be copied, and with the following characteristics:
(a') before proceeding to the recording stage (c) of the information, a layer (7) formed of zones (8a) of a first material and zones (8b) of a second material, with different reflectivities at the wavelengths of the given recording light beam (4), where these zones of different reflectivity comprise a marking, is interposed between the turntable (3) of the recording machine and the support (1) bearing the photosensitive resin (2).
(a) depositing a layer of photosensitive material (2) on one side of a support (1).
(b) depositing this support (1), bearing the layer of photosensitive resin (2) onto the turntable (3) of a master disk recording machine.
(c) recording the information to be copied and to be read later by an optical disk reader, in the form of a latent image, in the layer of photosensitive resin (2), by the relative motion of an appropriate light beam (4).
(d) removal of the zones of photosensitive resin in the zones (5) of exposed resin, this removal then leading to the creation of a series of microslots (6) which are representative of the information to be copied, and with the following characteristics:
(a') before proceeding to the recording stage (c) of the information, a layer (7) formed of zones (8a) of a first material and zones (8b) of a second material, with different reflectivities at the wavelengths of the given recording light beam (4), where these zones of different reflectivity comprise a marking, is interposed between the turntable (3) of the recording machine and the support (1) bearing the photosensitive resin (2).
2. A process in accordance with claim 1, with the characteristic that the said marking (8) of the layer (7) is made up by reflecting zones (8a) of a first reflecting material at the wavelengths of a recording light beam (4), and of non-reflecting zones (8b) of a second material which is non-reflecting at the wavelengths of the recording light beam (4), the zones (8a) of the first reflecting material representing the marking (8) as a positive image.
3. A process in accordance with claim 1, with the characteristic that the said marking (8) is made up by reflecting zones (8a) of a first reflecting material at the wavelengths of the light beam (4), and of non-reflecting zones (8b) of a second material which is non-reflecting for the recording light beam (4), the said zones (8b) of the second non-reflecting material representing the marking as a positive image (8).
4. A process in accordance with claim 2 or claim 3, with the characteristic that the non-reflecting zones (8b) are created by not depositing the said second material.
5. A process in accordance with claim 1, with the characteristic that the marking is made up from the zones (8a) of a first material which is more reflecting for the recording light beam (4) and the zones of a second material (8b) which is less reflecting for the recording light beam (4), with the zones (8a) of the first more reflecting material representing the said marking as a positive image (8).
6. A process in accordance with claim 1, with the characteristic that the marking (8) is made up from the zones (8a) of a first material which is more reflecting for the recording light beam (4) and the zones (8b) of a second material which is less reflecting for the recording light beam (4), with the zones (8b) of the second less reflecting material representing the said marking as a positive image (8).
7. A process in accordance with any of the above claims, with the characteristic that the layer (7) is formed on an independent support plate.
8. A process in accordance with any of the above claims 1 to 6, with the characteristic that the layer (7) it can be formed directly on the turntable (3) of the recording machine.
9. A process in accordance with any of the above claims 1 to 6, with the characteristic that the layer (7) can also be formed directly on the support (1), on the surface of this support (1) opposite to that bearing the resin layer (2).
10. A process in accordance with any of the above claims, with the characteristic that after stage (d) for removal of the zones (5) of exposed zones, the following stages are carried out:
(e) transfer to the support (1) of the microslots obtained by stage (d), and (f) removal of the zones of residual resin.
(e) transfer to the support (1) of the microslots obtained by stage (d), and (f) removal of the zones of residual resin.
11. The master disk, bearing a marking, particularly of the anti-pirate type, obtained by the process in accordance with one of the foregoing claims.
12. The manufacturing process for an optical disk pressing matrix bearing a marking, particularly of the anti-pirate type, characterised by the fact that that it includes the manufacturing stages for a master disk according to the process covered by any of the claims 1 to 10.
13. A pressing matrix for the pressing of an optical disk bearing a marking, especially of the anti-pirate type, obtained by claim 12 or from the master disk according to claim 11.
14. The process for manufacture of optical disks bearing a marking, particularly of the anti-pirate type, with the characteristic that it includes the manufacturing stages for a master disk in accordance with any of the claims 1 to 10 and/or the manufacturing process for a pressing matrix in accordance with claim 12.
15. An optical disk bearing a marking, particularly of the anti-pirate type, obtained in accordance with the process of claim 14, or from the master disk in accordance with claim 11 or the pressing matrix according to claim 13.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FR9606761A FR2749432B1 (en) | 1996-05-31 | 1996-05-31 | METHOD FOR MANUFACTURING A MASTER DISC FOR PRODUCING PRESSING DIES FOR OPTICAL DISCS INCLUDING A MARKING, PARTICULARLY ANTI-HACK, MASTER DISC, PRESSING MATRIX AND OPTICAL DISC OBTAINED |
| FR9606761 | 1996-05-31 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2206364A1 true CA2206364A1 (en) | 1997-11-30 |
Family
ID=9492619
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002206364A Abandoned CA2206364A1 (en) | 1996-05-31 | 1997-05-28 | Process for the manufacture of a master disk for the production of optical disk pressing matrices bearing a marking, particularly of the anti-pirate type, a master disk, a pressing matrix and the optical disk obtained |
Country Status (5)
| Country | Link |
|---|---|
| EP (1) | EP0810593A1 (en) |
| JP (1) | JPH1055571A (en) |
| BR (1) | BR9703352A (en) |
| CA (1) | CA2206364A1 (en) |
| FR (1) | FR2749432B1 (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5958651A (en) * | 1996-07-11 | 1999-09-28 | Wea Manufacturing Inc. | Methods for providing artwork on plastic information discs |
| US6631359B1 (en) * | 1999-09-10 | 2003-10-07 | Dphi Acquisitions, Inc. | Writeable medium access control using a medium writeable area |
| US8369562B2 (en) | 2007-03-30 | 2013-02-05 | Hitachi Global Storage Technologies Netherlands B.V. | Encryption methods for patterned media watermarking |
| ES2332393B2 (en) * | 2007-04-12 | 2010-06-23 | Universidad De Granada | OPTICAL METHOD AND APPARATUS FOR THE DETECTION OF COPIES PIRATES OF CDS. |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0648546B2 (en) * | 1984-07-14 | 1994-06-22 | 日本ビクター株式会社 | Method of manufacturing information record carrier |
| JP3109866B2 (en) * | 1990-11-17 | 2000-11-20 | 太陽誘電株式会社 | Substrate for optical information recording carrier and method of manufacturing the same |
| DE4311683C2 (en) * | 1993-04-08 | 1996-05-02 | Sonopress Prod | Disc-shaped optical memory and method for its production |
-
1996
- 1996-05-31 FR FR9606761A patent/FR2749432B1/en not_active Expired - Fee Related
-
1997
- 1997-05-28 CA CA002206364A patent/CA2206364A1/en not_active Abandoned
- 1997-05-29 JP JP9140341A patent/JPH1055571A/en active Pending
- 1997-05-29 EP EP97401185A patent/EP0810593A1/en not_active Withdrawn
- 1997-05-30 BR BR9703352-9A patent/BR9703352A/en not_active Application Discontinuation
Also Published As
| Publication number | Publication date |
|---|---|
| BR9703352A (en) | 2003-08-26 |
| FR2749432B1 (en) | 1998-07-10 |
| EP0810593A1 (en) | 1997-12-03 |
| JPH1055571A (en) | 1998-02-24 |
| FR2749432A1 (en) | 1997-12-05 |
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| Date | Code | Title | Description |
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| FZDE | Discontinued | ||
| FZDE | Discontinued |
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