AN IMPROVED MANUFACTURING SYSTEM FOR OPTICAL MEDIA AND AN IMPROVED MANUFACTURING METHOD THEREOF
FIELD OF THE INVENTION
The present invention, in general, relates to an improved manufacturing system for optical media and to an improved method for manufacturing optical media and in particular, to application of an ID vacuum pin assembly instead of capillary table for bringing glue up to mote area, by capillary action, during bonding process , in optical media manufacturing lines and in particular, to an improved method for spreading resin over the discs prior to spinning , involved in bonding process of optical media manufacturing lines, which minimize chances of rejection due to resin bubble formations.
BACKGROUND OF THE INVENTION
Traditionally, manufacturing process for optical media such as DVDRS, involves the three principal steps of dye coating,.sputtering and bonding. In such manufacturing processes known in the art, bonding involves, joining of discs with the help of Resin. Resin dispenses at bonding chuck between discs through a needle. Thereafter, capillary action takes place and resin is spread all over the disc. Then the disc goes for spinning. After spinning, disc is picked from spin cup and placed at the UV Area.
Spreading of resin over the discs, prior to spinning is of vital importance, in bonding process. Hitherto, this was achieved by capillary action by capillary tube, so that the glue can reach mote by capillary action before spinning takes place. However, whenever there is stoppage in line or capillary time fluctuates, there is huge rejection, particularly due to bubble formation, which may go up to 3.5% to 4%.

Attempts are on over the years, to overcome this problem. To some extent, it has been possible to compensate this problem by increasing capillary time for initial few discs when the line starts after a stoppage. However, significant improvement has not been achieved, in reducing capillary time fluctuation. Furthermore, rejection by resin bubble formation could not be reduced to a substantial extent.
Patent no. US6254716 B1 teaches application of some kind of apparatus, to join the two discs together bu{ it does not teach how to avoid capillary time fluctuation. Patent no. US20030179693 A1 teaches bonding in a closed Chamber, and this patent describes the DL 2P process. Patent no. EP9O8876 A2 teaches a bonding process, where glue is brought up to the moat, with the help of the force applied by the second substrate.
However, none of the aforesaid patents teach minimization of rejection by bubble formation and minimization of stoppage inl production line or capillary time fluctuation to a significant extent.
Hence, there was a long felt need for an improved manufacturing system for optical media and for an improved method for manufacturing optical media, whereby during bonding process in the manufacturing lines, spreading of resin on the discs, prior to spinning is initiated by an improved technology other than capillary action, so that capillary time fluctuation, stoppage in production line and
rejection by resin bubble formation are minimized.
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The present invention meets the aforesaid long felt need and prevents bonding from becoming the bottle neck in optical media manufacturing lines. . Thus, the present invention also ensures minimization of production cost and consequently, minimization of cost of the final product.

At places through out the specification, the term DVDR, discs, optical discs have been referred to, purely for the sake of understanding and not by way of any sort of limitation and the present invention includes similar devices in the field of optical media and related fields.
OBJECTS OF THE INVENTION
It is a principal object of the present invention to provide an improved manufacturing system for optical media, which minimizes rejection due to bubble formation during bonding process from between 3.5% and 4% to between 1% and 1.5%.
It is a further object of the present invention to provide a method for manufacturing optical media, including an improved bonding process which minimizes rejection due to bubble formation, during bonding process from between 3.5% and 4% to between 1% and 1.5%.
It is a further object of the present invention, to provide an improved method for bonding, involved in the process of manufacturing optical media , which utilizes a ID vacuum pin assembly rather than capillary table, for spreading of resin on the discs prior to spinning in bonding process , to be precise for bringing glue up to the mote area , whereby rejection of discs due to bubble formation, stoppage in production line and capillary time fluctuation are minimized.
It is yet another object of the present invention to provide an improved method for manufacturing optical media which reduces the overall cost of production and consequently, the overall cost of the final product.
It,is a further object of the present invention to provide a method for reducing resin bubble formation and consequently rejection during the bonding process,

involved in manufacturing optical media.
It is a further object of the present invention to provide an improved Id vacuum pin assembly for spreading of resin on the discs prior to spinning in bonding process , to be precise for bringing glue up to the mote area , whereby rejection of discs due to bubble formation, stoppage in production line and capillary time fluctuation, are minimized.
It is a further object of the present invention to provide an improved optical medium, obtained by the improved manufacturing system as stated aforesaid.
The foregoing objects and the other aspects of the present invention, will be clear from the following description which is purely by way of understanding and not by way of any sort of limitation.
SUMMARY OF THE INVENTION
Accordingly, the present invention provides an improved manufacturing system for optical media including means for dyeing, sputtering and bonding wherein said means for bonding has an improved ID vacuum pin assembly, for spreading of resin on the discs prior to spinning in bonding process , to be precise for bringing glue up to the mote area , configuration of said assembly being modified for sucking, whereby rejection due to bubble formation is minimized by approximately 70% to 75% and stoppage in production line and capillary time fluctuation are minimized.
In accordance with preferred embodiments of the manufacturing system in accordance with the invention:
-said assembly includes ID Vacuum pin,a mounting plate and a pneumatic cylinder, all operatively connected to each other for ensuring working inter¬relation.
-said ID Vacuum pin includes disc base, mounting, tightening screw and lift, all operatively connected to each other to facilitate sucking glue up to the moat area.

-said assembly, is installed separately after the bonding station.
The present invention also provides an improved method for manufacturing
optical media including dyeing, sputtering and bonding, said process for bonding
involving, joining of discs, with the help of resin, dispensing resin at bonding
chuck between the discs, initiation of sucking action by a ID vacuum pin
assembly, for spreading of resin all over the discs, to be precise for bringing glue
up to the mote, area, followed by spinning, picking of discs from spin cup and
placing at the UV Area, wherein configuration of said assembly is modified for
sucking, whereby rejection due to bubble formation is minimized by
approximately 70% to 75% ,and stoppage in production line and capillary time
fluctuation are minimized.
In accordance with preferred embodiment of the method of the invention:
-said assembly is modified by operatively connecting ID Vacuum pin,a mounting
plate and a pneumatic cylinder, each other for ensuring working inter-relation
wherein said ID vacuum pin includes disc base, mounting, tightening screw and
lift, all operatively connected to each other to facilitate sucking glue up to the
mote area.
The present invention also provides an optical media manufactured by the
method as claimed herein before.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
The nature and scope of the present invention, will be better understood from the
accompanying drawings, which are by way of illustration of some preferred
embodiments and not by way of any sort of limitation. In the accompanying
drawings:
Fig 1 illustrates an exploded view lot the capillary tube and the spin cup, used in
the existing systems for manufacturing optical media.
Fig 2 illustrates an exploded view:of the base plate showing the mounting plate for capillary table used in the existina svstems for manufacturing optical media.

Fig 3 illustrates an isometric view of the capillary table, used in the existing systems for manufacturing optical media.
Fig 4 illustrates the flow of discs in the existing optical media manufacturing systems.
Fig 5 illustrates an exploded view of the ID vacuum pin in accordance with a preferred embodiment of the present invention.
* Fig 6 illustrates an exploded view of the ID vacuum pin in accordance with a
preferred embodiment of the present invention, showing the location of the disc
to be placed and the vacuum to be created.
Fig 7 illustrates a top view and a two-dimensional view of a preferred embodiment of the fixture applied, in accordance with the present invention.
Fig 8 illustrates a top view and a two-dimensional view of a preferred embodiment of the mounting plate , in accordance with the present invention.
Fig 9 illustrates an enlarged view of a preferred embodiment of the ID vacuum pin assembly, in accordance with the present invention.
Fig 10 illustrates the flow of discs in the optical media manufacturing systems
in accordance with the invention.
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Fig 11(a) illustrates an enlarged view of the technology known in the art for initiating capillary action.
Fig 11(b) illustrates a preferred embodiment of the ID vacuum pin assembly in accordance with the invention, which is proposed to be installed in place of the existing technology for initiating capillary action.
Fig 12 illustrates a comparative graphical representation, of resin bubble

rejection before and after implementation of the invention.
BRIEF DESCRIPTION OF THE INVENTION
The following describes some preferred embodiments of the present invention, which are purely for the sake of understanding the performance of the invention, and not by way of any sort of limitation.
As stated aforesaid traditionally, manufacturing process for optical media such as DVDRS, involyes the three principal steps of dye coating, sputtering and bonding. In such manufacturing processes known in the art, bonding involves, joining of discs, with the help of Resin. Resin dispenses at bonding chuck between discs . Thereafter, capillary action takes place and resin is spread all over the disc. Then the disc goes for spinning. After spinning, disc is picked from spin cup and placed at the UV Area, The present invention, lies in the domain of finding an alternative, for spreading of resin over the discs,by capillary action. Presently, this spreading is dependent on capillary action, utilizing capillary table. However, defects such as capillary time fluctuation and high percentage of rejection due to resin bubble formation, have cropped up over the years, on applying this technology.
The present invention utilizes an ID vacuum pin assembly to suck glue up to the
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moat, rather than capillary action prior to spinning, said assembly being installed separately after the bonding station. By doing so, no requirement for capillary action will exist and hence, no capillary time fluctuation will take place. Also by using such ID vacuum pin assembly, resin bubble rejection gets reduced by 70 to 75 %.The modification ensures reduction in the resin bubble rejection, reduction in the BSR rejection oh Challenger-1 lines. Thus productivity of lines get increased on same cycle time and bonding will not remain the bottle neck for reducing cycle time. In a nut sh^ll the present invention is directed to use of Vacuum at ID to get glue up to the mote area, instead of Capillary action as

presently prevalent in Challenger-1 lines.
The acknowledged patent no. US6254716 B1, teaches that some kind of apparatus is used to join the two discs together, but in the present invention no such apparatus is being used, rather, a vacuum is utilized to bring glue up to the mote area. The present invention teaches designing a way on existing Challenger-1 lines to eliminate delay table, which was earlier used to bring glue up to mote area by capillary action. The acknowledged Patent no. EP9O8876 A2 teaches bringing up of bonding glue to the mote with the help of the force applied by the second substrate, but on the contrary, the present invention utilizes vacuum to suck glue up to the mote, on a stationary pin installed, separately after the bonding station.
Fig 1 shows the arrangement of the spin cup (1) and the capillary table(2) in the systems known in the art. Fig 2 shows the mounting plate (3) for capillary table known in the art. Fig 3 shows the arrangement of slotted pin (4), mounting plate(3) and indexing plate(5), in the capillary table known in the art.
On a comparative study, of the flow of discs in the existing optical media manufacturing systems and the flow of discs in the optical media manufacturing systems in accordance with the invention, the advantages of the present invention would be clear. This has been clearly illustrated in Figures 4 and 10 respectively.
The configuration of the Id vacuum pin in accordance with the invention, will be clear from Fig 5. Typically, it comprises a disc base(6), mounting (7), tightening screw(8) and a lift(9) operatively connected to each other. Fig 6 indicates the location of the disc to be placed (10) and that of the vacuum(11) to be generated for sucking glue up to the mote, rather than capillary action prior to spinning, in bonding process. Figures 7 and 8 illustrate preferred embodiments of

the fixture and the mounting plate to be applied in accordance with the invention.
Figure 9 illustrates preferred embodiment of the ID vacuum pin assembly of the present invention which comprises a ID vacuum pin (12) mounting plate(7) and pneumatic cylinder(13) for sucking glue up to the mote to facilitate spreading of resin on discs, prior to spinning in bonding process, involved in optical media.
From Figures 11(a) and 11(b), the difference in configuration between the
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technology existing in the art for initiating capillary action for sucking the glue up to the mote and that of the proposed ID vacuum pin assembly, proposed to replace the existing technology. The highlighted portions in the Figures 11(a) and 11(b), very clearly illustrate the improvement. Furthermore, the comparative results, manifested in the graph shown in Figure 12, unequivocally establish, drastic reduction in resin bubble rejection, after implementation of the ID vacuum pin assembly in accordance with the invention.
The present invention has been described with reference to some drawings and preferred embodiments, purely for the sake of understanding and not by way of any limitation and the present invention includes all legitimate developments within the scope of what has been described hereinbefore and what has been claimed hereinafter.

WE CLAIM
1. An improved manufacturing system for optical media including means for dyeing, sputtering and bonding wherein said means for bonding has an improved ID vacuum pin assembly for spreading of resin on the discs prior to spinning in bonding process , to be precise for bringing glue up to the mote area , configuration of said assembly being modified for sucking, whereby rejection due to bubble formation is minimized by approximately 70% to 75% and stoppage in production line and capillary time fluctuation are minimized.
2. The improved manufacturing system for optical media wherein said assembly includes ID Vacuum pin,a mounting plate and a pneumatic cylinder, all operatively connected to each other for ensuring working inter-relation.
3.The improved manufacturing system as claimed in claim 2 wherein said ID Vacuum pin includes disc base, mounting, tightening screw and lift, all operatively connected to each other to facilitate sucking glue up to the mote area.
4. The improved manufacturing system for optical media as claimed in any preceding claim, wherein said assembly, is installed separately after the bonding station,
5.An improved method for manufacturing optical media including dyeing, sputtering and bonding, said process for bonding involving, joining of discs, with the help of resin, dispensing resin at bonding chuck between the discs, initiation of sucking action by a ID vacuum pin assembly, for spreading of resin all over the discs, to be precise for bringing glue up to the mote area, followed by spinning, picking of discs from spin cup and placing at the UV Area, wherein configuration of said assembly is being modified for sucking, whereby rejection due to bubble formation is minimized by approximately 70% to 75% and stoppage in production line and capillary time fluctuation are minimized.

6. The improved method for manufacturing optical media as claimed in claim 5 wherein said assembly is modified by operatively connecting ID Vacuum pin,a mounting plate and a pneumatic cylinder, each other for ensuring working inter¬relation wherein said ID vacuum pin includes disc base, mounting, tightening screw and lift, all operatively connected to each other to facilitate sucking glue up to the mote area.
7..Optical media manufactured by the method as claimed in claims 5 to 6.