Title of Invention

"VAPOR DEPOSITION APPARATUS FOR COATING OPTICAL SUBSTRATES"

Abstract

For the vacuum coating plant for vacuum evaporating antireflection coatings onto optical substrate surfaces, such as plastic spectacle lenses, which can be clamped onto carrier means, located above or below replaceable evaporation sources in a container that can be evacuated, the carrier means are formed by a reversible carrier device (3) with a plurality of reversible carriers (21), arranged radially around a circular carrier plate (23), which reversible carriers are each supported on a rotational axis (22) that can be rotated temporarily by 180°, wherein each reversible carrier (21) comprises means for a clamped holding of a substrate to be coated on both sides or for holding two substrates to be coated on one side, and wherein reversing means for the simultaneous reversal of all reversible carriers act upon the reversible carriers (21) or the rotational axes (22) . As a result of these measures, the cyclical replacement of the evaporation sources is reduced by one half and thus also their heating up, which in turn considerably reduces the danger of a decomposition of the evaporation materials as well as the suboxide formation and the resulting changes in the refraction value. (Figure 1)

Full Text

•Ant iref lection—Coatings—onto—Opfeioa-1—Sur-facea The invention at hand concerns a vacuum coating plant for the vacuum evaporation of nntirofloction contingn onto optical substrate surfaces, such as plastic spectacle lenses, which can be clamped onto carrier means, located either above or below replaceable evaporation sources in a container that can be evacuated. In such known plants where at least one surface layer is evaporated onto optical substrates, in particular spectacle glasses, in a vacuum, a predetermined number of such substrates are removed from the plane in which the substrate nurfaccs wore subjected to the effects of the replaceable evaporation sources, following the depositing of, as a rule, several layers through vacuum evaporation, and an egual number of substrate surfaces are again moved into this plane, which are then also coated once or several times. A rotating table, for example, can be used for this, which can be placed under vacuum and has along its circumference a plurality of stations for the removable fastening of substrates. This plant further includes at least one evaporation source that can effectively act upon the substrate surface facing it. In this case, each station is provided with a reversing device with fastening means for a removable fastening of two each substrates with a screen between them. Once the individual antireflection layers have been deposited successively onto one substrate surface side by vacuum evaporation, the fastening means are reversed by turning the rotational table and the other substrate surfaces are then coated. Such a plant is, however, complicated, involved and very slow. On the other hand, a plant is also known which uses as carrier means a plurality of so-called calottes that extend respectively dome-shaped and rotatable in the upper section of the container and which have a plurality of, for example a total of 36, clamping openings that are distributed evenly over the calottes and which hold the substrates. With this, a plurality of substrates each can be turned simultaneously by turning each calotte. If the individual antireflection coatings are then deposited on one side by vacuum evaporation onto the substrate surfaces, the calottes are turned by moving past a turning mechanism and the other substrate surfaces are vacuum coated. However, such facilities do not meet today's requirements, especially since after each vacuum coating operation, the evaporation source must be turned off and, following cooling down, a new source must be used for a new antiref lection coating. All of this is again repeated for coating the surfaces of the substrates which have been turned. In addition, as a result of the frequent heating up of the evaporation sources, which can for example be electron-beam evaporators or resistance-heated thermal evaporators, there, is the danger of a decomposition of the evaporation materials as well as the suboxide formation and the resulting changes in the refraction value. In a parallel patent application, the same applicant now has claimed a method for coating optical substrates, in particular spectacle glasses or lenses in a plant of the aforementioned type, where according to the invention the surfaces facing the evaporation source of the substrates clamped onto carrier means are initially coated within one each vacuum coating operation for producing an ant;ireflection coating, and for which the carrier means with the substrates are then rotated quickly without shutting down the evaporation source and the substrate surfaces now facing the evaporation source are also vacuum coated. This is followed by a cyclical replacement of evaporation sources for respectively applying another antireflection coating onto the substrate surfaces during a new vacuum coating operation. These measures reduce the cyclical replacement of the evaporation sources by one half and thus also their heating up, which in turn considerably reduces the danger of a decomposition of the evaporation materials as well as the suboxide formation and the resulting changes in the refractory value. It is the object of the invention at hand to create a vacuum coating plant of the aforementioned type, which makes it possible to turn all substrates simultaneously and without interrupting the evaporation flow. In accordance with the invention, this is achieved in that the carrier means are formed by a reversible carrier device, with a plurality of reversible carriers arranged radially around a circular carrier plate, which are each supported on a rotational axis that can be rotated temporarily by 180°, wherein each reversible carrier has means for the clamped holding of a substrate that must be coated on both sides or the holding of two substrates that must be coated on one side and wherein turning means for the simultaneous turning of all reversible carriers act upon the reversible carriers or rotational axes. In this case, one advantageous embodiment of the invention provides that the reversing means comprise a gear ring that projects from the circumference of the carrier plate and meshes with one each driving gear, which is operationally connected to the rotational axis of the reversible carrier as well as with another, temporarily rotatable counter gear ring. It is important here that at least the operational connection can be made hydraulically or pneumatically and that it can be controlled with a computer control. During each coating operation for producing an antireflection coating, it is possible with these measures to vacuum coat initially the surfaces facing the evaporation source of the substrates clamped onto the carrier means, then turn the carrier means with substrates quickly without shutting down the evaporation source and also coat the substrate surfaces now facing the evaporation source, whereupon a cyclical replacement of the evaporation sources occurs for respectively depositing another antireflection coating onto the substrate surfaces during a new vacuum coating operation. As a result of this, the cyclical replacement of the evaporation sources is reduced by one half and thus also the heating up, which in turn considerably reduces the danger of a decomposition of the evaporation coating materials as well as the suboxide formation and the resulting changes in the refraction value. Exemplary embodiments of the inventive subject are explained in more detail in the following with the aid of the drawing. Shown are in: Figure I A longitudinal cut of a diagrammatic, simplified representation of a vacuum coating plant for vacuum coating several optical substrates on a reversible carrier device; Figure 2 A diagrammatic, graphic illustration on a larger scale of the inventive reversible carrier device for the plant according to Figure 1. The exemplary embodiment for the vacuum coating plant shown in Figure 1 for evaporating antireflection coatings onto optical substrates, e.g. plastic spectacle lenses 10 in this case, comprises a container 1 that can be evacuated via a vacuum pump 2. Located in the upper chamber region of this container 1 is the inventive reversible carrier device 3 with a plurality of reversible carriers 21, arranged radially around a circular carrier plate 23, of which two are visible here, which are supported on one each rotational axis 22 that can be rotated temporarily by 180°, wherein each reversible carrier 21 comprises moans for a clamped holding of a subatrato to bo coated on both sides or for holding two substrates to be coated on one side each (not shown). The inventive reversible carrier device 3 is described in more dotnil in tha following. An evaporation source 100 is indicated in the lower region of the container 1, which here comprises a so-called electron-beam tube with a filament 15, where following heating of the tube, the exiting electrons are focused into a beam in a focussing device 16. The electron beam can, for example, be generated by a tungsten cathode applied to negative high voltage and can be prefocused with a 'formed Wehnelt cylindjer. With the aid of magnetic deflection means 13, this electron beam can then be deflected to a pan 17 where the evaporation material is located. Devices that extend from the outside into the vacuum chamber (not shown) and have operating components are necessary to operate or drive the plant components in the evacuated container 1, e.g. the screen 14 and the like. Since the design and function of such vacuum evaporation plants are known per se, a more detailed description of the configuration is not necessary. Above all, it is essential to the invention that the reversible carrier device 3, as can be seen in Figure 2, comprises a plurality of reversible carriers 21, arranged radially around a circular carrier plate 23, which are supported on one each rotatable axis 22 that can be rotated temporarily by 180°, wherein each reversible carrier 21 comprises means for a clamped holding of a substrate to be coated on both nidon or for holding two Gubntraton to bo coatod on one side and wherein reversing means for the simultaneous reversal of all reversible carriers act upon the reversible carriers 21 or the rotational axes 22. In this case, the reversing means comprise a ring gear 25 that projects along the circumference from the carrier plate 23 and meshes with one each driving gear 24 that is operationally connected to the rotational axis 22 for, the reversible carriers 21 as well as with another, temporarily rotatablc counter ring gear 26. With this and at a suitable point in time, it is possible to turn the counter ring gear 26 relative to the ring gear 25 until tho rovorniblo cnrriorn 21 with their nubntratoo have been turned by 180° via the respective driving gear 24. This occurs within fractions of a second, meaning so fast that the coating stream does not have to be interrupted. Thus, a vacuum coating plant for the vacuum evaporation of multiple antireflection coatings onto optical substrates follows from the above description, which meets all present requirements for such a plant. Of course, it is possible to make a series of modifications to the aforementioned plant without actually straying from the inventive idea. This relates to the design of the reversing means as well as the reversible carriers or their means for a clamped holding of the substrates. Furthermore, there are many ways of establishing the operational connection either hydraulically or pneumatically and to control this connection via a computer control. The following is claimed: 1. Vacuum coating plant for vacuum evaporating antireflection coatings onto the surfaces of optical substrates, such as plastic spectacle lenses, which can be clamped onto carrier means that are located either above or below replaceable evaporation sources in a container that can be evacuated, characterized in that the carrier means are formed by a reversible carrier device (3), with a plurality of reversible carriers (21) arranged radially around a circular carrier plate (23), which are respectively supported on a rotational axis (22) that can be rotated temporarily by 180°, wherein each reversible carrier (21) comprises means for a clamped holding of a substrate to be coated on both sides or for holding two substrates to be coated on one side each, and wherein reversing means for the simultaneous turning of all reversible carriers act upon the reversible carriers (21) or the rotational axes (22) . 2. Vacuum coating plant according to Claim 1, characterized in that the reversing means comprise a ring gear (25) that projects around the circumference from the carrier plate (23) and meshes with one each driving gear (24) and is operationally connected to the rotational axis (22) for the reversible carriers (21) as well as with a temporarily rotatable counter ring gear (26) . 3. Vacuum coating plant according to Claim 2, characterized in that at least the operational connection can be made hydraulically or pneumatically and that it can be controlled via a computer control. 4. Vacuum coating plant for vacuum evaporating antireflection coatings onto the surfaces of optical substrates/ substantially as hereinbefore described with reference to the accompanying drawings.

Documents:

1179-del-1997-abstract.pdf

1179-del-1997-claims.pdf

1179-DEL-1997-Correspondence-Others-(07-11-2008).pdf

1179-del-1997-correspondence-others.pdf

1179-del-1997-correspondence-po.pdf

1179-del-1997-description (complete).pdf

1179-del-1997-drawings.pdf

1179-DEL-1997-Form-1-(07-11-2008).pdf

1179-del-1997-form-1.pdf

1179-del-1997-form-13-(07-11-2008).pdf

1179-del-1997-form-19.pdf

1179-del-1997-form-2.pdf

1179-DEL-1997-Form-26-(07-11-2008).pdf

1179-del-1997-form-4.pdf

1179-del-1997-form-6.pdf

1179-del-1997-gpa.pdf

1179-DEL-1997-Others-Document-(07-11-2008).pdf

1179-del-1997-petition-137.pdf

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