COATING DEVICE AND METHOD FOR SUPPLYING A LACQUER AND A SOLVENT TO A LACQUER MIXTURE

Abstract

A coating device for dip coating an ophthalmic lens is provided. The coating device includes a lacquer basin for receiving a lacquer mixture, which contains a lacquer and a solvent. The coating device has an overflow channel arranged at the lacquer basin for collecting the lacquer mixture overflowing from the lacquer basin, and a tubing system for providing an influx of the lacquer mixture to the lacquer basin, which is connected to the overflow channel for collecting a return flux of the lacquer mixture from the overflow channel to enable circulation of the lacquer mixture through the lacquer basin, the overflow channel, and the tubing system. The coating device includes a supply unit for dosing the lacquer and the solvent for the lacquer mixture, which is connected to the tubing system and configured to feed at least one of the lacquer and the solvent directly into the tubing system.

Claims

1. A coating device for dip coating an ophthalmic lens, the coating device comprising: a lacquer basin for receiving a lacquer mixture, wherein the lacquer mixture includes a lacquer and a solvent; an overflow channel arranged at the lacquer basin for collecting the lacquer mixture overflowing from the lacquer basin; a tubing system, which is connected to the lacquer basin for providing an influx of the lacquer mixture to the lacquer basin, and which is connected to the overflow channel for collecting a return flux of the lacquer mixture from the overflow channel, such as to enable a circulation of the lacquer mixture through the lacquer basin, the overflow channel and the tubing system; a supply unit for dosing the lacquer and the solvent for supplying the lacquer mixture; wherein the tubing system includes a pump for circulating the lacquer mixture through the lacquer basin, the overflow channel and the tubing system, wherein the return flux of the lacquer mixture is a flux of lacquer mixture from the overflow channel to the pump generating a circulation of the lacquer mixture, and the influx is a flux of the lacquer mixture from the pump generating the circulation of the lacquer mixture to the lacquer basin, wherein the supply unit is connected to the tubing system and configured to feed at least one of the lacquer and the solvent directly into the tubing system; and wherein the supply unit is connected via a supply tubing to a lacquer reservoir and a solvent reservoir, wherein the supply tubing includes a lacquer supply tubing for connecting the supply unit with the lacquer reservoir and a solvent supply tubing for connecting the supply unit with the solvent reservoir, and wherein the lacquer supply tubing includes a lacquer valve and a lacquer dosing pump for supplying and dosing the lacquer from the lacquer reservoir and wherein the solvent supply tubing includes a solvent dosing pump for supplying and dosing the solvent from the solvent reservoir; wherein the solvent supply tubing includes a solvent valve for supplying and dosing the solvent from the solvent reservoir, and wherein the supply unit is configured to feed at least one of the lacquer and the solvent directly into the influx of the lacquer mixture supplied to the lacquer basin.

2. The coating device according to claim 1, wherein the supply unit is configured to feed the lacquer and the solvent directly into at least one of the return flux of the lacquer mixture collected from the overflow channel and the influx of the lacquer mixture supplied to the lacquer basin.

3. The coating device according to claim 1, wherein the tubing system further comprises a flow cooler having an inlet and an outlet, wherein the tubing system is configured to feed the return flux collected from the overflow channel into the inlet of the flow cooler.

4. The coating device according to claim 3, wherein the tubing system further comprises a static mixer and wherein the static mixer is optionally integrated into the flow cooler.

5. The coating device according to claim 3, wherein the supply unit is connected to the tubing system upstream of the inlet of the flow cooler or the static mixer.

6. The coating device according to claim 1, wherein the lacquer basin is passively thermally isolated from its surrounding and wherein the coating device is optionally configured to entirely passively control a temperature of the lacquer basin.

7. The coating device according to claim 1, wherein the tubing system further comprises at least one of the following elements: a density meter for measuring the density of the lacquer mixture; and a filter unit for filtering particles from the lacquer mixture.

8. A method for supplying a lacquer and a solvent to a lacquer mixture in a coating device for dip coating an ophthalmic lens, the method comprising: providing a lacquer basin for receiving a lacquer mixture, an overflow channel arranged at the lacquer basin for collecting the lacquer mixture overflowing from the lacquer basin, and a tubing system, which is connected to the lacquer basin for providing an influx of the lacquer mixture to the lacquer basin, and which is connected to the overflow channel for collecting a return flux for the lacquer mixture from the overflow channel; generating a circulation of the lacquer mixture through the lacquer basin, the overflow channel and the tubing system; measuring a density of the circulating lacquer mixture, wherein the method further comprises: feeding the lacquer and the solvent directly into the tubing system and dosing at least one of the lacquer and the solvent depending on the measured density of the circulating lacquer mixture, wherein the tubing system includes a pump for circulating the lacquer mixture through the lacquer basin, the overflow channel and the tubing system, wherein the return flux of the lacquer mixture is a flux of lacquer mixture from the overflow channel to the pump generating a circulation of the lacquer mixture, and the influx is a flux of the lacquer mixture from the pump generating the circulation of the lacquer mixture to the lacquer basin, wherein the supply unit is connected via a supply tubing to a lacquer reservoir and a solvent reservoir, wherein the supply tubing includes a lacquer supply tubing for connecting the supply unit with the lacquer reservoir and a solvent supply tubing for connecting the supply unit with the solvent reservoir, and wherein the lacquer supply tubing includes a lacquer valve and a lacquer dosing pump for supplying and dosing the lacquer from the lacquer reservoir, wherein the solvent supply tubing includes a solvent valve and a solvent dosing pump for supplying and dosing the solvent from the solvent reservoir, and wherein the supply unit is configured to feed at least one of the lacquer and the solvent directly into the influx of the lacquer mixture supplied to the lacquer basin.

9. A method for dip coating an ophthalmic lens, the method comprising: providing a lacquer basin for receiving a lacquer mixture, an overflow channel arranged at the lacquer basin for collecting the lacquer mixture overflowing from the lacquer basin, and a tubing system, which is connected to the lacquer basin for providing an influx of the lacquer mixture to the lacquer basin, and which is connected to the overflow channel for collecting a return flux for the lacquer mixture from the overflow channel, generating a circulation of the lacquer mixture through the lacquer basin, the overflow channel and the tubing system; dip coating the ophthalmic lens in the lacquer mixture received in the lacquer basin; measuring a density of the circulating lacquer mixture; wherein the method further comprises: feeding the lacquer and the solvent directly into the tubing system and dosing at least one of the lacquer and the solvent depending on the measured density of the circulating lacquer mixture; wherein the tubing system includes a pump for circulating the lacquer mixture through the lacquer basin, the overflow channel and the tubing system, wherein the return flux of the lacquer mixture is a flux of lacquer mixture from the overflow channel to the pump generating a circulation of the lacquer mixture, and the influx is a flux of the lacquer mixture from the pump generating the circulation of the lacquer mixture to the lacquer basin; wherein the supply unit is connected via a supply tubing to a lacquer reservoir and a solvent reservoir, wherein the supply tubing includes a lacquer supply tubing for connecting the supply unit with the lacquer reservoir and a solvent supply tubing for connecting the supply unit with the solvent reservoir, wherein the lacquer supply tubing includes a lacquer valve and a lacquer dosing pump for supplying and dosing the lacquer from the lacquer reservoir, wherein the solvent supply tubing includes a solvent valve and a solvent dosing pump for supplying and dosing the solvent from the solvent reservoir, and wherein the supply unit is configured to feed at least one of the lacquer and the solvent directly into the influx of the lacquer mixture supplied to the lacquer basin.

10. A coating device for dip coating an ophthalmic lens, the coating device comprising: a lacquer basin for receiving a lacquer mixture, wherein the lacquer mixture contains a lacquer and a solvent; an overflow channel arranged at the lacquer basin for collecting the lacquer mixture overflowing from the lacquer basin; a tubing system, which is connected to the lacquer basin for providing an influx of the lacquer mixture to the lacquer basin, and which is connected to the overflow channel for collecting a return flux of the lacquer mixture from the overflow channel, such as to enable a circulation of the lacquer mixture through the lacquer basin, the overflow channel and the tubing system; and a supply unit for dosing the lacquer and the solvent for supplying the lacquer mixture; wherein the tubing system includes a pump for circulating the lacquer mixture through the lacquer basin, the overflow channel and the tubing system, wherein the return flux of the lacquer mixture is a flux of lacquer mixture from the overflow channel to the pump generating a circulation of the lacquer mixture, and the influx is a flux of the lacquer mixture from the pump generating the circulation of the lacquer mixture to the lacquer basin, wherein the supply unit is connected to the tubing system and configured to feed at least one of the lacquer and the solvent directly into the tubing system, wherein the tubing system further includes a flow cooler having an inlet and an outlet, and wherein the tubing system is configured to feed the return flux collected from the overflow channel into the inlet of the flow cooler.

11. The coating device according to claim 10, wherein the tubing system further comprises a static mixer and wherein the static mixer is optionally integrated into the flow cooler.

12. The coating device according to claim 10, wherein the supply unit is connected to the tubing system upstream of the inlet of the flow cooler or the static mixer.

13. The coating device according to claim 10, wherein the lacquer basin is passively thermally isolated from its surrounding and wherein the coating device is optionally configured to entirely passively control a temperature of the lacquer basin.

14. The coating device according to claim 10, wherein the supply unit is configured to feed at least one of the lacquer and the solvent directly into the return flux of the lacquer mixture collected by the overflow channel.

15. The coating device according to claim 10, wherein the supply unit is configured to feed at least one of the lacquer and the solvent directly into the influx of the lacquer mixture supplied to the lacquer basin.

16. The coating device according to claim 14, wherein the supply unit is configured to feed the lacquer and the solvent directly into at least one of the return flux of the lacquer mixture collected from the overflow channel and the influx of the lacquer mixture supplied to the lacquer basin.

17. The coating device according to claim 10, wherein the supply unit is connected via a supply tubing to a lacquer reservoir and a solvent reservoir.

18. The coating device according to claim 17, wherein the supply tubing comprises at least one of a lacquer or solvent valve and a dosing pump for supplying and dosing at least one of the lacquer from the lacquer reservoir and the solvent from the solvent reservoir.

19. The coating device according to claim 17, wherein the supply tubing comprises a lacquer supply tubing for connecting the supply unit with the lacquer reservoir and a solvent supply tubing for connecting the supply unit with the solvent reservoir.

20. The coating device according to claim 19, wherein the lacquer supply tubing comprises at least one of a lacquer valve and a lacquer dosing pump for supplying and dosing the lacquer from the lacquer reservoir and/or wherein the solvent supply tubing includes at least one of a solvent valve and a solvent dosing pump for supplying and dosing the solvent from the solvent reservoir.

21. The coating device according to claim 10, wherein the tubing system further comprises at least one of the following elements: a density meter for measuring the density of the lacquer mixture; and a filter unit for filtering particles from the lacquer mixture.

22. A method for supplying a lacquer and a solvent to a lacquer mixture in a coating device for dip coating an ophthalmic lens, the method comprising: providing a lacquer basin for receiving a lacquer mixture, an overflow channel arranged at the lacquer basin for collecting the lacquer mixture overflowing from the lacquer basin, and a tubing system, which is connected to the lacquer basin for providing an influx of the lacquer mixture to the lacquer basin, and which is connected to the overflow channel for collecting a return flux for the lacquer mixture from the overflow channel, wherein the tubing system includes a pump for circulating the lacquer mixture through the lacquer basin, the overflow channel and the tubing system, wherein the return flux of the lacquer mixture is a flux of lacquer mixture from the overflow channel to the pump generating a circulation of the lacquer mixture, and the influx is a flux of the lacquer mixture from the pump generating the circulation of the lacquer mixture to the lacquer basin; generating a circulation of the lacquer mixture through the lacquer basin, the overflow channel and the tubing system; measuring a density of the circulating lacquer mixture; and feeding the lacquer and the solvent directly into the tubing system and dosing at least one of the lacquer and the solvent depending on the measured density of the circulating lacquer mixture, wherein the tubing system includes a flow cooler having an inlet and an outlet and is configured to feed the return flux collected from the overflow channel into the inlet of the flow cooler.

23. A method for dip coating an ophthalmic lens, the method comprising: providing a lacquer basin for receiving a lacquer mixture, an overflow channel arranged at the lacquer basin for collecting the lacquer mixture overflowing from the lacquer basin, and a tubing system, which is connected to the lacquer basin for providing an influx of the lacquer mixture to the lacquer basin, and which is connected to the overflow channel for collecting a return flux for the lacquer mixture from the overflow channel, wherein the tubing system includes a pump for circulating the lacquer mixture through the lacquer basin, the overflow channel and the tubing system, wherein the return flux of the lacquer mixture is a flux of lacquer mixture from the overflow channel to the pump generating a circulation of the lacquer mixture, and the influx is a flux of the lacquer mixture from the pump generating the circulation of the lacquer mixture to the lacquer basin; generating a circulation of the lacquer mixture through the lacquer basin, the overflow channel and the tubing system; dip coating the ophthalmic lens in the lacquer mixture received in the lacquer basin; measuring a density of the circulating lacquer mixture; and feeding the lacquer and the solvent directly into the tubing system and dosing at least one of the lacquer and the solvent depending on the measured density of the circulating lacquer mixture, wherein the tubing system comprises a flow cooler having an inlet and an outlet and is configured to feed the return flux collected from the overflow channel into the inlet of the flow cooler.

24. A coating device for dip coating an ophthalmic lens, the coating device comprising: a lacquer basin for receiving a lacquer mixture, wherein the lacquer mixture contains a lacquer and a solvent; an overflow channel arranged at the lacquer basin for collecting the lacquer mixture overflowing from the lacquer basin; a tubing system, which is connected to the lacquer basin for providing an influx of the lacquer mixture to the lacquer basin, and which is connected to the overflow channel for collecting a return flux of the lacquer mixture from the overflow channel, such as to enable a circulation of the lacquer mixture through the lacquer basin, the overflow channel and the tubing system; and a supply unit for dosing the lacquer and the solvent for supplying the lacquer mixture, wherein the tubing system includes a pump for circulating the lacquer mixture through the lacquer basin, the overflow channel and the tubing system, wherein the return flux of the lacquer mixture is a flux of lacquer mixture from the overflow channel to the pump generating a circulation of the lacquer mixture, and the influx is a flux of the lacquer mixture from the pump generating the circulation of the lacquer mixture to the lacquer basin, wherein the supply unit is connected to the tubing system and configured to feed at least one of the lacquer and the solvent directly into the tubing system, and wherein the lacquer basin is passively thermally isolated from its surrounding, and wherein a side wall of the lacquer basin is provided at least partly from a material having a heat conductivity of 10 W/(m.Math.K) or less, and/or with one or more integrated evacuated chambers.

25. The coating device according to claim 24, wherein the coating device is configured to entirely passively control a temperature of the lacquer basin.

26. The coating device according to claim 24, wherein the supply unit is configured to feed at least one of the lacquer and the solvent directly into the return flux of the lacquer mixture collected by the overflow channel.

27. The coating device according to claim 24, wherein the supply unit is configured to feed at least one of the lacquer and the solvent directly into the influx of the lacquer mixture supplied to the lacquer basin.

28. The coating device according to claim 26, wherein the supply unit is configured to feed the lacquer and the solvent directly into at least one of the return flux of the lacquer mixture collected from the overflow channel and the influx of the lacquer mixture supplied to the lacquer basin.

29. The coating device according to claim 24, wherein the supply unit is connected via a supply tubing to a lacquer reservoir and a solvent reservoir.

30. The coating device according to claim 29, wherein the supply tubing comprises at least one of a valve and a dosing pump for supplying and dosing at least one of the lacquer from the lacquer reservoir and the solvent from the solvent reservoir.

31. The coating device according to claim 29, wherein the supply tubing comprises a lacquer supply tubing for connecting the supply unit with the lacquer reservoir and a solvent supply tubing for connecting the supply unit with the solvent reservoir.

32. The coating device according to claim 31, wherein the lacquer supply tubing comprises at least one of a lacquer valve and a lacquer dosing pump for supplying and dosing the lacquer from the lacquer reservoir, and/or wherein the solvent supply tubing includes at least one of a solvent valve and a solvent dosing pump for supplying and dosing the solvent from the solvent reservoir.

33. The coating device according to claim 24, wherein the tubing system further comprises a flow cooler having an inlet and an outlet, and wherein the tubing system is configured to feed the return flux collected from the overflow channel into the inlet of the flow cooler.

34. The coating device according to claim 33, wherein the tubing system further comprises a static mixer, and wherein the static mixer is optionally integrated into the flow cooler.

35. The coating device according to claim 33, wherein the supply unit is connected to the tubing system upstream of the inlet of the flow cooler or the static mixer.

36. The coating device according to claim 24, wherein the tubing system further comprises at least one of the following elements: a density meter for measuring the density of the lacquer mixture; a pump for circulating the lacquer mixture through the lacquer basin, the overflow channel and the tubing system; and a filter unit for filtering particles from the lacquer mixture.

37. A method for supplying a lacquer and a solvent to a lacquer mixture in a coating device for dip coating an ophthalmic lens, the method comprising: providing a lacquer basin for receiving a lacquer mixture, an overflow channel arranged at the lacquer basin for collecting the lacquer mixture overflowing from the lacquer basin, and a tubing system, which is connected to the lacquer basin for providing an influx of the lacquer mixture to the lacquer basin, and which is connected to the overflow channel for collecting a return flux for the lacquer mixture from the overflow channel, wherein the tubing system includes a pump for circulating the lacquer mixture through the lacquer basin, the overflow channel and the tubing system, wherein the return flux of the lacquer mixture is a flux of lacquer mixture from the overflow channel to the pump generating a circulation of the lacquer mixture, and the influx is a flux of the lacquer mixture from the pump generating the circulation of the lacquer mixture to the lacquer basin; generating a circulation of the lacquer mixture through the lacquer basin, the overflow channel and the tubing system; and measuring a density of the circulating lacquer mixture, wherein the method further comprises feeding the lacquer and the solvent directly into the tubing system and dosing at least one of the lacquer and the solvent depending on the measured density of the circulating lacquer mixture, and wherein a side wall of the lacquer basin is provided at least partly from a material having a heat conductivity of 10 W/(m.Math.K) or less, and/or with one or more integrated evacuated chambers.

38. A method for dip coating an ophthalmic lens, the method comprising: providing a lacquer basin for receiving a lacquer mixture, an overflow channel arranged at the lacquer basin for collecting the lacquer mixture overflowing from the lacquer basin, and a tubing system, which is connected to the lacquer basin for providing an influx of the lacquer mixture to the lacquer basin, and which is connected to the overflow channel collecting a return flux for the lacquer mixture from the overflow channel, wherein the tubing system includes a pump for circulating the lacquer mixture through the lacquer basin, the overflow channel and the tubing system, wherein the return flux of the lacquer mixture is a flux of lacquer mixture from the overflow channel to the pump generating a circulation of the lacquer mixture, and the influx is a flux of the lacquer mixture from the pump generating the circulation of the lacquer mixture to the lacquer basin; generating a circulation of the lacquer mixture through the lacquer basin, the overflow channel and the tubing system; dip coating the ophthalmic lens in the lacquer mixture received in the lacquer basin; and measuring a density of the circulating lacquer mixture. wherein the method further comprises feeding the lacquer and the solvent directly into the tubing system and dosing at least one of the lacquer and the solvent depending on the measured density of the circulating lacquer mixture, and wherein a side wall of the lacquer basin is provided at least partly from a material having a heat conductivity of 10 W/(m.Math.K) or less, and/or with one or more integrated evacuated chambers.

39-40. (canceled)

41. A coating device for dip coating an ophthalmic lens, the coating device comprising: a lacquer basin for receiving a lacquer mixture, wherein the lacquer mixture contains a lacquer and a solvent; an overflow channel arranged at the lacquer basin for collecting the lacquer mixture overflowing from the lacquer basin; a tubing system, which is connected to the lacquer basin for providing an influx of the lacquer mixture to the lacquer basin, and which is connected to the overflow channel for collecting a return flux of the lacquer mixture from the overflow channel, such as to enable a circulation of the lacquer mixture through the lacquer basin, the overflow channel and the tubing system; and a supply unit for dosing the lacquer and the solvent for supplying the lacquer mixture, wherein the supply unit is connected to the tubing system and configured to feed at least one of the lacquer and the solvent directly into the tubing system and wherein the tubing system comprises a density meter for measuring the density of the lacquer mixture, wherein the supply unit is connected via a supply tubing to a lacquer reservoir and a solvent reservoir, wherein the supply tubing includes a lacquer supply tubing for connecting the supply unit with the lacquer reservoir and a solvent supply tubing for connecting the supply unit with the solvent reservoir, wherein the lacquer supply tubing includes a lacquer valve and a lacquer dosing pump for supplying and dosing the lacquer from the lacquer reservoir, wherein the solvent supply tubing includes a solvent valve and a solvent dosing pump for supplying and dosing the solvent from the solvent reservoir, and wherein the supply unit is configured to dose at least one of the lacquer and the solvent depending on the measured density of the circulating lacquer mixture, wherein the supply unit is configured to feed at least one of the lacquer and the solvent directly into the influx of the lacquer mixture supplied to the lacquer basin.

42. (canceled)

43. The coating device according to claim 41, wherein the tubing system further comprises a flow cooler having an inlet and an outlet, and wherein the tubing system is configured to feed the return flux collected from the overflow channel into the inlet of the flow cooler.

44. (canceled)

45. The coating device according to claim 43, wherein the supply unit is connected to the tubing system upstream of the inlet of the flow cooler or the static mixer.

46-47. (canceled)

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0040] It is understood by a person skilled in the art that the above-described features and the features in the following description and drawings are not only disclosed in the explicitly disclosed embodiments, examples, and combinations, but that also other technically feasible combinations as well as the isolated features are comprised by the disclosure. In the following, exemplary embodiments and specific examples are described with reference to the drawings for illustrating the disclosure without limiting the disclosure to the described exemplary embodiments.

[0041] FIG. 1 depicts a coating device for dip coating of ophthalmic lenses according to an exemplary embodiment;

[0042] FIG. 2 schematically illustrates a method 100 according to an exemplary embodiment for dip coating an ophthalmic lens; and

[0043] FIG. 3 schematically illustrates a method according to an exemplary embodiment for supplying a lacquer and a solvent to a lacquer mixture in a coating device for dip coating an ophthalmic lens.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

[0044] FIG. 1 shows an exemplary embodiment of a coating device 10 for dip coating of one or more ophthalmic lenses. The coating device 10 comprises a lacquer basin 12, an overflow channel 14 arranged next to the lacquer basin 12, a tubing system 16 and a supply unit 18 for dosing and supplying a lacquer and a solvent to the tubing system 16.

[0045] The lacquer basin 12 is formed as a receptacle for receiving a liquid lacquer mixture 20, wherein an influx of lacquer mixture 20 into the lacquer basin 12 is provided by the tubing system 16 at an inlet 22 at the bottom of the lacquer basin 12. For keeping the lacquer mixture 20 contained in the lacquer basin 12 at a temperature suitable for the dip coating process, a sidewall 12a of the lacquer basin 12 is thermally isolated to reduce a heat flow from the surrounding to the lacquer mixture 20 and vice versa. In particular, the sidewall 12a and the lacquer basin 12 do not require any tubing or inlets for dosing lacquer and solvent and do not require any active cooling means. Thus, the side wall 12a and the lacquer basin 12 can be kept at a low level of technical complexity and may be optimized for passive thermal isolation. The lacquer basin 12 is opened at the top to allow dipping one or more ophthalmic lenses to be coated into the lacquer mixture 20 contained in the lacquer basin 12 for dip coating.

[0046] The overflow channel 14 is arranged directly at the upper end of the lacquer basin 12 such as to surround the opening of the lacquer basin 12. This allows collecting any lacquer mixture 20 overflowing the lacquer basin 12 and returning the collected overflown lacquer mixture 20 via an outlet 24 as a return flux of lacquer mixture 20 into the tubing system 16.

[0047] The coating device 10 is adapted to generate a circulation of a lacquer mixture 20 through the coating device 10, i.e., through the tubing system 16, the lacquer basin 12 and the overflow channel 14, wherein the circulating lacquer mixture 20 enters the lacquer basin 12 through the inlet 22 at the bottom of the lacquer basin 12 and flows in a laminar flow in an upward direction to overflow the lacquer basin 12 and enter the overflow channel 14 to be collected and fed via the outlet 24 as return flux into the tubing system 16. The upward directed laminar flow of the lacquer mixture 20 inside the lacquer basin 12 is advantageous for the dip coating process in order to achieve a homogenous coating at an ophthalmic lens dipped into the lacquer mixture 20. The volume of lacquer mixture 20 which is displaced by dipping an ophthalmic lens inside the lacquer mixture 20 likewise flows over into the overflow channel 14 and is collected and becomes part of the return flux.

[0048] The tubing system 16 forms a closed loop allowing the lacquer mixture 20 to circulate in a constant flow through the tubing system 16, the lacquer basin 12 and the overflow channel 14. For generating the circulation, the coating device 10 comprises a pump 26, which may form a part of the tubing system 16, for generating a suction to provide a flow of the lacquer mixture through the tubing system 16. In addition, the tubing system 16 comprises a filter unit 28 for filtering undesired particles, contaminations and/or air bubbles from the circulating lacquer mixture 20 streaming through the filter unit 28.

[0049] In order to keep the lacquer mixture 20 at a desired density and/or viscosity and/or to keep a certain ratio of lacquer and solvent within the lacquer mixture 20, the supply unit 18 is provided. The supply unit 18 comprises a lacquer supply tubing 30 connecting a lacquer reservoir 32 with the tubing system 16 for dosing and supplying the lacquer to the lacquer mixture 20 flowing through the tubing system 16. According to the presented exemplary embodiment, the lacquer supply tubing 30 comprises a lacquer valve 34a and a lacquer dosing pump 36, which allow a precise dosing of the lacquer supplied from the lacquer reservoir 32 to the tubing system 16 independently of a possible suction generated by the pump 26 driving the circulation of the lacquer mixture 20. The supply unit 18 further comprises a solvent supply tubing 38 connecting a solvent reservoir 40 with the tubing system 16, which may be identical or similar to the lacquer supply tubing 30. Likewise, also the solvent supply tubing 38 may comprise a solvent valve 34b and a solvent dosing pump 36b for dosing and supplying the solvent to the tubing system 16. The valves 34a, 34b may be check valves for preventing an undesired flow of lacquer or solvent or lacquer mixture back into the lacquer reservoir 32 or solvent reservoir 40, respectively. An active and/or passive cooling may be provided for the lacquer reservoir 32 and/or the solvent reservoir 40.

[0050] In addition, the tubing system may comprise a density meter 42 for measuring the density of the lacquer mixture 20. The dosing and supply of lacquer and solvent by the supply unit 18 may be based on the density measured by the density meter 42. This allows controlling the dosing and the supply of the lacquer and/or the solvent and in a closed loop to constantly provide the lacquer mixture with a desired density.

[0051] Moreover, the tubing system 16 comprises a flow cooler 44 for cooling the lacquer mixture 20 while flowing through the flow cooler 44. The flow cooler 44 may have one or more inlets and outlets for a cooling fluid, such as water. According to the presented exemplary embodiment, the supply unit 18 is arranged such that the lacquer and solvent are provided into the return flux of the lacquer mixture returning from the overflow channel 14 and prior to the inlet of the flow cooler 44. Hence, right after dosing and supplying the lacquer and solvent to the tubing system 16, the lacquer and solvent enter the flow cooler 44 together with the return flux of the lacquer mixture 20. During the passage of the lacquer, the solvent and the lacquer mixture through the flow cooler 44 an efficient mixing of these components may occur, which may result in a homogeneous lacquer mixture 20 having the desired density. According to an exemplary embodiment, the flow cooler 44 may be provided with a static mixer (not shown) included in the flow cooler 44. This may further enhance the mixing process. Alternatively or additionally, a separate static mixer (not shown) may be provided independently of the flow cooler 44 in the tubing system 16.

[0052] The arrangement of the supply unit 18, the flow cooler 44 and the density meter 42 between the overflow channel 14 and the pump 26, i.e., in the return flux, bears the advantage that there is a significant remaining flow distance of the supplied lacquer and solvent until the resupplied lacquer mixture 20 reaches an ophthalmic lens dipped into the lacquer basin 12. Hence, a homogeneous lacquer mixture 20 can be achieved. Moreover, the resupplied lacquer mixture 20 flows through the pump 26 prior to reaching the lacquer basin 12, which may provide an additional mixing of the components. However, according to other exemplary embodiments the supply unit may be arranged at a different position of the tubing system 16, such as between the flow cooler 42 and the pump and/or between the pump and the lacquer basin 12.

[0053] FIG. 2 schematically illustrates a method 100 according to an exemplary embodiment for dip coating an ophthalmic lens.

[0054] In a first step 102, the method comprises providing a lacquer basin 12 for receiving a lacquer mixture 20, an overflow channel 14 arranged at the lacquer basin 12 for collecting the lacquer mixture 20 overflowing from the lacquer basin 12, and a tubing system 16, which is connected to the lacquer basin 12 for providing an influx of the lacquer mixture 20 to the lacquer basin 12, and which is connected to the overflow channel 14 for collecting a return flux for the lacquer mixture 20 from the overflow channel 14.

[0055] In a second step 104, the method comprises generating a circulation of the lacquer mixture through the lacquer basin 12, the overflow channel 14 and the tubing system 16.

[0056] In another step 106, the method comprises dip coating the ophthalmic lens in the lacquer mixture 20 received in the lacquer basin (14).

[0057] In yet another step 108, the method comprises measuring a density of the circulating lacquer mixture (20).

[0058] In yet another step 110, the method comprises feeding the lacquer and the solvent directly into the tubing system 16 and dosing at least one of the lacquer and the solvent depending on the measured density of the circulating lacquer mixture 20.

[0059] FIG. 3 schematically illustrates a method 200 according to an exemplary embodiment for supplying a lacquer and a solvent to a lacquer mixture in a coating device 10 for dip coating an ophthalmic lens.

[0060] In a first step 202, the method comprises providing a lacquer basin 12 for receiving a lacquer mixture 20, an overflow channel 14 arranged at the lacquer basin for collecting the lacquer mixture 20 overflowing from the lacquer basin 12, and a tubing system 16, which is connected to the lacquer basin 12 for providing an influx of the lacquer mixture 20 to the lacquer basin 12, and which is connected to the overflow channel 14 for collecting a return flux for the lacquer mixture 20 from the overflow channel 14.

[0061] In a second step 204, the method comprises generating a circulation of the lacquer mixture 20 through the lacquer basin 12, the overflow channel 14 and the tubing system 16.

[0062] In another step 206, the method comprises measuring a density of the circulating lacquer mixture 20.

[0063] In yet another step 208, the method comprises feeding the lacquer and the solvent directly into the tubing system 16 and dosing at least one of the lacquer and the solvent depending on the measured density of the circulating lacquer mixture 20.

[0064] The disclosure further includes the following optional clauses without being limited to these clauses:

[0065] Clause 1. Coating device (10) for dip coating an ophthalmic lens, the coating device (10) comprising: [0066] a lacquer basin (12) for receiving a lacquer mixture (20), wherein the lacquer mixture (20) comprises a lacquer and a solvent; [0067] an overflow channel (14) arranged at the lacquer basin (12) for collecting the lacquer mixture (20) overflowing from the lacquer basin (12); [0068] a tubing system (16), which is connected to the lacquer basin (12) for providing an influx of the lacquer mixture (20) to the lacquer basin (12), and which is connected to the overflow channel (14) for collecting a return flux of the lacquer mixture (20) from the overflow channel (14), such as to enable a circulation of the lacquer mixture (20) through the lacquer basin (12), the overflow channel (14) and the tubing system (16); [0069] a supply unit (18) for dosing the lacquer and the solvent for supplying the lacquer mixture; [0070] characterized in that [0071] the supply unit (18) is connected to the tubing system (16) and adapted to feed at least one of the lacquer and the solvent directly into the tubing system (16).

[0072] Clause 2. Coating device (10) according to clause 1, wherein the supply unit (18) is adapted to feed at least one of the lacquer and the solvent directly into the return flux of the lacquer mixture (20) collected by the overflow channel (14).

[0073] Clause 3. Coating device (10) according to clause 1 or 2, wherein the supply unit (18) is adapted to feed at least one of the lacquer and the solvent directly into the influx of the lacquer mixture (20) supplied to the lacquer basin (12).

[0074] Clause 4. Coating device (10) according to clause 2 or 3, wherein supply unit (18) is adapted to feed the lacquer and the solvent directly into at least one of the return flux of the lacquer mixture (20) collected from the overflow channel (14) and the influx of the lacquer mixture (20) supplied to the lacquer basin (12).

[0075] Clause 5. Coating device (10) according to any one of the preceding clauses, wherein the supply unit (18) is connected via a supply tubing (30, 38) to a lacquer reservoir (32) and a solvent reservoir (40).

[0076] Clause 6. Coating device (10) according to clause 5, wherein the supply tubing (30, 38) comprises at least one of a valve (34) and a dosing pump (36) for supplying and dosing at least one of the lacquer from the lacquer reservoir (32) and the solvent from the solvent reservoir (40).

[0077] Clause 7. Coating device (10) according to clause 5 or 6, wherein the supply tubing (30, 38) comprises a lacquer supply tubing (30) for connecting the supply unit (18) with the lacquer reservoir (32) and a solvent supply tubing (38) for connecting the supply unit (18) with the solvent reservoir (40).

[0078] Clause 8. Coating device (10) according to clause 7, wherein the lacquer supply tubing (30) comprises at least one of a lacquer valve (34a) and a lacquer dosing pump (36a) for supplying and dosing the lacquer from the lacquer reservoir (32) and/or wherein the solvent supply tubing (38) comprises at least one of a solvent valve (34b) and a solvent dosing pump (36b) for supplying and dosing the solvent from the solvent reservoir (40).

[0079] Clause 9. Coating device (10) according to any one of the preceding clauses, wherein the tubing system (16) further comprises a flow cooler (44) having an inlet and an outlet, wherein the tubing system (16) is adapted to feed the return flux collected from the overflow channel (14) into the inlet of the flow cooler (44).

[0080] Clause 10. Coating device (10) according to clause 9, wherein the tubing system (16) further comprises a static mixer and wherein the static mixer is optionally integrated into the flow cooler (44).

[0081] Clause 11. Coating device (10) according to clause 9 or 10, wherein the supply unit (18) is connected to the tubing system (16) upstream of the inlet of the flow cooler (44) or the static mixer.

[0082] Clause 12. Coating device (10) according to any one of the preceding clauses, wherein the lacquer basin (12) is passively thermally isolated from its surrounding and wherein the coating device (10) is optionally adapted to entirely passively control a temperature of the lacquer basin (12).

[0083] Clause 13. Coating device (10) according to any one of the preceding clauses, wherein the tubing system (16) further comprises at least one of the following elements: [0084] a density meter (42) for measuring the density of the lacquer mixture (20); [0085] a pump (26) for circulating the lacquer mixture (20) through the lacquer basin (12), the overflow channel (14) and the tubing system (16); and [0086] a filter unit (28) for filtering particles from the lacquer mixture (20).

[0087] Clause 14. Method for supplying a lacquer and a solvent to a lacquer mixture (20) in a coating device (10) for dip coating an ophthalmic lens, the method comprising: [0088] providing a lacquer basin (12) for receiving a lacquer mixture (20), an overflow channel (14) arranged at the lacquer basin for collecting the lacquer mixture (20) overflowing from the lacquer basin (12), and a tubing system (16), which is connected to the lacquer basin (12) for providing an influx of the lacquer mixture (20) to the lacquer basin (12), and which is connected to the overflow channel (14) for collecting a return flux for the lacquer mixture (20) from the overflow channel (14), [0089] generating a circulation of the lacquer mixture (20) through the lacquer basin (12), the overflow channel (14) and the tubing system (16); [0090] measuring a density of the circulating lacquer mixture (20); [0091] characterized in that the method further comprises: [0092] feeding the lacquer and the solvent directly into the tubing system (16) and dosing at least one of the lacquer and the solvent depending on the measured density of the circulating lacquer mixture (20).

[0093] Clause 15. Method for dip coating an ophthalmic lens, the method comprising: [0094] providing a lacquer basin (12) for receiving a lacquer mixture (20), an overflow channel (14) arranged at the lacquer basin for collecting the lacquer mixture (20) overflowing from the lacquer basin (12), and a tubing system (16), which is connected to the lacquer basin (12) for providing an influx of the lacquer mixture (20) to the lacquer basin (12), and which is connected to the overflow channel (14) for collecting a return flux for the lacquer mixture (20) from the overflow channel (14), [0095] generating a circulation of the lacquer mixture (20) through the lacquer basin (12), the overflow channel (14) and the tubing system (16); [0096] dip coating the ophthalmic lens in the lacquer mixture (20) received in the lacquer basin (14); [0097] measuring a density of the circulating lacquer mixture (20); [0098] characterized in that the method further comprises: [0099] feeding the lacquer and the solvent directly into the tubing system (16) and dosing at least one of the lacquer and the solvent depending on the measured density of the circulating lacquer mixture (20).

LIST OF REFERENCE SIGNS

[0100] 10 coating device [0101] 12 lacquer basin [0102] 12a sidewall of lacquer basin [0103] 14 overflow channel [0104] 16 tubing system [0105] 18 supply unit [0106] 20 lacquer mixture [0107] 22 inlet of lacquer basin [0108] 24 outlet of overflow channel [0109] 26 pump [0110] 28 filter unit [0111] 30 lacquer supply tubing [0112] 32 lacquer reservoir [0113] 34a lacquer valve [0114] 34b solvent valve [0115] 36a lacquer dosing pump [0116] 36b solvent dosing pump [0117] 36 dosing pump [0118] 38 solvent supply tubing [0119] 40 solvent reservoir [0120] 42 density meter [0121] 44 flow cooler [0122] 100 Method for dip coating an ophthalmic lens [0123] 200 Method for supplying a lacquer and a solvent [0124] 102-110 Method steps [0125] 202-208 Method steps