Coating system with a device for mixing and / or dosing liquid coating materials and method for coloring optical glasses

Description

TECHNICAL FIELD

[0001] The present invention relates generally to a coating system for individually coating substrates according to the preamble of patent claim 1 and a method for individually coloring optical glasses according to patent claim 12. More specifically, the invention relates to a coating system for individually coating spectacle lenses and a method for individually coloring spectacle lenses.

[0002] When, in the context of the coating of substrates, paints are mentioned below as examples of liquid coating materials that are mixed, dosed or applied to a substrate, this should not be understood as being limited to paints, but rather should also include other liquid coating materials, such as photochromic substances for darkening optical glasses, clear primers, clear hard coatings, etc., insofar as these are to be dosed and / or mixed from several components. STATE OF THE ART

[0003] To protect the eyes from the unpleasant or harmful effects of sunlight, lenses are tinted or colored, which reduces the light transmission through the lenses to the wearer's eyes. The individual color preference of the wearer, often subject to fashion influences, can vary greatly. Furthermore, it is common practice to specifically reduce individual visible light components (e.g., blue light) or invisible light components (ultraviolet light radiation) with certain tints or coatings.

[0004] Various processes for coloring ophthalmic lenses are already known in the prior art. For example, mineral glass lenses can be colored during the melting process by adding a dye or later by vapor deposition of absorbing layers. Coloring plastic lenses is usually done by immersion in an aqueous dye solution, usually using textile dyes. The coloring occurs through the diffusion of the dye into the plastic material of the lens or into a coating previously applied to the plastic material that is suitable for absorbing corresponding dyes. The intensity of the coloration depends on various factors, such as the exposure time, the temperature, and the dye concentration present in the immersion bath.Therefore, it is necessary to manually remove the lenses from the dipping bath during the process and visually inspect them to achieve the desired color, which precludes fully automating the dipping process. Achieving a specific color also depends heavily on the experience of the personnel involved, making the reproducibility of a specific color problematic. Furthermore, this process cannot economically produce customized shades for individual lenses or pairs of lenses because a dipping bath with a specific color composition would have to be maintained or prepared for each individual shade.

[0005] EP 1 388 607 A2 discloses an alternative process for dyeing plastic ophthalmic lenses. This process involves the sublimation and deposition of a dye on the ophthalmic lens to be dyed, followed by the dye's subsequent diffusion into the plastic material of the lens. The diffusion behavior is influenced by the plastic material used and its age, so the reproducibility of certain dyeings appears problematic with this approach as well. Furthermore, the time required for the individual process steps makes this a very slow process, which precludes its use on an industrial scale.

[0006] JP 09-099494 A further proposes printing the spectacle lenses directly with a color using an inkjet printer. As an alternative, WO 2006 / 079715 A1 discloses a process in which the spectacle lenses are first provided with a printable primer before being individually colored by inkjet printing of the primer. In both processes, dyes or pigments are bound to the lens surface by adding a binder or resin. Both processes make it possible to create color or tint gradients. However, one problem with this approach is that, due to the process, rasterized or pixelated color applications are created during printing, which is usually undesirable.

[0007] EP 1 683 645 A1 further describes a method for coloring optical lenses, in which a printable and easily removable layer is applied to a lens. This layer is then printed using an inkjet printer and removed from the lens after the dye has diffused through the layer into the lens. However, this method also requires a considerable amount of time, which again precludes industrial use.

[0008] For the production of uniformly coloured spectacle lenses, the document DE 695 35 130 T2 proposes applying a liquid and curable coating containing a colouring material, e.g. .by spin or dip coating and then curing this coating using UV light. The coloring dyes or pigments can be used either in the primer or in the hard coating of the spectacle lens, or in both. Such hard coatings, which also serve as dye carriers, are also described in publication KR 100807001 B1. However, details on the design and function of suitable mixing devices or coating systems are not provided in these publications.

[0009] A coating system having the features of the preamble of patent claim 1 is known from the document US 2008 / 0035053 A1.

[0010] Furthermore, WO 2014 / 135859 A1 discloses a synthesis apparatus for the automated performance of desired reactions with biochemical molecules such as DNA, RNA, and proteins. The required reaction components are, as described in Fig. 2 As shown in this publication, the liquid is stored in storage containers that can be optionally connected to a syringe pump driven by a magnetic drive via a multiple valve. Furthermore, the synthesis apparatus has a reaction vessel, the inlet of which can also be connected to the syringe pump via the multiple valve. The reaction vessel is emptied via a funnel-shaped section that opens into an outlet of the reaction vessel and can be connected to a second syringe pump via a second multiple valve. The second syringe pump can finally be connected to a liquid outlet via the second multiple valve.

[0011] Furthermore, this prior art generally indicates that, in one embodiment, a single pump would be used to provide the reaction components and to agitate and withdraw the reaction mixture. However, this document does not provide any further details on this.

[0012] Finally, EP 2 963 459 A1 discloses a method and a device for the double-sided spin coating of spectacle lenses. However, details of a device for mixing and / or dosing liquid coating materials for this purpose are not provided in this prior art. TASK

[0013] The invention is based on the object of creating a coating system for the individual coating of substrates, namely spectacle lenses, equipped with a device for mixing and / or dosing liquid coating materials that is as simple as possible. This system allows liquid coating materials to be mixed and / or dosed in a highly reproducible manner and is suitable, in particular, for use in an automated, fast, and cost-effective process for the individual coloring of individual spectacle lenses. The object of the invention further includes specifying a process for the individual coloring of optical lenses, namely spectacle lenses. PRESENTATION OF THE INVENTION

[0014] These objects are achieved by a coating system for individually coating substrates, namely spectacle lenses, having the features of patent claim 1 and a method for individually coloring optical lenses, namely spectacle lenses, having the features of patent claim 12. Advantageous embodiments of the invention are the subject of patent claims 2 to 11.

[0015] In a coating system for the individual coating of substrates, namely spectacle lenses, which has a device for mixing and / or dosing liquid coating materials, a substrate holder for holding the substrates during coating, and a coating chamber into which a liquid outlet of the device opens via a nozzle in order to dispense the liquid coating material mixed and / or dosed in the device in the direction of the substrate holder, which can be designed, for example, as a suction head, the device for mixing and / or dosing liquid coating materials comprises, according to the invention, at least one first and at least one second storage container for liquid starting materials, a conveying device for sucking in and ejecting liquids, a mixing container, the liquid outlet for mixed and / or dosed liquid coating materials, and a multiple valve arranged therebetween.wherein the multiple valve is switchable into different valve positions and is adapted to establish one of the following connections and thereby to separate the other connections: (a) connection between the first storage container and the conveying device, (b) connection between the second storage container and the conveying device, (c) connection between the conveying device and the mixing container and (d) connection between the conveying device and the liquid outlet.

[0016] In other words, in a coating system designed according to the invention, all fluid movements required for dosing or mixing are generated in the device for mixing and / or dosing liquid coating materials by means of a single conveying device for sucking in and expelling fluids, which can be connected via the multiple valve to only one of the above-mentioned containers or the fluid outlet in order to suck in or discharge a fluid via the respective connection. Since all non-switched connections are separated or blocked by the multiple valve, no additional valves are required for dosing and / or mixing, so that the device can be designed to be particularly simple, compact, and cost-effective.

[0017] In addition, such a device can be automated particularly easily because only the multiple valve needs to be switched and the conveying device has to be operated in order to suck in or expel a defined volume of liquid.

[0018] The fact that only one multi-valve and one conveyor system are used for mixing and / or dosing also promotes a fast mixing and dosing process and good reproducibility of the mixing result, because multiple components do not have to be coordinated or synchronized with each other with regard to delivery quantities and times, which poses the risk of dosing errors. Furthermore, such a simply constructed device is less prone to failure, easy to clean and maintain, and can be integrated into the coating system with little effort.

[0019] The spatial integration of the mixing and / or dosing device into the coating system has the particular advantage that the liquid coating materials mixed in the device can be used directly in the coating system, eliminating additional transport steps and advantageously shortening conveyor paths and process times. A shared control system can also be provided for the mixing and / or dosing device and the coating system. Ultimately, a coating system equipped in this way is particularly well-suited for fully automated production.

[0020] In the coating system, the nozzle forms a defined closure of the device's liquid outlet, which determines the direction for the dispensing of the liquid coating material onto the substrates, aiming at the center of the respective substrate. The nozzle can have a free cross-section that widens in the direction of flow to even out the dispensing of the liquid coating material.

[0021] Last but not least, the device with its previously described design is particularly well-suited to mixing or dosing liquid coating materials in very small quantities, as demonstrated by experiments carried out by the inventors in connection with the coloring of individual spectacle lenses.

[0022] In principle, it is conceivable to configure the conveying device with a fixed-displacement pump for each conveying direction, such as a diaphragm or piston pump, which conveys into or from a common intermediate reservoir. However, a preferred embodiment is one in which the conveying device comprises a syringe pump with a syringe barrel and a syringe piston that can be positioned relative to the syringe barrel by means of a lifting drive. Due to its design, a syringe pump conveys in both directions, and a reversal of the flow direction, which is advantageous for a mixing process, is easy to accomplish. Furthermore, liquids can be dosed very precisely using a syringe pump. Furthermore, syringe pumps are highly impermeable – even against air – which promotes high process reliability.In addition, the syringe cylinder serves as an intermediate storage for the pumped liquid volume during pumping, which can be easily calculated by knowing the cross-section of the syringe cylinder and the stroke of the syringe plunger, so that a separate recording of the pumped liquid volume is unnecessary.

[0023] In principle, it is possible to use a simple crank drive, for example. Solutions using a linear motor or a piston-cylinder arrangement to generate the stroke are also conceivable. However, with regard to both low costs and, in particular, very good metering of the pumped liquid, it is preferred if the lifting drive has an electric motor that is drive-connected to the syringe plunger via a gear mechanism that can convert a rotary movement into a longitudinal movement. By selecting a suitable gear ratio for the gear mechanism, very sensitive movements of the syringe plunger can be achieved, so that the volume of liquid to be pumped can be adjusted very precisely. Particularly preferably, the electric motor can be a stepper motor, which can be positioned very precisely without a sensor for position feedback.Depending on the step size (angle of rotation) of the stepper motor and the design of the gear ratio of the gear mechanism, even very small flow rates can be pumped with the syringe pump in a well-reproducible manner.

[0024] In principle, the mixing container can be of any design, e.g., spherical. However, particularly with regard to particularly good and rapid mixing of the liquid starting materials into the liquid coating material, it is preferred for the mixing container to have a mixing funnel. Due to the constant transition from a large to a small cross-section, vortex formation occurs when the liquid coating material is drawn from the mixing funnel, which promotes mixing. This is also advantageous for cleaning the mixing funnel. Such a mixing funnel is also simple and inexpensive to manufacture.

[0025] The interior surfaces of the mixing funnel, i.e., those wetted by the liquid coating material, can in principle be untreated or polished. In a preferred embodiment, however, the interior surfaces of the mixing funnel are electropolished or have a non-stick coating—such as Teflon® or another FEP coating. This not only advantageously facilitates cleaning of the mixing funnel but also improves the mixing result due to the more pronounced vortex formation associated with the achieved lower friction.

[0026] Various designs are also conceivable for the multiple valve. For example, the multiple valve can be a longitudinal slide valve or a valve island. However, particularly with regard to a particularly compact design, a preferred design is one in which the multiple valve comprises a distributor housing with connections for the storage tanks, the mixing tank, the liquid outlet, and the conveying device, as well as a valve body rotatably accommodated in the distributor housing. The valve body has a connecting channel which, depending on the rotational position of the valve body in the distributor housing, can connect the connection for the conveying device with one of the connections for the storage tanks, the mixing tank, and the liquid outlet.A multi-valve designed in this way is not only characterized by the fact that it has only one moving part (the valve body), but also by its ease of cleaning because all fluids are routed through the same connecting channel in the rotating valve body. Furthermore, such a multi-valve advantageously features low dead volume, short travel distances, and short, constant fluid paths.

[0027] Although manual adjustment of the valve body of the multiple valve is possible, it is preferred if the valve body of the multiple valve can be rotated by means of an electric motor in the distributor housing, which advantageously enables automatic adjustment of the valve body. A stepper motor, connected directly or via a gear connection, can be used as the drive.

[0028] In a suitable embodiment of the coating system, each storage container of the mixing and / or dosing device can be assigned a filter located upstream of the multi-way valve. This prevents any impurities or clumps of the liquid starting materials from reaching the multi-way valve and causing a blockage there. The storage containers can be pressurized if necessary, so that the liquid starting materials are forced through the filters without creating a vacuum. A filter can also be arranged between the multi-way valve and the liquid outlet to filter the liquid coating materials before coating.

[0029] To prevent unintentional coating of the substrates, for example, immediately after cleaning the mixing and / or dosing device, several measures are conceivable. z.B. the substrates are moved away from the coating chamber by means of the substrate holder of the coating system or the position of the nozzle is changed in the coating chamber such that coating of the substrates is excluded. Particularly with regard to a simple design of the coating system and short process times, it is preferred if a diverting device is assigned to the nozzle in the coating chamber, which can be moved optionally from a diverting position between the nozzle and the substrate holder, which prevents unintentional coating of the substrates, to a release position in which the diverting device is not located between the nozzle and the substrate holder, and vice versa. In principle, the diverting device for covering the nozzle can, for example, have a linearly movable slider, which is driven by an electric motor.To achieve a compact arrangement and high functional reliability, however, it is preferred if the discharge device has a flap that can be pivoted by means of a pneumatic cylinder. The flap can be pivoted, for example, via a shaft extending from the outside into the coating chamber, which—unlike a guide mechanism in a linear movement—can be easily protected against disruptive influences caused by any curing liquid coating materials. Furthermore, pneumatic cylinders are very cost-effective compared to other conceivable electric drives, and compressed air is usually available in a coating system anyway.

[0030] The mixing and / or dosing device described above is, in principle, suitable for integration into any coating system of the type that uses liquid coating materials, i.e., a coating system that operates with any coating principle—for example, dip coating or inkjet printing. However, it is particularly preferred if the coating system is a rotary coating system, which is characterized in particular by the ability to produce highly uniform or evenly distributed coatings and short coating process times.

[0031] In further pursuit of the inventive concept, a method for individually coloring optical glasses, namely spectacle lenses, in which the coating system described above can be used in particular, comprises the following method steps: (i) providing a spectacle lens or a pair of spectacle lenses; (ii) selecting an individual color for the spectacle lens or the pair of spectacle lenses from a plurality of colors, for the mixing of which a mixing ratio of different starting colors is known; (iii) dosing the various starting colors provided in the partial quantities required to mix the selected individual color according to the known mixing ratio for a total quantity that is just sufficient to color the spectacle lens or the pair of spectacle lenses; (iv) mixing the dosed partial quantities of starting colors to obtain a mixed total quantity of the selected individual color;and (v) coating the spectacle lens or pair of spectacle lenses with the mixed total amount of the selected individual color.;

[0032] In contrast to the previously described prior art, different dye pots are not kept ready as immersion baths for dyeing spectacle lenses, with the associated problems, particularly with regard to the reproducibility of certain dyes. Instead, the desired individual color is individually mixed according to the known mixing ratio in a very small quantity, namely an amount that is just sufficient to coat the respective spectacle lens or pair of spectacle lenses, and no more. This means that - compared to the prior art - a significantly larger number of individual color requests can be realized easily and with less effort. The reproducibility of certain color shades is very good because it does not depend on the skill of the dyeing personnel or subjective color impressions, but is objectively determined based on the known mixing ratio.Furthermore, there is no risk of the color changing due to environmental influences and / or aging, because the individual color is mixed precisely on demand for the respective coating process. Last but not least, the inventive method for customized coloring is highly suitable for automation, making it particularly suitable for the customized coloring of optical glass on an industrial scale. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The invention will be explained in more detail below using a preferred embodiment with reference to the accompanying, partially schematic drawings. The drawings show: Fig. 1 is a perspective view of a coating system according to the invention for individually coating substrates, namely spectacle lenses, obliquely from the top front right, with a substrate holder for holding the substrates during coating and a coating station to which a device for mixing and / or dosing liquid coating materials is connected; Fig. 2 is a perspective view of the coating system according to Fig. 1 from the top rear left, looking at the coating station and the device connected to it for mixing and / or dosing, which generally comprises several storage containers for liquid starting materials, a conveyor device for sucking in and discharging liquids, a mixing container, a liquid outlet for mixed and / or dosed liquid coating materials leading into a coating chamber of the coating station, and a multiple valve arranged therebetween; Fig. 3 a rear view of the coating system according to Fig. 1 ; Fig. 4a compared to the scale of the Fig. 3 Enlarged sectional view of the coating system, broken off upwards, downwards and to the right, according to Fig. 1 according to the offset section line IV-IV in Fig. 3 , with a view of a nozzle of the device for mixing and / or dosing, which opens into the coating chamber of the coating station and is connected to the liquid outlet, wherein the nozzle is arranged below a flap of a discharge device which is located between the nozzle and a substrate shown in dashed lines; Fig. 5 a sectional view of the coating system according to Fig. 1 according to the section line VV in Fig. 3 on the scale of Fig. 4 , with a view of the floor of the coating chamber and the flap of the discharge device in a discharge position preventing unintentional coating of the substrates, with a dashed line also indicating a release position of the flap in which the flap is not located between the nozzle and the substrate holder; Fig. 6 a sectional view of the coating system according to Fig. 1 according to the offset section line VI-VI in Fig. 3 on the scale of Fig. 4 , which shows further details of the conveying device and the multiple valve of the device for mixing and / or dosing; Fig. 7 a scaled-down view of the Fig. 4 enlarged, completely broken-off sectional view of the coating system according to Fig. 1 according to the section line VII-VII in Fig. 4 , to illustrate further details of the multiple valve and the mixing container of the device for mixing and / or dosing; Fig. 8 an enlarged scale view of detail VIII in Fig. 6 ; Fig. 9a scale comparison of the Fig. 2 enlarged, completely broken away perspective view of the coating system according to Fig. 1 from the rear bottom right, with a view in particular of the multiple valve and the conveying device designed as a syringe pump of the device for mixing and / or dosing; Fig. 10 a scale view of the Fig. 2 enlarged, completely broken away perspective view of the coating system according to Fig.1 from the rear, bottom left, with a view in particular of a pneumatic cylinder for pivoting the flap of the discharge device; and Fig. 11 is a flow chart showing the individual process steps associated with the device for mixing and / or dosing of the coating system according to the invention, which are carried out during the individual dyeing of a spectacle lens in the coating system according to Fig. 1 be run through one after the other.

[0034] With regard to the drawings, it should be noted at this point that in order to provide a clear view of essential components or assemblies of the coating system according to the invention and the device for mixing and / or dosing and to simplify the illustration, in particular parts of the cladding, doors, shelves for workpieces and operating materials, the supply devices (including lines, hoses and pipes) for electricity and compressed air as well as the measuring, maintenance and safety devices have mostly been omitted because they do not appear necessary for understanding the invention and are familiar to the person skilled in the art anyway. DETAILED DESCRIPTION OF THE EMBODIMENT

[0035] In the Fig. 1 bis 10 As an example, a coating system 10 for the individual coating of substrates, namely spectacle lenses L, is shown in a rotation coating system in which, according to the Fig. 2 bis 10 a device for mixing and / or dosing liquid coating materials - hereinafter referred to as mixing device 12 - is integrated, which will be described in more detail below.

[0036] The mixing device 12 generally comprises at least one first (14, 16) and at least one second (18, 20, 22, 24) storage container for liquid starting materials (solvents as well as clear and differently colored primers), wherein in the illustrated embodiment a total of six storage containers 14, 16, 18, 20, 22, 24 for - in the Fig. 2 and 3 From left to right - solvent (reservoir 14), clear primer (reservoir 16), black-tinted primer (reservoir 18), blue-tinted primer (reservoir 20), red-tinted primer (reservoir 22) and yellow-tinted primer (reservoir 24) are provided. Furthermore, the mixing device 12 has a particularly Fig. 6 shown conveying device 26 for sucking in and ejecting liquids, a particularly in Fig. 7 Mixing container 28 shown and a best in Fig. 4 liquid outlet 30 for mixed and / or metered liquid coating materials. Between them, a multi-valve, generally designated by reference numeral 32, is arranged (see in particular the Fig. 6 bis 8 ), which can be switched into different valve positions and - as will also be explained in detail below - is adapted to establish each of the following connections (a, b, c, d) and in the process to separate the other connections: (a) connection between the respective first storage container 14 or 16 and the conveying device 26, (b) connection between the respective second storage container 18, 20, 22 or 24 and the conveying device 26, (c) connection between the conveying device 26 and the mixing container 28 and (d) connection between the conveying device 26 and the liquid outlet 30, in the embodiment shown here a total of eight different connections.

[0037] Regarding the interaction of the mixing device 12 and the coating system 10, it should be mentioned at this point that the coating system 10 generally has several substrate holders 34 for holding the spectacle lenses L (among others) during the coating and a coating space 38 delimited by a coating bowl 36 (so-called "coating bowl"), in which according to Fig. 4 the liquid outlet 30 of the mixing device 12 opens via a nozzle 40 in order to dispense the liquid coating material mixed and / or dosed in the mixing device 12 in the direction of the substrate holder 34.

[0038] According to the Fig. 1 bis 3 The coating system 10 has a frame 42 that supports and surrounds the various components of the coating system 10 and comprises a plurality of supports and struts that are connected to one another in a box-like configuration. Covering parts are attached all around the frame 42 to prevent contaminants from entering the interior of the coating system 10, which, during operation of the coating system 10, is subject to a slight negative pressure generated by a fan provided in the floor area of ​​the coating system 10, which fan is not shown in the figures. Fig. 2 However, exhaust air pipes 43 are shown, which are connected to this fan. The aforementioned cladding parts are also mostly omitted in the figures in order to provide a view into the interior of the coating system 10. Examples of these cladding parts are shown in Fig. 1 a front plate 44 is shown which covers part of the front of the frame 42.

[0039] The frame 42 is further provided on its underside at all four corners with height-adjustable casters 45, which allow the coating system 10 to be moved easily and safely. Furthermore, the casters 45 ensure a stable stand for the coating system 10 at the respective installation location and enable precise height adjustment, particularly to level the coating system 10 for a smooth spin coating process (so-called "spin coating").

[0040] Within the frame 42, the coating system 10 comprises a number of work stations for performing one or more operations on the spectacle lenses L. First, a loading station 46 is provided, via which the spectacle lenses L are loaded into the coating system 10. Reference numeral 48 designates a washing station in which the spectacle lenses L are washed and dried. At reference numeral 50, the coating system 10 comprises a coating station with the coating bowl 36, in which the coating is applied to the spectacle lenses L by spin coating. This is followed by a curing station 52 for drying and curing the coating applied to the spectacle lenses L by means of UV radiation. Finally, an unloading station 54 is provided, via which the finished spectacle lenses L are transported out of the coating system 10.

[0041] For transporting the spectacle lenses L from workstation to workstation, the coating system 10 has a carousel 56, described in more detail below, which can be rotated about a vertically extending rotation axis by means of a rotary drive 57 arranged below the carousel 56. Furthermore, the carousel 56 can be raised and lowered along the rotation axis by means of a preferably pneumatic or hydraulic lifting mechanism (not shown in the figures).

[0042] The operation of the carousel 56 and the individual work stations 46, 48, 50, 52 and 54 as well as the integrated mixing device 12 is controlled by a central control unit 58. According to Fig. 1 The control unit 58 comprises a touchscreen 60 for entering operating parameters and displaying status information of the coating system 10. Further operating elements of the control unit 58 are Fig. 1 an on / off switch 61 and an emergency stop switch 62 are shown.

[0043] In order to maintain a clean environment within the coating system 10 and thus in particular to prevent particles from entering the interior of the coating system 10, which could lead to contamination of the coated spectacle lenses L, Fig. 1 and 2 A centrifugal fan 63 is mounted at a central location on the top side of the frame 42, which fan cooperates with a HEPA-type particulate filter (not shown) arranged below the centrifugal fan 63 for air purification, so that - also due to the negative pressure present inside the coating system 10 (see above) - particle-free air is circulated inside the coating system 10.

[0044] Like the Fig. 1 and 2As can also be seen, the carousel 56 has an inner hub section 64, from which a total of five arms 65 of equal length extend, corresponding to the number of work stations 46, 48, 50, 52, 54, which arms are evenly angularly spaced from one another around the hub section 64. A rotary union 66 is arranged above the hub section 64 of the carousel 56, which in turn is supported on an upper, stationary part relative to the frame 42 via a frame fastening element 67 acting as a torque support.

[0045] At the free ends of the arms 65 of the carousel 56 facing away from the hub section 64, one of the substrate holders 34 is attached to each arm 65. More precisely, each substrate holder 34 comprises, in particular, Fig. 1 (right side), 3 (right side), and 4 (in dashed lines) comprise a housing section 68 that is firmly connected to the free end of the respective arm 65. A drive shaft 69 is rotatably mounted in the housing section 68. Attached to a lower end of each drive shaft 69 is a rubber-elastic suction cup 70 surrounded by a splash guard, shown only schematically in the figures. A disc-shaped magnetic coupling 71 is attached to an upper end of each drive shaft 69, extending through the respective arm 65.

[0046] The reference number 72 numbers in the Fig. 1 bis 3 a vacuum connection provided on each housing section 68, via which a vacuum can be applied to the respective suction cup 70 in order to suck and hold the spectacle lens L in a manner known per se (cf. Fig. 4 ). The vacuum connections 72 are connected via vacuum hoses (not shown in the figures) to associated vacuum connections 73 of a distributor section 74 of the rotary union 66, which can rotate with the carousel 56. The distributor section 74 is in turn connected to a vacuum source (not shown) via vacuum connections 75 on the upper, stationary part of the rotary union 66.

[0047] The washing station 48 and the coating station 50 are each further assigned a rotary drive arrangement 76 and 77, respectively, which is adapted to cooperate with the magnetic couplings 71 of the substrate holders 34 and serves, in a manner known per se, to drive the drive shaft 69 of the respective substrate holder 34 in rotation via the magnetic coupling 71 when the respective substrate holder 34 is located at the washing station 48 or the coating station 50.

[0048] With regard to the substrate-side kinematics of the coating system 10, it is apparent to those skilled in the art that the ophthalmic lenses L to be coated can be held on the substrate holders 34 by means of suction cups 70 under negative pressure. These holders, in turn, can be moved from workstation to workstation by rotating the carousel 56 and can be lowered into and lifted out of the respective workstation by a lifting movement of the carousel 56. Furthermore, the ophthalmic lenses L held on the substrate holders 34 can be rotated about their own axes in the washing station 48 and the coating station 50 by means of the rotary drive arrangement 76 and 77, respectively, via the respective magnetic coupling 71.

[0049] To washing station 48 is the Fig. 1 It can also be seen that the washing station 48 comprises a washing container 78 in which the rotating lenses L are washed with washing water. The washing water is conveyed from a container 79 for washing water arranged below the washing station 48 via a filter 80 by a pump (not shown) through a washing water supply hose 81 into the washing container 78. Furthermore, Fig. 1 From the washing station 48, a suction device 82 connected to the washing tank 78 and a tank 83 for waste water can be seen.

[0050] The Fig. 2 shows a light box 84 from the curing station 52, which is covered by a cover 85. The cover 85 has Fig. 1 on its upper side an opening through which the spectacle lenses L held on the substrate holder 34 can be lowered via the carousel 56 into the light box 84. A UV lamp (not shown) is arranged in the light box 84, which serves to irradiate and cure the coating applied to the spectacle lenses L in the coating station 50. If necessary, a rotary drive arrangement (not shown here) can also be provided at the curing station 52 in order to rotate the spectacle lenses L during curing of the coating via the magnetic coupling 71 of the respective substrate holder 34. Curing can also take place in an inert atmosphere (CO 2 or N 2 ).

[0051] Before further details of the coating station 50 are given based on the Fig. 2 bis 5 , 9 und 10 are to be described, it should be noted at this point that further details on the structure and function of the coating system 10 described in this regard can be found in the document US 2008 / 0035053 A1, to which express reference is made here.

[0052] How best in Fig. 4 As can be seen, the coating bowl 36 of the coating station 50, which is arranged below a horizontal partition 86, is accessible from above through an opening 87 in the partition 86. The spectacle lens L held on the suction cup 70 of the respective substrate holder 34 can thus be lowered selectively by means of the carousel 56 through the opening 87 into the coating bowl 36, as shown in Fig. 4 shown to face the nozzle 40 of the mixing device 12.

[0053] The coating bowl 36 generally comprises a bottom section 88 and a hollow cylindrical wall section 89 attached thereto, which together define the coating chamber 38 downwards and laterally. The bottom section 88 of the coating bowl 36 is connected to the coating chamber 38 via two mounting brackets 90 (see also Fig. 10 ) is mounted on a vertical partition wall 91 of the coating system 10. On its upper side, the bottom section 88 of the coating bowl 36 is provided with a substantially conical recess 92, which forms a trough-like depression in the bottom section 88, at the lowest point of which a drain 93 is formed. The always-open drain 93 is connected via a connecting angle 94 to a drain hose 95, which leads to a waste container 96 for liquid waste materials arranged next to the storage container 24.

[0054] According to Fig. 4 Furthermore, a pipe section 97 of an extraction system for solvent vapors is attached in a through-hole in the bottom section 88 of the coating bowl 36 in a sealed manner, which protrudes both upwards and downwards over the bottom section 88. From above, a cap 98 is placed on the pipe section 97, which according to Fig. 4 The pipe section 97 is covered at the top, but still leaves a free cross-section for the passage of solvent vapors. A suction hose 99 is attached to one end of the pipe section 97 from below. The other end of the suction hose 99 is connected to a suction shaft 101 via a nozzle 100, as best shown in Fig. 3 which in turn communicates with the aforementioned blower (not shown) in the bottom area of ​​the coating system 10. A slide valve 102 provided in a lower area of ​​the extraction shaft 101 enables a change in the negative pressure in the extraction shaft 101, which can influence the thickness of the coating applied in the coating bowl 36.

[0055] Furthermore, in particular the Fig. 4 and 5As can be seen, the nozzle 40 in the coating chamber 38 of the coating bowl 36 is assigned a deflection device 103, which can be selectively moved from a deflection position between the nozzle 40 and the substrate holder 34, preventing unintentional coating of the spectacle lenses L, to a release position in which the deflection device 103 is not located between the nozzle 40 and the substrate holder 34, and vice versa. In the illustrated embodiment, the deflection device 103 has a flap 104, which can be pivoted by means of a pneumatic cylinder 105, which is best placed in the Fig. 9 und 10 can be seen.

[0056] More precisely, according to Fig. 4 In a stepped bore formed in the bottom section 88 of the coating bowl 36 next to the outlet 93, a bearing tube 106 of the discharge device 103 is fastened in a suitably sealed manner, which rotatably receives a cylindrical connecting bolt 107 which projects beyond the bearing tube 106 on both sides. At the end of the connecting bolt 107 projecting into the coating chamber 38, the top view (cf. Fig. 5 ) is suitably fastened to a substantially rectangular flap 104 made of an aluminum alloy, e.g. by means of a pin connection. On the end of the connecting bolt 107 projecting downwards beyond the bearing tube 106, however, as shown in particular in the Fig. 9 und 10 show, a lever 108 is suitably mounted at one end, for example again by means of a pin connection. At its other end, the lever 108 is pivotally connected to a fork head 109, as best shown in Fig. 10 which is attached to a piston rod 110 of the double-acting pneumatic cylinder 105, which protrudes from a cylinder housing 111 of the pneumatic cylinder 105. At the end of the cylinder housing 111 facing away from the fork head 109, the cylinder housing 111 is pivotally connected to a holder 112, which in turn is indicated at the reference numeral 113 in Fig. 10 is screwed from below to the bottom section 88 of the coating bowl 36.

[0057] It will be apparent to the person skilled in the art that the flap 104 can be moved from its position in Fig. 5 with a solid line drawn discharge position above the nozzle 40 into its Fig. 5 The valve 104 can be pivoted to the release position indicated by a dashed line next to the nozzle 40 and vice versa. A proximity sensor (not shown) provided on the pneumatic cylinder 105 can provide information about the respective position of the flap 104.

[0058] Further details of the mixing device 12 are particularly Fig. 6 bis 9 How best to start by Fig. 6 shows, the mixing device 12 has its own housing 114 with a front, ie in Fig. 6 left opening, to which a flange plate 115 is flanged as a support for the conveyor device 26, the mixing container 28 and the multiple valve 32. The housing 114 itself is according to in particular Fig. 5 attached to the vertical partition wall 91 of the coating system 10 by means of an angle plate 116.

[0059] Furthermore, in particular the Fig. 6 As shown, the conveying device 26 comprises a syringe pump 117 with a syringe cylinder 118 and a syringe plunger 119, which can be positioned relative to the syringe cylinder 118 by means of a lifting drive 120. The lifting drive 120 has an electric motor 121, which is drive-connected to the syringe plunger 119 via a gear mechanism 122, which is capable of converting a rotational movement into a longitudinal movement.

[0060] More precisely, the electric motor 121 is flanged to a flange portion 123 of the housing 114. A threaded spindle 124 of the gear mechanism 122 is rotatably mounted between the flange portion 123 of the housing 114 and the flange plate 115 by means of a loose bearing-fixed bearing arrangement comprising roller bearings 125. The electric motor 121 is drivingly connected to the threaded spindle 124 via a belt drive 126 of the gear mechanism 122. An actuating arm 128 is seated on an externally threaded portion 127 of the threaded spindle 124, which has an eye-like end with an internally threaded portion 129 engaging with the externally threaded portion 127. The actuating arm 128 extends, suitably guided, through a longitudinal slot 130 formed in the flange plate 115 and is connected with its end facing away from the internally threaded portion 129 to a Fig. 6 lower end of the syringe plunger 119.

[0061] It will be apparent to a person skilled in the art that the threaded spindle 124 can be driven in rotation by means of the electric motor 121 via the belt drive 126. As a result of the threaded engagement between the external thread section 127 of the threaded spindle 124 and the internal thread section 129 of the actuating arm 128, which is guided against rotation around the threaded spindle 124, the actuating arm 128 moves in Fig. 6 Up or down, depending on the direction of rotation of the electric motor 121. Consequently, the syringe plunger 119, which is preferably made of borosilicate glass and also preferably provided with a PTFE coating, is displaced into the glass syringe barrel 118, depending on the direction of displacement, either to displace liquid from the syringe barrel 118 or to suck liquid into the syringe barrel 118. The syringe barrel 118 can, for example, have a capacity of 5 ml.

[0062] Furthermore, as regards the design of the multiple valve 32, particular attention should be paid to the Fig. 3 and 6 bis 8 It can be seen that the multiple valve 32 has a distributor housing 131 flanged to the flange plate 115 with a total of nine connections. This is initially in a star-like arrangement in a clockwise direction in Fig. 7 to (1.) a connection 132 for a hose 133 to the storage container 14, (2.) a connection 134 for the mixing container 28, (3.) a connection 136 for a hose 137 to the storage container 24, (4.) a connection 138 for a hose 139 to the storage container 22, (5.) a connection 140 for a hose 141 to the storage container 20, (6.) a connection 142 for a hose 143 to the storage container 18, (7.) a connection 144 for an ejection hose 145 of the liquid outlet 30 leading to the nozzle 40 in the coating bowl 36 and (8.) a connection 146 for a hose 147 to the storage container 16 as well as - the common plane of these connections 132, 134, 136, 138, 140, 142, 144, 146 according to Fig. 4, 6 and 8upstream - (9.) a connection 148 for the syringe cylinder 118 of the syringe pump 117. Furthermore, the multiple valve 32 has a valve body 149 which is rotatably received in the distributor housing 131 and has a connecting channel 150 which, depending on the rotational position of the valve body 149 in the distributor housing 131, connects the connection 148 for the syringe cylinder 118 of the conveyor device 26 with only one of the connections 132, 134, 136, 138, 140, 142, 144, 146 for the storage containers 14, 16, 18, 20, 22, 24, the mixing container 28 or the liquid outlet 30.

[0063] According to Fig. 8 The syringe cylinder 118 of the syringe pump 117 is connected via a connector 151 with the aid of a seal 152 directly to the front connection 148 of the distributor housing 131, which leads to a connector 153 fixedly arranged in the distributor housing 131. In Fig. 8 It can also be seen that the connecting channel 150 has two angular sections 154, 155, namely an angular section 154 in the rotationally fixed connecting piece 153 and an angular section 155 in the substantially cylindrical valve body 149, wherein the angular sections 154, 155 open into one another on a rotation axis 156 of the valve body 149. By rotating the valve body 149 about the rotation axis 156, the radially extending end of the angular section 155 in the valve body 149 is aligned with the respective connection 132, 134, 136, 138, 140, 142, 144, 146 in order to establish the corresponding connection and simultaneously separate the other connections in this plane. The connection 148 for the conveying device 26, on the other hand, always remains connected to the connecting channel 150.

[0064] As the Fig. 6 and 8As further shown, the valve body 149 of the multiple valve 32 is rotatable about the rotation axis 156 by means of an electric motor 157 in the distributor housing 131, so that the respective connections can be established automatically. The electric motor 157 is flanged to the flange plate 115 on an inner side of the housing 114 and is drive-connected to the valve body 149 of the multiple valve 32 by an output shaft 158 ​​via a cross pin 159.

[0065] According to in particular Fig. 7 The mixing container 28, which is directly connected to the connection 134 at the highest point of the multiple valve 32, has a mixing funnel 160, preferably made of stainless steel. The mixing funnel 160 is closed at the top by a container lid 161, also made of stainless steel, which is sealed against the mixing funnel 160 by means of an O-ring 162. The container lid 161 is further provided with a threaded bore in which a connecting bracket 163 is fastened, to which a ventilation hose 164 is connected. The ventilation hose 164 communicates with the interior of the coating system 10, so that filtered air can enter the mixing funnel 160. In order to prevent the coating materials from adhering to the inner walls of the mixing funnel 160 as far as possible and to simplify and accelerate the cleaning of the mixing funnel 160, the inner surfaces of the mixing funnel 160 are electropolished or have a non-stick coating, such as an FEP coating.

[0066] Finally, it should be noted that storage containers 14, 16, 18, 20, 22, 24 are designed according to the Fig. 4 und 6 each closed with a lid 165 having a central opening for the passage of the respective hose 133, 137, 139, 141, 143, 147. Each storage container 14, 16, 18, 20, 22, 24 is assigned a filter 166 located upstream of the multiple valve 32. In the illustrated embodiment, this filter 166 is located at the end of the respective hose 133, 137, 139, 141, 143, 147 in the corresponding storage container 14, 16, 18, 20, 22, 24. The filters 166 can be, for example, 10µm PTFE filters, whereby the choice of the filters 166 depends on the size of the particles in the respective coating material and on the viscosity of the coating materials as well as the desired spraying speed.

[0067] Using the flow chart according to Fig. 11 Finally, a possible procedure will be described as to how the coating system 10 can be used with the mixing device 12 in order to individually color a spectacle lens L.In general, a method for individually coloring, in particular, spectacle lenses L is characterized by the following method steps: (i) providing a spectacle lens L or a pair of spectacle lenses; (ii) selecting an individual color for the spectacle lens L or the pair of spectacle lenses from a plurality of colors, for the mixing of which a mixing ratio of different starting colors is known; (iii) dosing the provided different starting colors in partial quantities required to mix the selected individual color according to the known mixing ratio for a total quantity that is just sufficient to color the spectacle lens L or the pair of spectacle lenses; (iv) mixing the dosed partial quantities of starting colors to obtain a mixed total quantity of the selected individual color; and (v) coating the spectacle lens or the pair of spectacle lenses with the mixed total quantity of the selected individual color.

[0068] In detail, the above process steps can be described with particular reference to the mixing device 12 according to the flow chart of Fig. 11 which basically distinguishes four process steps, namely dosing, mixing, coating and cleaning.

[0069] In the first process step (dosing), the liquid starting materials (colors 1 to 4) are dosed using the syringe pump 117 (syringe). For this purpose, the flap 104 of the discharge device 103 is first closed, i.e., pivoted by the pneumatic cylinder 105 so that unintentional coating of the respective spectacle lens L is prevented (close flap).

[0070] To dispense a total amount of the selected individual color, the multi-valve 32 is initially switched so that the Fig. 2 and 3The third reservoir 18 from the left is connected to the syringe cylinder 118 of the syringe pump 117 (valve position color 1; black in the example). The syringe piston 119 of the syringe pump 117 is then moved by the stroke drive 120 by a specific first distance in the direction out of the syringe cylinder 118, so that a defined first partial quantity of color 1 is sucked into the syringe cylinder 118 (draw up syringe x 1 / 1000).

[0071] The multiple valve 32 is then switched to a valve position in which the fourth reservoir 20 is connected to the syringe cylinder 118 of the syringe pump 117 (valve position color 2; blue in the example), whereupon the syringe piston 119 is moved a certain second distance further out of the syringe cylinder 118 in order to suck a defined second partial quantity of the color 2 into the syringe cylinder 118 (draw up syringe x 2 / 1000).

[0072] Subsequently, the partial quantities of color 3 from the reservoir 22 (valve position color 3; in the example, red) and color 4 from the reservoir 24 (valve position color 4; in the example, yellow) are metered in an analogous manner via certain third and fourth additional paths of the syringe piston 119 in the syringe cylinder 118 (draw syringe x 3 / 1000 or draw syringe x 4 / 1000). The partial quantities x 1 / 1000 to x 4 / 1000 result from the known mixing ratio for the selected individual color.

[0073] In the second process step (mixing), colors 1 to 4, which have been sucked into the syringe cylinder 118 in the mixing ratio corresponding to the selected individual color, are mixed together. For this purpose, the multiple valve 32 is switched to a valve position in which the syringe cylinder 118 of the syringe pump 117 is connected to the mixing container 28, which has the mixing funnel 160 (mixing funnel valve position). The syringe piston 119 is then moved into the syringe cylinder 118 of the syringe pump 117 by means of the lifting drive 120, so that the colors 1 to 4 previously sucked into the syringe cylinder 118 are expelled via the multiple valve 32 into the mixing container 28 (syringe emptying).

[0074] The mixed ink is then drawn into the syringe barrel 118 in the usual way (drawing up the syringe). As it passes through the mixing funnel 160, the ink is swirled for better mixing. To achieve particularly thorough mixing, this process is repeated, for example, 6 to 8 times (alternating between emptying the syringe and drawing up the syringe).

[0075] To coat the spectacle lens L in the third process step (coating), the multiple valve 32 is switched to a valve position in which the syringe cylinder 118 is connected to the liquid outlet 30 (valve position "ejection"). As already described above, the nozzle 40 of the liquid outlet 30, located in the coating chamber 38, is connected to the multiple valve 32 via an ejection hose 145. Before the spectacle lens L, which is held rotating on the substrate holder 34 in the coating chamber 38, can be coated, the liquid outlet 30, which is filled with solvent from a previous process and comprises the nozzle 40 and the ejection hose 145, must be filled with the mixed individual color. For this purpose, the syringe piston 119 is displaced by the stroke drive 120 by a corresponding distance into the syringe cylinder 118 of the syringe pump 117 (empty syringe / fill hose y 1 / 1000).Liquid escaping from the nozzle 40 of the liquid outlet 30 cannot reach the spectacle lens L because the spectacle lens L is shielded by the flap 104 of the discharge device 103.

[0076] The flap 104 of the discharge device 103 is then pivoted into the release position by means of the pneumatic cylinder 105 (opening the flap). Subsequently, the coating of the spectacle lens L is carried out in a known manner, with the syringe piston 119 being displaced a certain further distance into the syringe cylinder 118 of the syringe pump 117 by means of the lifting drive 120. The syringe piston 119 thereby displaces the quantity of mixed individual color required to coat the spectacle lens L, so that it is ejected via the nozzle 40 in the direction of the rotating spectacle lens L (empty syringe / coating y 2 / 1000). Since two spectacle lenses L are to be coated in this exemplary embodiment, this process is repeated once again for the second spectacle lens L (empty syringe / coating y 3 / 1000).

[0077] In the final process section (cleaning) with respect to the mixing device 12, the flap 104 of the discharge device 103 is first closed in a known manner (closing the flap), whereupon the multiple valve 32 is switched to a valve position in which the Fig. 2 and 3 From the left, the first solvent reservoir 14 is connected to the syringe barrel 118 (valve position "cleaning agent"). The solvent is sucked in a known manner in the amount required for cleaning via the syringe plunger 119 into the syringe barrel 118 of the syringe pump 117 (draw syringe z / 1000).

[0078] The multiple valve 32 is then switched to a valve position in which the syringe cylinder 118 is connected to the mixing container 28 (mixing funnel valve position). The solvent for cleaning the mixing container 28 and the syringe pump 117 is then ejected, for example, three times from the syringe cylinder 118 into the mixing container 28 (emptying the syringe) and drawn from the mixing container 28 into the syringe cylinder 118 (drawing up the syringe).

[0079] The multiple valve 32 is then switched to a valve position in which the syringe cylinder 118 is connected to the liquid outlet 30 (valve position "ejection"). The residual ink remaining in the ejection hose 145 and the nozzle 40 from the coating process is displaced by the solvent ejected from the syringe cylinder 118. Furthermore, the ejection hose 145 and the nozzle 40 are rinsed with the solvent and then refilled with solvent (empty syringe / fill hose). The displaced residual ink and excess solvent are conveyed into the waste container 96 via the drain 93 of the coating bowl 36, the connecting angle 94, and the drain hose 95. Finally, the flap 104 of the discharge device 103 in the coating chamber 38 is pivoted back into the release position by means of the pneumatic cylinder 105 (open flap).

[0080] In a coating system for ophthalmic lenses, a device for mixing / dosing liquid coating materials has at least a first and a second storage container for liquid starting materials, a conveying device for sucking in and ejecting liquids, a mixing container, and a liquid outlet for mixed / dosed liquid coating materials. A multiple valve is arranged between them, which can be switched to different valve positions and is adapted to establish one of the following connections while simultaneously disconnecting the other connections: (a) connection between the first storage container and the conveying device, (b) connection between the second storage container and the conveying device, (c) connection between the conveying device and the mixing container, and (d) connection between the conveying device and the liquid outlet.This also makes it possible to carry out a process for the individual colouring of spectacle lenses, in which the individual colour is mixed reproducibly for only one spectacle lens or a pair of spectacle lenses according to a known mixing ratio. LIST OF REFERENCE SYMBOLS

[0081] 10 Coating system 12 Mixing device 14 Storage tank (solvent) 16 Storage tank (clear primer) 18 Storage tank (black primer) 20 Storage tank (blue primer) 22 Storage tank (red primer) 24 Storage tank (yellow primer) 26 Conveyor device 28 Mixing tank 30 Liquid outlet 32 ​​Multi-way valve 34 Substrate holder 36 Coating bowl 38 Coating chamber 40 Nozzle 42 Frame 43 Exhaust pipe 44 Front panel 45 Caster base 46 Loading station 48 Washing station 50 Coating station 52 Curing station 54 Unloading station 56 Carousel 57 Rotary drive 58 Control unit 60 Touchscreen 61 On / off switch 62 Emergency stop switch 63 Centrifugal fan 64Hub section 65Arm 66Rotary union 67Frame fastener 68Housing section 69Drive shaft 70Suction cup 71Magnetic coupling 72Vacuum connection 73Vacuum connection 74Distributor section 75Vacuum connection 76Rotary drive assembly 77Rotary drive assembly 78Washer tank 79Washer water tank 80Filter 81Washer water supply hose 82Suction83 Wastewater container 84 Light box 85 Cover 86 Horizontal partition 87 Opening 88 Floor section 89 Wall section 90 Mounting bracket 91 Vertical partition 92 Recess 93 Drain 94 Connection bracket 95 Drain hose 96 Waste container 97 Pipe section 98 Cap 99 Suction hose 100 Nozzle 101 Exhaust shaft 102 Slide valve 103 Drainage device 104 Flap 105 Pneumatic cylinder 106 Bearing tube 107 Connecting bolt 108 Lever 109 Fork head 110 Piston rod 111 Cylinder housing 112 Holder 113 Screw connection 114 Housing 115 Flange plate 116 Angle plate 117 Syringe pump 118Syringe barrel 119Syringe plunger 120Lifting drive 121Electric motor 122Gear mechanism 123Flange section 124Threaded spindle 125Rolling bearing 126Belt drive 127External thread section 128Actuating arm 129Internal thread section 130Longitudinal slot 131Distributor housing 132Port (solvent) 133Tubing (solvent) 134Port (metered / mixed substances) 136Port (yellow primer) 137Tubing (yellow primer) 138Port (red primer) 139Tubing(red primer) 140Connection (blue primer) 141Hose (blue primer) 142Connection (black primer) 143Hose (black primer) 144Connection (metered / mixed materials) 145Discharge hose (metered / mixed materials) 146Connection (clear primer) 147Hose (clear primer) 148Connection (all materials) 149Valve body 150Connection channel 151Connection piece 152Seal 153Connection piece 154Elbow section 155Elbow section 156Rotary axis 157Electric motor 158Output shaft 159Cross pin 160Mixing hopper 161Tank cover 162O-ring 163Connection elbow 164Venting hose 165Cover 166Filter LGlasses lens

Claims

1. Coating system (10) for individual coating of substrates, namely spectacle lenses (L), comprising a device (12) for mixing and / or metering liquid coating materials, a substrate holder (34) for holding the substrate during the coating and a coating chamber (38) into which a liquid outlet (30) of the device (12) opens by way of a nozzle (40) so as to deliver the liquid coating material, which is mixed and / or metered in the device (12), in the direction of the substrate holder (34), characterized in that the device (12) for mixing and / or metering liquid coating materials comprises at least one first and at least one second storage container (14 - 24) for liquid starting materials, a conveying device (26) for sucking up and expelling liquids, a mixing container (28), the liquid outlet (30) for mixed and / or metered liquid coating materials, and a multi-way valve (32) arranged therebetween, wherein the multi-way valve (32) is switchable into different valve settings and adapted to produce one of the following connections (a, b, c, d) and in that case to separate the respective other connections: (a) connection between the first storage container and the conveying device (26), (b) connection between the second storage container and the conveying device (26), (c) connection between the conveying device (26) and the mixing container (28), and (d) connection between the conveying device (26) and the liquid outlet (30).

2. Coating system (10) according to claim 1, characterized in that the conveying device (26) comprises a syringe pump (117) with a syringe cylinder (118) and a syringe piston (119), which is positionable with respect to the syringe cylinder (118) by a stroke drive (120).

3. Coating system (10) according to claim 2, characterized in that the stroke drive (120) comprises an electric motor (121) disposed in drive connection with the syringe piston (119) by way of a transmission mechanism (122) capable of converting a rotational movement into a longitudinal movement.

4. Coating system (10) according to any one of the preceding claims, characterized in that the mixing container (28) comprises a mixing funnel (160).

5. Coating system (10) according to claim 4, characterized in that internal surfaces of the mixing funnel (160) are electropolished or have an anti-adhesion coating.

6. Coating system (10) according to any one the preceding claims, characterized in that the multi-way valve (32) comprises a distributor housing (131) with connectors (132, 134, 136, 138, 140, 142, 144, 146, 148) for the storage containers (14, 16, 18, 20, 22, 24), the mixing container (28), the liquid outlet (30) and the conveying device (26) as well as a valve body (149), which is rotatably mounted in the distributor housing (131) and has a connecting channel (150) which as a function of the rotational setting of the valve body (149) in the distributor housing (131) is capable of connecting the connector (148) for the conveying device (26) with one of the connectors (132, 134, 136, 138, 140, 142, 144, 146) for the storage containers (14, 16, 18, 20, 22, 24), the mixing container (28) and the liquid outlet (30).

7. Coating system (10) according to claim 6, characterized in that the valve body (149) of the multi-way valve (32) is rotatable by an electric motor (157) in the distributor housing (131).

8. Coating system (10) according to any one of the preceding claims, characterized in that a filter (166) disposed upstream of the multi-way valve (32) is associated with each storage container (14, 16, 18, 20, 22, 24).

9. Coating system (10) according to any one of the preceding claims, characterized in that a diverter device (103) is associated with the nozzle (40) in the coating chamber (38) and is selectably movable from a diverting position, which prevents unintended coating of the substrates, between the nozzle (40) and the substrate holder (34) into a clearance position, in which the diverter device (103) is not disposed between the nozzle (40) and the substrate holder (34), and conversely.

10. Coating system (10) according to claim 9, characterized in that the diverter device (103) comprises a flap (104) which is pivotable by a pneumatic cylinder (105).

11. Coating system (10) according to any one of the preceding claims, characterized in that the coating system (10) is a rotary coating system.

12. Method for individual coloring of optical glasses, namely spectacle lenses (L), particularly with use of a coating system (10) according to any one of the preceding claims, comprising the following method steps: (i) providing a spectacle lens or a spectacle lens pair; (ii) selecting an individual color for the spectacle lens or the spectacle lens pair from a plurality of colors, for the mixing of which a respective mixing ratio of different starting colors is known; (iii) metering the provided different starting colors in sub-quantities, which are needed for mixing the selected individual color in correspondence with the known mixing ratio, for a total quantity just sufficient for coloring the spectacle lens or the spectacle lens pair; (iv) mixing the metered sub-quantities of starting colors in order to obtain a mixed total quantity of the selected individual color; and (v) coating the spectacle lens or the spectacle lens pair with the mixed total quantity of the selected individual color.