DE10310561B4 - Method and device for producing spectacle lenses and other shaped bodies with optically active surfaces - Google Patents

Abstract

method for prescription or individual recipe production of spectacle lenses and other moldings with optically active surfaces using plastic blanks (1) taking the form of flat, round discs have to be stretched at their outer edge and with mechanical material removal a desired surface geometry and quality obtained by a convex lens front (19) and / or a concave lens back (27) machined with milling and / or turning tools as well as by grinding, fine grinding and optionally prepared by polishing, wherein on the outer periphery of the workpiece (16) an annular one Area (30) of greater thickness (33), which is used for clamping and / or depositing the workpiece (16). as well as for support and stabilizing the shaped body and / or the actual spectacle lens (32) in processing and transport processes serves and finally removed is, wherein the annular Area (30) Markings and / or shapes to identify the Processing axes receives and being on the surface of the molding or the actual spectacle lens (32) fine marks attached which are the axis position of the generated ...

Description

The The invention relates to a method and a device for prescription or individual prescription Production of spectacle lenses and other moldings with optically active surfaces corresponding to those mentioned in the preamble of claim 1 and claim 15 Features.

The here mentioned lenses and shaped bodies consist predominantly of plastics, which at high refractive index over a have a low specific weight and are easy to machine. The But it can also be for lenses made of silicate glass.

to Linguistic simplification will be described below instead of "spectacle lenses and lenses other moldings "only spoken of spectacle lenses, but always meant "others moldings with similar ones Properties". Although the text below only refers to "plastic lenses", nevertheless, silicate glass is always meant.

The following requirements apply to the manufacturing processes of modern spectacle lenses:
A so-called thickness optimization must be possible with which the weight of the lenses is minimized to increase the wearing comfort.

at Plus glasses (Lens center is thicker than the lens edge) and neutral lenses (lens center is the same thickness as the lens edge) is in the thickness optimization the Thickness of the lenses is reduced as much as this with regard to remaining edge thickness (= thickness at the peripheral edge of the finished spectacle lens) is possible. The edge thickness must be maintained so that the lens in the spectacle frame mounted properly can be, d. H. this thickness must be approximately the width of the frame correspond to the spectacle frame.

at Minus lenses (Lens center is thinner than Lens edge) is in the context of thickness optimization, the thickness of the lenses reduced as far as this in view of the remaining residual thickness possible in lens center is. A certain minimum thickness in the center of the lens is required thus the mechanical stability ensured the spectacle lens is.

at The following description of the method according to the invention is essentially on Plus lenses Referenced, since the benefits of the process here emerge particularly concise. The procedure leaves analog, but also for neutral and minus glasses. To the linguistic Simplification is spoken in the following text only of eyeglass lenses.

There the two optically active surfaces of Plus glasses (front and back) are not plane-parallel to each other, but in different places have different angles to each other, plays in the thickness optimization the size of the lens a crucial role. The shape and size of the spectacle frame must therefore be known before the thickness optimization.

outgoing of the given thickness at the edge (eyeglass frame) is then the greater thickness determined in the middle of the lens.

• 1. Die Brillengläser lassen sich während der Herstellungsprozesse (Flächenbearbeitung und Randbearbeitung) nach dem Stand der Technik nur mit besonders großem Aufwand für die verschiedenen Bearbeitungsschritte festspannen, da bei der Flächenbearbeitung der Randbereich angeschnitten wird und der Rand außerdem bearbeitet werden muß. Der Rand ist daher als Spannfläche nur geeignet, wenn besondere Verfahren angewandt werden. Nach der Randbearbeitung sind die Brillengläser am Umfang nicht mehr kreisrund, sondern entsprechen den verschiedenen Formen und Größen der Brillenfassungen (entweder exakt oder mit einer Bearbeitungszugabe für den Optiker). Diese nahezu beliebigen Formen und Größen machten es erforderlich, spezielle Spann- und Fertigungsverfahren zu entwickeln.
• 2. Durch die Dickenoptimierung (Brillenglas so dünn wie möglich) und die verwendeten Kunststoffe als Linsenmaterial (geringe Festigkeit) werden die erzeugten Brillengläser während der spannehmenden Fertigung zunehmend instabiler. In dem Maße wie sie durch den Materialabtrag dünner werden, verlieren sie an Stabilität und weichen dem Druck der Bearbeitungswerkzeuge aus, was zu unerwünschten Veränderungen der Oberflächengeometrie führt. Auch in diesem Zusammenhang mußten Verfahren gefunden werden, die der genannten Instabilität entgegen wirken.

In the production of spectacle lenses in compliance with the aforementioned requirement (thickness optimization), the following problems arise:

• 1. The lenses can be clamped during the manufacturing processes (surface treatment and edge processing) according to the prior art only with great effort for the different processing steps, since in the surface treatment of the edge region is cut and the edge must also be edited. The edge is therefore suitable as a clamping surface only if special procedures are used. After edge processing, the lenses on the circumference are no longer circular, but correspond to the different shapes and sizes of the spectacle frames (either exactly or with a machining allowance for the optician). These almost any shapes and sizes made it necessary to develop special clamping and manufacturing processes.
• 2. Through the thickness optimization (spectacle lens as thin as possible) and the plastics used as lens material (low strength), the spectacle lenses produced become increasingly unstable during the exciting manufacturing. As they become thinner due to the removal of material, they lose stability and give way to the pressure of the processing tools, which leads to undesirable changes in the surface geometry. Also in this context, procedures had to be found which counteract the instability mentioned.

method which avoids the problems mentioned under 1. and 2. above can, and device for carrying out the methods are known per se.

So z. B. in the DE 40 03 002 A1 a method for the production of spectacle lenses described in which the lenses are blocked before processing. This is understood to mean the attachment of the cast or pressed plastic blank to a so-called block piece Woodchem metal. The block piece is designed such that on the one hand it can be easily fastened to the workpiece spindles of the processing machines and on the other hand has structures on which the Woodche metal adheres well.

Preferably Plastic blanks are used, one side (preferably the convex front) during of the casting or pressing process is already completed. That is the surface geometry and the surface quality already meets the final one Requirements and are not changed anymore. The surface geometry is usually bifocal with sliding transitions (progressive) executed. This side is blocked so that the concave back (Raw state) and the scope can be edited.

make the surface geometry is corresponding Specification, with simultaneous thickness optimization. Since the blank already has a finished page that does not need to be edited, just a single Block process. After blocking, the lens may be attached to the workpiece spindle be clamped the processing machine. Through the connection with the Woodchen metal (supporting effect) is also given the required mechanical stability for subsequent processing operations.

The procedure according to the mentioned prior art method is then as follows:
The semi-finished plastic blank is coated on the already finished page with a protective varnish and then brought into connection with the block piece. In this case, the axis position of the already finished lens surface (eg bifocal) must be aligned very precisely with the axis position (angle of rotation) of the block piece.

This is important so later the surface geometries match the lens front and back sides. The space between the two parts (plastic blank and Block pieces) is then poured out with Woodchem metal. The metal connects it is with the protective coating, so that a firm adhesion arises.

Of the Plastic blank is made by means of the block piece on the workpiece spindle attached to a machine tool and the desired surface geometry on the previously rough surface the second lens side (usually concave lens backside) mill or turning produced. Here also the edge is processed and the thickness is optimized.

Further mechanical machining operations like fine grinding by means of forming tools (with grinding pad) on fine grinding machines and polishing also by means of molds (with polishing foil) on Close polishing machines on.

It follows the blocking in hot Water and removing the protective varnish.

The lenses are then coated with a so-called coating layer, which is for improvement the optical properties (eg anti-reflection) and the scratch resistance serves.

in this connection have to the lenses be placed on masks whose neckline is approximately the outer circumference the glasses equivalent. This prevents that during the coating process that from the top Coating material passes down the eyeglass lenses and unwanted impurities arise.

Because of the adaptation of the masks to the outer contour of the lenses has to be greater Stock kept on masks. This results in considerable Costs.

The final Edging and adjustment to the eyeglass frame is then later by Eyewear optician performed.

• – Das Aufblocken mit Woodschem-Metall ist ein aufwändiger, teurer Arbeitsschritt und eignet sich nur bedingt für automatische Fertigungsverfahren.
• – Das Woodsche-Metall enthält gesundheitsschädliche Bestandteile (z. B. 12,5 % Cadmium) und ist daher nur unter Einhaltung besonderer Schutzmaßnahmen zu verarbeiten.
• – Beim Auf- und Abblocken gehen ca. 10 % des Metalls verloren. Bei einer jährlichen Fertigungsmenge von weltweit einigen 100 Millionen Brillengläsern stellt dies nicht nur einen erheblichen Kostenfaktor dar, sondern ist auch ein großes Umweltproblem.
• – Da aus Kostengründen nur ein Aufblockvorgang durchgeführt werden soll, muß eine Seite des Brillenglases an dem Kunststoffrohling (vorzugsweise die Außenkurve) durch den vorausgehenden Gieß- oder Preßvorgang bereits angeformt werden. Als Konsequenz hieraus folgt, dass zahlreiche halbfertige Kunststoffrohlinge auf Lager gelegt werden müssen. Allein für die bifokalen Brillengläser ergibt sich folgende Rechnung: Z. B. 9 verschiedene Außenkurven, 11 verschiedene Nahteilkombinationen, 3 bis 4 verschiedene Brechungsindizes und 3 bis 4 verschiedene Designs (abhängig von der Brillenform) und alle genannten Parameter sowohl für das rechte als auch für das linke Brillenglas. Dies ergibt 3.000 verschiedene halbfertige Kunststoffrohlinge. Bei einer Lagerreichweite von 2 bis 3 Monaten errechnet sich hieraus ein Lagerbestand von 500.000 Stück. Da der Preis für die halbfertigen Kunststoffrohlinge im Mittel bei 13,-- Euro/Paar liegt, ergibt sich hieraus ein Lagerbestand im Wert von über 3 Millionen Euro. Die Kosten für dieses Lager sind sehr hoch und verteuern das genannte Verfahren erheblich.
• – Ein weiterer Nachteil besteht darin, dass eine sogenannte Rezeptfertigung nicht möglich ist. Hierunter versteht man das exakte Anpassen der Brillengläser an den zu korrigierenden Augenfehler, wie im Rezept des Augenarztes beschrieben. Da bei dem hier genannten Verfahren eine Seite an dem Kunststoffrohling bereits fertig gestellt ist, müssen die Außenkurven und die Nahteilkombinationen relativ grob abgestuft sein (z. B. Stufensprung ist ¼ Dioptrie), damit der Lagerbestand nicht noch weiter vergrößert wird. Der Brillenoptiker kann daher nur ein Brillenglas innerhalb der vorgegebenen Dioptriesprünge auswählen, das dem Rezept möglichst nahe kommt.
• – Das Vorhalten der vielen unterschiedlichen Masken für das Coating verursacht hohe Kosten.

The method described above, as in DE 40 03 002 A1 has a number of significant disadvantages:

• - The blocking with Woodschem metal is a complex, expensive operation and is only partially suitable for automated manufacturing processes.
• - The Woodsche metal contains harmful components (eg 12.5% cadmium) and must therefore only be processed in compliance with special protective measures.
• - When blocking and blocking, about 10% of the metal is lost. With an annual production of some 100 million spectacle lenses worldwide, this not only represents a significant cost factor, but is also a major environmental problem.
• - Since only a Aufblockvorgang is to be performed for cost reasons, one side of the lens on the plastic blank (preferably the outer curve) must already be formed by the preceding casting or pressing. As a consequence, many semi-finished plastic blanks must be stocked. For the bifocal lenses alone the following calculation results: Eg 9 different outer curves, 11 different Nahteilkombinationen, 3 to 4 different refractive indices and 3 to 4 different designs (depending on the spectacle shape) and all the above parameters for both the right and the left lens , This results in 3,000 different semi-finished plastic blanks. With a warehouse reach of 2 to 3 months, this results in a stock of 500,000 Piece. Since the price for semi-finished plastic blanks is on average 13, - Euro / pair, this results in a stock worth more than 3 million euros. The cost of this camp are very high and considerably increase the cost of the procedure mentioned.
• - Another disadvantage is that a so-called recipe production is not possible. By this is meant the exact fitting of the lenses to the eye defect to be corrected, as described in the prescription of the ophthalmologist. Since one side of the plastic blank is already completed in the method mentioned here, the outer curves and the Nahteilkombinationen must be relatively coarse graded (eg increment is ¼ diopter), so that the stock is not further increased. The eyewear optician can therefore only select a lens within the predetermined Dioptriesprünge that comes as close as possible to the recipe.
• - The provision of the many different masks for the coating causes high costs.

Another method is used in the DE 100 36 158 C1 proposed, which works without blocking, but provides that the lenses must be cut in the course of processing and welded together again.

Also here arise the same problems in connection with the Thickness optimization as previously described (the lens must be stretched and mechanically stabilized). Plastic blanks are used in the form of round, flat slices whose diameter is distinct is bigger, as the one of the spectacle lenses to be produced. The plastic blanks are either completely raw or roughly preformed. in principle could also semi-finished plastic blanks are used, but also here the disadvantage of the big one Inventory would result and a recipe production is not possible would.

If These disadvantages should be avoided, so have both sides of the lens to be edited.

Since blocking is avoided here, the following production sequence is provided:
The plastic blank is stretched at its edge and first processed the convex front of the lens. This page is chosen because it can be easily reached by the tools used because of its convex shape.

To the mechanical processing of the front is followed by polishing and the coating of the finished surface with protective varnish. At the half-finished lens then the back to be edited. If so, using thickness optimization done so would because of the contact angle between the front and back of the outer, yet circular edge of the half-finished lens from the tool trimmed before the desired edge thickness on the outer contour of the spectacle lens would be achieved. This step is therefore not possible because the lens his Clamping edge and lose its mechanical strength.

Out For this reason, it is provided, the half-finished spectacle glass along its final outer contour Cut out (circumference) from the edge area, using a laser shall be.

To an axial displacement of the half-finished spectacle lens relative to the left outer ring of the plastic blank by a few millimeters, it will be in this position with the outer ring re-welded by laser. Since the half-finished lens now clearly protrudes beyond the outer ring, it can be used to create the second side (concave back) be machined without the outer ring is cut. The half-finished lens can be thus still on the outer circumference tension and is through the outer ring mechanically stabilized.

The Eyeglass lenses finished on both sides are subsequently used Coating layers coated, the outer ring the mentioned mask replaced to prevent contamination.

The finished spectacle lens is then, also by laser, in the field the weld from the outer ring cut out and made ready for despatch.

• – Das Ausschneiden der halbfertigen Linse aus dem äußeren Rand mit axialem Verschieben und anschließendem Verschweißen der beiden Teile, erfordert eine aufwändige Spezialmaschine mit Lasereinrichtungen, die entsprechend teuer ist.

Although that in the DE 100 36 158 C1 described method some disadvantages of the in DE 40 03 002 A1 does not have the proposed method, however, there are other disadvantages:

• - The cutting of the semi-finished lens from the outer edge with axial displacement and subsequent welding of the two parts, requires a complex special machine with laser devices, which is correspondingly expensive.

The Manufacturing process is due to the additional work steps the special machine considerably more expensive.

The Cut twice and weld the two parts using Laser leads to considerable, lasting thermal stresses in the finished lenses. However, many of the plastics used are very vulnerable against such thermal stresses and after some time, they react with cracks in the edge area. This however, is not acceptable and presents a significant disadvantage of the method.

The Cut out the semi-finished lens with mechanical tools (to avoid thermal stress) can not, because the gap would be too big and not the lens with the outer ring could fit more accurately.

Other methods and devices for the production of spectacle lenses and other moldings with optically active surfaces are in DE 102 48 103 A1 . US 2,237,744 A . US 5,365,701 A and DE 21 02 820 A1 described.

• 1. Das Aufblocken ist nicht erforderlich.
• 2. Das Verfahren muß sich automatisieren lassen.
• 3. die Herstellung der Brillengläser muß kostengünstig sein.
• 4. Rezeptfertigung muß möglich sein (genaue Anpassung des Brillenglases an das vorgegebene Rezept, ohne Dioptriensprünge).
• 5. Für das Coating werden keine individuellen Masken benötigt.
• 6. Der Lagervorrat an Kunststoffrohlingen soll möglichst gering sein.
• 7. Teure Spezialmaschinen werden nicht benötigt.
• 8. Wärmespannungen in den Brillengläsern werden vermieden.

The own invention described below was based on the object of finding a method with which the abovementioned disadvantages can be avoided and spectacle lenses can be produced with the following specifications:

• 1. The blocking is not required.
• 2. The procedure must be automated.
• 3. the production of the lenses must be inexpensive.
• 4. Recipe production must be possible (exact adjustment of the spectacle lens to the given recipe, without diopter jumps).
• 5. No individual masks are needed for the coating.
• 6. The stock of plastic blanks should be as low as possible.
• 7. Expensive special machines are not needed.
• 8. Thermal stresses in the lenses are avoided.

These Task is solved according to the invention, with a method and a device of the type mentioned, according to the characterizing features of claim 1 and 15. Advantageous Embodiments result from the features of the subclaims.

at the method according to the invention are used as starting material for the spectacle lenses to be produced also used plastic blanks, which take the form of flat, have round discs (thickness is smaller than diameter). Form of the two surfaces (Front and back side) is arbitrary. The diameter of the plastic blanks will be 5 to 7 mm larger than selected this is common in the prior art methods. This results in a slightly larger material consumption, the but in the overall context of the process and its advantages negligible is.

At the Starting material is divided into two variants:

version 1

When Plastic blanks are used so-called blanks whose surfaces flat are or over one or have preformed structures on both sides. These may be included in the to water or pressing the plastic blanks formed. Finished surfaces with optical qualities are not present in this case.

Variant 2

When Plastic blanks are used semi-finished parts, d. H. the one side becomes during the manufacturing process of the plastic blank so formed that the desired Geometry and surface quality available is. This surface with optical qualities is not changed during processing and is preferably located on the concave back of the plastic blank. The gradation of diopters becomes relative roughly chosen, to keep the number of semi-finished parts as low as possible. By the manufacturing steps described below will nevertheless become a Recipe production allows.

to linguistic simplification becomes the starting material according to variant 1 and 2 in the text below referred to as plastic blanks. Just if differentiated between the blanks and the semi-finished parts must become, the corresponding terms are used.

The Basic principle of the method according to the invention is that the plastic blanks during all processing steps on the outer circumference be tense (closing or spreading) and the exciting processing is performed so that a ring-shaped Received area on the outer circumference remains, whose thickness corresponds approximately to that of the plastic blank.

at The following description will always be of closing tools but it is just as possible with expanding tools to work. With the expanding tools, the clamping elements move while clamping the workpiece from the inside to the outside and attach themselves to a collar (edge) of the plastic blank, the must be shaped accordingly in this case.

First if all operations (Milling, Turning, fine grinding, if necessary polishing, marking and coating) finished are, the actual lens from the outer, annular area separated. This can be z. B. done mechanically by means of milling cutters.

This manufacturing process can be used to great advantage on all lens shapes (plus, minus and neutral glasses). These advantages are especially great for plus and neutral glasses, since These have a thin edge and therefore the problems with clamping and the stability of the workpieces are particularly large here.

at Minus lenses the edge is thicker, but also here there are clear Advantages when tightening the outer annular area preserved.

These Type of production of spectacle lenses is possible, because the plastic blanks have a slightly larger diameter than usual and also Manufacturing devices are used, with which the desired geometry on the surface of the spectacle lens without having the annular one Area on the outer circumference of the workpiece is cut. To further linguistic simplification will be the attached plastic blanks in the following text referred to as workpieces.

Thereby, that on the outer circumference of the workpiece said annular Range in approximate full thickness of the plastic blank is preserved during the entire machining ideal clamping surfaces available. In addition, that can workpiece on the annular Area are filed. The presence of these clamping or storage surfaces in always uniform size and shape is for all other processing and transport processes a very big advantage, because the tools and devices are standardized (standardized) can be. this leads to at significant cost savings.

Of the annular Area is because of its large Thickness and also very stable due to its circular ring shape and therefore able to be stuck in his inner realm with him to support connected spectacle lenses. This one gets thereby the mechanical stability, which for further processing is required. This naturally applies in particular for the Edge region of the spectacle lens.

The mechanical machining to produce the desired surface geometry takes place according to the invention on special Milling / turning machines, with which both the rough contour of the processed lens side by milling lets manufacture as well subsequently a fine machining of the surface possible by a turning process is. It results in the very great advantage that the high Cutting performance of the milling process can be combined with the fine machining when turning. It is but also possible the surface geometry only by milling manufacture.

Before the plastic blank on its front and / or back are machined at its outer periphery two opposite Flattening (similar Key surfaces) or a larger notch attached for clamping and defining the Achslage the first machined side (preferably concave back side) serve.

In nearby the one flattening or the larger notch will also a smaller notch milled into the circular circumference of the workpiece.

These smaller notch is relative to the one flattening or to the larger notch by a few degrees (eg 60 °) offset on the circumference and is used as indexing (marking) for the second lens side (preferably the convex front).

The Indexing is used to define the right and left lenses and prevents the workpiece erroneously rotated by 180 ° during further processing becomes.

to linguistic simplification is used in the following text only on the Flattening reference. Meant but are always the versions with notches instead of flattening.

To the mill the two flats of the plastic blank on the aforementioned milling / lathe clamped. Since the edge has to be machined, the clamping tool has (eg collet) on the edge also over flats, which is something stronger are pronounced as those on the workpiece, so that the workpiece clamped at the edge is accessible for processing here, without the router touches the clamping tool.

To the Initial milling indexing the workpiece remains clamped on the circumference, wherein the clamping tool also here the corresponding work area free leaves.

advantageously, will produce the two flats and the indexing as well as the first spectacle lens surface, as described, carried out in one setting.

It can carry However, the steps mentioned are also spanned when resulting in benefits.

It but it is also possible the flattening and / or indexing in conjunction with other, preceding ones operations (eg when casting or pressing the semi-finished parts).

For the position definition, of course, other markings and geometrical shapes may be used instead of the flats, notches and indices men are attached to the circumference of the workpiece or on the annular area or at the front or back of the plastic blank. In this respect, the features mentioned above are only exemplary representations of preferred embodiments.

To editing the two flats, the indexing and the first side of the lens (milling and turning preferably in one clamping) becomes the second, optically active side of the workpiece the milling / lathe processed.

To the mill and turning the desired geometry becomes the workpiece turned and on the outer circumference clamped in a second clamping tool. The two flattenings and the indexing serve for the correct position clamping of the workpiece.

The Clamping tool has two fittings, which adhere to the flats create and a bolt that encompasses the indexing, so that a correct position of the workpiece is given.

The Phase angle (angle of rotation) of clamping tool with workpiece spindle is programmed in the machine control. On the clamping tool itself is the phase angle through the two flats and the bolt for the Indexing defined.

The Processing of the two lens surfaces preferably starts with the concave lens back, if it is not already present on the plastic blank (Semi-finished part).

to Processing of the optically active surfaces of the lenses have the Milling / turning machines according to the invention in its lower part over one vertically arranged workpiece spindle, which are rotationally and rotationally driven in rotation can (C axis) and at its upper end over a clamping tool for the admission of the workpiece features.

simultaneously the workpiece spindle can be fast perform axial movements in the Z-axis (feed movements), what necessary, since the surface geometries to be produced the lenses usually are not rotationally symmetric and therefore on each processing circle spatial Curves must be traveled.

It But it is also conceivable to perform the processing on machines whose Workpiece spindle horizontal is arranged.

In have their upper part the milling / lathes over a Tool spindle, which also rotationally and phased controlled rotational can be driven (B-axis). The tool spindle carries on her front end a tool storage for the turning tools and in some distance from the milling tool on coaxial shaft.

at the milling tool it is a roller cutter with a large radius (perpendicular to the axis of rotation) and a smaller width (in the direction the axis of rotation). The milling cutter has semi-circular at its periphery Cutting surfaces, which have a small radius.

Instead of of the narrow mill cutter huge Diameter and small thickness, can also be used ball end mills become.

Of the Radius of the turning tools may preferably have a similar dimension as the one the cutting surfaces of the milling cutter to have.

It is also provided, the z. B. annular milling cutter of the mill cutter as To use turning tools. In this case, a separate turning tool omitted. The tool cutting edges in this case have both Milling as even when turning the same angular position to the workpiece.

angle tracking, how later for the described special turning tools, but are not possible here.

The controlled in the B-axis and rotationally driven tool spindle is located on a tool slide, in the X axis and as a special feature in the Y-axis can be moved.

During the Machining with the milling cutter rotating around the B-axis move the tool spindle in the Y-axis (feed movements), while the workpiece rotates about the C-axis speed and phased and in the direction of Z-axis oscillates. This oscillation takes place in dependence of the speed and phase of the workpiece in the C-axis and of the position of the milling cutter in the Y-axis. The Y-axis, as well as the Z and C-axis are for this purpose electrically linked together in the machine control.

The desired surface geometry is due to the interaction of the cutter feed in the Y-axis and the movements of the workpiece generated in the Z and C axes.

After completion of the milling process (cutter has reached the center of the lens), the tool spindle and the workpiece spindle are moved so that one of the turning tools on the factory accumulator memory comes into engagement with the workpiece.

The Start position of the rotary tool on the workpiece is 90 ° relative to that of the milling tool offset, as well as the cutting edges of the milling cutter or turning tools rotated by 90 ° are arranged to each other.

According to the invention can the tool memory for the turning tools different inserts from different Material and / or with different dimensions, cutting radii and Clearance angles are attached. This makes it possible to store the tool to use as a tool changer in cooperation with the B-axis, by the required each Tool by briefly turning the B-axis to the lower position, d. H. in working position, being turned.

The Turning tool on the tool spindle is then according to the situation its cutting edge in the direction of the X-axis over the workpiece up to its Center moves (feed motion), with the workpiece spindle with the workpiece again speed and phased controlled rotated about the C-axis and in the direction of the Z-axis controlled oscillates (feed movement).

The Tool spindle with the turning tool can during the turning process in the B-axis small rotational movements (Winkelnachführbewegungen) execute, which is achieved that the turning tool when moving the lens geometry with its main axis always at the same predetermined angle (z. B. right angle) to the workpiece surface.

This is particularly advantageous if the cutting edge of the turning tool no has circular shape, but z. B. consists of a diamond blade.

The X- and Z-axis, as well as the B- and C-axis are in the machine control electrically linked, so that the given geometry can be generated. For certain However, turning tools can also be locked with a tool spindle to be worked. The B-axis is then not with the other axes connected.

By the interaction of the feed of the turning tool in the X-axis and the movements of the workpiece in the Z and C axes, and the Winkelnachführbewegung the rotary tool in the B axis, the previously generated by milling geometry of the Spectacle lenses in the fine range traced and optimized. It will produces a very low roughness on the surface. When the turning tool the center of the workpiece has reached, the turning operation is completed.

If the annular ones Cutting the mill cutter be used as a turning tool, so one of these cutting through Turning the tool spindle in the B axis brought into working position. The turning process itself is running then with locked in the B-axis tool spindle, in this Case according to the arrangement of the cutting tool feed movements in the Y-axis.

The workpiece leads as well here again controlled movements in the C and Z axis. In the mentioned procedure with the Frässchneiden are the Y-axis, as well as the Z and C axis linked together.

It is in principle also possible to abandon the turning operation, if already after milling the desired Surface quality achieved is that for economical processing by fine grinding or polishing sufficient.

The operations mill and turning are in principle also with other axle combinations at the Processing machine possible.

To the milling and turning the workpieces Reclined on subsequent machines for fine grinding or polishing, wherein again the outer annular area is used for clamping. The two flats and the indexing take care of one positionally correct positioning of the workpiece in the clamping tool.

The fine grinding or the polishing process are carried out with molds in particular also with flexible tools, which are covered with abrasive pads or polishing film. The molds must present an accurate imprint of the lens surface, which would result in a relatively large stock of expensive molds, unless flexible tools are used, as suggested herein (see DE 101 06 007 A1 ).

These Flexible tools are designed to work with theirs working surface to the lens surface press while taking the geometric shape of the lens surface. In a next Work step is fixed this shape, so that a dimensionally accurate Mold is created. The fixation can be canceled again, so that virtually any number of molding operations are performed can.

The fine grinding or polishing with the flexible molds is very cost-effective, since on the one hand requires no large inventory of expensive molds and on the other hand, no logistics effort is required. This one would However, in connection with the conventional molds arise because the respective mold should be assigned to the given lens geometry, which makes a targeted access to the large stock of molds required.

at certain coating processes can be dispensed with the polishing, if the surface created during the fine grinding is sufficiently small Roughness has. The remaining bumps are at Coating covered.

• 1. Der Kunststoffrohling wird an der Werkstückspindel (C-/Z-Achse) der Fräs-/Drehmaschine mittels Spannwerkzeug (Spannzange) am äußeren Rand festgespannt und die beiden Abflachungen und die Indexierung werden angebracht. Bei bestimmten Ausführungen ist auch vorgesehen, die Oberfläche des Kunststoffrohlings (Linsenrückseite) abzuplanen. Dies ergibt eine gute Auflage des Werkstücks beim Bearbeiten der Linsenvorderseite und eine genaue Lagedefinition (Höhenlage, Abstand) der Geometrien an Linsenvorder- und Linsenrückseite.
• 2. Anschließend wird in der gleichen Aufspannung vorzugsweise die konkave Linsenrückseite bearbeitet. Zum Fräsen und Drehen der gewünschten Geometrie, entsprechend Rezept, bleibt das Werkstück am äußeren Umfang in dem Spannwerkzeug festgespannt. Beim Fräsen und Drehen wird verfahren wie zuvor beschrieben. Bei dem Herstellen der Oberflächengeometrie an der Linsenrückseite gibt es keine Probleme mit dem Anschneiden des äußeren, ringförmigen Bereichs. Dies resultiert aus der konkaven Form der Linsenrückseite und der relativ flachen Wölbung von Brillengläsern. Es können so relativ große Brillengläser bearbeitet werden, ohne dass die Werkzeuge den ringförmigen Bereich anschneiden. In diesem Zusammenhang ist auch die geringfügige Vergrößerung des äußeren Durchmessers des Kunststoffrohlings von Vorteil.
• 3. Nach dem Herstellen der vorgegebenen Oberflächengeometrie an der Linsenrückseite wird diese feingeschliffen und ggf. poliert, wobei wie vorher beschrieben vorzugsweise flexible Formwerkzeuge zum Einsatz kommen.
• 4. Zum Schutz der fertig bearbeiteten Oberfläche wird diese zunächst gereinigt (z. B. mit Ultraschall) und anschließend mit einem Schutzlack oder einer Folie versehen.
• 5. Das Werkstück wird dann gewendet und erneut auf der Fräs-/Drehmaschine aufgespannt, damit die konvexe Linsenvorderseite zunächst durch Fräsen bearbeitet werden kann. Zum Spannen wird wieder der äußere Umfang benutzt, wobei die Abflachungen für den festen Halt und die Indexierung für die lagerichtige Position sorgen. Die grobe Kontur wird durch Fräsen erzeugt, an das sich später ein Drehvorgang zur Feinbearbeitung der Linsenoberfläche anschließt. Beide Arbeitsgänge werden durchgeführt, wie bereits beschrieben und ergeben die gewünschte Oberflächengeometrie, entsprechend Rezept (Rezeptfertigung). Da der Fräser beim Bearbeiten der konvexen Linsenvorderseite im Randbereich des Werkstücks tief in das Material eintauchen muß, würde bei der herkömmlichen Bearbeitung der äußere, ringförmige Bereich des Werkstücks, der zum Spannen dient, weggefräst bzw. der Fräser würde mit dem Spannwerkzeug kollidieren. Dies gilt insbesondere im Zusammenhang mit der Dickenoptimierung bei Plus- bzw. Neutral-Gläsern. Damit der äußere, ringförmige Bereich zum Spannen des Werkstücks und zur Stabilisierung des eigentlichen Brillenglases im Innenbereich bei der weiteren Bearbeitung in annähernd voller Dicke erhalten bleibt, wird zu Beginn des Fräsvorgangs eine kreisförmige Rille am Rand des Werkstücks eingefräst. Diese Rille wird so plaziert und dimensioniert, dass einerseits im Außenbereich des Werkstücks der ringförmige Bereich erhalten bleibt und andererseits im Innenbereich die gewünschte Dicke am Rand des eigentlichen Brillenglases (im Rahmen der Dickenoptimierung) erreicht wird. Durch die Form des Fräswerkzeuges erhält die Rille einen Querschnitt mit einem Radius (im Querschnitt des Werkstücks gesehen), der mindestens demjenigen der Schneiden des Fräswerkzeugs entspricht. Da diese Rille außerhalb der eigentlichen Nutzfläche d. h. außerhalb des Brillenglases liegt, ist es zweckmäßig den genannten Radius möglichst klein zu halten, damit nicht unnötig Material zerspant werden muß bzw. verloren geht. Hieraus resultiert auch die Forderung nach einem Walzenfräser mit kleiner Dicke bzw. kleinem Radius an den Schneiden. Der Außendurchmesser des Kunststoffrohlings kann dann möglichst klein gehalten werden. Die Rille stellt den Übergang zwischen dem eigentlichen Brillenglas und dem äußeren, ringförmigen Bereich dar und ermöglicht durch ihre Form einerseits die geringe Dicke am Rand des eigentlichen Brillenglases und anderseits die große Dicke am ringförmigen Bereich. Der Fräsvorgang zum Herstellen der Geometrie an der Linsenvorderseite läuft dann so ab, dass das Werkstück mit der Werkstückspindel in der C-Achse rotiert (drehzahl-und phasengesteuert) und gleichzeitig in der Z-Achse der Spindel schnelle translatorische Bewegungen (Oszillation) ausführt, die als Zustellbewegungen dienen. Gleichzeitig wird der Walzenfräser mit der Werkzeugspindel in der Y-Achse gesteuert verfahren (Vorschubbewegungen), wobei er um die B-Achse der Werkzeugspindel mit konstanter Drehzahl rotiert (nicht gesteuert). Die Y-, Z- und C-Achse sind in der Maschinensteuerung so miteinander verknüpft, dass durch die Addition der Bewegungen zunächst die genannte Rille und anschließend die Oberflächengeometrie der Linsenvorderseite erzeugt wird.
• 6. An das Fräsen der Linsenvorderseite schließt sich ein Drehvorgang im Feinbereich an, mit dem im wesentlichen kleine Korrekturen an der Geometrie vorgenommen werden und vor allem die Rauhtiefe verbessert wird. Vor Arbeitsbeginn taucht das kreisrunde Drehwerkzeug in die genannte ringförmige Rille ein, deren Radius in etwa demjenigen des Werkzeugs entspricht. Dies erfolgt durch Verfahren der X-, Y-, Z- und B-Achse. Die Eintauchstelle ist zu derjenigen des Fräsers am Umfang des Werkstücks um 90° versetzt, wie es der Lage der Drehwerkzeuge an dem entsprechenden Werkzeugspeicher entspricht. Der Drehvorgang läuft dann wie vorher – unter 5. – für das Fräsen beschrieben ab. Wenn die Schneiden des Fräswerkzeugs als Drehwerkzeug benutzt werden, so läuft der Arbeitsgang Drehen ähnlich ab, wie der Fräsvorgang. In diesem Fall ist die Werkzeugspindel mit dem Werkzeug jedoch in der B-Achse festgesetzt, nachdem durch kleine Bewegungen in der B-Achse eine der Schneiden des Fräswerkzeugs in Arbeitsposition gedreht wurde. Die Vorschubbewegung findet wie beim Fräsen in der Y-Achse statt.
• 7. Nach dem Herstellen der vorgegebenen Oberflächengeometrie an der Linsenvorderseite erfolgt auf Folgemaschinen (Feinschleif- bzw. Poliermaschinen) das Feinschleifen und ggf. Polieren. Auch hier werden vorzugsweise flexible Formwerkzeuge eingesetzt. Gespannt wird das Werkstück wieder an dem äußeren, ringförmigen Bereich.
• 8. Nach den genannten mechanischen Bearbeitungsvorgängen erfolgt nochmals ein Reinigungsvorgang. Auch hierbei ist die standardisierte Form des Werkstücks mit gleichen Außendurchmessern (bedingt durch den äußeren, ringförmigen Bereich) von großem Nutzen, da die Haltevorrichtungen (Waschrahmen) stark vereinfacht und vor allen Dingen universell verwendbar konzipiert sein können. Die einheitliche Größe dieser Waschrahmen führt zu erheblichen Kosteneinsparungen. Anschließend wird im Randbereich der Linsenvorderseite eine Gravur angebracht, die für das Brillenglas die Position des Nahteils und die Achslage des Rezepts kennzeichnet und ggf. auch das Logo des Herstellers enthält.
• 9. Es folgt das Coating des Werkstücks, d. h. das Auftragen dünner Schichten zur Verbesserung der Gebrauchseigenschaften auf beiden Seiten. Auch hier ist der äußere, ringförmige Bereich wieder von großem Vorteil, da das Werkstück während des Coatings daran festgespannt oder darauf abgelegt werden kann. Der standardisierte Durchmesser des ringförmigen Bereichs reduziert die Vielzahl der früher benötigten Haltesysteme bzw. Abdeckmasken auf eine einzige Größe. Es ist weiterhin vorgesehen, sowohl die erst als auch die zweite Brillenglasseite in einem Arbeitsgang zu vergüten, wozu eine automatische Schwenkeinrichtung benutzt wird. Auch diese kostensparende Vorrichtung wird erst durch die einheitliche Größe und Form der Werkstücke ermöglicht.
• 10. Das Werkstück wird zum Trennen von Brillenglas und ringförmigem Bereich auf einer Fräsmaschine mittels des ringförmigen Bereichs aufgespannt und mit einem geeigneten Fräser (z. B. Fingerfräser kleinen Durchmessers) das Brillenglas von dem ringförmigen Bereich getrennt. Das Trennen von Brillenglas und ringförmigen Bereich kann jedoch auch mit anderen Bearbeitungsverfahren durchgeführt werden. In Frage kommt hier z. B. das sogenannte Waterjet-Verfahren, bei dem zum Schneiden ein sehr feiner Wasserstrahl mit hoher Geschwindigkeit benutzt wird. Bei dem Trennen des Brillenglases von dem ringförmigen Bereich wird vorzugsweise eine optimierte Außenkontur des Brillenglases erzeugt, die der vorgesehenen Brillenfassung weitgehend entspricht, dass heißt nur ein sehr geringes Aufmaß hat. Bei dem nachfolgendem Einschleifen in die Brillenfassung durch den Optiker wird hierdurch der Aufwand minimiert. Nach einer Endreinigung steht das Brillenglas dann für den Versand bereit.

The basic production process for variant 1 (both sides without finished surfaces) is as follows:

• 1. The plastic blank is clamped to the workpiece spindle (C / Z axis) of the milling / lathe by means of clamping tool (collet) on the outer edge and the two flats and the indexing are attached. In certain embodiments, it is also planned to plan the surface of the plastic blank (lens back side). This results in a good support of the workpiece when editing the lens front side and a precise position definition (altitude, distance) of the geometries on the front of the lens and the back of the lens.
• 2. Subsequently, the concave lens back is preferably processed in the same setting. To mill and rotate the desired geometry, according to recipe, the workpiece remains clamped on the outer circumference in the clamping tool. During milling and turning, the procedure is as described above. In producing the surface geometry on the lens back, there are no problems with cutting the outer annular portion. This results from the concave shape of the lens back and the relatively flat curvature of spectacle lenses. It can be processed so relatively large lenses without the tools cut the annular area. In this context, the slight increase in the outer diameter of the plastic blank is also advantageous.
• 3. After the production of the given surface geometry on the lens back, this is finely ground and, if necessary, polished, whereby preferably flexible molds are used as previously described.
• 4. To protect the finished surface, it is first cleaned (eg with ultrasound) and then provided with a protective varnish or a foil.
• 5. The workpiece is then turned and clamped again on the milling / lathe, so that the convex lens front side can be first processed by milling. For tensioning, the outer circumference is again used, the flats providing the firm hold and the indexing the correct position. The rough contour is produced by milling, which is later followed by a turning process for fine machining of the lens surface. Both operations are carried out as already described and give the desired surface geometry, according to recipe (recipe production). Since the cutter must be deeply immersed in the material in the processing of the convex lens front side in the edge region of the workpiece, in the conventional machining, the outer, annular portion of the workpiece, which serves for clamping, would be milled away or the cutter would collide with the clamping tool. This applies in particular in connection with the thickness optimization for plus or neutral lenses. In order for the outer, annular region for clamping the workpiece and for stabilizing the actual spectacle lens in the inner region to be maintained in approximately full thickness during further processing, a circular groove is milled at the edge of the workpiece at the beginning of the milling process. This groove is placed and dimensioned so that on the one hand in the outer region of the workpiece, the annular region is maintained and on the other hand in the interior of the desired thickness at the edge of the actual spectacle lens (in the context of thickness optimization) is achieved. Due to the shape of the milling tool, the groove is given a cross section with a radius (seen in the cross section of the workpiece) which corresponds at least to that of the cutting edges of the milling tool. Since this groove is outside the actual effective area ie outside of the lens, it is expedient to keep the said radius as small as possible, so that unnecessary material does not have to be machined or lost. This also results in the demand for a roll mill with a small thickness or small radius on the cutting edges. The outer diameter of the plastic blank can then be kept as small as possible. The groove represents the transition between the actual spectacle lens and the outer, annular region and, by virtue of its shape, enables, on the one hand, the small thickness at the edge of the actual spectacle lens and, on the other hand, the large thickness at the annular region. The milling process for producing the geometry on the front of the lens then proceeds so that the workpiece with the workpiece spindle in the C-axis rotates (speed and phased) and simultaneously performs in the Z-axis of the spindle fast translational movements (oscillation), the serve as delivery movements. At the same time the mill cutter with the factory in the Y-axis (feed movements), whereby it rotates about the B axis of the tool spindle at a constant speed (not controlled). The Y, Z and C axes are linked together in the machine control in such a way that the said groove and then the surface geometry of the front of the lens are generated by the addition of the movements.
• 6. The milling of the lens front side is followed by a turning operation in the fine area, with which essentially small corrections to the geometry are made and, above all, the surface roughness is improved. Before starting work, the circular rotary tool dips into said annular groove whose radius corresponds approximately to that of the tool. This is done by moving the X, Y, Z and B axes. The immersion point is offset from that of the milling cutter on the circumference of the workpiece by 90 °, as it corresponds to the position of the turning tools on the corresponding tool storage. The turning process then proceeds as before - under 5. - described for milling. If the cutting edges of the milling tool are used as a turning tool, the turning operation is similar to that of the milling operation. In this case, however, the tool spindle with the tool is fixed in the B axis after one of the cutting edges of the milling tool has been rotated to the working position by small movements in the B axis. The feed movement takes place as in milling in the Y-axis.
• 7. After the production of the given surface geometry on the front of the lens, fine grinding and possibly polishing are carried out on following machines (fine grinding or polishing machines). Again, preferably flexible molds are used. The workpiece is clamped again on the outer, annular area.
• 8. After the mentioned mechanical machining operations, another cleaning process takes place. Again, the standardized shape of the workpiece with the same outer diameters (due to the outer, annular area) of great benefit, since the holding devices (washing frame) can be greatly simplified and above all things designed to be universally applicable. The uniform size of these washing frames leads to significant cost savings. Subsequently, an engraving is applied in the edge region of the lens front side, which marks the position of the near portion and the axis position of the prescription for the spectacle lens and possibly also contains the logo of the manufacturer.
• 9. It follows the coating of the workpiece, ie the application of thin layers to improve the performance on both sides. Again, the outer annular area is again of great advantage, since the workpiece during the coating can be tightened or placed on it. The standardized diameter of the annular region reduces the plurality of previously required holding systems or Abdeckmasken to a single size. It is further provided to compensate for both the first and the second lens side in one operation, including an automatic pivoting device is used. This cost-saving device is made possible only by the uniform size and shape of the workpieces.
• 10. The workpiece is clamped on a milling machine by means of the annular region for the separation of spectacle lens and annular region, and the spectacle lens is separated from the annular region with a suitable milling cutter (eg small diameter end mill). The separation of spectacle lens and annular region can, however, also be carried out with other processing methods. In question here comes z. As the so-called waterjet process, in which a very fine water jet is used at high speed for cutting. In the separation of the spectacle lens from the annular region, an optimized outer contour of the spectacle lens is preferably generated which largely corresponds to the intended spectacle frame, that is, has only a very small oversize. In the subsequent grinding into the spectacle frame by the optician thereby the effort is minimized. After a final cleaning, the lens is then ready for shipment.

The basic production process for variant 2 (one side has a finished surface) is then as follows or similar:
In this variant, semi-finished parts are used as plastic blanks, which already receive their final surface when casting or pressing on one side, which is no longer processed.

Prefers is used as a finished surface the concave back of the spectacle lens with a coarse gradation of Dioptriewerte (z. B. 0.5 or 1 diopter) to the number of semi-finished parts in stock to reduce.

at the method according to the invention can in principle but also semi-finished parts with finished surface on the convex front to be used. The annular Range then becomes when processing the concave lens back manufactured and again for holding and transporting the workpiece at used for further processing.

The following is the manufacturing process for semi-finished parts with finished concave lens back. For semi-finished parts with a finished convex lens front, the corresponding applies.

There the backside already finished and roughly graded in the diopters is, when editing the front are special calculation methods used, which lead to surface geometries, with which the diopter jumps on the back side can be interpolated.

The Interaction of the optical properties of front and back results in a lens with ideal adaptation to the prescription of the ophthalmologist (Recipe production).

Of the Eyewear optician is no longer forced, under predetermined lenses the one to choose the one closest to the recipe comes, as any lenses also produced in bifocal design can be. This interpolation of the diopter jumps on the back by a special geometry on the front of the lens an essential feature of the method proposed here according to the invention.

The Special geometry of the front side (prescription surface) is designed so that the overall effect of the lens seen from the front also aesthetic (Eg no distorted imaging properties when looking through from the front). This is also true, although in these lenses the optical effect for the far and the far part are optimized (bifocal, progressive) and a thickness optimization with adaptation to the spectacle frame and a Adjusting the relative position of the lens axes to the eye is performed (Individual glasses).

• 1. Torische Formgebung (= Differenz zu der groben Abstufung der Brillenglasrückseite)
• 2. Atorische Formgebungen (zur Optimierung des Gewichts und der Abbildungseigenschaften)
• 3. Bifokaler Bereich in progressiver Ausführung (üblicherweise 1,0-3,5 Addition)
• 4. Prismatische Gestaltung (abhängig vom Rezept, der Addition und der relativen Lage in der Brillenfassung sowie relativ zum Auge)
• 5. Dickenoptimiert (abhängig von Form der Fassung)

The production of the lenses takes place in variant 2 similar to that described for variant 1. Only steps 2 and 3 are eliminated. When machining the front side, a special geometry is produced which has the following features:

• 1. Toric shaping (= difference to the coarse gradation of the lens back)
• 2. Atoric shapes (to optimize weight and imaging properties)
• 3. Progressive bifocal region (usually 1.0-3.5 addition)
• 4. Prismatic design (depending on the recipe, the addition and the relative position in the spectacle frame and relative to the eye)
• 5. Thickness-optimized (depending on the shape of the frame)

These Special geometry of the front can of course also in spectacle lenses be realized according to variant 1.

Overlaying said features 1 to 5 and an additional optimization of the lens back with similar ones Optimizations like on the front of the lens or a combination from optimizations of front and back (double individualization or optimization), is one of the essential features of here proposed, inventive method.

It is thereby enabled to carry out a prescription production of individual glasses, even if the back of the lens relatively simple and roughly graduated in the diopters is.

• – Es ist eine blockfreie Fertigung möglich, so dass alle mit dem Aufblocken verbundene Nachteile vermieden werden.
• – Es werden keine teuren Spezialmaschinen mit Lasereinrichtungen benötigt. Wärmespannungen durch thermisches Schneiden oder Schweißen treten nicht auf.
• – Es ist Rezeptfertigung möglich.
• – Wegen der Spezialgeometrie an einer Linsenseite (vorzugsweise Vorderseite) kann auch bei Rezeptfertigung mit halbfertigen Kunststoffrohlingen (Halbfertigteile) in grober Abstufung gearbeitet werden. Daraus folgt eine Minimierung der Fertigungskosten (nur 1 Seite wird bearbeitet) und der Lagerkosten (wenig Halbfertigteile, da grobe Abstufung).
• – Die zur Durchführung des Verfahrens vorgeschlagene Fräs-/Drehmaschine kann durch Fortentwicklung von der Maschinentechnik abgeleitet werden, wie sie in der Optikmaschinen-Industrie bekannt ist.
• – Das Verfahren ist automatisierbar, da keine Arbeitsgänge erforderlich sind (z. B. Aufblocken), die Handeingriff erfordern.
• – Mit dem Verfahren lassen sich Brillengläser mit deutlich besserer Qualität und optimierter Dicke herstellen, als dies mit den Verfahren nach dem Stand der Technik möglich ist. Daraus resultieren eine bessere Sehleistung und Verträglichkeit für den Brillenträger.
• – Das Verfahren ist sehr kostengünstig, da es mit deutlich weniger Arbeitsgängen auskommt, als dies bei den bekannten Verfahren der Fall ist.
• – Auch die Anzahl der Haltewerkzeuge und Vorrichtungen ist geringer, da die Werkstücke an dem standardisierten Durchmesser des ringförmigen Bereichs gespannt bzw. aufgelegt werden können.

The method according to the invention has the following advantages in summary:

• - A block-free production is possible, so that all the disadvantages associated with the blocking are avoided.
• - No expensive special machines with laser devices are needed. Thermal stresses due to thermal cutting or welding do not occur.
• - Recipe production is possible.
• - Due to the special geometry on one side of the lens (preferably the front side) it is also possible to work in coarse gradation with recipe production with half-finished plastic blanks (semi-finished parts). This results in a minimization of the production costs (only 1 side is processed) and the storage costs (few semi-finished parts, there rough graduation).
• The milling / turning machine proposed for carrying out the method can be derived by further development from the machine technology known in the optical machine industry.
• The method is automatable since no operations are required (eg blocking) which require manual intervention.
• - The method can produce lenses with significantly better quality and optimized thickness, as is possible with the method according to the prior art. This results in better vision and compatibility for the wearer of the glasses.
• - The process is very cost-effective, since it requires significantly fewer operations than is the case with the known methods.
• - The number of holding tools and devices is lower, since the workpieces can be stretched or placed on the standardized diameter of the annular region.

Hereinafter, the method and the apparatus for carrying out the method for variant 1 using an example and the 1 to 10 explained in more detail.

at this example to variant 1 is based on a plastic blank, whose front is flat while his back has a molding without finished surface. It is about in this example, one of several procedural and device variants associated with Plus glasses. For neutral and Minus glasses applies mutatis mutandis, however exactly the same.

In the device illustrations do not show the machines themselves, but only their tool and workpiece spindles with the attached Machining and clamping tools. These simplifications were chosen so that the Details of the devices according to the invention better can be shown.

1 shows the production of the two flats ( 3 ) and ( 4 ) on the milling / lathe in a view and a plan view (sectional views).

2 shows how to make the indexing ( 15 ) on the milling / lathe in a view and a plan view (partial sections).

3a shows the manufacturing state of the workpiece ( 16 ) according to the manufacturing steps 1 and 2 with the flattenings ( 3 ) and ( 4 ) and indexing ( 15 ).

3b alternatively shows the manufacturing state of the workpiece ( 16 ), if instead of the flattening ( 3 ) and ( 4 ), a larger notch ( 35 ) and the indexing ( 15 ) were attached.

4 shows the production of the surface geometry on the concave lens back ( 27 ) by means of roller cutter ( 9 ) on the milling / lathe in a view and a plan view (sectional views).

5 shows the production of the surface geometry in the fine area and the smoothing of the surface by means of a turning tool ( 12 ) on the concave lens back ( 27 ) in a view and a plan view (sectional views).

6 shows the fine grinding or polishing of the concave lens back ( 27 ) on a fine grinding or polishing machine in a view (sectional view) and a plan view. The grinding or polishing tool is not shown, since not the subject of the proposed method.

7 shows the preparation of the surface geometry at the convex lens front side ( 19 ) by means of roller cutter ( 9 ) on the milling / lathe at the working end in a view and a plan view (sectional views) and a cut-out enlargement of the edge region of the cut workpiece ( 16 ).

8a shows the preparation of the surface geometry in the fine area and the smoothing of the surface on the convex lens front side ( 19 ) by means of a turning tool ( 12 ) on the milling / lathe in a view and a plan view (sectional views) at the working end.

8b shows the preparation of the surface geometry at the convex lens front side ( 19 ) by means of a turning tool ( 12.1 ) on the milling / lathe with Bachelism axis tracking movements in a view (sectional views).

9 shows the fine grinding or polishing of the convex lens front side ( 19 ) on a fine grinding or polishing machine in a view (sectional view) and a plan view. The fine grinding or polishing tool is not shown, since not the subject of the proposed method.

10a shows the manufacturing state of the workpiece ( 16 ) according to the manufacturing steps 1 to 9 with a plus glass (cross section and top view).

10b shows the manufacturing state of the workpiece ( 16 ) according to the manufacturing steps 1 to 9 with a neutral glass (cross-section).

10c shows the manufacturing state of the workpiece ( 16 ) according to the manufacturing steps 1 to 9 with a minus glass (cross section).

To 1 :

This figure shows how to make the two flats ( 3 ) and ( 4 ) on the milling / lathe in a view and a plan view (sectional views).

The plastic blank ( 1 ) is in a clamping tool ( 2 ), which is connected to the workpiece spindle ( 21 ) of the milling / lathe is in communication.

The workpiece spindle ( 21 ) executes translatory movements (infeed movements) in the Z-axis during this processing step, while it performs only short rotational movements (180 °) in the C-axis when the first flattening ( 3 ) and the second flattening ( 4 ) should be milled.

As you can see in the view, are on the side of the clamping tools ( 2 ) two recesses ( 6 ), which is the processing of the plastic blank ( 1 ) allow in these two areas, so that the flats ( 3 ) and ( 4 ) can be milled. The clamping and centering edge ( 5 ) of the clamping tool ( 2 ) ends at the edges ( 7 ) and has a further recess ( 8th ) for the later milling of the indexing.

For milling the two flats ( 3 ) and ( 4 ) is a roll mill ( 9 ), the milling cut at its periphery ( 10 ) having a relatively small diameter (eg, 11 mm), since it will later also be used for producing the surface geometry of the lens front and rear surfaces.

The mill cutter ( 9 ) is in common with the later required tool memory ( 11 ) for the turning tools ( 12 ), on the tool spindle ( 20 ) attached. The tool spindle ( 20 ) performs translational movements in the X-axis (feed) and continuous rotational movements in the B-axis.

The milling process for producing the two flats ( 3 ) and ( 4 ) runs as usual. Working with the milling / lathe in this context has the great advantage that the polar coordinates of the flats ( 3 ) and ( 4 ), and their dimensions in the machine control are already known very well and can be used for all other milling and turning operations.

To 2 :

This figure shows how to make the indexing ( 15 ) on the milling / lathe in a view and a top view.

The processing is again carried out on the milling / lathe, wherein the plastic blank ( 1 ) in the same clamping tool ( 2 ) remains tightened, as before at 1 described.

The processing with a roller milling cutter ( 14 ) can take place when the plastic blank ( 1 ), by briefly moving the workpiece spindle ( 21 ) in the C-axis, has been rotated to the machining position and the roll mill ( 14 ) is in the correct position by X and Y axis methods. During machining, the milling cutter rotates ( 9 ) continuously around the B-axis and travels in the X-axis (infeed movements).

The mill cutter ( 14 ) reaches through the recess ( 8th ) in the clamping and centering edge ( 5 ) of the clamping tool ( 2 ) and produced on the plastic blank ( 1 ) the indexing ( 15 ) in the form of a groove.

In the picture is a special mill cutter ( 14 ). However, it is also possible to use indexing ( 15 ) with the milling cutter ( 9 ), which is used for the other steps. This would have the advantage that no tool change is required.

The plastic blank ( 1 ) with the two flats ( 3 ) and ( 4 ), as well as the indexing ( 15 ) is used in the description of the following work steps as a workpiece ( 16 ) designated. This label is also retained if further edits have been made.

To 3a :

This figure shows the condition of the workpiece ( 16 ) according to the manufacturing steps 1 and 2 ,

In both representations, the indexing ( 15 ) to recognize. In the lower illustration with a view to the indentation ( 13 ) one recognizes additionally the two flattenings ( 3 ) and ( 4 ). This is the position of the workpiece ( 16 ) clearly defined. Impression ( 13 ) on the back of the lens is not processed yet.

To 3b :

This figure shows alternatively the manufacturing state of the workpiece ( 16 ), if instead of the flattening ( 3 ) and ( 4 ), a larger notch ( 35 ) and the indexing ( 15 ) were attached.

In the plan view with a view to the indentation ( 13 ) are the score ( 35 ) and the indexing ( 15 ), which are arranged offset on the circumference and thereby enclose an angle <90 ° to each other. This is the position of the workpiece ( 16 ) clearly defined.

To 4 :

This figure shows how to make the surface geometry on the concave lens backside ( 27 ) by means of roller cutter ( 9 ) on the milling / lathe in a view and a plan view (sectional views).

The machining is carried out on the milling / turning machine with the milling cutter (as in the previous operations). 9 ) carried out. The workpiece ( 16 ) is connected to the workpiece spindle ( 21 ) via the clamping tool ( 18 ) connected. The processing of the surface geometry takes place in the same setting as in the production of the flats ( 3 ) and ( 4 ) or indexing ( 15 ) was see. This allows optimum positional precision between the concave lens back ( 27 ) and indexing ( 15 ).

During machining, the workpiece rotates ( 16 ) continuously in the C axis with controlled speed and phasing. At the same time, it performs translatory movements in the Z axis, which serve as advancing movements. These movements in the Z-axis take place with high dynamics in the form of oscillations.

The mill cutter ( 9 ) is on the tool spindle ( 20 ) and rotates continuously in the B axis. At the same time, he is using the tool spindle ( 20 ) in the Y-axis. The addition of the movements of the workpiece ( 16 ) and milling cutter ( 9 ) gives the desired surface geometry at the concave lens backside ( 27 ).

The machining for milling the given geometry on the concave lens back ( 27 ) starts at the edge of the workpiece ( 16 ) and is finished when the mill cutter ( 9 ) has reached its center.

Basically however, any of the operations listed here (milling and turning) as well start in lens center and at the outer edge end up.

In order to be able to generate the desired geometry, the Y, Z and C axes are linked to each other during this machining. The rotation of the milling cutter ( 9 ) around the B axis without linking. In the picture is the workpiece ( 16 ) at the end of this processing step.

After this processing, at the edge region of the concave lens back of the workpiece ( 16 ) a plane surface ( 17 ), which serves as a support when the workpiece ( 16 ) to edit the convex lens front side is turned and re-tensioned.

This plane surface allows a clear determination of the relative height of both the concave lens backside ( 27 ), as well as the convex lens front side ( 19 ), with respect to this plane surface of the workpiece ( 16 ) and allows a precise definition of the lens thickness.

This is very important in the production of a thick-optimized spectacle lens, so that later when editing the convex lens front side ( 19 ) the altitude (in the direction of the thickness of the workpiece ( 16 ) seen the concave lens back ( 27 ) is known exactly.

To 5 :

This figure shows the preparation of the surface geometry in the fine area and the smoothing of the surface by means of a turning tool ( 12 ) on the concave lens back ( 27 ) in a view and a plan view (sectional views).

For this machining, the tool spindle ( 20 ) with the tool memory ( 11 ) for the turning tools ( 12 ) in the B-axis rotated by a few degrees until the desired turning tool ( 12 ) is in the edit start position.

The B axis of the tool spindle ( 20 ) is then switched to a controlled state in which it can perform small rotational movements, the angle of attack of the main axis of the rotary tool ( 12 ) relative to the surface of the workpiece ( 16 ) (= angle tracking movements).

Then the tool spindle ( 20 ) in the X and Y axes so that this rotary tool ( 12 ) to the starting position above the workpiece ( 16 ) comes.

This starting position of the turning tool ( 12 ) on the edge of the workpiece ( 16 ) is in plan view at 90 ° relative to that of the milling cutter ( 9 ) twisted, as well as the cutting ( 10 ) of the milling cutter ( 9 ) or the cutting of the turning tools ( 12 ) are arranged rotated by 90 ° to each other.

The workpiece spindle ( 21 ) with the workpiece ( 16 ) is then in the C-axis in controlled rotation (speed and phase angle controlled) and at the same time in the Z-axis translationally moved up until the turning tool ( 12 ) in contact with the workpiece ( 16 ) comes.

The turning tool ( 12 ) on the tool spindle ( 20 ) is then moved according to the position of its cutting edge in the direction of the X-axis over the workpiece ( 16 ) moved to its center (feed movement), wherein the workpiece spindle ( 21 ) with the workpiece ( 16 ) is again rotationally and phase-controlled rotated about the C-axis and oscillates in the direction of the Z-axis (infeed movements).

The tool spindle ( 20 ) with the turning tool ( 12 ) performs during the turning operation in the B-axis said small rotational movements (Winkelelnachführbewegungen), whereby it is achieved that the main axis of the rotary tool ( 12 ) is always below the predetermined, equal and optimum relative cutting angle (eg right angle) to the workpiece surface when the lens geometry is being lowered (in this case, to the concave lenses) back side ( 27 )).

This is particularly advantageous when the cutting edge of the rotary tool ( 12 ) has no circular shape, but z. B. consists of a diamond blade. Without the B axis angle tracking motions, the relative cut angle would constantly change due to the three-dimensional lens geometry.

The angle tracking movements of the turning tool ( 12 ) in the B axis are controlled and dependent on the positions of the X, Z and C axes when (as in this exemplary case) the feed movement of the rotary tool ( 12 ) takes place in the X-axis.

With the angle tracking movements in the B axis, the angle of incidence of the rotary tool ( 12 ) also constantly relative to the surface of the workpiece ( 16 ), if this should be necessary in the specific case and keeping constant this angle of attack is not expedient.

Further explanations of the angle tracking movements emerge 8b in connection with the processing of the convex lens front side ( 19 ).

The X- and Z-axis, as well as the B- and C-axis are in the machine control electrically linked, so that the above movement is possible.

Through the interaction of the movements of the turning tool ( 12 ) in the X and B axes and the movements of the workpiece ( 16 ) in the Z and C axes, the previously generated by milling geometry on the concave lens back ( 27 ) in the fine area and thereby generates a very low surface roughness on the surface. When the turning tool ( 12 ) the center of the workpiece ( 16 ), the turning operation is completed.

To 6 :

This figure shows the fine grinding or polishing of the concave lens backside ( 27 ) on a fine grinding or polishing machine in a view (sectional view) and a plan view. The fine grinding or polishing tool is not shown, since not the subject of the proposed method.

The workpiece ( 16 ) is for fine grinding or polishing in the vacuum clamping tool ( 22 ) of a fine grinding or polishing machine, wherein the two flats ( 3 ) and ( 4 ) represent an additional anti-rotation. At this place corresponding fittings ( 25 ) in the area of the top of the vacuum clamping tool ( 22 ) at. This has the advantage that it is possible to work with higher grinding or polishing pressure without the workpiece ( 16 ) thereby slipped.

The vacuum is applied to the vacuum clamping tool ( 22 ) via air ducts in the workpiece spindle ( 34 ) the fine grinding or polishing machine and a hose connection ( 24 ). The upper part of the vacuum clamping tool ( 22 ) is by means of a ball joint ( 26 ) gimbaled.

The fine grinding or polishing process takes place according to the prior art by the workpiece spindle ( 34 ) with the workpiece ( 16 ) and a molding tool (preferably a flexible molding tool), which is fastened to the tool spindle (both not shown), rotates onto the surface of the workpiece to be fine-ground or polished ( 16 ) and also performs rotating movements around the tool axis.

The Fine grinding or polishing tool is with a grinding pad or a Polishing foil occupied and the fine sanding or polishing process is lost Add suspension.

By a slight inclination of the tool spindle relative to the workpiece spindle ( 34 ) is a small relative movement between fine grinding or polishing tool and workpiece ( 16 ), which causes the grinding or polishing.

When Finishing or polishing tool is preferably the mentioned flexible Tool used, as this saves considerable tooling costs to let. On the fine grinding or polishing process is not here as it is not the subject of the proposed procedure is.

It is important in connection with 6 however, the clamping of the workpiece ( 16 ) using both flats ( 3 ) and ( 4 ) in cooperation with the fittings ( 25 ) as well as using the indexing ( 15 ) in cooperation with the bolt ( 29 ).

After the fine grinding or polishing, the finished surface of the concave lens back ( 27 ) (eg with ultrasound) and provided with a protective varnish, so that they in the further processing of the workpiece ( 16 ) is not damaged.

To 7 :

This figure shows how to make the surface geometry on the convex lens front side ( 19 ) by means of roller cutter ( 9 ) on the milling / lathe in a view and a plan view (sectional views) at the end of work, and an enlarged detail of the edge region of the cut workpiece ( 16 ).

The workpiece ( 16 ) is again clamped on the milling / lathe, so that the convex lens front side ( 19 ) can first be processed by milling. For clamping, the outer circumference is again used, the two flats ( 3 ) and ( 4 ) and the indexing ( 15 ) ensure the correct position.

The two flattenings ( 3 ) and ( 4 ) are also used for clamping, to which 28 ), with the clamping tool ( 18 ) and to the two flats ( 3 ) and ( 4 ) and provide a firm hold. For inclusion of indexing ( 15 ) is a bolt ( 29 ), also with the clamping tool ( 18 ) and exactly to the indexing ( 15 ) that partially encloses it. In this operation is a firm grip of the workpiece ( 16 ) in the clamping tool ( 18 ) is particularly important, because a lot of cutting with the milling cutter ( 9 ) must be performed.

The rough contour of the surface geometry at the convex front of the lens ( 19 ) is generated by milling. This operation is performed as in the context of the concave lens backside ( 27 ) already described. The generated surface geometry can be designed arbitrarily and corresponds to the given recipe (recipe production) in cooperation with the concave lens back ( 27 ).

The processing of the convex lens front side ( 19 ) with the milling cutter ( 9 ) starts again at the outer periphery and ends when the tool is the center of the workpiece ( 16 ) has reached by advancing in the Y-axis. The mill cutter ( 9 ) must because of the convex shape of the lens front side ( 19 ) in the edge region of the workpiece ( 16 ) first dive deep into the material so that here the small wall thickness ( 23 ) in the edge region of the lens, in the context of thickness optimization, can be achieved. For this purpose, the workpiece spindle ( 21 ) in the Z axis (feed movement).

This operation can also be carried out with reversed tool feed, wherein the tool from the center of the workpiece ( 16 ) would be led to its edge.

Because the outer, annular area ( 30 ) is to be maintained (serves for clamping and for stiffening the lens), sets the feed motion between mill cutter ( 9 ) and workpiece ( 16 ) only when the mill cutter ( 9 ) by moving in the Y-axis the predetermined position above the workpiece ( 16 ) has reached. This position is selected so that the distance of the milling cutter ( 9 ) to the outer periphery of the workpiece ( 16 ) is sufficiently large to reach the low wall thickness ( 23 ) the annular region ( 30 ) in the desired size.

At the beginning of the milling process arises in connection with the generation of the small wall thickness ( 23 ) and while maintaining the annular region ( 30 ) with a large thickness ( 33 ) a circular groove ( 31 ) on the edge of the workpiece ( 16 ).

Due to the shape of the milling cutter ( 9 ) receives the circular groove ( 31 ) in cross-section a radius at least that of the milling cutters ( 10 ) of the milling cutter ( 9 ) corresponds.

The circular groove ( 31 ) represents the transition between the actual spectacle lens ( 32 ) and the outer, annular region ( 30 ) and allows by their form on the one hand, the small thickness ( 23 ) at the edge of the spectacle lens ( 32 ) and on the other hand, the large thickness ( 33 ) at the annular area ( 30 ).

After making the small wall thickness ( 23 ) the further milling process for producing the geometry on the convex lens front side ( 19 ) so that the workpiece ( 16 ) with the workpiece spindle ( 21 ) in the C-axis (rotational speed and phased) and simultaneously in the Z-axis of the workpiece spindle ( 21 ) performs fast translational movements (oscillations), which serve as delivery movements.

At the same time the mill cutter ( 9 ) with the tool spindle ( 20 ) in the Y-axis controlled (feed movement), wherein it is about the B-axis of the tool spindle ( 20 ) at constant speed (not controlled). The Y, Z and C axes are linked together in the machine control in such a way that, by the addition of the movements, the said groove (FIG. 31 ) and then the surface geometry of the convex lens front side ( 19 ) is produced. When the mill cutter ( 9 ) the center of the workpiece ( 16 ) has reached, the milling process is completed.

To 8a :

This figure shows the preparation of the surface geometry in the fine area and the smoothing of the surface on the convex Lin senvorderseite ( 19 ) by means of a turning tool ( 12 ) on the milling / lathe in a view and a plan view (sectional views) at the working end.

For this machining, the tool spindle ( 20 ) with the tool memory ( 11 ) for the turning tools ( 12 ) in the B-axis rotated by a few degrees until one of the turning tools ( 12 ) is in the edit start position. Then the tool spindle ( 20 ) in the X and Y axes so that this rotary tool ( 12 ) to the starting position above the workpiece ( 16 ) comes.

This starting position of the turning tool ( 12 ) on the edge of the workpiece ( 16 ) is analogous to that as for 5 already described.

The workpiece spindle ( 21 ) with the clamping tool ( 18 ) and the workpiece ( 16 ) is then placed in the C-axis in controlled rotation (speed and phase angle controlled) and at the same time in the Z-axis translationally moved upward until the rotary tool ( 12 ) in the region of the circular groove ( 31 ) in contact with the workpiece ( 16 ) comes.

The turning tool ( 12 ) on the tool spindle ( 20 ) is then moved according to the position of its cutting edge in the direction of the X-axis over the workpiece ( 16 ) moved to its center (feed movement), wherein the workpiece spindle ( 21 ) with the workpiece ( 16 ) is further rotated in terms of speed and phasing about the C-axis and oscillates in the direction of the Z-axis (infeed movements).

During the turning process and the feed movement of the turning tool ( 12 ) in the X-axis, it simultaneously executes the aforementioned B axis angle tracking motions which determine the relative angle of attack between the main axis of the rotary tool (FIG. 12 ) and the workpiece surface (here the convex lens front side ( 19 )) is kept constant.

The X- and Z-axis as well as the B- and C-axis are in the machine control electrically linked, thus the desired Movement possible is.

Through the interaction of the movements of the turning tool ( 12 ) in the X and B axes and the movements of the workpiece ( 16 ) in the Z and C axes, the previously generated by milling geometry of the workpiece ( 16 ) on its convex lens front side ( 19 ) in the fine area and thereby also produces a very low surface roughness on the surface. When the turning tool ( 12 ) the center of the workpiece ( 16 ), the turning operation is completed.

To 8b

This figure shows how to make the surface geometry on the convex lens front side ( 19 ) by means of a turning tool ( 12.1 ) on the milling / lathe with Bachelism axis tracking movements in a view (sectional views).

With this simplistic 8b the operation Turn with Winkelnachführbewegungen is explained and the function of the tool memory ( 11 ).

The workpiece ( 16 ) is in a clamping tool ( 18 ) connected to the workpiece spindle ( 21 ) and performs the already mentioned several times, controlled Z-axis infeed and controlled C-axis rotations.

Turning takes place at the convex lens front ( 19 ) of the workpiece ( 16 ), using a turning tool ( 12.1 ) attached to a tool memory ( 11 ), wherein the main axis of the rotary tool ( 12.1 ) in the 8b perpendicular to the surface of the workpiece ( 16 ) stands.

As the turning tool ( 12.1 ) by the advancing movement in the X-axis over the surface of the convex lens front side ( 19 ), the tool memory ( 11 ) with the turning tool ( 12.1 ) Angle tracking movements in the B axis, so that said right angle between the main axis of the rotary tool ( 12.1 ) and the workpiece surface is maintained.

At the tool memory ( 11 ) are the turning tools ( 12.1 ) to ( 12.4 ) attached. Turning before the actual operation, one of the turning tools ( 12.1 ) to ( 12.4 ) are rotated to the machining start position, as required by the manufacturing requirements. To select one of the desired turning tools ( 12.1 ) to ( 12.4 ) the tool spindle ( 20 ) with the tool memory ( 11 ) is rotated accordingly in the B axis.

The turning tools shown in the picture ( 12.1 ) to ( 12.4 ) have different diameters. Of course, turning tools ( 12.1 ) to ( 12.4 ) with other distinguishing features and in other quantities on the tool memory ( 11 ) be attached.

To 9 :

This figure shows the fine grinding or polishing of the convex lens front side ( 19 ) on a fine grinding or polishing machine in a view (sectional view) and a plan view. The fine grinding or polishing tool is not shown, since not the subject of the proposed method.

The workpiece ( 16 ) is for fine grinding or polishing back into the vacuum clamping mechanism stuff ( 22 ) on the workpiece spindle ( 34 ) of a fine grinding or polishing machine, wherein the two flats ( 3 ) and ( 4 ) are an additional anti-rotation. At this place corresponding fittings ( 25 ) in the area of the top of the vacuum clamping tool ( 22 ) at.

The structure of the finisher and the polishing and polishing process are similar as in 6 already described.

When Fine grinding or polishing tool is again preferably the mentioned flexible Tool used, since hereby also in this operation save considerable tooling costs. On the fine sanding or polishing process will not be discussed here, since he does not Subject of the proposed method is.

Important in connection with 9 is however the clamping of the workpiece ( 16 ) using the two flats ( 3 ) and ( 4 ) in cooperation with the fittings ( 25 ) as well as using the indexing ( 15 ) in cooperation with the bolt ( 29 ). Furthermore, it is crucial here to the stiffening of the workpiece ( 16 ) through the annular region ( 30 ), because the structure of the workpiece ( 16 ) is heavily loaded during clamping with negative pressure.

It is also important that the vacuum clamping tool ( 22 ) for all workpieces to be machined ( 16 ) has the same shape and the same dimensions, since the annular region ( 30 ) is standardized in its outer contour.

After the fine grinding or polishing, the finished surface of the convex lens front side ( 19 ), eg with ultrasound, using standardized washing frames, which saves considerable costs.

Then a very fine mark, z. B. by engraving, on the convex lens front side ( 19 ) containing information relating to the performance characteristics of the spectacle lens and the manufacturer's logo. Again, the annular area ( 30 ) with its standardized dimensions and flats ( 3 ) and ( 4 ) and indexing ( 15 ) of considerable advantage. For clamping the workpieces ( 16 ) requires only a single device.

Then the workpiece ( 16 ) provided with a coating for improving the optical properties and the scratch resistance. This process uses standardized masking, which in turn reduces manufacturing costs.

To 10a :

This figure shows the condition of the workpiece ( 16 ) according to the manufacturing steps 1 to 9 ,

In the lower illustration you can see the two flats ( 3 ) and ( 4 ), as well as the indexing ( 15 ). The upper illustration shows the workpiece ( 16 ) on average. The circular groove ( 31 ) is pronounced according to the lens shape.

Both the convex lens front side ( 19 ) as well as the concave lens back ( 27 ) are finished and coated. An engraving for the identification of the lens is attached (not shown).

To 10b :

This figure shows the condition of the workpiece ( 16 ) according to the manufacturing steps 1 to 9 with a neutral glass (cross-section).

This figure is essentially the same as 10a , Again, the circular groove ( 31 ) strongly pronounced.

To 10c :

This figure shows the condition of the workpiece ( 16 ) according to the manufacturing steps 1 to 9 with a minus glass (cross section).

Since with minus glasses the edge area of the spectacle lens ( 32 ) is thicker than its center, here is the circular groove ( 31 ) is less pronounced for geometrical reasons.

In a last step (not shown), the actual spectacle lens ( 32 ) of the annular region ( 30 ) separated. For this purpose, the workpiece ( 16 ) stretched at the edge and the actual spectacle lens ( 32 ) held by vacuum and / or a soft lower and upper clamping device and then the separating cut z. B. with a small diameter end mill, performed.

This separation section follows an outline that corresponds to that of the spectacle frame, possibly with a small supplement as processing allowance for the spectacle optician. The spectacle lens ( 32 ) is ready for shipment after a further cleaning.

1

Plastic blank

2

clamping tool

3

first flattening

4

second flattening

5

prestressed and centering edge

6

recess

7

edge

8th

recess

9

rolling mills

10

milling cutting edge

11

Tool memory ( 11 )

12

turning tool

12.1

turning tool

12.2

turning tool

12.3

turning tool

12.4

turning tool

13

indentation

14

rolling mills

15

indexing

16

workpiece

17

plane surface

18

clamping tool

19

convex Front of the lens

20

tool spindle

21

Workpiece spindle

22

Vacuum chuck

23

low wall thickness

24

hose connection

25

fitting

26

ball joint

27

concave Lens back

28

clamping element

29

bolt

30

annular area

31

circular groove

32

lens

33

big thickness

34

Workpiece spindle

35

bigger score

Claims (26)

Process for the prescription or individual recipe production of spectacle lenses and other shaped bodies with optically active surfaces using plastic blanks ( 1 ), which have the shape of flat, round discs, are tensioned at their outer edge and, with mechanical removal of material, obtain a desired surface geometry and quality by virtue of the fact that a convex lens front side (FIG. 19 ) and / or a concave lens back ( 27 ) is produced by cutting and / or turning tools as well as by grinding, fine grinding and optionally by polishing, wherein on the outer circumference of the workpiece ( 16 ) an annular region ( 30 ) of greater thickness ( 33 ), which is used for clamping and / or depositing the workpiece ( 16 ) and for supporting and stabilizing the shaped body and / or the actual spectacle lens ( 32 ) is used in machining and transport operations and is finally removed, the annular region ( 30 ) Receives markings and / or shapes for the identification of the processing axes and wherein on the surface of the shaped body or of the actual spectacle lens ( 32 ) Fine marks are applied, which characterize the axial position of the generated surface geometries, wherein when milling the convex lens front side ( 19 ) in the edge region of the workpiece ( 16 ) a circular groove ( 31 ) is formed, which has a radius in cross-section which corresponds at least to that of the milling cutter of the milling cutter, and wherein the groove ( 31 ) to the outside in the annular area ( 30 ) and inwardly into the spectacle lens ( 32 ) passes over. Method according to claim 1, characterized in that a preformed, optically effective concave lens back side ( 27 ) is present, which is formed in particular spherical or toric. Method according to claim 1 or 2, characterized in that a preformed optically effective concave lens backside (11) is provided on the blank. 27 ), which has diopter jumps of more than 0.25. Method according to one of claims 1 to 3, characterized in that blanks ( 1 ) are used, whose front and back have planar surfaces and / or preformed structures (semi-finished part), wherein at least one blank side has an optically effective surface. Method according to one of Claims 1 to 4, characterized in that, to produce the markings and / or shapes, the edge of each blank ( 1 ) is milled such that at the annular region ( 30 ) an indexing ( 15 ), two flattenings ( 3 . 4 ) and / or a notch ( 35 ) arise. Method according to one of claims 1 to 5, characterized that this Making the surface geometry first by milling and subsequently in the fine area by turning or that either only one milling or only a turning takes place. Method according to one of claims 1 to 6, characterized in that first the concave lens backside ( 27 ) of the spectacle lens ( 32 ) is produced by milling and turning, followed by fine grinding and optionally polishing operations, after which the spectacle lens ( 32 ) and coated with protective lacquer or protective film, and then that the turned spectacle lens ( 32 ) on the convex lens front side ( 19 ) with the same ar is processed. Method according to one of claims 1 to 7, characterized in that, during the production of the geometry, in particular also for bifocal glasses, on the convex lens front side ( 19 ) and / or the concave lens back ( 27 ) a prescription production without undesirable diopter jumps in the overall effect of the spectacle lens ( 32 ) is carried out. Method according to one of claims 1 to 8, characterized that at Making the geometry on the front of the lens as part of the recipe production an overlay performed by different curves or geometries. Method according to one of claims 1 to 9, characterized that at Making the geometry on the front of the lens as part of the recipe production superimposed on toric, atoric, prismatic and bifocal forms become. Method according to one of claims 1 to 10, characterized in that the angular position of the main axis of the rotary tool ( 12.1 ) relative to the surface of the workpiece ( 16 ) during the turning process by rotational movements in the B-axis either remains constant or is changed controlled. Method according to one of claims 1 to 11, characterized in that after milling and / or turning to smooth the surface roughness flexible molding tools are used, with which the surface geometry of the lenses ( 32 ) is sanded and / or polished. Method according to one of claims 1 to 12, characterized that yourself at the fine grinding and / or polishing a cleaning process with standardized washing frame connects, followed by a coating with standardized masks follows. Method according to one of claims 1 to 13, characterized in that for separating the actual spectacle lens ( 32 ) of the annular region ( 30 ) a mechanical tool, a small diameter end mill and / or a waterjet is used, the actual spectacle lens ( 32 ) when separating from the annular region ( 30 ) receives an outer, the provided eyeglass frame with a slight oversize adapted contour. Apparatus for carrying out the method according to one of claims 1 to 14, consisting of processing machines with two rotatably driven, translationally movable spindles, wherein the rotations and the translations are controlled and linked in the machine control and wherein the spindles clamping and machining tools are connected, characterized in that the milling / lathe via a tool spindle ( 20 ) which is rotationally controlled in phase and speed in the B axis and can be moved controlled in the Y axis and X axis (feed movements), while the workpiece spindle ( 21 ) with the clamping tools ( 2 ) or ( 18 ) rotationally controlled in phase and speed and translationally movable in the Z-axis with high dynamics (infeed movements), wherein the clamping tool ( 2 ) Recesses ( 6 . 8th ) and clamping elements ( 28 ) having. Apparatus according to claim 15, characterized in that a tool store ( 11 ) for the turning tools ( 12 ) together and coaxial with the roll mill ( 9 ) on the tool spindle ( 20 ) is attached. Apparatus according to claim 15 or 16, characterized in that on a tool storage ( 11 ) a number of turning tools, for example four turning tools ( 12.1 to 12.4 ), and that the tool storage ( 11 ) on the tool spindle ( 20 ) Performs rotational movements in the B-axis with which a desired turning tool is movable to the machining start position. Device according to one of claims 15 to 17, characterized in that milling / lathes are used for carrying out the method, the tool spindle ( 20 ) is rotatable in the B axis and translationally movable in the Y and X axes, while the workpiece spindle ( 21 ) is rotatable in the C-axis and in the Z-axis translationally movable, that the rotational and translational movements are controlled movements and that the axes are electrically linked together in the machine control. Device according to Claim 18, characterized in that milling cutters ( 9 ) whose diameter is perpendicular to the axis of rotation significantly greater than its thickness in the direction of the axis of rotation, and that the milling cutters ( 10 ) on the circumference of the milling cutter ( 9 ) are formed semicircular with a small diameter (11 mm). Device according to one of claims 18 or 19, characterized that as ball mills trained roll milling be used, whose diameter is perpendicular to the axis of rotation big or similar in size is like their extension in the direction of the axis of rotation. Device according to one of claims 18 to 20, characterized in that turning tools ( 12 ), which are located on the outer periphery of a tool storage ( 11 ) and are either circular or circular at the cutting edges Have partial areas of small diameter. Device according to one of claims 18 to 21, characterized in that the milling cutters ( 10 ) of the milling cutter ( 9 ) can be used as a turning tool. Device according to one of claims 18 to 22, characterized in that for milling and turning tools are used, which together on the tool spindle ( 20 ) are mounted and / or their round cutting have similar or the same diameter. Device according to one of claims 19 to 23, characterized in that the tool spindle ( 20 ) with a tool memory ( 11 ) and its turning tools ( 12 ) is blocked in the B axis turning operation and also performs controlled translational movements in the X axis, while the workpiece spindle ( 21 ) with the clamping tool ( 18 ) and the workpiece 16 rotates in phase and speed controlled in the C-axis and executes translatory movements with high dynamics in the Z-axis. Device according to one of claims 19 to 24, characterized in that the tool spindle ( 20 ) with the milling cutter ( 9 ) rotates continuously during the milling of the lens geometry in the B-axis and executes controlled translatory movements in the Y-axis, while the workpiece spindle ( 21 ) with the clamping tool ( 18 ) and the workpiece ( 16 ) rotates phase-controlled and speed-controlled in the C-axis and performs translatory movements with high dynamics in the Z-axis. Apparatus according to claim 25, characterized in that the tool storage ( 11 ) with the on the workpiece ( 16 ) engaged rotary tool ( 12.1 ) during the advancing movement of the tool spindle ( 20 ) performs small rotational movements in the B-axis in the X-axis, whereby an angular tracking movement takes place and the main axis of the rotary tool ( 12.1 ) during the entire work Turning a desired relative angular position to the surface of the workpiece ( 16 ) occupies.