EP1436119B2 - Device and method for complete machining of lenses that are optically active on two sides - Google Patents

Description

The invention relates to a device for processing a two-sided optically active lens with a cutting and / or milling unit for processing at least a first side of the lens, wherein a first holding device for clamping the lens and a transformer unit for re-clamping the lens from the first side is provided on a second side for processing the second side of the lens and a method for producing a lens from a lens blank with two unprocessed sides, which is clamped in a rotatable about a workpiece spindle axis lens mount, after which a first optically active surface with an optical axis the first side of the lens blank is machined, wherein the optical axis of this surface lies substantially in the workpiece spindle axis and a method for processing a two-sided optically active lens with a cutting and / or milling unit for processing at least the first side of the lens, wherein the lens is held by a first holding device associated with a second side, and a transformer unit is provided for circumscribing the lens from the first side to the second side for processing the second side of the lens.

In the previously known methods, a lens blank made of plastic or glass is used, whose one or first side identifies already the final optically effective form. In the case of spectacle lenses, this is the front side, ie the side facing away from the eye, which as a rule forms a spherical surface. Such lens blanks are in gradations stockpiled in terms of the radii of curvature of the spherical surface. For the abrasive toric processing of the rear surface or second side of the lens blank is blocked, that is, fixed with the front surface or first side of a block piece, which is clamped in the chuck of a lens grinding machine.

In order to produce an individual lens that is adapted to the multiple eye defect of a specific person, the front or first side is usually provided with an individual progressive addition surface by means of a cutting process. A progressive addition surface is understood to mean a surface which deviates in some areas from a symmetrical-generally spherical-base surface, so that a progressive lens with near and far-vision regions and the corresponding transition regions is formed. To compensate for certain eye defects, it is also necessary that the base surface of the front surface or first side relative to the rear surface or second side is tilted, offset and / or phase-rotated.

To produce the progressive addition surface of the lens blank is previously attached to the rear surface on a block piece by means of a metallic paste. The thus blocked lens is clamped for processing in the head of a workpiece spindle. Since the lens blank is mounted directly on the block piece, the tilt, offset, and / or phase of blocking must be taken into account by tilting the lens blank on the block piece. As a result, the blocking takes a long time. In addition, this requires a separate machine. Despite all care This additional step results in certain unavoidable inaccuracies.

There is already a machine for making lenses from the EP 0 849 038 A3 known. The machine has a cutting unit and a polishing unit for processing one side of a lens. A complete processing of the lens on both sides is not provided.

From the US Pat. No. 5,205,076 a method is known in which also when editing the first side of the lens blank for a contact lens made of plastic, a lateral surface is worked out. Obviously, the axis of the lateral surface coincides with the workpiece spindle axis, whereby no tipping of the lens blank takes place when the lens blank is received in a holding device for processing the second side, so that the method is not suitable for easily producing lenses in which the optical axes both sides do not coincide.

From the EP 0868972 For example, a method and apparatus for two-sided processing of optical lenses is known in which the blanks have a chucking heel.

The invention has for its object to form a device and a method in such a way and to design that a complete machining of the lens is ensured on both sides.

The object is achieved according to the invention by a device according to claim 1.

It is advantageous for this purpose that the positioning feature is a reference to the orientation of the first and / or the second side of the lens. The reference between the positioning feature and the first side serves to align the lens in the second holder with respect to an optical axis of the first side. The positioning feature is generated during machining of the first page in the same setup. The relation between this first holding surface and the supporting part to the first side is given. The relationship between the first page and the second page is present anyway. The support member is then removed after clamping by the second holder. As a second holding device or for re-clamping, a robot arm can also be used.

The reference surface is a portion of the edge of the lens that remains after processing the first side of the lens. With or after editing the second page, this reference surface is removed.

It is also advantageous that the second holding device has at least two holding parts, each with at least one, at least one reference surface associated plant. The uniform design of the system and the holding part ensures accurate positioning of the lens without additional reference between the system and the holding part. The attachment of the lens holder is designed as a counter surface to the annular surface or reference surface of the lens blank and extends perpendicular to the workpiece spindle axis.

According to a preferred embodiment of the solution according to the invention, it is finally provided that a support part which can be brought into abutment with the first side of the lens is provided, wherein the support part has a plastically and / or elastically deformable surface which can be applied to the first side of the lens and the surface is made of bandage - And / or filler formed and / or curable. Thus, a support of the lens is given, which ensures the processing of the second page. The curing of the surface or of the adhesive ensures a pretension-free support of the lens and thus a reproducible processing of the second side.

It is also advantageous that a device for signing and / or marking the lens is provided. This ensures the positioning of the lens in its subsequent recording within a component, such as a spectacle frame. The signing takes place here either in a cutting unit by a tool and / or in a transformer unit by a laser. In addition, the marking also serves to position the lens relative to the holding device, as long as the cover is not guaranteed by the re-tightening device when re-clamping.

Moreover, it is advantageous that a washing and / or rinsing device is provided for the lens. The first side of the lens can thus be cleaned prior to removal and the finished lens before removal. The washing and / or rinsing device is provided here in a polishing unit.

The orthogonally arranged reference surface is used for vertical alignment, wherein the reference surface arranged in parallel determines the radial position of the lens. It is also possible to ensure the alignment of the lens in the vertical and in the radial direction over a molding surface.

The respective required inclination or the respectively required offset of the lens blank when editing the second side is thus obtained by working out a Spannabsatzes whose axis is tilted relative to the optical axis of the first optical surface and / or offset , So that the turned lens blank can be tilted and / or offset clamped. The second surface is now machined with its optical axis coincident with the workpiece spindle axis. As a result, the leadership of the tool is greatly simplified; this only needs to follow a path which follows mainly the symmetrical base. Elevations or depressions that define the progressive surface represent only a small deviation that can be easily included in the trajectory.

Overall, this results in smaller strokes of the tool in the axial direction, as if additionally the tilt or an offset would have to be worked out. Both methods are thus common that can be dispensed with the time-consuming, requiring an additional machine and quite fraught with errors blocking.

When in the description of the invention of an optical axis of a progressive lens is mentioned, so it is meant an axis which describes the mean curvature of the progressive power surface and is oriented on the optical axis of the underlying symmetrical base.

As explained, the clamping shoulder has a cylindrical lateral surface and an annular support surface extending perpendicular thereto. The lateral surface is detected by pliers or holding parts of a lens holder or holding device in order to hold the lens blank in a rotationally fixed manner, the bearing surface resting on the abutments of the holding parts. Since the normal of the support surface is tilted relative to the blank axis and the upper end or the system of holding parts or their system is in a perpendicular to the workpiece spindle axis counter surface, the lens blank is held with a tilted relative to the workpiece spindle axis axis in the lens holder.

The major surface axes of the two sides must be correlated with each other. This, too, can be taken into account in the clamping paragraph by incorporating a phase marking, which interacts mechanically or optically with a corresponding counter mark on the lens mount, into the clamping shoulder. This makes it possible to use the turned lens blank phase-accurate in the lens mount, so that the controller, which knows the relative position of the workpiece spindle to the machining tool, thus also receives information about the phase alignment of the lens blank and thus a phase-matched Edit the second page can cause.

Because of the tilting of the axis of the lateral surface arise on one side of the lens undercuts, so that is used to generate the Spannabsatzes with a turning tool, which is offset or cranked to the blank axis.

In the processing of the first page also one or more bar marks or signatures are incorporated, which make it possible to adjust the angular position of the two optical surfaces to each other for the processing of the second side and to control. Such stroke marks, also called signatures, are also applied on the second side. In particular, the bar marks contain information about the position of the major and minor axes of the lens base. Markings on both sides are mainly needed for edge processing of spectacle lenses, which must be used in exact phase in spectacle frames.

The object is also achieved by a method according to claim 12. The positioning feature can also be incorporated as a phase marker in the clamping paragraph, so that a phase-accurate insertion of the turned lens blank is possible.

In addition to the usual mechanical and chemical treatment, polishing includes the finest diamond processing or machining without additives, only with water. As a result, minimal cutting marks are revised or removed.

In this case, if necessary, a receiving adapter arranged on the second side of the lens for processing the first side is released from the second side of the lens, and the second side of the lens is processed by the cutting unit.

Finally, it is advantageous that the lens is stretched by holding parts of the second holding device in the radial direction, wherein the positioning feature formed as a reference surface of the lens is brought into abutment with at least one holding part or a bearing of the holding part. The system is here punctiform, linear or flat, so that the reference surface can be applied.

The support member has a plastic-elastic surface, which is cured after application, so that the lens is supported stress-free.

Ultimately, it is advantageous that a marking and / or signing for later aligning the lens on the first side and / or on the second side is placed or incorporated, wherein after the processing of the first side, a protective layer or a protective film is placed on this , The signing can be done by a laser immediately before re-clamping or with the cutting or milling process. In addition to the simplified later positioning of the lens in the component or spectacle frame, the marking also serves to position the lens relative to the holding device, provided that the reference is not guaranteed by the relay during re-clamping. By signing the phase angle of the lens is ensured relative to another lens or relative to the eyeglass frame or the transformer.

It is also advantageous that the lens is washed after processing the first side or after polishing and before applying the protective layer or the protective film and the first side and / or the second side is provided with a coating. For practical reasons, the coating of both sides at once is of greater importance.

Finally, it is advantageous for the lens to be held by the clamping jaws of the second holding device after the first side has been processed and removed from the first holding device. Thus, the relative position of the lens to the first holding device from the system controller to the second holding device is transferable. The use of signatures and / or markings can be omitted.

For this purpose, it is advantageous that after processing the first side, the lens is released from a receiving adapter and / or is released after processing of the second side by a support member. This ensures the processing or completion of the lens after the respective processing step.

Finally, it is advantageous that before or after the coating edge processing for later positioning and attachment of the lens takes place on the spectacle frame. Edge finishing after coating removes critical edge coating areas and creates special mounting options through shaping, grooving and drilling the lens to attach it to the eyeglass frame.

Figur 1

eine Prinzipskizze einer Linse mit Aufnahmeadapter an der zweiten Seite;

Figur 2

eine Prinzipskizze einer Linse mit Stützteil und Klemmbacken;

Figur 3

eine Prinzipskizze einer Komplettbearbeitungseinheit mit einer Schneid- und/oder Fräseinheit, einer Poliereinheit und einer Umspanneinheit;

Figur 4-9

die aufeinander folgenden Schritte bei der Herausarbeitung einer Linse aus einem Linsenrohling.

Further advantages and details of the invention are explained in the patent claims and in the description and illustrated in the figures. It shows:

FIG. 1

a schematic diagram of a lens with receiving adapter on the second side;

FIG. 2

a schematic diagram of a lens with support member and jaws;

FIG. 3

a schematic diagram of a complete processing unit with a cutting and / or milling unit, a polishing unit and a transformer unit;

Figure 4-9

the successive steps in the elaboration of a lens from a lens blank.

In the FIG. 1 illustrated lens 1 has an optically active first page 1.1 and a second page to be machined 1.2. According to FIG. 1 the lens 1 is connected via a receiving adapter 6 and a receiving pin 6.1 with a workpiece spindle, not shown, a cutting, milling unit 7. In an embodiment not shown, the cylindrically shaped lens is received directly in the tool spindle.

The lens 1 is according to FIG. 1 glued to the receiving adapter 6, so that the first side 1.1 of the lens 1 can be processed. In addition to the generated lens shape of the first side 1.1 with the resulting optical axis 1.3, the lens 1 also has a reference surface 4.1, which is arranged orthogonal to the optical axis 1.3. The reference surface 4.1 is part of the still protruding material of the former raw lens 1, according to FIG. 2 is processed in a further processing step to the second side 1.2 of the lens 1. In addition to the reference surface 4.1, a side surface 4.2 is provided, which is arranged perpendicular to the reference surface 4.1 and also has a reference to the optical axis 1.3.

According to FIG. 2 the lens 1 is arranged rotated, so that the already processed first side 1.1 of the lens 1 by two jaws 3.1, 3.2 of a second holding device 3 a transformer unit 2 can be accommodated. The second page 1.2 is now according to FIG. 2 upwards and the receiving adapter 6 is removed. The second page 1.2 is freely accessible in this position and can be edited. The relative position of the lens 1 to the workpiece spindle, not shown, after FIG. 1 and the relative position of the lens 1 to the holding part 3.1 are hereby ensured.

The lens 1 rests with the reference surface 4.1 on a system 3.3 or Appendix 3.3 'of the jaw 3.2 and the clamping jaw 3.1 and is thus the optical axis 1.3 of the first page 1.1 aligned. The optical axis 1.3 now runs approximately parallel to a tool spindle (not shown) or parallel to the side surface 4.2 of the first side 1.1. The side surface 4.2 is used here for determining the position relative to the radial orientation of the lens 1. About the side surface 4.2, the lens 1 is held by the jaws 3.1, 3.2 in the radial direction.

To support the lens 1 for the purpose of processing the second side 1.2, a support member 5 is provided, which has a curable surface 5.1, such as an adhesive. The support member 5 is connected via a receiving pin 5.2 with a tool spindle, not shown. The surface 5.1 in this case is elastically-plastically deformable and can be applied or pressed against the lens 1 or the first side 1.1 for clamping the lens 1 by the clamping jaw 3.1 from below. The surface 5.1 thus adapts to the geometry of the first side 1.1 of the lens 1 and provides sufficient support after curing.

According to FIG. 3 For example, a complete processing unit 10 has, on the one hand, a cutting and milling unit 7, an adjoining polishing unit 8, a transformer unit 2 and a coating unit 9. After processing the first page 1.1 in the cutting, milling unit 7, the lens is passed on to the polishing unit 8. After polishing, the lens 1 is washed in the polishing unit 8, via the transformer unit 2 according to FIG. 1, 2 rotated and delivered to the cutting or milling unit 7 for processing the second side 1.2. Thereafter, the second side 1.2 is polished and washed in the polishing unit 8. In the transformer unit 2, the lens 1 is detached after the processing of the first page 1.1 of the receiving adapter 6 and after editing the second side 1.2 of the support member 5 and held by the jaws 3.1, 3.2.

Optionally, after washing, a unit or station for coating the lens 1 with a protective layer or a protective film such as a plastic film is provided, so that the surface of the already processed first page 1.1 is not damaged during processing by the second side 1.2.

After cutting or milling and polishing the first side 1.1 and / or the second side 1.2, the lens is signed in the transformer unit 2, for example with a laser and / or passed on to the coating unit 9, which then leaves completely processed.

FIG. 4 shows a cylindrical lens blank 1 with a first side 1.1 and a second side 1.2, both of which extend perpendicular to the blank axis 1.4. The lens blank 1 is clamped in a holding parts or tongs 3.1, 3.2 having lens holder 3 of a workpiece spindle, not shown, so that the blank axis 1.4 coincides with the workpiece spindle axis.

According to FIG. 5 First, the optically active surface of the first page 1.1 is worked out with a turning tool 11. In the simplest case, the optically active surface 1.1 is a spherical surface whose optical axis 1.3 coincides with the blank axis 1.4. But even here, a progressive power surface can be generated, wherein the optical axis 1.3 is the axis of the base surface of the progressive addition surface. The machining is done with a fast rotating workpiece spindle, wherein the turning tool 11 is moved in accordance with the rotation of the workpiece spindle in the axial direction up and down and thereby slowly adjusted in the radial direction. Thus, the acceleration of the tool in the axial direction is not too large, the rotation or rotation in areas with large changes in the local curvatures may be slowed down. The workpiece spindle axis is thus a controlled, ie phase-controlled axis.

According to FIG. 6 In the same clamping a clamping shoulder 4 is generated. This consists of a peripheral step 4.3 with a lateral surface 4.2 and a perpendicular thereto ring surface 4.1. It is crucial that the clamping shoulder 4 is tilted relative to the blank axis 1.4 and thus with respect to the optical axis 1.3 of the optically active surface 1.1 of the first side, ie that the surface normal of the annular surface 4.1, which is the axis 12 of the clamping paragraph, is tilted relative to these axes , In principle, the stage 4.3 can also be additionally offset from the optical axis 1.3. In order to be able to work out the step 4.3, a laterally offset lathe chisel 11 is used in order to be able to process also the areas that represent themselves as an undercut.

The processing of the first page 1.1 of the lens blank 1 is thus completed. He is now removed from the clamping and turned and used with the first page 1.1 down again phase-exact by means of a phase marker in the form of a bar mark in the clamping. Such a marking can be dispensed with, if the clamping takes place in a controlled manner, that is to say when the phase angle of the lens 1 to the spindle is known and this information is not lost due to the controlled movement of the conversion tool 3, so that the turned lens 1 is again in phase alignment with the spindle Chuck of a phase-controlled spindle is used. It will - as the FIG. 7 shows - the lens blank 1 detected at the stage 4.3, wherein the pliers 3.1, 3.2 of the lens holder 3 detect the lateral surface 4.2 and hold the lens blank 1 rotation. At the same time, the annular surface 4.1 rests on the upper end of the tongs 3.1, 3.2, so that the blank axis 1.4 is tilted relative to the workpiece spindle axis. The now lying above the second side 1.2 of the lens blank 1 is tilted relative to the workpiece spindle axis.

According to FIG. 8 Now, the overhead second side 1.2 to a progressive power surface, which is the second optical surface 1.2, processed, wherein the optical axis 1.4 coincides with the workpiece spindle axis and thus tilted relative to the optical axis 1.3 of the first page 1.1 and possibly offset.

In order for the angular orientation of the two optical surfaces 1.1, 1.2 to have the desired dimension, a bar marking can be generated during the processing of the first page 1.1, which is taken into account in the processing of the second page 1.2. Before the cutting process begins, the lens blank 1 is aligned with the bar mark. It also forms the starting point for editing the second page 1.2.

As soon as the second side 1.2 is processed, the resulting from the lens blank 1 lens of the lens holder 3 is removed and carried out a border processing, at least the material area, here double hatched, which forms the annular surface of the clamping is removed.

LIST OF REFERENCE NUMBERS

1

lens

1.1

first page, first optical surface

1.2

second side or optical surface, progressive surface

1.3

optical axis

1.4

optical axis, blank axis

2

reclamping

3

second holding device, lens holder, Umsetzwerkzeug

3.1

Holding part, jaw, pliers

3.2

Holding part, jaw, pliers

3.3

Plant, counter surface

3.3 '

Plant, counter surface

4

clamping shoulder

4.1

Positioning feature, reference surface

4.2

Side surface, lateral surface

4.3

step

5

supporting part

5.1

surface

5.2

spigot

6

receiving adapter

6.1

spigot

7

Cutting, milling unit

8th

polishing unit

9

coating unit

10

Complete machining unit

11

lathe tool

12

Axis of the clamping shoulder

Claims (21)

1. A device for the machining of a bilaterally optically active lens (1) with a cutting, milling (7) and/or a polishing unit (8) for the machining of at least a first side of the lens, whereby there is provided a first holding device for the clamping of the lens (1) and a reclamping unit (2) for the reclamping of the lens (1) from the first side (1.1) onto the second side (1.2) for the purpose of machining the second side (1.2) of the lens (1), characterised in that the device is used for the machining of a bilaterally optically active lens (1) having two optical axes (1.3, 1.4) tilted towards one another, wherein a clamping shoulder (4) formed as a positioning feature (4) and having a cylindrical lateral surface (4.2) and an annular surface (4.1), said clamping shoulder having an axis (12) defined by the lateral surface (4.2) and the annular surface (4.1), can be produced by means of the cutting and/or milling unit (7) in such a way that the axis (12) runs offset and/or tilted with respect to the optical axis (1.3) of the first side (1.1) and the clamp-round unit (2) comprises a second holding device (3) for the lens (1), which is designed in such a way that the lens (1), with respect to its axial position, can be supported by means of the positioning feature (4) relative to the second holding device (3).
2. The device according to claim 1, characterised in that the positioning feature (4) has a reference to the first side (1.1) and/or to the second side (1.2) of the lens (1) and/or to their alignment.
3. The device according to any one of the preceding claims, characterised in that the positioning feature (4.1) is designed as a reference face (4), whereby the reference face (4) is aligned with respect to an optical axis (1.3, 1.4) of the first side (1.1) and/or of the second side (1.2).
4. The device according to any one of the preceding claims, characterised in that the second holding device (3) has at least two holding parts (3.1, 3.2) each with at least one seating (3.3) assigned to a least one reference face (4).
5. The device according to any one of the preceding claims, characterised in that a supporting part (5) is provided which can be brought into contact with the first side (1.1) of the lens (1).
6. The device according to any one of the preceding claims, characterised in that the supporting part (5) has a plastically and/or elastically deformable surface (5.1) which can be placed onto the first side (1.1) of the lens (1).
7. The device according to any one of the preceding claims, characterised in that the surface (5.1) is formed from binder and/or filler and/or is hardenable.
8. The device according to any one of the preceding claims, characterised in that a device is provided for the polishing, signing and/or marking of the lens (1).
9. The device according to any one of the preceding claims, characterised in that a washing and/or rinsing device is provided for the lens (1).
10. The device according to any one of the preceding claims, characterised in that the reference face (4) is arranged orthogonal and/or parallel to the optical axis (1.3, 1.4) of the first side (1.1) and/or of the second side (1.2) of the lens (1).
11. A method for the production of a lens from a lens blank (1) with unmachined sides, which is clamped in a lens mounting (3) rotatable about a workpiece spindle axis, according to which a first optically active face with an optical axis (1.3) on the first side (1.1) of the lens blank (1) is worked, whereby the optical axis (1.2) of this face essentially lies in the work piece spindle axis, characterised by the following process steps:

    a) producing a clamping shoulder (4)with a cylindrical lateral surface (4.2) and an annular seating surface (4.1), which serve as a positioning feature (4.1) with reference to the optical axis (1.3) of the first side (1.1), whereby the axis (12) defined by the lateral surface (4.2) and the annular surface (4.1) runs offset and/or tilted to the optical axis (1.3) of the first optically active face (1.1), whereby this step can also take place before the working of the first optically active face (1.1),

    b) removal and turning round of the lens blank (1) so far machined,

    c) clamping of the turned-round lens blank (1) into the already employed or another lens mounting (3), so that the axis (12) of the clamping shoulder (4) coincides with the workpiece spindle axis,

    d) working of a second optical face (1.2) with an optical axis (1.4) on the second side of the lens blank (1), whereby the optical axis (1.4) of this face also essentially lies in the workpiece spindle axis.
12. A method for the machining of a bilaterally optically active lens (1) with a cutting and/or a polishing unit for the machining of at least the first side (1.1) of the lens (1), whereby the lens (1) is held via a first holding device assigned to the second side (1.2) and a reclamping unit (2) for the reclamping of the lens (1) from the first side (1.1) onto the second side (1.2) is provided for the purpose of machining the second side (1.2) of the lens (1), characterised by the following process steps:

    a) the lens (1) is provided by means of the cutting process with at least one positioning feature (4.1) having a reference to the first side (1.1) and/or to the second side (1.2),

    b) the lens (1) is gripped by the second holding device (3) after the cutting and/or after the polishing of the first side (1.1) and before the removal from the first holding device and is aligned by means of the positioning feature (4) relative to the second holding device (3),

    c) the second side (1.2) of the lens (1) is machined by the cutting unit.
13. The method according claim 12, characterised in that the lens (1) is clamped in the radial direction by holding parts (3.1) of the second holding device (3), whereby the positioning feature of the lens (1) formed as a reference face (4) is brought into contact with at least one holding part (3.1) or a seating (3.3) of the holding part (3.1).
14. The method according claim 12 or 13, characterised in that the reference face (4) is arranged normal to or parallel to an optical axis (1.3, 1.4) of the lens (1).
15. The method according claim 12, 13 or 14, characterised in that the supporting part (5) is brought into contact with the first side (1.1).
16. The method according claim 12 to 14 or 15, characterised in that a marking and/or signing for the subsequent alignment of the lens (1) is placed or incorporated on the first side (1.1) and/or on the second side (1.2).
17. The method according claim 12 to 15 or 16, characterised in that, after the machining of the first side (1.1), a protective layer or a protective film is arranged on the latter.
18. The method according claim 12 to 16 or 17, characterised in that the lens (1) is washed after the machining of the first side (1.1) or after the polishing and before the application of the protective layer or the protective film.
19. The method according claim 12 to 17 or 18, characterised in that the first side (1.1) and/or the second side (1.2) is provided with a coating.
20. The method according claim 12 to 18 or 19, characterised in that the lens (1) is held by the clamping jaws (3.1, 3.2) of the second holding device after the machining of the first side (1.1) and before removal from the first holding device.
21. The method according claim 19 or 20, characterised in that, before or after the coating, an edge working takes place for the subsequent positioning and/or fixing of the lens (1) in the spectacle frame.

Images