DE102020128088B3 - Process for precision grinding or polishing an optical lens on a workpiece carrier - Google Patents

Abstract

The invention relates to a method for precision grinding or polishing an optical lens with a first and second lens side (S1, S2) and a lens circumference (LU), with a workpiece spindle (10) driven about a spindle axis (A1) and having a workpiece holder (11) with a front hydraulic chamber (12) in which a pressurized polishing suspension (S) is located, wherein the optical lens (50) is inserted with the first lens side (S1) first into the front hydraulic chamber (12) in such a way that the polishing suspension (S) behind the first lens side (S1) in the hydraulic chamber (12) and a gap (SP) is formed between the lens periphery (LU) and the workpiece holder (11), through which the polishing suspension (S) exits, the second Lens side (S2) of the optical lens (50) with a tool axis (A2) driven rotating mold (40) is finely ground or polished, while the optical lens (50) with the pressurized n polishing suspension (S) is pressed against the mold (40), and wherein on the first lens side (S1) a workpiece carrier (20) is fixed, which projects into the hydraulic chamber (12). The invention also relates to a workpiece carrier for this.

Description

The invention relates to a method for fine grinding or polishing an optical lens according to the preamble of claim 1 and the use of a workpiece carrier for fixing to a first lens surface of an optical lens in the method according to claim 12.

Optical lenses are made from transparent materials by multiple grinding operations or other machining methods. It can be mineral glass or suitable plastics. In any case, the shaping processes mentioned are followed by at least one polishing process, with which the surface roughness of the optical lens is reduced to such an extent that the light scattering on the surface becomes negligible.

• Die Poliermaschinen verfügen über einen obenliegenden Schwenkkopf, der die Werkzeugspindel trägt, an deren unterem Ende ein Formwerkzeug befestigt ist. Der Schwenkkopf seinerseits ist, um die sogenannte B-Achse schwenkbar, an einem X-Schlitten befestigt, der horizontale Bewegungen senkrecht zur B-Achse ausführen kann. Im unteren Teil der Poliermaschine befindet sich ein Z-Schlitten, der sich vertikal bewegen kann und die Werkstückspindel mit vertikaler Achse trägt. Die Achsen von Werkzeugspindel und Werkstückspindel liegen in einer gemeinsamen Ebene, die auf der B-Achse senkrecht steht. Beide Spindeln verfügen über einen eigenen Antrieb, der sie in Rotation versetzen kann. Andere Achsaufteilungen sind natürlich ebenso möglich wie eine Vertauschung von oben nach unten.

Polishing the lenses takes significantly more time than the preceding, coarser shaping processes. It is therefore a particularly important development goal to shorten the polishing times. According to the state of the art, lenses are polished using the following technology:

• The polishing machines have an overhead swivel head that carries the tool spindle, at the lower end of which a forming tool is attached. The swivel head, for its part, can be swiveled around the so-called B-axis and is attached to an X-slide, which can perform horizontal movements perpendicular to the B-axis. In the lower part of the polishing machine there is a Z-slide, which can move vertically and supports the workpiece spindle with a vertical axis. The axes of the tool spindle and workpiece spindle lie in a common plane that is perpendicular to the B axis. Both spindles have their own drive that can set them in rotation. Of course, other axis divisions are just as possible as swapping them from top to bottom.

To ensure that the relative speed between the mold and the lens is as optimal as possible at every point on the lens surface, one of the two spindle axes must be set at an angle during polishing. In the polishing machines that are customary today, this is achieved by pivoting the above-mentioned, overhead pivoting head with the tool spindle attached thereto, which is thus at an angle. The mold has about twice the diameter of the lens, which is placed against the mold in such a way that its edge does not extend beyond the center of rotation of the mold. For geometric reasons, the intersection of the two spindle axes must coincide with the center of curvature of the lens, which can be achieved after tilting the swivel head by moving the X slide and the Z slide.

The molds are lined with a soft material on the side that touches the lens during polishing. The desired material removal is achieved by adding a polishing suspension containing fine solid particles. Even if only the surface roughness is reduced during polishing, a certain correction of the lens shape still takes place in the fine range. For this reason, the polishing tools have to be worked very precisely and, because of the wear that occurs during polishing, they have to be reworked again and again with a so-called dressing tool.

JP H07-68 457 A specifies a hydrostatically mounted workpiece holder. The workpiece holder has a plate-shaped support plate, on the back of which there is a pin-shaped projection. A lens to be processed is fixed in the center of the front side of the carrier plate. With the pin-shaped projection, the workpiece holder is inserted in a bearing recess that is surrounded by an end face. A gap remains between the workpiece holder and the bearing recess, which is formed at the end of the peg-shaped projection, at the periphery of the peg-shaped projection, and between the rear side of the plate-shaped support plate and the end face. A fluid is pressed into the gap in the area of the end of the peg-shaped projection, which fluid subsequently exits through the gap on the circumference of the plate-shaped carrier plate. As a result, the workpiece holder is hydrostatically mounted. This makes it possible to press the lens to be processed against the processing tool with the fluid pressure acting on the workpiece holder, with compensating movements of the lens also remaining free in the axial direction due to the open gap. In addition, JP H07-68 457 A provides a mechanical suspension of the component with the bearing recess in order to be able to adjust the angle of the workpiece holder.

In order to polish or finely grind optical lenses with modern CNC machines, processes are typically used today that press the lens against the polishing tool indirectly via a membrane or directly via air or with the help of a liquid. The lens is, so to speak, cardanically accommodated in the workpiece holder and can be aligned with the polishing tool. This can also be referred to as a floating or hydrostatic bearing.

EP 0 916 448 B1 describes a special method for polishing an optical lens in which the lens is placed in a first workpiece holder and polished on a first side with a power forming tool. The first workpiece holder is designed with a cavity behind the optical lens, which contains a polishing suspension that is under pressure. This pressure of the polishing suspension presses the optical lens against the polishing tool to create the necessary polishing pressure. The polishing suspension also escapes from the very fine gap between the lens and the workpiece holder and splashes against the polishing tool, from where it is carried into the polishing zone.

The polishing suspension is practically incompressible and presses the optical lens stably and evenly against the mold. Due to the good heat conduction and high specific heat of the water, the lens is cooled very well on the front and back and thus unwanted heating of the lens, which can lead to processing errors, is avoided. In addition, the polishing suspension constantly escaping from the aforementioned annular gap ensures that the lens also remains moist at the edge and that no dried-on residues can form in this area.

A disadvantage of this hydrostatic bearing, however, is that it only works with larger optical lenses such as those used in spectacle lenses. Small optical lenses, especially those with a diameter of less than 3 cm, have been found to tend to wobble on the hydrostatic bed. In addition, the small lenses do not rotate reliably enough with the rotation of the workpiece spindle, so that the polishing result cannot be reproduced even with constant speeds and pressures. A slowly rotating lens is simply less polished than a fast rotating one. Another disadvantage of running after EP 0 916 448 B1 is that the small lenses can no longer be traced one-to-one, because here it is usually not possible to insert identifications, for example on the circumference.

The object of the invention is to provide a solution in which even small optical lenses, which are hydrostatically mounted, can be polished cost-effectively, quickly, precisely and in a traceable manner.

This object is achieved by a method according to patent claim 1 and by using a workpiece carrier according to independent claim 12.

Main features of the invention are set out in the characterizing part of claim 1 and claim 12, respectively. Configurations are the subject of claims 2 to 11 and the description.

The invention relates to a method for fine grinding or polishing an optical lens, which has a first lens side, a second lens side and a lens periphery, with a workpiece spindle driven about a spindle axis, which has a workpiece holder with a front-side hydraulic chamber containing a pressurized polishing suspension , wherein the optical lens is inserted into the front hydrochamber with the first lens side first in such a way that the polishing suspension is located behind the first lens side in the hydrochamber and a gap is formed between the lens periphery and the workpiece holder, through which the polishing suspension exits. In this case, the second lens side of the optical lens is finely ground or polished with a mold that is driven in rotation about a tool axis, while the optical lens is pressed against the mold with the polishing suspension that is under pressure. According to the invention, it is also provided that a workpiece carrier is fixed on the first side of the lens and protrudes into the hydraulic chamber, with the unit consisting of optical lens and workpiece carrier being arranged at a distance from the walls of the hydraulic chamber in such a way that it is in the polishing suspension in the hydraulic chamber along the spindle axis is movable and / or gimballed.

The advantage of this is that the workpiece carrier increases the surface area of the area in contact with the rotating polishing suspension compared to the variant without such a workpiece carrier. The contact surface for the frictional entrainment is increased by means of the workpiece carrier, which means that even small optical lenses can now be polished or finely ground using hydrostatic pressure technology. Due to the larger contact surface for transmitting torque to the optical lens, even small optical lenses of less than 2 cm can be reliably set at a defined speed and the machining process can be carried out reproducibly. Another contributing factor is that the mass of the unit made up of optical lens and workpiece carrier is increased, as a result of which the rotating unit is stabilized in position and the optical lens does not tumble so easily. This significantly expands the area of application of hydrostatic bearing technology for fine grinding or polishing. The workpiece carrier is preferably made of metal. This is heavy and leads to a high stabilizing flywheel mass.

In the process, the forming tool is usually driven in rotation with a tool spindle about the tool axis. Furthermore, the workpiece spindle and the tool spindle should be driven so that they can be moved relative to one another, preferably linearly and in a rotating or pivoting manner.

According to the embodiment of the method according to the invention, the unit consisting of optical lens and workpiece carrier is arranged at a distance from the walls of the hydraulic chamber in such a way that it is displaceably and/or cardanically mounted in the polishing suspension in the hydraulic chamber along the spindle axis. The longitudinal displaceability can be sufficient to achieve a desired contact pressure of the optical lens against the mold. A cardanic bearing contributes to a position correction, so that the contact pressure over the second lens surface is more homogeneous.

In a preferred variant of the method, the diameter of the workpiece carrier transversely to the spindle axis is smaller than a diameter of the optical lens. This allows the unit consisting of optical lens and workpiece carrier to be easily inserted into the hydraulic chamber. Preferably, the hydraulic chamber is stepped on its circumference to correspond to the unit made up of optical lens and workpiece carrier. A narrow gap is thus also achieved on the circumference of the workpiece carrier, which promotes rotational entrainment by the rotating polishing suspension. In addition, the degree of freedom of an optional cardanic bearing is effectively limited. The unit of optical lens and workpiece carrier can then only adjust its angle to the spindle axis to a limited extent.

In a special embodiment, a length of the workpiece carrier along the spindle axis is greater than a maximum distance between the first and second lens sides. As a result, the unit consisting of the optical lens and the workpiece carrier achieves a length at which a high level of position stabilization is achieved through rotation. The length of the workpiece carrier along the spindle axis is preferably no greater than five times the maximum distance between the first and second lens sides. The receiving workpiece spindle thus remains compact.

Above all, an embodiment according to which the diameter of the workpiece carrier is greater than the length of the workpiece carrier also contributes to this goal. With dimensions of this type, the unit made up of optical lens and workpiece carrier can also be designed relatively easily in such a way that it can be set down on such a base without the optical lens coming into contact with the base.

With regard to the dimensions, an embodiment is also possible in which the diameter of the mold is larger than the diameter of the optical lens, preferably at least 1.3 times and more preferably at least 1.5 times. In this way, during processing, the forming tool protrudes beyond the lens circumference of the optical lens. Polishing suspension spraying out through the gap between the lens periphery and the workpiece holder then sprays against the protruding area of the mold and is then transported by the mold into the polishing zone. The diameter of the molding tool is particularly preferably at least twice the diameter of the optical lens. This avoids contact of the second lens surface with the center point of the forming tool, in which there is almost no relative movement on the tool side for processing.

According to the method, it can be provided that the workpiece carrier is balanced in relation to the spindle axis or is designed without imbalances. This enables high positional stability through rotation.

Another advantage is that the workpiece carrier can be used as a transport and holding system for many work processes. For this purpose, the machines and measuring devices involved should have a uniform or standardized clamping system, preferably a collet or a vacuum attachment.

In an advantageous embodiment, it is provided that the workpiece carrier has a gripper groove on its circumference, in particular a circumferential gripper groove. This means that the unit consisting of the optical lens and the workpiece carrier can be safely and automatically handled. An automatic handling system can be used for transport between individual machines or measuring stations. This system can have a gripper that transports the workpiece via the gripper groove attached to the workpiece carrier.

It is optionally provided that an RFID chip is arranged in or on the workpiece carrier, on which a component identification and/or process parameters are stored. For example, the RFID chip enables all the process data required for the attached optical lens to be saved and read out via a host computer system and archived.

The RFID chip is advantageously arranged opposite the optical lens. This is where it is the least disturbing and an imbalance can also be avoided in a simple manner. the RFID chip preferably sits in a recess in the workpiece carrier. On the one hand it is so easy to integrate, on the other hand it is relatively well protected against external influences. With the help of the RFID chip, a fully automatic production of optical lenses based on 4.0 information technologies can be made possible.

According to an embodiment variant, the first side of the lens can have a protective layer, protective film or adhesive film, to which the workpiece carrier is fixed. As a result, the optically effective surface of the first lens side is protected against mechanical and chemical damage caused by particles and/or adhesive.

The workpiece carrier can be fixed in particular by gluing or adhering to the first side of the lens. This enables a connection without special contours having to be formed on the optical lens for this purpose. The workpiece carrier preferably does not protrude beyond the circumference of the optical lens. In particular, the first side of the lens can be connected to the workpiece carrier, for example, with UV adhesive, putty foil, hot melt adhesive or wax putty.

A special feature can be that the workpiece carrier has a flow structure and the polishing suspension rotating with the workpiece spindle acts on this flow structure in such a way that the unit of optical lens and workpiece carrier is accelerated in the direction of rotation. This further improves the rotational drive of the optical lens. The flow structure can be a deviation from a rotational symmetry of the workpiece carrier. In particular, this can include projections and/or depressions that are suitable for generating flow vortices in the laminar flow of the polishing suspension flowing past.

In a special embodiment variant, the workpiece carrier has at least one groove or twist structure on its circumference, preferably at least one, more preferably at least two and particularly preferably at least three twist ridges or twist grooves, with the polishing suspension rotating with the workpiece spindle acting on this twist structure in such a way that the unit of optical lens and workpiece carrier is accelerated in the direction of rotation. This improves the rotational drive of the optical lens and achieves a high degree of positional stability, similar to a projectile that is set in rotation by a train in a projectile barrel.

For this purpose, it can be provided as an optional detail that the twisted web or the twisted groove or the twisted webs or the twisted grooves run obliquely on the circumference of the workpiece carrier, in particular winding around the circumference, this preferably with a constant pitch, and particularly preferably helically or helically. The bevel can be aligned in such a way that the rotating polishing suspension acts on the twist structure in such a way that the unit made up of optical lens and workpiece carrier is pressed against the mold along the spindle axis of the workpiece spindle. The hydrostatic pressure of the polishing suspension and the pressure via the twist structure then add up. A reverse orientation can also be implemented.

In an alternative or additional detailed configuration, it can be provided that the walls of the hydraulic chamber surrounding the unit of optical lens and workpiece carrier have a train or twist structure, preferably at least one, more preferably at least two and particularly preferably at least three twist ridges or twist grooves. This causes the polishing suspension to rotate more intensively and the transmission of the rotation from the workpiece holder via the polishing suspension to the unit is improved.

The workpiece carrier for attachment to a first lens surface of an optical lens and for use in a hydraulic chamber of a workpiece spindle, with a carrier axis, a front receiving surface and a circumference, can have a flow structure which is designed in such a way that a fluid rotating around the circumference is such can act on this flow structure that the workpiece carrier is accelerated in the direction of rotation, in particular around the carrier axis. Such a workpiece carrier contributes to the fact that even small lenses with hydrostatic bearings can be accommodated and driven in workpiece holders and can be processed with high quality using fine grinding or polishing tools.

The workpiece carrier for attachment to a first lens surface of an optical lens and for use in a hydraulic chamber of a workpiece spindle, with a carrier axis, a front receiving surface and a circumference, can have at least one train or twist structure on its circumference, namely preferably at least one further preferably at least two and particularly preferably at least three helical webs or helical grooves. Such a workpiece carrier contributes to the fact that even small optical lenses with hydrostatic bearings can be accommodated and driven in workpiece holders and can be processed with high quality using fine grinding or polishing tools.

• - dass der Durchmesser des Werkstückträgers größer ist als die Länge des Werkstückträgers; und/oder
• - dass der Werkstückträger bezogen auf die Trägerachse gewuchtet ausgebildet ist; und/oder
• - dass der Werkstückträger an seinem Umfang eine Greifernut aufweist, insbesondere eine umlaufende Greifernut; und/oder
• - dass im oder am Werkstückträger ein RFID-Chip angeordnet ist, auf dem eine Bauteilidentifizierung und/oder Prozessparameter gespeichert sind; und/oder
• - dass der RFID-Chip gegenüber von der Aufnahmefläche angeordnet ist; und/oder
• - dass der RFID-Chip in einer Ausnehmung im Werkstückträger sitzt; und/oder
• - dass der Drallsteg oder die Drallnut bzw. die Drallstege oder die Drallnuten am Umfang des Werkstückträgers schräg verlaufen, insbesondere sich um den Umfang windend, dies vorzugsweise mit konstanter Steigung, und besonders bevorzugt helix- oder schraubenförmig; und/oder
• - dass die Ausrichtung der Schräge dabei derart ausgerichtet ist, dass die rotierende Poliersuspension derart an der Drallstruktur angreift, dass die Einheit aus optischer Linse und Werkstückträger entlang der Spindelachse der Werkstückspindel gegen das Formwerkzeug gedrückt wird.

The workpiece carriers can each have one or more of the optional features that have already been described in connection with the method. These include, among other things, possible optional design features:

• - That the diameter of the workpiece carrier is greater than the length of the workpiece carrier; and or
• - that the workpiece carrier is balanced in relation to the carrier axis; and or
• - that the workpiece carrier has a gripper groove on its circumference, in particular a circumferential gripper groove; and or
• - That an RFID chip is arranged in or on the workpiece carrier, on which a component identification and/or process parameters are stored; and or
• - that the RFID chip is arranged opposite the receiving surface; and or
• - That the RFID chip sits in a recess in the workpiece carrier; and or
• that the helical web or the helical groove or the helical webs or the helical grooves run obliquely on the circumference of the workpiece carrier, in particular winding around the circumference, this preferably with a constant pitch, and particularly preferably helically or helically; and or
• - That the orientation of the bevel is aligned such that the rotating polishing suspension acts on the twist structure in such a way that the unit of optical lens and workpiece carrier is pressed against the mold along the spindle axis of the workpiece spindle.

The advantages of the design options for the workpiece carriers correspond to those previously explained in the section on the method.

Finally, the invention relates to the use of a workpiece carrier as described above and below in a method as specified above and below. The workpiece carrier for fixing to a first lens surface of an optical lens has a carrier axis, a front receiving surface and a circumference. In addition, the workpiece carrier has either (a) a flow structure which is designed in such a way that a fluid rotating around the circumference can act on this flow structure in such a way that the workpiece carrier is accelerated in the direction of rotation; or (b) on its circumference at least one line or twist structure, preferably at least one, more preferably at least two and particularly preferably at least three twist ridges or twist grooves. The carrier axis is aligned coaxially to the spindle axis in a central position, with the unit consisting of the optical lens and workpiece carrier being arranged at a distance from the walls of the hydrochamber in such a way that it can be displaced and/or gimballed along the spindle axis in the polishing suspension in the hydrochamber. This use of a workpiece carrier in the specified method contributes to the fact that even small optical lenses with hydrostatic bearings can be accommodated and driven in workpiece holders and can be processed with high quality using fine grinding or polishing tools.

• 1 einen Schnitt durch einen Teilbereich einer Poliermaschine mit einer Werkzeug- und einer Werkstückspindel; und
• 2 eine Seitenansicht mit Teilschnitt einer Einheit aus einer optischen Linse und einem Werkstückträger.

Further features, details and advantages of the invention result from the wording of the claims and from the following description of exemplary embodiments with reference to the drawings. Show it:

• 1 a section through a portion of a polishing machine with a tool and a workpiece spindle; and
• 2 a side view with partial section of a unit from an optical lens and a workpiece carrier.

1 shows a section through a portion of a polishing machine 1 with a tool spindle 41 and a workpiece spindle 10.

The tool spindle 41 has a forming tool 40 and drives it to rotate about a tool axis A2. The forming tool 40 has a diameter D3 transverse to the tool axis A2. A processing layer is arranged on the front side, which in the present case has a convex shape.

The workpiece spindle 10 has a workpiece holder 11 and is driven to rotate about a spindle axis A1. Outside the image area, the polishing machine 1 has actuators, with which the tool spindle 41 together with the forming tool 40 on the one hand and the workpiece spindle 10 on the other hand can be displaced and pivoted relative to one another.

The workpiece holder 11 has a hydraulic chamber 12 on the front or end face, in which a pressurized polishing suspension S is located. An optical lens 50 for processing is accommodated therein. For this purpose, the optical lens 50 is inserted into the front hydraulic chamber 12 with a first lens side S1 in front in such a way that the polishing suspension S is located behind the first lens side S1 in the hydraulic chamber 12 and a gap SP is formed between the lens circumference LU and the workpiece holder 11. through which the polishing suspension S emerges.

A second lens side S2, opposite the first lens side S1, faces away from the hydraulic chamber 12 and can now be finely ground or polished with the mold 40, which is driven in rotation about the tool axis A2, while the optical lens 50 is pressed against the mold 40 with the polishing suspension S under pressure will.

Such a polishing machine 1 together with the specified workpiece carrier 20 is also the subject of the invention. Such a workpiece carrier 20 is according to 1 fixed to the first lens side S1 and protrudes into the hydraulic chamber 12. The polishing suspension S, which is set in rotation with the workpiece spindle 10 (this should also include fine grinding suspensions and cooling lubricants), then rotates according to the method around the workpiece carrier 20 and excites it together with the fixed optical lens 50 a rotation.

In the following, special and optional configurations of the workpiece carrier 20 are specified, some of which are 1 and partly in 2 are recognizable. 2 shows in particular a side view with a partial section of a unit consisting of the optical lens 50 and a specially designed workpiece carrier 20.

How to get into the 1 and 2 recognizes, the optical lens 50 has a lens circumference LU in addition to the first and second lens side S1, S2. The unit of this optical lens 50 and the specified workpiece carrier 20 is according to FIG 1 arranged at a distance from the walls of the hydraulic chamber 12 in such a way that it can be displaced in the polishing suspension S in the hydraulic chamber 12 along the spindle axis A1 and is cardanically mounted. A carrier axis TA of the workpiece carrier 10 is in the center position shown 1 aligned coaxially with spindle axis A1, but can tilt slightly relative to spindle axis A1 when loaded by the forming tool 40.

A diameter D1 of the workpiece carrier 20 transversely to the spindle axis A1 is according to FIG 2 smaller than a diameter D2 of the optical lens 50. A length L of the workpiece carrier 20 along the spindle axis A1 is greater than a maximum distance between the first and second lens side S1, S2. The diameter D1 of the workpiece carrier 20 is also greater than the length L of the workpiece carrier 20. It can also be seen in FIG 1 that the diameter D3 of the mold 40 is larger than the diameter D2 of the optical lens 50, namely by at least 1.3 times.

The workpiece carrier 20 is balanced in relation to the spindle axis A1 or to its carrier axis TA, i.e. it is designed without imbalances, so that it rotates stably. The workpiece carrier 20 has a circumferential gripper groove 21 on its circumference 24 . The polishing machine 1 can optionally have a gripper or be arranged in its work area, which transports the optical lens 50 via the gripper groove 21 attached to the workpiece carrier 20 .

According to 2 an RFID chip 22 is arranged in a recess 27 in the workpiece carrier 20, on which, for example, a component identification and/or process parameters are stored. The polishing machine 1 preferably has an RFID reader and preferably communicates with a host computer system, which stores and archives, for example, all the process data that are necessary for the optical lens 50 . The recess 27 and the RFID chip 22 are arranged in particular opposite the optical lens 50 on the workpiece carrier 20 .

Furthermore, the first lens side shows S1 2 a protective layer, protective film or adhesive film 28 on which the workpiece carrier 20 is fixed by gluing or adhesion.

The workpiece carrier 20 has a flow structure 23 which interacts with the rotating polishing suspension S in such a way that the unit consisting of the optical lens 50 and the workpiece carrier 20 is accelerated in the direction of rotation, reinforced by friction and flow pressure. According to 2 the workpiece carrier 20 has, in particular, more than three spiral grooves 26 on its circumference 24 . These interact with the rotating polishing suspension S in such a way that it acts on the twist structure 25 and the unit made up of optical lens 50 and workpiece carrier 20 is accelerated in the direction of rotation. The spiral grooves 26 can be milled, turned, cut or ground into the circumference 24 . Twist bars remain between the twist grooves 26 . If the helical grooves 26 are narrower than the helical ridges, as shown, one speaks more of helical grooves 26 in the circumference 24 of the workpiece carrier 20. In the opposite case one will probably rather speak of helical ridges on the circumference 24 of the workpiece carrier 20.

In any case, the twisted webs and twisted grooves 26 run obliquely on the circumference 24 of the workpiece carrier 20 and wind around the circumference 24 . The gradient is constant, so that one can speak of a helical or helical course.

The polishing suspension S always tends to rotate a little faster than the workpiece carrier 20 (except when the workpiece spindle speed is decelerating), so that a possible rotation of the workpiece spindle 10 in the direction in which the twist ridges and spiral grooves 26 wind around the carrier axis TA, the workpiece carrier 20 by train loaded into the hydraulic chamber 12. On the other hand, if the workpiece spindle 10 rotates in the opposite direction, the excess speed of the polishing suspension S ensures that the workpiece carrier 20 is pressed out of the hydraulic chamber 12 Polishing suspension S and the contact pressure of the mold 40 against.

Reference List

1

polishing machine

10

workpiece spindle

11

workpiece holder

12

hydro chamber

20

workpiece carrier

21

gripper groove

22

RFID chip

23

flow structure

24

Scope

25

twist structure

26

twist grooves

27

recess (in the workpiece carrier)

28

Protective layer, protective film or adhesive film

29

recording surface

40

molding tool

41

tool spindle

50

optical lens

A1

Spindle axis (workpiece spindle)

A2

tool axis

D1

Diameter (workpiece carrier)

D2

diameter (optical lens)

D3

diameter (form tool)

L

Length (workpiece carrier)

LU

lens circumference

S

polishing suspension

SP

gap

S1

first lens side

S2

second lens side

TA

beam axis

Claims (12)

Method for precision grinding or polishing an optical lens (50) with a first lens side (S1), a second lens side (S2) and a lens circumference (LU), - with a workpiece spindle (10) driven about a spindle axis (A1) and having a workpiece holder (11) having a front hydraulic chamber (12) in which a pressurized polishing suspension (S) is located, - wherein the optical lens (50) is inserted into the front hydraulic chamber (12) with the first lens side (S1) first, that the polishing suspension (S) is located behind the first lens side (S1) in the hydraulic chamber (12) and a gap (SP) is formed between the lens periphery (LU) and the workpiece holder (11) through which the polishing suspension (S) exits , and - the second lens side (S2) of the optical lens (50) being finely ground or polished with a mold (40) driven in rotation about a tool axis (A2) while the optical lens (50) is under pressure ending polishing suspension (S) is pressed against the mold (40), characterized in that - a workpiece carrier (20) which protrudes into the hydraulic chamber (12) is fixed on the first lens side (S1), - the unit consisting of an optical lens (50) and workpiece carrier (20) is arranged at a distance from the walls of the hydraulic chamber (12) in such a way that it is displaceably and/or cardanically mounted in the polishing suspension (S) in the hydraulic chamber (12) along the spindle axis (A1). procedure after claim 1 , characterized in that a diameter (D1) of the workpiece carrier (20) transverse to the spindle axis (A1) is smaller than a diameter (D2) of the optical lens (50). Method according to one of the preceding claims, characterized in that a length (L) of the workpiece carrier (20) along the spindle axis (A1) is greater than a maximum distance between the first and second lens sides (S1, S2). Procedure according to claims 2 and 3 , characterized in that the diameter (D1) of the workpiece carrier (20) is greater than the length (L) of the workpiece carrier (20). Method according to one of the preceding claims, characterized in that the workpiece carrier (20) is designed to be balanced in relation to the spindle axis (A1). Method according to one of the preceding claims, characterized in that the workpiece carrier (20) has a gripper groove (21) on its circumference (24). Method according to one of the preceding claims, characterized in that an RFID chip (22), on which a component identification and/or process parameters are stored, is arranged in or on the workpiece carrier (20). Method according to one of the preceding claims, characterized in that the Workpiece carrier (20) has a flow structure (23) and the polishing suspension (S) rotating with the workpiece spindle (10) acts on this flow structure (23) in such a way that the unit made up of optical lens (50) and workpiece carrier (20) is accelerated in the direction of rotation . Method according to one of the preceding claims, characterized in that the workpiece carrier (20) has at least one groove or twist structure (25), preferably at least one, more preferably at least two and particularly preferably at least three twist webs or twist grooves (26 ) and the polishing suspension (S) rotating with the workpiece spindle (10) acts on this twist structure (25) in such a way that the unit of optical lens (50) and workpiece carrier (20) is accelerated in the direction of rotation. procedure after claim 9 , characterized in that the twisted web or the twisted groove (26) or the twisted webs or the twisted grooves (26) run obliquely on the circumference (24) of the workpiece carrier (20), in particular winding around the circumference (24), this preferably with a constant Pitch, and most preferably helical or helical. Method according to one of the preceding claims, characterized in that the walls of the hydraulic chamber (12) surrounding the unit consisting of the optical lens (50) and the workpiece carrier (20) have a train or a twist structure, preferably at least one, more preferably at least two and particularly preferably at least three helical webs or helical grooves. Use of a workpiece carrier (20) for fixing to a first lens surface (S1) of an optical lens (50) in a method according to one of Claims 1 until 11 , - wherein the workpiece carrier (20) has a carrier axis (TA), a front receiving surface (29) and a circumference (24), and - wherein the workpiece carrier (20) ◯ either has a flow structure (23) which is designed in such a way that a fluid rotating around the circumference (24) can act on this flow structure (23) in such a way that the workpiece carrier (20) is accelerated in the direction of rotation; ◯ or has at least one train or twist structure (25), preferably at least one, more preferably at least two and particularly preferably at least three twist ridges or twist grooves (26) on its circumference (24); wherein the carrier axis (TA) is aligned coaxially to the spindle axis (A1) in a central position, the unit consisting of the optical lens (50) and workpiece carrier (20) being arranged at a distance from the walls of the hydraulic chamber (12) in such a way that it is in the polishing suspension (S) in the hydraulic chamber (12) along the spindle axis (A1) is displaceable and/or cardanically mounted.

Images