WO2005058544A1

WO2005058544A1 - Device and method for surface working

Info

Publication number: WO2005058544A1
Application number: PCT/EP2004/014418
Authority: WO
Inventors: Aeugle Hellmuth; Joachim Hoga; Thomas Irtenkauf; Wolfgang Rupp
Original assignee: Carl Zeiss Smt Ag
Priority date: 2003-12-18
Filing date: 2004-12-17
Publication date: 2005-06-30
Also published as: US20050164605A1

Abstract

The invention relates to a method for surface working of a body (2) having a first surface (2.1) to be worked and a second surface (2.2) to be worked. The method comprises, in a first step, providing a first tool (3.1) and a second tool (4.1), in a second step, placing the body (2) between the first tool (3.1) and the second tool (4.1), and, in a third step, working the first surface (2.1) and the second surface (2.2). The first surface (2.1) is worked by a first working surface (3.6) of the first tool (3.1), the first working surface (3.6) having a first central area (3.8). The second surface (2.2) is worked by a second working surface (4.6) of the second tool (4.1), the second working surface (4.6) having a second central area (4.8). In the third step, the second tool (4.1) lies opposite to the first tool (4.1) to form a working gap (1.1), the working gap (1.1) mainly extending in a working gap plane. Furthermore, in the third step, the body (2), in at least one guide movement, is guided substantially parallel to the working gap plane between the first tool (3.1) and the second tool (4.1), and at least a part of at least one of the first surface (2.1) and the second surface (2.2) is guided over the central area (3.8, 4.8) of the associated one of the first working surface (3.6) and the second working surface (4.6). The invention further relates to a corresponding device (1) for surface working.

Description

DEVICE AND METHOD FOR SURFACE WORKING

BACKGROUND OF THE INVENTION

The invention relates to a device for the surface working of a body, in particular an LCD mask. The invention further relates to a corresponding method for the surface working of a body.

Surfaces with a particularly high surface quality, especially a low surface roughness, are required for numerous applications in the optical industry but also in other branches of industry. Two high-quality surfaces parallel to one another are required, in particular, for comparatively thin LCD masks, such as those used for flat screens. In order to achieve a high surface quality, a plurality of different methods are known for fine surface working, for example, grinding, in particular precision grinding, lapping, honing, polishing etc. With all these methods, in order to achieve a high surface quality, it is necessary to achieve a removal of material which is as uniform as possible over the entire surface of the body.

Two different working methods are usually used for the fine working of plane surfaces of bodies. With the so-called single-disk method, the body to be worked is affixed to a support. The body is then guided by corresponding support kinematics in circular, oscillating movements over a rotating disk-shaped tool. Thus, an epicycloidal relative movement between the body and the tool is achieved. The epicycloids formed can be guided over the body in a surface-covering fashion by suitably controlling the speeds of the guide and tool movements and the excursions of the guide movement such that a homogeneous removal of material is achieved.

A disadvantage with these single-disk methods is that working of the body is in each case only possible from one side such that strong requirements with respect to parallelism of two surfaces can only be satisfied at very high expenditure. In addition, the body must be af- fixed to the support in an expensive fashion to be as free from stresses as possible. In addition, not least for this reason, only a comparatively low removal performance can be achieved. Higher removal performances can be achieved using so-called two-disk methods in which the body is guided between two rotating parallel disk-shaped tools. In order to counteract any inhomogeneous removal of material due to the decrease of the circumferential speed towards the center of the rotating disk, in a corresponding generic device, the body to be worked is guided by a planet wheel of a planetary-gearing-like guide device. In this case, predetermined by the geometry of the guide device, a plane guide movement of the body in two directions running transverse to one another is obtained. As a result of the superposition with a rotary movement of the respective tool, an epicycloidal relative movement between body and tool is also obtained here. The epicycloids formed in this case can be guided over the body in a surface-covering fashion by suitably controlling the speeds of the guide and tool movements such that a homogeneous removal of material is achieved.

Thanks to the arrangement of the body to be worked between the two tool disks, higher contact pressures and, therefore, a higher removal performance can be achieved compared to the single-disk method, but comparatively narrow limits are imposed on the trans- verse dimensions of the body for a predetermined size of working device. This is because, as a result of the planetary-gearing-like guide device, at any time only one ring-segment- shaped area of the tool disks can be used. The ratio of the diameter of a tool disk to the maximum transverse dimension of a body to be worked is usually at about 3.5 to 4. In order to work bodies having larger transverse dimensions, considerably larger devices are therefore required. With such large devices however, considerable problems arise with regard to maintaining the working precision which can only be overcome, if at all, at very great expense.

SUMMARY OF THE INVENTION

It is thus an object of the invention to provide a device and a method for surface working which does not or at least to a lesser extent have the aforesaid disadvantages and especially makes it possible to work large surfaces economically.

The invention is based on the cognition that an improved usage of the available working surface of the tool is achieved if at least a part of at least one of the surfaces of the body to be worked is guided over the central area of the associated working surface. Unlike in the known devices in which the centrally arranged sun wheel of the planetary- gearing-like guide device prevents the surface of the body to be worked from being guided over this central area, it is hereby possible to use at least a majority of the available working surface at the same time. As a result, bodies having larger dimensions can be worked with- out the need to change the tool dimensions.

One object of the invention is thus a method for surface working of a body having a first surface to be worked and a second surface to be worked. In a first step, a first tool and a second tool are provided. In a second step, the body is placed between the first tool and the second tool. In a third step, the first surface and the second surface are worked. The first surface is worked by a first working surface of the first tool, the first working surface having a first central area. The second surface is worked by a second working surface of the second tool, the second working surface having a second central area. The second tool, in the third step, lies opposite to the first tool to form a working gap, the working gap mainly extending in a working gap plane. The body, in at least one guide movement in the third step, is guided substantially parallel to the working gap plane between the first tool and the second tool. At least a part of at least one of the first surface and the second surface is guided over the central area of the associated one of the first working surface and the second working surface.

A further object of the invention is a device for surface working of a body having a first sur- face to be worked and a second surface to be worked, comprising a first tool, a second tool, and a guide device. The first tool has a first working surface for working the first surface, the first working surface having a first central area. The second tool has a second working surface for working the second surface, the second working surface having a second central area. The second tool is located opposite to the first tool when working the body to form a working gap, the working gap mainly extending in a working gap plane. The guide device, in at least one guide movement, is guiding the body substantially parallel to the working gap plane, the body being arranged between the first tool and the second tool within the working gap. The guide device is guiding at least a part of at least one of the first surface and the second surface over the central area of the associated one of the first working surface and the second working surface.

Further, aspects and embodiments of the invention will become apparent from the dependent claims and the following description of preferred embodiments which refers to the ap- pended figures. All combinations of the features disclosed, whether explicitly recited in the claims or not, are within the scope of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a schematic diagram of a preferred embodiment of the device for surface working according to the invention for executing a preferred embodiment of the method for surface working according to the invention;

Figure 2 is a schematic sectional view of a part of the device from Figure 1 along the line ll-ll in Figure 1 ;

Figure 3 is a schematic block diagram of the control device of the device from Figure 1 ;

Figure 4 is a schematic partial view of a further preferred embodiment of the device for surface working according to the invention;

Figure 5 is a schematic partial view of a further preferred embodiment of the device for surface working according to the invention;

Figure 6 is a schematic partial view of a further preferred embodiment of the device for surface working according to the invention.

DETAILED DESCRIPTION OF THE INVENTION

First embodiment

In the following, a preferred embodiment of a device 1 for surface working according to the invention, with which a preferred embodiment of the method according to the invention may be executed, is described with reference to Figures 1 to 3.

Figure 1 shows a schematic perspective view of the device 1 with which the surfaces of a body 2 can be worked by means of a first tool 3.1 of a first tool device 3 and a second tool In the present case, the body 2 is an LCD mask for a flat screen. However, it is to be understood that, with the device 1, any other bodies for which a corresponding surface quality is required may also undergo corresponding surface working.

The first tool device 3 is arranged on a displaceable traverse 5.1 of a machine frame 5. In Figure 1 , the traverse 5.1 is shown in a displacement position at a distance from the body 2 in which the body 2 can be inserted into the device 1. For working the body 2 the traverse 5.1 is displaced by a traverse drive 5.3 - shown only in Figure 3 - into its operating position indicated by the dashed contour 5.2. In this operating position of the traverse 5.1 , the tool 3.1 is located above the body 2.

When the traverse 5.1 is located in its operating position 5.1 , the tool 3.1 for the working of the body 2 is displaced by a first tool drive device 3.2 along the first tool axis 3.3 in the direction of the body 2 until the first tool 3.1 in its operating position abuts against the body 2 with a predetermined pressure.

The first tool 3.1 is a circular-disk-shaped tool with a first disk carrier 3.4 which is connected via a shaft to the tool drive device 3.2, and a first working disk 3.5 which is exchangeably affixed to the first disk carrier 3.4. Depending on the application, the first working disk may be a grinding disk, a lapping disk, a honing disk, a polishing disk or a disk for any other type of surface working.

The second tool device 4 is arranged below the receptacle for the body 2. For working the body 2, the second tool 4.1 is displaced by the second tool drive device 4.2 along the second tool axis 4.3 in the direction of the body 2 until the second tool 4.1 is located in its operating position. The operating^' position of the second tool 4.1 is defined by a pre-definable position along the second tool axis 4.3. When the second tool 4.1 is located in this operating position, the body 2 is inserted into the device 1 , wherein it then rests on the second tool 4.1. At the time of insertion of the body 2, the first tool 3.1 is still located in its displacement position shown in Figure 1 , i.e. at a distance from the body 2. The contact pressure between the second tool 4.1 and the body 2 is then mainly produced by means of the first tool device 3 which has been driven to its operating position, such that it abuts against the body 2 with a pre-defined pressure. This pressure can be varied during working the body 2 by the first tool drive device 3.2 if the application requires this.

It is to be understood here that, with other variants of the invention, it may also be provided tool device. It may likewise be provided that this pressure is detected and controlled by means of both tool devices.

The second tool 4.1 also comprises a circular-disk-shaped tool with a second disk carrier 4.4 which is connected to the tool drive device 4.2 via a shaft, and a second working disk 4.5 which is exchangeably affixed to the second disk carrier 4.4. Depending on the application, the second working disk may be a grinding disk, a lapping disk, a honing disk, a polishing disk or a disk for any other type of surface working.

As can be seen from Figure 2, for working the body 2, the first tool 3.1 lies opposite to the second tool 4.1. Thus, a working gap 1.1 is formed between them, in which the body 2 is arranged. The working gap 1.1 mainly extends in a working gap plane which runs perpendicular to the tool axes 3.3 and 4.3.

In the representation of Figure 2, the first tool axis 3.3 is in direct alignment with the second tool axis 4.3. For certain applications, however, it may be favorable or necessary that the two tool axes 3.3 and 4.3 are offset transverse to one another. In order to achieve this, the first tool device 3 may be displaced in the direction of the double arrow 6 by means of a transverse drive 5.4 - only shown in Figure 3 - on the traverse 5.1. Additionally or alternatively, the first tool device 3 may be displaced for this purpose by the traverse drive 5.3. If necessary, this displacement movement may also take place during the working of the body 2 with an arbitrarily pre-definable movement profile.

In the operating position of the first tool 3.1 , said tool abuts with its substantially plane first working surface 3.6 against the substantially plane first surface 2.1 of the body 2, said first surface 2.1 being one of the surfaces to be worked. In the operating position of the second tool 4.1 , said tool abuts with its substantially plane second working surface 4.6 against the substantially plane second surface 2.2 of the body 2, said second surface 2.2 being the second one of the surfaces to be worked. Here, the second surface 2.2 is substantially parallel to the first surface 2.1 of the body 2. The working surfaces 3.6 and 4.6 then run parallel to the working gap plane.

The body 2 arranged in the working gap 1.1 between the two tools 3.1 and 4.1 located in their operating position is guided parallel to the working gap plane of the working gap 1.1, i.e., in the present case, parallel to the plane of the first surface 2.1. This guiding is provided by a guide device 7. The guide device 7 has a device designed in the fashion of a cross slide. It comprises a first frame 7.1 supported in the machine frame 5 which is linearly displaceable along a first direction 7.3 by means of a first drive device 7.2. Here, the first direction 7.3 runs parallel to the working gap plane of the working gap 1.1 and, therefore, also parallel to the first sur- face 2.1 of the body 2. The guide device 7 further comprises a second frame 7.4 supported on the first frame 7.1. This second frame 7.4 is displaceable in a second direction 7.6 by means of a second drive device 7.5 affixed to the first frame 7.1. Here, the second direction 7.6 runs parallel to the working gap plane of the working gap 1.1 and, therefore, also parallel to the first surface 2.1 of the body 2 and transverse, namely perpendicular, to the first direction 7.3.

It is to be understood that, with other variants of the invention, more than one device executed in the fashion of a cross slide may be combined in order to be able to superpose a plurality of linear guide movements which are offset with respect to one another by predetermined angles in the working gap plane. Thus, for example, three linear guide move- ments offset with respect to one another by 120° may be realized in the working gap plane. In this case, individual frames may also be associated with a plurality of cross-slide-like devices.

Supported in the second frame 7.4 is a cage 7.7 which has a receptacle in the form of a receiving opening 7.8 for receiving the body 2. The cage 7.7 is freely rotatable about an axis running perpendicular to the plane of the second frame 7.4. It is hereby achieved that, in cases of increased contact force with the tool which may occur locally as a result of local inhomogeneities, the body 2 can yield so that, during working, forces as uniform as possible act on the body 2. However, it is to be understood that, for certain applications, especially in order to achieve a higher removal of material, it may be provided to fix the cage 7.7 with respect to the second frame 7.4. For this purpose, corresponding fixing means - not shown - are provided.

A first guide movement along the first direction 7.3 may be imposed on the body 2 by means of the first drive device 7.2. A second guide movement running transverse to the first guide movement along the second direction 7.6 may be imposed on the body 2 by means of the second drive device 7.5. The first drive device 7.2 and the second drive device 7.5 are independent of one another so that the two guide movements may be selected independently of one another. It is to be understood here that, with other variants of the invention, a single drive device may also be provided which produces both guide movements by means of a suitable gearing which, if necessary, has a variable gear ratio. Furthermore, it is understood that, if necessary, the production of only a single guide movement may also be provided.

The body 2 may be displaced with the guide device 7 such that a part of the first surface 2.1 to be worked is displaced over the center of area 3.7 of the first working surface 3.6 of the first tool 3.1. In this case, the center of area lies at the central point of the circular working surface 3.6. Thus, a part of the first surface 2.1 to be worked is also displaced over the first central region 3.8 of the first working surface 3.6. At the same time the body 2 is displaced such that a part of its second surface 2.2 to be worked is displaced over the center of area 4.7 of the second working surface 4.6 of the second tool 4.1 The center of area 4.7 lies at the central point of the circular working surface 4.6. Thus, a part of the second surface 2.2 to be worked is displaced over the second central region 4.8 of the second working surface 4.6.

Herewith, it is possible to use a comparatively large area of the respective working surface of the respective tool 3.1 and 4.1 at the same time. Among other things, on this occasion, the central area around the center of area of the working surface of the respective tool 3.1 and 4.1 may also be used so that, compared with the known devices or methods, significantly larger bodies may be worked with the same tool size. With the invention it is thus possible to work bodies the maximum transverse dimension of which parallel to the working gap plane of the working gap 1.1 is only slightly less than the transverse dimension of the respective tool 3.1 and 4.1 parallel to this plane.

With the equipment^'curreritly available on the market having a tool diameter of about 2 m, it is hereby possible to work bodies having a maximum transverse dimension of up to ap- proximately 2 m. Despite the large transverse dimensions of the body, in this case it is possible to achieve deviations from the desired surface of the body which lie in the range between 10 μm and 100 μm, especially in the range between 10 μm and 50 μm.

During the working of the body 2 the first tool 3,1 is set in a rotary movement about the first tool axis 3.3 by means of the first tool drive device 3.2 so that this results in a rotary first working surface movement about the first tool axis 3.3. The instantaneous axis of the first working surface movement in this case passes through the center of area 3.7. Likewise, the second tool 4.1 is set in a rotary movement about the second tool axis 4.3 by means of the second tool drive device 4.2 so that this results in a rotary second working surface movement about the second tool axis 4.3. The instantaneous axis of the second working surface movement in this case passes through the center of area 4.7.

It is to be understood on this occasion that, with other variants of the invention, if neces- sary, only one single tool drive device may be provided which produces both working surface movements by means of a corresponding gearing. In particular, the gear ratio of such a gearing may be variable during operation, if necessary. Likewise, it may also be provided that only one of the tools is driven to produce the corresponding working surface movement.

A central control device 8 is connected to the first drive device 7.2, the second drive device 7.5, the first tool drive device 3.2, the second tool drive device 4.2, the traverse drive 5.3 and the transverse drive 5.4 which may all be controlled independently of one another by said control device 8. The control device 8 controls the drives 7.2, 7.5, 3.2, 4.2, 5.3 and 5.4 connected thereto such that, as a result of the superposition of the guide movements and the working surface movements, over the entire first surface 2.1 to be worked and the entire second surface 2.2 to be worked, a uniform removal of material and, thus, a uniform surface quality are obtained. By the term uniform surface quality should be understood, in the sense of the present application, that the surface roughness over the surface to be worked varies by less than 30% of an average value of the surface roughness.

The control is executed such that the amount of the relative speed between the respective surface to be worked and the associated working surface is subject to as little variation as possible at every point. Particularly favourable force ratios are hereby achieved during the working which result in a high surface quality. In particular, the control is executed such that the amount of this relative speed is never zero at any point in time. The guide movements can be superposed for this purpose such that, overall, a sinusoidal guide movement is obtained. Furthermore, the rotary working surface movements may be selected to be in the same or in opposite directions.

The control 8 and the drives 7.2, 7.5, 3.2, 4.2, 5.3 and 5.4 connected thereto are constructed such that the speed and the excursion and, thus, the movement profile of the re- spective movement produced by them may be freely, in particular continuously, varied or set. It is to be understood however that, with other variants of the invention, this may not be provided at all or only for some of these drives. Second embodiment

In the following, a second preferred embodiment of a device for surface working according to the invention, with which a preferred embodiment of the method according to the invention may be executed, is described with reference to Figures 1 to 4.

Figure 4 shows a schematic representation of the guide device 107 of this preferred embodiment of the device for surface working. This device for surface working, apart from the guide device 107, does not differ from the one from Figures 1 to 3. Thus, only the differences with regard to the guide device 107 will be discussed here.

The guide device 107 comprises a first frame 107.1 mounted in a machine frame - not shown - which may be displaced linearly in a first direction 107.3 by means of a first drive device 107.2 connected to the control unit 8. Here, the first direction 107.3 runs parallel to the plane of the working gap and, therefore, parallel to the first surface 2.1 of the body 2. The guide device 107 further comprises a circular second frame 107.4 mounted on the first frame 107.1. This second frame 107.4 may be rotated in a second direction 107.6 by means of a second drive device 107.5 affixed to the first frame 107.1 and connected to the control unit 8. Here, the second direction 107.6 runs parallel to the plane of the working gap and, therefore, parallel to the first surface 2.1 of the body 2 and transverse to the first direction 107.3.

Supported in the second frame 107.4 is a cage 107.7 which has a receiving opening to re- ceive the body 2. The cage 107.7 is freely rotatable about an axis running perpendicular to the plane of the second frame 107.4. In order to achieve a higher removal of material for certain applications, ifi particular, it is provided to fix the cage 107.7 with respect to the second frame 107.4. For this purpose corresponding fixing means - not shown - are provided.

A linear first guide movement along the first direction 107.3 may be imposed on the body 2 by means of the first drive device 107.2. A rotary second guide movement running transverse to the first guide movement along the second direction 107.6 may be imposed on the body 2 by means of the second drive device 107.5. The first drive device 107.2 and the second drive device 107.5 are independent of one another such that the two guide movements may be set independently of one another.

With the guide device 107 as well, the body 2 may be displaced such that a part of the first 3.6 of the first tool 3.1 from Figure 1. At the same time, the body 2 is displaced such that a part of its second surface 2.2 to be worked is displaced over the center of area 4.7 of the second working surface 4.6 of the second tool 4.1 from Figure 1.

It is hereby possible to use a comparatively large area of the respective working surface 3.6 and 4.6 of the respective tool 3.1 and 4.1 at the same time. Here, among other things, the central area 3.8 and 4.8 of the respective tool 3.1 and 4.1 may be used such that, compared with the known devices or methods, significantly larger bodies may be worked using an unchanged tool size. With the invention, it is thus possible to work bodies whose maximum transverse dimension parallel to the working gap plane of the working gap 1.1 and, thus, parallel to the plane of the first surface 2.1 is only slightly less than the transverse dimension of the respective tool 3.1 and 4.1 parallel to this plane.

Using the guide device 107 it is possible, among other things, to control the guide movements and the tool movements by the control unit 8 such that, as a result of their superposition, an epicycloidal relative movement is obtained between the body 2 and the respective tool 3.1 and 4.1. The resulting epicycloid tracks of a tool point on the body 2 may then be guided in a surface-covering fashion to achieve substantially uniform removal of material over the entire surface of the body 2 to be worked.

Third embodiment

In the following, a third preferred embodiment of a device for surface working according to the invention, with which a preferred embodiment of the method according to the invention may be executed, is described with reference to Figures 1 to 3 and 5.

Figure 5 shows a schematic representation of the guide device 207 of this preferred embodiment of the device for surface working according to the invention. This device for surface working, apart from the guide device 207, does not differ from the one from Figure 1. Thus, only the differences with regard to this guide device 207 will be discussed here.

The guide device 207 comprises a circular first frame 207.1 supported in the machine frame - not shown - which may be rotated in a first direction 207.3 by means of a first drive device 207.2 connected to the control unit 8. Here, the first direction 207.3 runs parallel to the plane of the working gap and, therefore, parallel to the first surface 2.1 of the body 2. The guide device 207 further comprises a circular second frame 207.4 supported eccentri- tion 207.6 by means of a second drive device 207.5 affixed to the first frame 207.1 and connected to the control unit 8. Here, the second direction 207.6 runs parallel to the plane of the working gap and therefore parallel to the first surface 2.1 of the body 2.

Supported in the second frame 207.4 is a cage 207.7 which has a receiving opening to re- ceive the body 2. The cage 207.7 is freely rotatable about an axis running perpendicular to the plane of the second frame 207.4. In order to achieve a higher removal of material for certain applications, in particular, it is provided to fix the cage 207.7 with respect to the second frame 207.4. For this purpose corresponding fixing means - not shown - are provided.

A rotary first guide movement along the first direction 207.3 may be imposed on the body 2 by means of the first drive device 207.2. A rotary second guide movement in the second direction 207.6 may be imposed on the body 2 by means of the second drive device 207.5. The first drive device 207.2 and the second drive device 207.5 are independent of one another such that the two guide movements as well may be set independently of one another.

With the guide device 207 as well, the body 2 may be displaced such that a part of the first surface 2.1 to be worked is displaced over the center of area 3.7 of the first working surface 3.6 of the first tool 3 from Figure 1. At the same time, the body 2 is displaced such that a part of its second surface 2.2 to be worked is displaced over the center of area 4.7 of the second working surface 4.6 of the second tool 4 from Figure 1.

It is hereby possible to use a comparatively large area of the respective working surface 3.6 and 4.6 of the respective tool 3.1 and 4.1 at the same time. Here, among other things, the central area 3.8 and 4.8 of the respective tool 3.1 and 4.1 may be used such that, compared with the^'known devices or methods, significantly larger bodies may be worked using an unchanged tool size. With the invention, it is thus possible to work bodies whose maximum transverse dimension parallel to the working gap plane of the working gap 1.1 and, thus, parallel to the plane of the first surface 2.1 is only slightly less than the transverse dimension of the respective tool 3.1 and 4.1 parallel to this plane.

Using the guide device 207 it is possible, among other things, to control the guide movements and the tool movements by the control unit 8 such that as a result of their superposition, an epicycloidal relative movement is obtained between the body 2 and the tool. The resulting epicycloid tracks of a tool point on the body 2 may then be guided in a surface- covering fashion to achieve uniform removal of material over the entire surface of the body Fourth embodiment

In the following, a fourth preferred embodiment of a device for surface working according to the invention, with which a preferred embodiment of the method according to the invention may be executed, is described with reference to Figures 1 to 3 and 6.

Figure 6 shows a schematic representation, not to scale, of the first tool device 303 of this fourth embodiment of the device for surface working according to the invention. This device for surface working, apart from the first tool device 303, does not from that from Figure 1. Thus, the differences with respect to the tool device 303 will be discussed here.

One difference from the first tool device 3 from Figure 1 is that the first tool device 303 has a first tool 303.1 with a concave spherical first working surface 303.6. The curvature of the first working surface 303.6 is shown greatly exaggerated in Figure 6 for reasons of better perceptibility. In actual applications, working surfaces with a considerably smaller curvature, i.e. a considerably larger radius of curvature, are used. It is hereby possible to work surfaces of a body which deviate from a plane geometry.

A further difference from the first tool device 303 from Figure 1 consists in the fact that the first tool device 303 comprises a first tool drive device 303.2 which is additionally constructed to tilt the first tool axis 303.3 in the plane of the drawing in the direction of the double arrow 310 about a pivot point lying on the first tool axis 303.3. Furthermore, the first tool drive device 303.2 may additionally be constructed to tilt the tool axis 303.3 in a plane lying transverse to the plane of the drawing about a pivot point lying on the first tool axis 303.3. As a result, a particularly variable use of the device according to the invention is possible for almost any surfaces to be worked.

It is to be understood that the first working surface, in other variants of the invention, may also have a different geometry. Thus, for example, it may have a convex spherical geome- try as is indicated by the dashed contour 311 in Figure 6. Furthermore, it may also have a concave or convex conical geometry, as is indicated by the contours 312 and 313 in Figure 6. It is furthermore understood that section-wise combinations of such geometries are also possible. Finally, it is to be understood that, in the case of a convex geometry of the working surface, the tilting movements of the tools are adapted hereto. The pivot point of the pivoting movement then generally lies on the other side of the tool compared to the concave geometry. As already mentioned, the curvatures or angles of inclination of the first working surface are shown highly exaggerated in Figure 6 for reasons of better perceptibility. In actual applications working surfaces with a considerably smaller curvature or smaller angles of inclination are used. It is hereby possible also to work surfaces of a body which deviate from a plane geometry.

It is to be understood that, with other variants of the invention, the second tool may also have a second working surface which deviates from a plane geometry. Furthermore, it is understood that, according to the required application, any combinations of tools with different geometries of the working surface are possible.

In general, but especially in connection with the variants having a working surface which deviates from a plane geometry, it is to be understood that the working surface must not necessarily touch or work the part of the surface to be worked which is guided over the central area when this part of the surface to be worked is guided over the central area of the working surface. Rather, the guidance of an area of a surface over an area of another surface in the sense of the present application shall also comprise constellations in which these areas do not touch but are merely guided past one another at a distance. In such cases, it is furthermore to be understood that, in this central area, the working surface must not necessarily be constructed to work the body or in this central area, a working surface must not necessarily be provided. Rather, for example, the central area, especially the center, i.e., the center of area, of an annular working surface lies at the center, of this circular ring without a working surface actually being provided here.

The invention is described hereinbefore with reference to examples in which, exclusively, rotatiό^'nally symmetrical surfaces of a body are worked. It is to be understood that, by suitably specifying the movement profile of the relative movement between the working surfaces and the body, non-rotationally symmetrical surfaces of a body, in particular aspherical surfaces and free-form surfaces, may also be worked using the invention.

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Claims

1. A method for surface working of a body (2) having a first surface (2.1 ) to be worked and a second surface (2.2) to be worked, comprising in a first step, providing a first tool (3.1 ; 303.1 ) and a second tool (4.1 ), - in a second step, placing said body (2) between said first tool (3.1 ; 303.1) and said second tool (4.1 ), and, - in a third step, working said first surface (2.1 ) and said second surface (2.2); said first surface (2.1 ) being worked by a first working surface (3.6) of said first tool (3.1; 303.1), said first working surface (3.6) having a first central area (3.8), - said second surface (2.2) being worked by a second working surface (4.6) of said, second tool (4.1 ), said second working surface (4.6) having a second central area (4.8), said second tool (4.1), in said third step, lying opposite to said first tool (3.1 ; 303.1 ) to form a working gap (1.1 ), said working gap (1.1 ) mainly extending in a working gap plane, said body (2), in at least one guide movement in said third step, being guided substantially parallel to said working gap plane between said first tool (3.1 ; 303.1) and said second tool (4.1 ), and at least a part of at least one of said first surface (2.1) and said second surface (2.2) being guided over said central area (3.8, 4.8) of the associated one of said first working surface (3.6) and said second working surface (4.6).

2. The method according to claim 1 , wherein at least a part of at least one of said first surface (2.1 ) and said second surface (2.2) is guided over the center of area (3.7, 4.7) of the associated one of said first working surface (3.6) and said second working surface (4.6).

3. The method according to claim 1 or 2, wherein - at least one of said first working surface (3.6) and said second working surface - said first working surface (3.6) executing an at least partly rotary first working surface movement, - said second working surface (4.6) executing an at least partly rotary second working surface movement and - at least a part of at least one of said first surface (2.1 ) and said second surface (2.2) is guided over the instantaneous center of motion of the associated one of said first working surface (3.6) and said second working surface (4.6).

4. The method according to any one of claims 1 to 3, wherein, in at least one guide movement in said third step, said body (2) is guided substantially parallel to said working gap plane between said first tool (3.1 ; 303.1 ) and said second tool (4.1 ).

5. The method according to claim 4, wherein said body (2) is guided in a first guide movement along a first guide direction (7.3) and is guided in a second guide movement along a second direction (7.6) running transverse to said first direction (7.3).

6. The method according to claim 5, wherein said first guide movement of said body (2) along said first direction (7.3) is selectable independently of said second guide movement of said body (2) along said second direction (7.6).

7. The method according to claim 5 or 6, wherein at least one of the speed and the excursion of at least of one of said first guide movement and said second guide movement is continuously adjustable.

8. The method according to any one of claims 4 to 7, wherein, in said third step, a linear or sinusoidal guide movement is imposed on said body (2).

9. The method according to any one of claims 4 to 8, wherein, in said third step, at least one of said first tool (3.1 ; 303.1 ) and said second tool (4.1 ) is displaced in at least one of a first tool displacement movement and a second tool displacement move- ment.

10. The method according to claim 9, wherein, - in said third step, at least one of said first tool (3.1 ; 303.1 ) and said second tool (4.1 ) is displaced in a first tool displacement movement and a second tool displacement movement, - said first tool displacement movement being directed along a first displacement direction (7.3) and said second tool displacement movement being directed along a second displacement direction (7.6) running transverse to said first displacement direction (7.3).

1 1. The method according to claim 9, wherein said first displacement direction (7.3) and said second displacement direction (7.6) run parallel to said working gap plane.

12. The method according to any one of claims 9 to 1 1 , wherein said first tool displacement movement is selectable independently of said second tool displacement movement.

13. The method according to any one of claims 9 to 12, wherein at least one of the speed and the excursion of at least of one of said first tool displacement movement and said second tool displacement movement is continuously adjustable.

14. The method according to any one of claims 9 to 13, wherein a linear or sinusoidal tool displacement movement is imposed on at least one of said first tool (3.1 ; 303.1 ) and said second tool (4.1).

15. The method according to any one of claims 1 to 14, wherein at least one of a first tool movement is imposed on said first tool (3.1 ; 303.1 ) and a second tool movement is imposed on said second tool (4.1 ).

16. The method according to claim 15, wherein at least one of said first tool movement and said second tool movement is a rotary movement, - said first tool movement being a first rotary movement about a first tool axis (3.3) which is substantially perpendicular to said working gap plane, said second tool movement being a second rotary movement about a second tool

17. The method according to claim 16, wherein said first tool axis (3.3) is adjustable transverse to said second tool axis (4.3).

18. The method according to claim 16 or 17, wherein said first tool axis (3.3) is arranged offset transverse to said second tool axis (4.3).

19. The method according to any one of claims 15 to 18, wherein said first tool movement is independent of said second tool movement.

20. The method according to any one of claims 15 to 19, wherein at least one of the speed and the excursion of at least one of said first tool movement and said second tool movement is continuously adjustable.

21. The method according to any one of claims 1 to 20, wherein at least one of a first tool movement is imposed on said first tool (3.1 ; 303.1 ) and a second tool movement is imposed on said second tool (4.1), said at least one guide movement and at least one of said first tool movement and said second tool movement are controlled such that, as a result of their su- perposition, a relative movement with substantially uniform surface-covering material removal from said body (2) is obtained between said body (2) and at least one of said first tool (3.1 ; 303.1 ) and said second tool (4.1 ).

22. The method according to claim 21 , wherein said at least one guide movement and at least one of said first tool movement and said second tool movement are controlled such that, as a result of their superposition, an epicycloidal relative movement is obtained between said body (2) and at least one of said first tool (3.1 ; 303.1 ) and said second tool (4.1 ).

23. The method according to any one of claims 1 to 22, wherein the contact pressure between at least one of said first tool (3.1 ; 303.1) and said second tool (4.1 ) and said body (2) is adjustable.

24. The method according to any one of claims 29 to 36, wherein it is used for grinding, lapping, honing or polishing said body (2).

25. The method according to any one of claims 1 to 24, wherein said body (2) is an LCD mask.

26. A device for surface working of a body (2) having a first surface (2.1 ) to be worked and a second surface (2.2) to be worked, comprising - a first tool (3.1 ; 303.1), - a second tool (4.1 ), and - a guide device (7; 107; 207); - said first tool (3.1 ; 303.1 ) having a first working surface (3.6) for working said first surface (2.1), said first working surface (3.6) having a first central area (3.8), - said second tool (4.1) having a second working surface (4.6) for working said second surface (2.2), said second working surface (3.6) having a second central area (3.8), - said second tool (4.1 ) being located opposite to said first tool (3.1 ; 303.1 ) when working said body (2) to form a working gap (1.1 ), said working gap mainly ex- tending in a working gap plane, - said guide device (7; 107; 207), in at least one guide movement, guiding said body (2) substantially parallel to said working gap plane, said body (2) being arranged between said first tool (3.1 ; 303.1 ) and said second tool (4.1 ) within said working gap, - said guide device (7; 107; 207) guiding at least a part of at least one of said first surface (2.1) and said second surface (2.2) over said central area (3.8, 4.8) of the - associated one of said first working surface (3.6) and said second working surface (4.6).

27. The device according to claim 26, wherein said guide device (7; 107; 207) is ar- ranged for guiding at least a part of at least one of said first surface (2.1 ) and said second surface (2.2) over the center of area (3.7, 4.7) of the associated one of said first working surface (3.6) and said second working surface (4.6).

28. The device according to claim 26 or 27, wherein - at least one of a first tool drive device (3.2) and a second tool drive (4.2) device is orovided. - said first tool drive device (3.2) effecting an at least partly rotary first working surface movement of said first working surface (3.6), - said second tool drive (4.2) device effecting an at least partly rotary second working surface movement of said second working surface (4.6) and - said guide device (7; 107; 207) being arranged for guiding at least a part of at least one of said first surface (2.1) and said second surface (2.2) over the instantaneous center of motion of the associated one of said first working surface (3.6) and said second working surface (4.6).

29. The device according to any one of claims 26 to 28, wherein said guide device (7; 107; 207) is imposing a first guide movement on said body (2) along a first direction (7.3; 107.3; 207.3) and imposing a second guide movement on said-body (2) along a second direction (7.6; 107.6; 207.6) running transverse to said first direction (7.3; 107.3; 207.3).

30. The device according to claim 29, wherein said first guide movement is independent of said second guide movement.

31. The device according to claim 29 or 30, wherein said guide device (7; 107; 207) comprises a first guide drive device (7.2; 107.2; 207.2) effecting said first guide movement.

32. The device according to claim 31 , wherein said guide device comprises a second guide drive device (7.5; 107.5; 207.5) effecting said second guide movement.

33. The device according to any one of claims 29 to 32, wherein said guide device (7; 107; 207) comprises at least one device constructed in the fashion of a cross slide.

34. The device according to any one of claims 29 to 33, wherein at least one of the speed and the excursion of at least one of said first guide movement and said sec- ond guide movement is continuously adjustable.

35. The device according to any one of claims 29 to 34, wherein said guide device (7; 107) is imposing a linear guide movement on said body (2).

36. The device according to any one of claims 29 to 35, wherein said guide device (7; 107; 207) is imposing a sinusoidal guide movement on said body (2).

37. The device according to any one of claims 26 to 36, wherein - at least one of a first tool drive device (3.2) and a second tool drive device (4.2) is provided, - said first tool drive device (3.2) effecting a first tool movement of said first tool (3.1 ; 303.1), - said second tool drive device (4.2) effecting a second tool movement of said second tool (4.1 ).

38. The device according to claim 37, wherein at least one control device (8) is provided, said control device (8) being connected to said guide device (7; 107; 207) and to at least one of said first tool drive device (3.2) and said second tool drive device (4.2), • - said control device (8) controlling said at least one guide movement and contrailing at least one of said first tool movement and said second tool movement such that, as a result of their superposition, a relative movement with substantially uniform surface-covering material removal from said body (2) results between said body (2) and at least one of said first tool (3.1 ; 303.1 ) and said second tool (4.1 ).

39. The device according to claim 38, wherein said control device (8) controls said at least one guide movement and controls at least one of said first tool movement and said second tool movement such that, as a result of their superposition, an epicycloidal relative movement results between said body (2) and at least one of said first tool (3.1 ; 303.1 ) and said second tool (4.1 ).

40. The device according to any one of claims 37 to 39, wherein - at least one of said first tool movement and said second tool movement is a rotary movement, - said first tool movement being a first rotary movement about a first tool axis (3.3) which is substantially perpendicular to said working gap plane,

41. The device according to claim 40, wherein said first tool axis (3.3) is adjustable transverse to said second tool axis (4.3).

42. The device according to claim 40 or 41 , wherein said first tool axis (3.3) is arranged offset to said second tool axis (4.3).

43. The device according to any one of claims 37 to 42, wherein said first tool movement is independent of said second tool movement.

44. The device according to any one of claims 37 to 43, wherein at least one of the speed and the excursion of at least one of said first tool movement and said second tool movement is continuously adjustable.

45. The device according to any one of claims 37 to 44, wherein at least one of said first tool drive device (3.2) and said second tool drive device (4.2) effects a first tool displacement movement and a second tool displacement movement, said first tool displacement movement being directed along a first displacement direction (7.3) and said second tool displacement movement being directed along a second displacement direction (7.6) running transverse to said first displacement direction (7.3).

46. The device according to claim 45, wherein said first displacement direction (7.3) and said second displacement direction run (7.6) parallel to said working gap plane.

47. The device according to claim 45 or 46, wherein said first tool displacement movement is selectable independently of said second tool displacement movement.

48. The device according to any one of claims 45 to 47, wherein at least one of the speed and the excursion of at least of one of said first tool displacement movement and said second tool displacement movement is continuously adjustable.

49. The device according to any one of claims 45 to 48, wherein a linear or sinusoidal 1 ^■ f~) 1 )

50. The device according to any one of claims 47 to 49, wherein at least one of said first tool drive device (3.2) and said second tool drive device (4.2) is arranged to adjust the contact pressure between the associated one of said first tool (3.1; 303.1) and said second tool (4.1) and said body (2).

51. The device according to any one of claims 26 to 50, wherein at least one of said first tool (3.1 ; 303.1) and said second tool (4.1) comprises a grinding disk or a lapping disk or a honing disk or a polishing disk.

52. The device according to any one of claims 36 to 52, wherein said body (2) is an LCD mask.