FR3027445A1 - - Google Patents

Abstract

The apparatus (1) has support mechanisms. Each mechanism includes a first member that includes support portions (104a, 104b) for supporting an object and a second member that supports the first member, the first member being tilted about an axis with respect to at least one degree of freedom . The mechanisms support the object by means of each of the first members being tilted about the corresponding axis supporting the object so that a plurality of forces applied to the plurality of support portions of the first members are balanced. . Each of the first members has, relative to each of the support portions, an actuator configured to receive at least a portion of the load acting on one of the support portions corresponding thereto in place of said support portion.

Description

BACKGROUND OF THE INVENTION Field of the Invention [0001] The present invention relates to a support apparatus and a method for supporting an object, a measuring apparatus, and a method of manufacturing an article. Description of the Related Art [0002] For astronomical / cosmic observation and in the semiconductor and similar industries, there is a growing demand for increasing the size of an optical element to be used in values from one to several meters. An optical element whose size has increased is generally thinned to obtain a reduction in weight. This thinning will cause deformation or birefringence due to an external force such as self weight when the optical element is supported by an apparatus, resulting in large variations in optical characteristics (e.g., the transmission wavefront ) of the element. Therefore, many support devices that support optical elements use a technique of reducing the degree of deformation by increasing the number of support points. [0003] The shape of an optical element is measured by a measuring apparatus and is obtained by a processing apparatus. The shape correction processing on the basis of the measurement results is called correction processing. In the correction processing, a region associated with the difference between the design form and the measurement result is selectively processed. In the case mentioned above, an optical element is mounted on different devices at the time of measurement and at the time of treatment. Since different characteristics are required at the time of measurement and at the time of processing, these support states are implemented by different support devices. Specifically, at the time of measurement, it is preferable to use a support apparatus that has adequate rigidity to not be subject to the influence of vibration and reduces deformation caused by external forces such as weight. of the optical element and the friction forces at the support points. On the other hand, at the time of treatment, it is preferable to use a support apparatus having sufficient rigidity for the load applied by a treatment apparatus. [0005] Furthermore, an optical element must be able to reproduce optical characteristics measured at the time of use in a product or the like. Therefore, it is necessary to sufficiently reproduce the support states at the time of measurement and at the time of use. By way of example, the non-patent literature 1 mentions a support apparatus that supports a large optical element having a size of about 1.5 m in a very large astronomical telescope. cut. In this case, the support apparatus supports the 27-point optical element on the back surface to reduce the self-weight deformation. At this point, the support points are arranged on a holding plate by means of deformable bending elements. In addition, the holding plate has a high degree of freedom of tilt relative to a reference member, thus accurately reproducing the deformation of the support. However, with the support apparatus mentioned in the literature 1 not relating to patents, it is difficult to fix / separate an optical element 35 to / from the device because of the fact that the support points are glued to the back surface of the optical element. When the optical element is processed and measured while attached to the support apparatus, the optical element is supported by bending members having low rigidity. This makes it difficult to process the optical element by applying a load, or increases the measurement error caused by the vibrations. The support apparatus mentioned in the patent literature 2 is provided with means for initializing a tilting support member which supports an object (so as to slightly tilt the member relative to the element optical in the mounted state). This is advantageous from the point of view of the reproducibility of a (slight) deformation caused by the friction forces at the support points. [LIST OF CITATIONS] [LITERATURE 1 NOT RELATING TO PATENTS] Williams EE et al., "Advancement of the Segment Support System for the Thirty Meter Telescope Primary Mirror", Proceeding of 20 SPIE, 7018, 2008) [PATENT LITERATURE 1] Japanese Patent Laid-Open No. 2014-181986 [0010] However, the support apparatus referred to in the literature 2 relating to patents may cause deformation of an object in because of the friction forces generated between the support points and the object by the displacement of the support points. SUMMARY OF THE INVENTION [0011] By way of example, the present invention relates to a carrier apparatus which is advantageous in terms of the reproducibility of a support state of an object and the weakness of the deformation of the object. object caused by a friction force applied thereto. According to one aspect of the present invention, a support apparatus comprises a plurality of support mechanisms each having a first member that includes a plurality of support portions for supporting an object, and a second member that supports the first member, the first member being tiltable about an axis with respect to at least one degree of freedom, wherein the plurality of support mechanisms is configured to support the object by means of each of the first members caused to tilt around the an axis corresponding thereto supporting the object such that a plurality of forces applied to the plurality of support portions of the first members are balanced, and each of the first members includes, with respect to each of the plurality of portions support, an actuator configured to receive at least a portion of the load acting on one of the plurality of support portions corresponding to ui-ci instead of said support part. Other features of the present invention will become apparent from reading the description given below of exemplary embodiments (with reference to the accompanying drawings). BRIEF DESCRIPTION OF THE DRAWINGS [0014] Figs. 1A and 1B are views showing the arrangement of a support apparatus according to the first embodiment; Figures 2A-2D are views for explaining a mounting process of a support object on the support apparatus according to the first embodiment; Figures 3A to 3C are views showing the arrangement of a tilting portion according to the first embodiment; Figures 4A to 4E are views showing an exemplary arrangement of an actuator according to the first embodiment; Figure 5 is a flowchart showing a mounting process of the support object according to the first embodiment; Figures 6A and 6B are views showing the arrangement of a support apparatus according to the second embodiment; Figures 7A-7G are views showing the arrangement of a tilting portion according to the second embodiment; Figures 8A and 8B are views showing the arrangement of a support apparatus according to the third embodiment; Figures 9A and 9B are views showing the arrangement of a support apparatus according to the fourth embodiment; Figures 10A and 10E are views showing a variant of the arrangement of the support apparatus according to the fourth embodiment; Figures 11A to 11C are views showing the arrangement of a support apparatus according to the fifth embodiment; and [0025] Fig. 12 is a view showing the arrangement of a measuring apparatus according to the sixth embodiment.

DESCRIPTION OF EMBODIMENTS [0026] Various examples of embodiments, features, and aspects of the invention will now be described in detail with reference to the drawings. Embodiments of the present invention will now be described in detail with reference to the accompanying drawings. The embodiments presented hereinafter are not to be construed as limiting the present invention and are only concrete practical examples of practice of the invention. Moreover, not all combinations of features that will be described in the embodiments presented hereinafter are essential to solving the problems of the present invention. [0028] <First Embodiment> A support apparatus and a measurement method 5 using the support apparatus according to this embodiment will be described hereinafter. [0029] Figs. 1A and 1B are views showing the arrangement of the support apparatus according to the first embodiment. Fig. 1A is a plan view of a support apparatus 1. Fig. 1B is a side view of the support apparatus 1. The reference symbol DG denotes a gravitational direction. FIGS. 2A-2D are side views of a mounting process 1. in an apparatus (will be described later) to be mounted, by mounting 101. The support apparatus 1 has a plurality of mounting 101 Each of the plurality of support mechanism mechanisms on the support plate has a holding plate 103 as the first member having a plurality of support portions 104a and 104b for supporting an object. In addition, each of the plurality of support mechanisms includes a tilting portion 102 as a second member which supports the holding plate 103 as the first member so as to tilt it about an axis having at least one degree of liberty. The two supporting portions 104a and 104b and the tilting portion 102 are coupled to the holding plate 103. Each tipping portion 102 couples the holding plate 103 to the mounting plate 101 so as to ensure that the holding plate either rocking with a degree of freedom. More specifically, each tray of the apparatus of the support apparatus 1 at a support object W on the support apparatus 1 is mounted as an example measuring apparatus in which the apparatus of the intermediate 1 support of a plate of a holding 103 can tilt around a central axis of tilting AX1 of the tilting portion 102. It will be noted, with reference to Figures lA and 2D, that it is clear that when an object W is mounted on the support apparatus 1, the three degrees of freedom of a rigid body of the object W are appropriately restricted. Indeed, the posture of the holding plate 103 can be freely tilted so as to balance the reaction forces at the respective support points 10 via the three tilting portions 102. FIGS. 3A to 3C are views showing an exemplary arrangement of the tilting portion 102. The tilting portion of the tilting portion 15 may be implemented by the rolling movement of a shaft 1021 or a bearing 1022, as illustrated. in Fig. 3A in the form of a side view and in Fig. 3B as a sectional view from the upper surface. In this case, the bearing 1022 is coupled to the mounting plate 101 via a bearing housing 1023. On the other hand, the shaft 1021 is coupled to the holding plate 103 via a 1024. This makes it possible to implement the tilting of each holding plate 103 relative to the mounting plate 101 in a state of friction in which the degree of bearing friction of the bearing is very low. Alternatively, as shown in Figure 3C, the tilting operation of the tilting portion 30 may be implemented by coupling the mounting plate 101 to each support plate 103 via a hinge uniaxial 1025 able to switch with said degree of freedom described above. When observed in the gravitational direction DG, the support portions 104a and 104b are respectively arranged in two regions delimited by the central tilting axis AX1 of each tilting portion 102. The support portions 104a and 104b respectively have contact regions that come into contact with the object W. The contact regions are for example formed of a resin so as to prevent (reduce) damage to the object W. [0034] This allows at the support apparatus 1 to support the object W by means of the two support portions 104a and 104b while tilting each holding plate 103 about the axis of the tilting portion 102 so as to balance the forces acting on the two support portions 104a and 104b. This embodiment has six support portions for the object W. This number of support portions is primarily chosen to prevent (reduce) degradation of the optical characteristics caused by the deformation of the self-weight of the object W. To reduce the deformation of own weight, support in a larger number of points may be required. It is therefore easily understandable that the total number of support portions is increased / decreased depending on physical properties such as the size and weight of the object W, and to consider an appropriate embodiment for this increase / decrease. The second embodiment and the following will describe by way of example support apparatus for this purpose. This embodiment is provided with a plurality of actuators 105a and 105b in correspondence with the plurality of support portions 104a and 104b. The actuators 105a and 105b are configured to receive at least a portion of the loads exerted by the object W on the corresponding support portions 104a and 104b in place of the support portions. The actuators 105a and 105b are respectively disposed near the support portions 104a and 104b. By way of example, the actuators 105a and 105b are configured to at least partially receive charges through concentric portions of the object W with which the corresponding support portions are in contact. By way of example, with reference to Figs. 1A and 1B, the actuators 105a and 105b are disposed in regions that surround and concentrically surround the support portions 104a and 104b, and drive an object in the extension direction of the support parts, that is, the gravitational direction. Each actuator 105 may have a spherical surface as a contact region with respect to the object W. In addition, the contact region of the actuator 105 may be made of a resin so as to prevent (reduce) damage to the object W. A control unit 110 controls the drive of the actuator 105. Each actuator 105 applies a load on an object in a predetermined drive direction (direction opposite to the gravitational direction) ). In addition, the rigidity of each actuator in directions other than the direction mentioned above is low. Specifically, the actuator lifts an object from the support portion by applying a load to the object in the opposite direction to the gravitational direction, but does not restrict the object in directions other than the opposite direction. This allows to release loads acting between the object and the support part in directions other than the driving direction. FIGS. 4A to 4E are views showing an exemplary arrangement and operation of each actuator. As illustrated in FIG. 4A, each actuator consists of a motor 1051 and a contact portion 1052, and can be configured to achieve a contact / non-contact state with respect to an object by making so that a control device (not shown) moves the motor vertically. Further, as shown in FIG. 4B, each actuator consists of a pneumatic cylinder 1053 and the contact portion 1052, and may be configured to cause a pneumatic control apparatus (not shown) to move vertically. the pneumatic cylinder. In a variant, the actuator comprises a gas bearing, and may consist of an air cushion 1054 that is not in contact with an object, as illustrated in FIG. 4C. In this case a pneumatic control apparatus (not shown) causes the levitation of an object to increase the gap between the object and the air cushion. In addition, each actuator 105 may be configured to promote the release of loads in directions other than the drive direction mentioned above. For example, as shown in Figure 4D, ball bearings 1055 may be disposed at the contact portion. In this case, the stresses acting on an object in directions other than the driving direction are released by the rolling movements of the ball bearings. Alternatively, as shown in FIG. 4E, the contact portion 1052 may be supported via a leaf spring mechanism 1056. The leaf spring mechanism 1056 may deform to relieve the stresses in directions other than the driving direction. The arrangements mentioned above may be implemented independently or may be implemented in a combined manner. Note that when each actuator is constituted of the air cushion 1054, as illustrated in FIG. 4C, since an object can be levitated, the stresses in directions other than the driving direction can be relaxed without providing any specific arrangement. In addition, when an arrangement such as that illustrated in FIG. 4C or 4D is used, for example, an actuator and a corresponding support part may share the structure of the arrangement. A control unit 110 controls the actuators 105a and 105b so as to make them temporarily support the object W instead of the support portions 104a and 104b once the object W has been brought to be supported by the support portions 104a and 104b. A mounting sequence of the object W on the support apparatus 10 1 will be described hereinafter as a concrete example of the operation mentioned above with reference to Figs. 2A to 2D and 5. Figs. 2A Fig. 5 is a side view showing a mounting process of the support object W on the support apparatus 1. Fig. 5 is a flowchart showing the process of mounting the support object W on the apparatus As illustrated in FIG. 2A and in Si in FIG. 5, the object W is brought close to the support apparatus 1 in the gravitational direction DG. In this case, the initial tilt degree of each tilt portion 102 may be any degree, and its tilt state need not be a particular state. Due to the displacement of the object W, as illustrated in FIG. 2E and at S2 in FIG. 5, the object W is supported on the support portions 104a and 104b. At this point, the weight of the object W is applied, in the form of support charges Fa and Fb, to the support portions 104a and 104b. [0042] It is possible to arbitrarily change the support load ratio of the object W at the respective support portions by changing the nominal distance between each support portion 104 and the central tilting axis AX1. With reference to FIG. 1A, since the ratio between the distance (horizontal distance) between the support portion 104a and the central tilting axis AX1 and the distance (horizontal distance) between the support portion 104b and the AX1 central tilting axis is equal to 1: 1, the support load ratio is 1: 1, and more specifically, Fa = Fb. If this ratio of distances is 2: 1, the support load ratio becomes 1: 2 because of the balance of moments that prevents the object from rotating. In addition, it is possible to arbitrarily adjust the loads exerted by the object W at the six support portions 104, an example of which is provided in the support apparatus 1, using, as parameters the distances between the respective support portions and the central tilting axis AX1 and the position of the tilting portion 102. In this embodiment, since the respective holding and support plates are arranged concentrically at equal intervals, the support weights at the six points are all the same. However, this is not exhaustive, and various types of arrangements can be adopted. It is possible to arbitrarily modify the arrangement on the basis of an adjustment strategy depending on the object to be mounted. On the other hand, reaction forces Fa and Fb equal to loads exerted at the parts of 25 applied to the object W. In addition, support 104 are friction forces Ffa and Ffb are generated in the regions of contact between the object and the support parts. These friction forces are generated by the offsets of the contact regions when the object W is mounted, and lie in the ranges defined by the inequalities (1) and (2) when a static coefficient of friction is represented by p0 0 <Ffa <pO.Fa ... (1) 0 <ffb <pO.Fb ... (2) 35 [0045] The reason why the inequalities (1) and (2) represent the fact that the forces of friction are within certain ranges, is that the degrees of offset of the contact regions vary according to initial states. More specifically, when an object is mounted on each holding plate 103 while it is generally tipped in a particular direction, a significant degree of rotation must be able to balance the holding plate 103 by means of the tilting portion 102 As a result, a friction force close to a maximum static friction force is generated. On the other hand, when an object is mounted on each holding plate in a state of slight tilting, a lower friction force is generated. Moreover, when a so-called grazing phenomenon has occurred in the contact regions, the friction forces can be predicted only in the ranges defined by the inequalities (1) and (2), and the directions of the forces can not be predicted in a unique way. In addition, the object W and each holding plate 103 are deformed by the charges. This is one of the causes for which friction forces are generated in the contact regions. If Dw and Db respectively represent the shapes of the object W and the holding plate 103, these can be expressed by functions such as those given by Dw (F, Ff) ... (3 ) Db (F, Ff) ... (4) Among the variables indicated in the expressions (3) and (4), the support charges F are uniquely chosen from the positioning of the support portions. On the other hand, the frictional forces Ff are not uniquely chosen as indicated by the inequalities (1) and (2). Therefore, these shapes vary depending on the mounted object, and have a reproducibility corresponding to the variations. After that, as illustrated in Figure 2C and S3 in Figure 5, the actuators 105a and 105b lift the object W. At this point, as described above, the actuators do not restrict the position of the object in directions other than the gravitational direction, and thereby allow the friction forces generated on the object to be released. This makes it possible to express the respective forms according to the expressions (5) and (6).

Dw (F, 0) ... (5) Db (F, 0) ... (6) [0049] More precisely, since the friction forces acting in the contact regions are no longer exerted on the object W and the holding plates 103, their shapes are uniquely chosen based solely on the support charges F. Note that this condition can be fulfilled when the shape of the object varies very little before and after the application of support loads near the support portions by the actuators. At this stage, the distances between the actuators and the support parts are chosen from the permissible degree of deformation of the object W. Indeed, when the positions of the support parts and the actuators 25 vary, the shapes the object and the holding plate vary due to the loads. It is therefore sufficient to ensure that a shape variation is sufficiently small compared to the required shape accuracy of the object W. To this end, the distances described above can be chosen by estimating the shape of the object W by FEM or other analysis and verifying whether the estimated shape error is sufficiently small (for example less than or equal to a permissible level). In other words, the distance between a part of an object with which each actuator is in contact and a part of the object with which a support part corresponding to the actuator is in contact, is set to a value which causes the degrees of deformation of the object and the holding plate due to actuation of the actuators to become less than or equal to allowable levels. Alternatively, the above-mentioned distances can be chosen according to the flexural stiffness (flexural strength) obtained from the thickness / physical property values of the object W. [0051] In addition, as illustrated in FIG. 2D and at S4 in FIG. 5, the actuators 105a and 105b are driven in the reverse direction to reassemble the object W on the support portions 104. At this point, the object W is mounted on the support portions 104 substantially without any offset in directions other than the driving direction with respect to (relative to) the support portions 104. Indeed, since the distances (positional relationships) between the actuators and the Since the support portions are set as described above, the shapes Dw and Db vary very little. Therefore, it is possible to support an object advantageously from the point of view of the reproducibility of the shape of the object and the weakness of the deformations caused by the friction forces. After that, as indicated for example by step S5, the object W (for example its optical or other characteristics) is measured. As described above, the control unit 110 drives a plurality of actuators to reduce the residual stresses on the object W and caused by the friction forces acting between the object W and the plurality of support portions. The support apparatus described above thus makes it possible to reduce the influence of the friction on the support parts. Furthermore, since an object can be supported with appropriate rigidity during stress reduction, it is possible to reduce vibration or other influences during subsequent processing (measurement or otherwise). [Second Embodiment] Figs. 6A and 6B are views showing the arrangement of a support apparatus according to the second embodiment. Fig. 6A is a plan view of a support apparatus 2. Fig. 6B is a side view of the support apparatus 2. The reference symbol DG denotes a gravitational direction. The support apparatus 2 is mounted in an apparatus in which the support apparatus 2 is to be mounted, via a mounting plate 201. The mounting plate 201 has three tilting portions 202. The three The tilting portions 202 are coupled to three holding trays 203. The tilting portions 202 couple the holding trays 203 to the mounting tray 201 so as to ensure that each tray is tilting with two degrees of freedom. In this case, two degrees of freedom indicate degrees of freedom of rotation about central tilting axes AX21 and AX22 passing through a tilting center CR2 of the holding plate 203. Specifically, each holding plate 203 can tilt relative to a plane perpendicular to the gravitational direction DG. [0054] Figs. 7A to 7G are views showing an exemplary arrangement of each tilt portion 202. As shown in Fig. 7A as a side view and in Fig. 7B as a drawing. A different side view, the tilting operation of each tilting portion 202 can be implemented by the rolling movements of a shaft 2021 and a bearing 2022. In this case, bearings 2022a and 2022b ( not shown) are coupled to the mounting plate 201 via bearing housings 2023a and 2023b (not shown). On the other hand, bearings 2022c and 2022d (not shown) are respectively coupled to the holding plate 203 via bearing housings 2023c and 2023d (not shown). In addition, a shaft 2021a is coupled to the bearings 2022a and 2022b (not shown), and a shaft 2021b is coupled to the bearings 2022c and 2022d (not shown). This makes it possible to implement the tilting of each holding plate 203 in a state of friction in which the rolling friction of each bearing is very small. As illustrated in FIG. 7C, the shafts 2021a and 2021b can be integrally formed, as illustrated in FIG. 7D or can be coupled to each other via a central member 2026 so that their tilt axes coincide with each other. In a variant, the tilting of each tilting portion 202 may be implemented by coupling the mounting plate 201 to the holding plate 203 via a biaxial hinge 2025 capable of tilting with two degrees of freedom. as shown in Fig. 7E as a side view and in Fig. 7F as a different side view. Alternatively, as shown in FIG. 7G, the tilting portion 202 can be tilted by coupling the mounting plate 201 to the holding plate 203 via a cardan joint 2027. For reasons of simplicity, this embodiment describes the use of the central tilting axes, that is, it provides an example of the tilting centers and the holding plate capable of tilting around the tilting centers with two degrees of freedom, thereby indicating that each tilting portion 202 may tilt relative to a plane perpendicular to the gravitational direction DG. More specifically, the present invention shows that the positioning and arrangement of the tilting axes of a real holding plate are not limited to those illustrated in the accompanying drawings. Each of the three holding plates 203 has three support portions 204a, 204b, and 204c. These support portions are respectively arranged at least one by one in the regions delimited by the respective central tilting axes of each tilting portion 202. Each support portion 204 has a contact region that contacts the W object. By way of example, each contact region is formed by a resin or the like to prevent (reduce) damage to the object W. [0057] The three support portions 204a, 204b, and 204c respectively comprise actuators 205a, 205b, and 205c. The actuators 205a, 205b, and 205c are respectively disposed near the three support portions 204a, 204b, and 204c. With reference to FIGS. 6A and 6B, the actuators 205a, 205b, and 205c are disposed in regions which are respectively located near the support portions 204 and are concentric with them. Each actuator 205 may have a spherical surface as a contact region with respect to the object W. In addition, the contact region of each actuator 205 may be made of a resin to prevent (reduce) damage to the object W. [0058] Each actuator 205 may adopt the arrangement 25 mentioned in the first embodiment. A mounting sequence of the object W on the support apparatus 2 will be described hereinafter. The sequence illustrated in Figure 5 can be applied to this case. More precisely, as illustrated in S1 in FIG. 5, the object W is brought close to the support apparatus 2 in the gravitational direction DG. In this case, the initial tilt degree of each tilt portion 202 may be any degree, and its tilt state need not be a specific state. Due to the displacement of the object W, as illustrated at S2 in FIG. 5, the object W is supported on the support portions 204a, 204b, and 204c. At this point, the self weight of the object W is applied, in the form of support charges Fa, Fb, and Fc, to the support portions 204. After that, as illustrated at S3 in FIG. 5, the actuators 205a, 205b, and 205c drive and lift the object W in the gravitational direction. At this stage, as described above, the rigidity of each actuator is low in directions other than the gravitational direction, and thereby allows the frictional stresses generated on the object to be relaxed. In addition, as illustrated at 34 in FIG. 5, the actuators 205a, 205b, and 205c are driven in the reverse direction to again assemble the object W on the support portions 204. At this point, the object W is mounted on the support portions 204 substantially without any offset in directions other than the driving direction with respect to (relative to) the support portions 204. Indeed, since the load distributions on the object W and the holding plates 203 vary very little, their shapes are virtually constant. The support apparatus described above can support an object advantageously from the point of view of the reproducibility of the shape of the object and the weakness of the deformations caused by the friction forces. [0063] <Third Embodiment> Figs. 8A and 8B are views showing the arrangement of a support apparatus according to the third embodiment. Figure 8A is a plan view of a support apparatus 3. Figure 8B is a side view of the support apparatus 3. The DG reference symbol 35 designates a gravitational direction. The support apparatus 3 is mounted in an apparatus in which the support apparatus 3 is to be mounted, via a mounting plate 301. The mounting plate 301 has three tilting portions 302. The three parts tilting portions 302 are respectively coupled to three retaining trays 303. The tilting portions 302 couple the retaining trays 303 to 301 so as to cause one tilt to pivot each tilt central axis each portion of mounting tray support each release tray freedom. More specifically, it may be tilted about one of the support portion 302 of a bearing or mechanism as mentioned in the first embodiment may be hinge, embodiment. Each holding plate 303 further includes two second tilt portions 312a and 312b. The two second tilting parts 312a and 312b are respectively coupled to second holding plates 313a and 313b. The second portions 312b respectively couple the retainers 313a and 313b to the platen to ensure that each second is tilting with a degree of shafts of holding portions 313 has a tilting portion 312a and second retaining plates 303. More specifically, the second platens 313a and 313b can tilt about central tilting AX3a and AX3b of the second tilting 312a and 312b. Each of the three trays of two support portions 314a and 314b. Support 314 has a contact contact region of the object W. The contact region is to prevent freedom. Each of the two support portions 314a and 314b are respectively arranged to damage the object W. [0066] The two support portions 314a and 314b respectively comprise 315a. and 315b. The proximity of the two support portions 314a and 314b. With reference to Figs. 8A and 8B, the actuators 315a and 315b are disposed in regions that are located near and concentric with the support portions 314a and 314b. Each actuator 315 may have a spherical surface as a contact region with respect to the object W. In addition, the contact region of the actuator 315 may be made of a resin so as to prevent (reduce) the damage to the object W. [0067] Each actuator 315 can adopt the arrangement mentioned in the first embodiment. A mounting sequence of the object W on the support apparatus 3 will be described hereinafter. The sequence illustrated in Figure 5 can be applied to this case.

More specifically, the object W is brought close to the support apparatus 3 in the gravitational direction DG, and is supported on the support portions 314a and 314b. At this point, the self-weight of the object W is applied, in the form of support charges Fa and Fb, to the support portions 314. After that, the actuators 315a and 315b drive and lift the object W in the gravitational direction. At this point, as described above, the frictional stresses generated on the object can be relaxed. In addition, the actuators 315a and 315b are driven in the reverse direction to reassemble the object W on the support portions 314. At this point, the object W is mounted on the support portions 314 substantially without any offset in directions other than the driving direction relative to (relative to) support portions 314. Indeed, since the load distributions on the object W and the holding plates 303 vary very little, their shapes are virtually constant. The support apparatus described above can support an object advantageously from the point of view of the reproducibility of the shape of the object and the weakness of the deformations caused by the friction forces. [0072] <Fourth Embodiment> Figs. 9A and 9B are views showing the arrangement of a support apparatus according to the fourth embodiment. Fig. 9A is a plan view of a support apparatus 4. Fig. 9B is a side view of the support apparatus 4. The reference symbol DG denotes a gravitational direction. The support apparatus 4 is mounted in an apparatus in which the support apparatus 4 is to be mounted, via a mounting plate 401. The mounting plate 401 has three tilting portions 402. The three parts tilting portions 402 are respectively coupled to three holding trays 403. The tilting portions 402 couple the holding trays 403 to the mounting plate 401 so as to ensure that each holding tray is tilting with two degrees of freedom. degrees toggling tipping precisely, gravitational DG. Each tilt portion 402 may be a bearing, hinge mechanism, or universal joint, as mentioned in the second embodiment. The three holding plates 403 further include three second tilt portions 412a, 412b, and 412c. The three second tilting parts are respectively coupled to second holding plates 413a, 413b, and 413c. The second tilting parts 412a, 412b, and 412c respectively couple the second holding plates 413a, 413b, and 413c to the two respective degrees of freedom to indicate freedom of rotation about center axes AX41 and AX42 through a CR4 center each at a ratio to the direction of each holding plate. More holding plate 403 can swing plane perpendicular holding plates 403 so as to ensure that each second holding plate is tilting with two degrees of freedom. More specifically, when considering the second retaining plate 413a by way of example, the second retaining plate 413a can tilt around central tilting axes AX41a and AX42a passing through a tilting center CR4a. The remaining holding trays can tilt in the same way. Each of the three holding substrates 413 comprises three support portions 414a, 414b, and 414c. Each support portion 414 has a contact region that contacts the object W. The contact region is, for example, formed of a resin to prevent (reduce) damage to the object W. [0075] three support portions 414a, 414b, and 414c respectively comprise actuators 415a, 415b, and 415c. The actuators 415a, 415b, and 415c are disposed near the three support portions 414a, 414b, and 414c. Referring to Figures 9A and 9B, each actuator is disposed in a region which is located near and concentric with the support portion 414. Each actuator 415 may have a spherical surface as a contact region with respect to the object W. In addition, the contact region of the actuator 415 may be made of a resin so as to prevent (reduce) damage to the object W. [0076] Each actuator 415 can adopt the arrangement mentioned in the first embodiment. A mounting sequence of the object W on the support apparatus 4 will be described hereinafter. The sequence illustrated in Figure 5 can be applied to this case. Specifically, the object W is brought close to the support apparatus 4 in the gravitational direction DG, and is supported on the support portions 414a, 414b, and 414c. At this point, the self-weight of the object W is applied, in the form of support charges Fa, Fb, and Fc, to the support portions 414. After that, the actuators 415a, 415b, and 415c cause and raise the object W in the gravitational direction. At this point, as described above, the frictional stresses generated on the object can be relaxed. In addition, the actuators 415a, 415b, and 415c are driven in the reverse direction to again mount the object W on the support portions 414. At this point, the object W is mounted on the support portions. 414 substantially without any offset in directions other than the driving direction with respect to (relative to) support portions 414. Indeed, since the load distributions on the object W and the holding plates 403 vary very few, their forms are practically constant. [0080] Note that the support apparatus according to this embodiment can be embodied as a support apparatus 4 ', as illustrated in FIGS. 10A and 103. The support apparatus 4' has second tilting parts 412a ', 412b', and 412c1 located below (in the gravitational direction DG) of the holding plate 403. The three second tilting parts are respectively coupled to second holding plates 413a ', 413b' In the support apparatus 4 ', a center of gravity CG of the movable portion above the holding plate 403 is located below (in the gravitational direction) of a center of rotation CR4 of the tilting portion 402. Because of this arrangement, the posture of each holding plate is stabilized by gravity while the object W is not mounted.This facilitates the mounting of the object W. In addition, since the shift (displacement) of each contact point is weak, this has the effect of reducing the initial frictional stress on the object W. This facilitates the relaxation of the frictional stresses. The support apparatus described above can support an object advantageously from the point of view of the reproducibility of the shape of the object and the weakness of the deformations caused by the friction forces. [0082] <Fifth Embodiment> Figs. 11A to 11C are views showing the arrangement of a support apparatus according to the fifth embodiment. Fig. 11A is a plan view of a support apparatus 5. Fig. 11B is a side view of the support apparatus 5. The reference symbol DG denotes a gravitational direction. Fig. 11C is a plan view of a support object W supported on the support apparatus. In this embodiment, the support object has a symmetrical shape with respect to a plane rather than a symmetrical shape of rotation. Therefore, the support apparatus which will be described hereinafter has a symmetrical arrangement with respect to a plane. Note that the embodiment described by way of example the arrangement of the support apparatus corresponding to the shape of an optical element. It is however easily understandable that the arrangement of the support apparatus can be easily changed depending on the shape of an optical element. The support apparatus 5 is mounted in an apparatus in which the support apparatus 5 is to be mounted via a mounting plate 501. The mounting plate 501 has a tilting portion 502. and two tilt portions 512. The tilt portion 502 is coupled to a retaining tray 503. The two tilt portions 512 are coupled to two retaining trays 513. The tilt portion 502 couples the tray 503 to the tray mounting 501 so as to ensure that the holding plate is tilting with a degree of freedom. On the other hand, the two tilt parts 512 couple the two holding plates 513 to the mounting plate 501 so as to ensure that each holding plate is tilting with two degrees of freedom. More specifically, the holding plate 503 and the two holding plates 513 can tilt relative to a plane perpendicular to the gravitational direction DG. The tilt portions 502 and 512 may adopt arrangements such as those mentioned in the first and second embodiments. The holding plate 503 and each of the two holding plates 513 respectively comprise two and three support portions 504. Each support portion 504 has a contact region which comes into contact with the object W. The region of For example, contact is formed of a resin to prevent (reduce) damage to the object W. [0085] Each support portion 504 includes an actuator 505. The actuator 505 is disposed near the support portion. 504. With reference to Figs. 11A and 11B, the actuator 505 is disposed in a region which is located near and concentric with the support portion 504. Each actuator 505 may adopt the arrangement mentioned in the first embodiment. A mounting sequence of the object W on the support apparatus will be described hereinafter. The sequence illustrated in Figure 5 can be applied to this case. Specifically, the object W is brought close to the support apparatus in the gravitational direction DG, and is supported on the support portions 504. [0088] After that, the actuators 505 drive and lift the object W. in the gravitational direction. At this stage, as described above, the frictional stresses generated on the object can be relaxed. In addition, the actuators 505 are driven in the reverse direction to reassemble the object W on the support portions 504. At this point, the object W is mounted on the support portions 504 substantially without any offset. in directions other than the driving direction with respect to (relative to) the support portions 504. Indeed, since the load distributions on the object W and the holding plates 203 vary very little, their shapes are 10 practically constant. [0090] The support apparatus described above can support an object advantageously from the point of view of the reproducibility of the shape of the object and the weakness of the deformations caused by the forces of the friction. [0091] <Sixth Embodiment> Fig. 12 is a view showing the arrangement of a measuring apparatus comprising (equipped with) the support apparatus described above. A measuring apparatus M 20 holds, for example, the support apparatus 1 according to the first embodiment on a measuring plate MS, and makes it possible to support (mount) the support object W on the support apparatus 1. Alternatively, any of the support apparatuses 2 to 5 described in the second to fifth embodiments may be held on the measurement platform MS. In the measuring apparatus M, the support apparatus executes the sequence illustrated in Fig. 5. After that, a measuring head MH measures the support object W in order to obtain measurement results advantageously from the point of view of the reproducibility of the shape of the object W and the weakness of the frictional stress. It should be noted that it is possible to use, as the measuring head MH, one of various types of measuring devices independently of the interferometer configurations, of a contact / non-contact probe type, or other. [0092] <Embodiment of the article manufacturing method> A method of manufacturing an article according to this embodiment is used to manufacture an article such as a metal component or an optical element. The method of manufacturing an article according to the embodiment comprises a step of measuring the shape or optical characteristics of an object (support object W) by means of the measuring apparatus mentioned above and a step processing the object based on the measurement results obtained in the step mentioned above. For example, the shape of an object is measured by means of a measuring device, and the object is processed (fabricated) so that it has a shape that respects the design values (being in permissible ranges) on the basis of the measurement results. The method of manufacturing an article according to this embodiment makes it possible to accurately measure the shape of an object by means of the measuring apparatus, and is therefore advantageous in comparison with the technique in question from the point of view of at least one of the performance, quality, productivity and cost of manufacturing articles compared to the method. Although the present invention has been described with reference to exemplary embodiments, it will be appreciated that the invention is not limited to the exemplary embodiments described. The scope of the claims presented hereinafter must be considered in the broadest sense as covering all such variants and structures and equivalent functions.

Claims (12)

REVENDICATIONS1. A support apparatus comprising a plurality of support mechanisms each having a first member that includes a plurality of support portions for supporting an object and a second member that supports the first member, the first member being tilted about an axis relative to at least one degree of freedom, wherein: the plurality of support mechanisms is configured to support the object by means of each of the first members rotated about the corresponding axis supporting the object in such a way that a plurality of forces applied to the plurality of support portions of the first members are balanced, and each of the first members includes, each of the plurality of actuator portions configured to receive at least the load acting on one of the plurality of carriers corresponding to this one instead of support. Apparatus according to claim 1 the actuator is configured to receive at least the portion of the load through a portion of the object which is concentric with a portion of the object with which said support portion is put in contact. An apparatus according to claim 1 or 2, wherein the actuator comprises a gas bearing and is configured to receive at least the portion of the load via the gas bearing. 30 An apparatus according to claim 1 or 2, wherein the actuator comprises a ball bearing and is configured to receive at least the portion of the load through the ball bearing. An apparatus according to claim 1 or 2, wherein the actuator comprises a member whose rigidity, in a direction different from a direction of the load, is relative to a support, a portion of portions of said portion. in which lower than its rigidity in the direction of the load, and is configured to receive at least the portion of the load through the member. Apparatus according to any one of claims 1 to 5, wherein the actuator is configured to share a structure thereof with one of the plurality of support portions corresponding thereto. Apparatus according to any one of claims 1 to 6, wherein a distance between a part of the object with which the actuator comes into contact and a part of the object with which said support part comes into contact. , is a value by which a degree of deformation of the object caused by actuation of the actuator is within a tolerance range and a degree of deformation of the first member caused by actuation is within a tolerance range . Apparatus according to any of claims 1 to 7, further comprising a control unit configured to control the actuator so as to cause the actuator to temporarily receive at least the portion of the load once the object is supported by the plurality of support portions. Apparatus according to claim 8, wherein the control unit is configured to cause the actuator to generate a force to reduce a residual stress in the object caused by a friction force acting between the actuator object and said support portion. A measuring apparatus for measuring an object, the apparatus comprising: a support apparatus according to any one of claims 1 to 9 and configured to support the object. A support method for supporting an object, by means of a plurality of support mechanisms, each having a first member which has a plurality of support portions for supporting the object and a second member which supports the first member , the first member being tilting about an axis with respect to at least one degree of freedom, the plurality of support mechanisms supporting the object by means of each of the first members brought to tilt about the axis corresponding thereto. supporting the object so that a plurality of forces applied to the plurality of support portions of the first members are balanced, the method comprising: bringing, once the object is supported by the plurality of support portions, a actuator, included in each of the first members relative to each of the plurality of support portions, to temporarily receive at least a portion of the load acting on the one of the plurality of support portions corresponding thereto in place of said support portion. A method of manufacturing an article, the method comprising: measuring an object using a measuring apparatus according to claim 10; and process the object based on the measurement made by the meter.