JP2006078187A - Three-point support device and three-dimensional geometry measuring device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize a three-point support device, capable of freely switching a solid contact support which has high rigidity and stability with a kinematic mount etc., of low rigidity and high degrees of freedom. <P>SOLUTION: Each of the three foot parts 3 of the three-point support, for supporting a body 1 to be supported, is provided with the high-rigidity support mode for making the fixed support 12 bring in contact with the foot 11 projecting from the under surface of the body 1 to be supported for three-point support and the low-rigidity support mode with four degree of freedom in directions X, Y, ωX, ωY by, bringing the thrust bearing 15 supported by the elastic support means 14, including a leaf spring into contact with flange 13 integrated with the foot 11, thereby the two support modes are switched by the bellows cylinder 16 of a lifting mechanism. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  In the present invention, for example, a reference mirror used for a three-point support device that supports a high-precision optical element in a semiconductor exposure apparatus or the like and a three-dimensional shape measurement device that measures the shape using the optical element as a test object is attached. The present invention relates to a three-point support device and a three-dimensional shape measurement device that support a supported object such as a frame or a test object in which deformation of 1 μm or less is a problem.

  A kinematic mount is a known three-point support device that holds or supports an object to be supported such as an optical element or a test object with an accuracy of 1 μm or less. Kinematic mounts were devised to reduce shape changes such as the deformation of the supported object due to the deformation of the mounting surface and the deformation of the supported object, and to improve the reproducibility of the shape of the supported object before deformation. Support mechanism.

  FIG. 6 shows a configuration of a kinematic mount according to a conventional example. A supported object 201 includes three legs through spheres 204 to 206 between a conical recess 202 and a bottom surface having a V-shaped groove 203. The leg portions 207 to 209 are erected and fixed to the support base 210. The first support portion includes a conical recess 207a provided in the first leg 207 fixed to the support base 210, a conical recess 202 of the supported object 201, and conical recesses 202 and 207a. And is constrained in three directions of X, Y, and Z directions, and has three degrees of freedom in rotation components ωX, ωY, and ωZ directions around each axis. The second support portion includes a V-shaped groove 208a provided in the second leg 208 fixed to the support base 210, a V-shaped groove 203 provided in the supported object 201, and V-shaped grooves 203 and 208a. It is composed of a sphere 205 to be inserted, is constrained in two directions, Y and Z, and has four degrees of freedom in the X, ωX, ωY, and ωZ directions. The third support portion includes a sphere 206 that contacts the upper surface 209a of the third leg 209 fixed to the support base 210 and the lower surface of the supported object 201, and is in the X, Y, ωX, ωY, and ωZ directions. Has 5 degrees of freedom and restrains only the Z direction.

  With such a configuration, for example, the support base 210 cannot be ignored with respect to the supported object 201 because the load F applied to the support base 210 changes or the heat distribution state changes. Even when the deformation is caused by the amount, the deformation of the supported object 201 accompanying the deformation can be reduced to a level at which it can be ignored. Even when the supported object 201 is removed once and mounted again on the kinematic mount, the reproducibility in which the shape of the supported object 201 hardly changes from the initial state can be obtained.

Next, as another method for obtaining good reproducibility with respect to the deformation of the supported object, there is a method disclosed in Patent Document 1. This is to reduce the influence of deformation of the test object due to how to hold the test object or how to place it on the mounting table when measuring the shape of the test object with a measuring instrument. For example, FIG. In the measuring apparatus shown in FIG. 1, a support post 302 that holds a measuring instrument 303 is erected on a gantry 301, and an object having a high flatness and an air supply hole 306 at the upper end of a spindle 304 supported by the gantry 301 is provided. By having the table 305, after mounting the test object 308 having a flat surface 308a on the mounting table 305, air is supplied from the compressed air supply unit 307, and the test object 308 is lifted up once. By releasing the distortion inside the object 308, the object 308 on the stage 305 can be always reproduced in a constant state.
Japanese Patent Laid-Open No. 2002-236013

  However, since the kinematic mount according to the conventional example shown in FIG. 6 is supported by point contact at three points, it is basically a support mechanism that does not increase rigidity compared to the case where the supported object is supported by a plane. In addition, there is one sphere per leg between the supported object and the support base, and stress concentration due to the point contact between the sphere and the supported object and between the sphere and the support base. There is an unsolved problem that the rigidity of the point contact portion is weak and the rigidity is small because the rigidity of the point contact portion dominates the rigidity between the supported object and the support base.

  The rigidity of the point contact part can be improved by increasing the Young's modulus of the sphere or the diameter of the sphere, but particularly when the supported object supports a heavy object having a weight exceeding 1000 kg, for example, In order to achieve the required level of rigidity of each support portion of the kinematic mount, it is necessary to extremely increase the diameter of the sphere, and it is difficult to realize the arrangement of one sphere at one place because of physical dimensions. As a countermeasure against this, a method of increasing the rigidity by arranging a plurality of spheres in place of one per place is also conceivable. However, since one place supports a plurality of points and does not support one point. As in the case of supporting by a surface, there is a variation in which of the plurality of points is subjected to the load, which causes deterioration of reproducibility. In addition, when the support stiffness is low, for example, when used to support a test object of a measurement device or a measurement reference structure, disturbance acceleration such as vibration from the floor or change in the direction of gravity acceleration due to the tilt of the device As a result, the measurement accuracy is degraded.

  In the configuration shown in FIG. 7, the test object is lifted by air once to release the strain, so that the shape of the test object can be reproducible, and since it is a bearing during measurement, it is rigid. Although it is strong and the influence of disturbance acceleration can be reduced, it is necessary to have a plane with a sufficient area to rise to the test object side, and because it is a bearing during measurement, A slight change in the flatness of the mounting table may directly change the shape of the test object.

  In addition, when placing the test object, if the test object is not mounted at a precisely determined position, the receiving point of the test object will change due to the flatness of the mounting table, There is also a possibility that the shape reproducibility of the holding of the specimen cannot be obtained.

  The present invention has been made in view of the above-mentioned unsolved problems of the prior art, and can freely reduce the shape change by arbitrarily releasing the distortion of the supported object, and kinematic It is an object of the present invention to provide a high-performance and high-reliability three-point support device and a three-dimensional shape measuring device that can obtain a larger support rigidity than the mount.

  To achieve the above object, a three-point support device of the present invention is a three-point support device that supports a supported object via three legs between a support base and at least one leg. , A first support mechanism by a fixed body that restrains at least the degrees of freedom in the X, Y, and Z directions, and a second mechanism by a movable body having at least one of the four degrees of freedom in the X, Y, ωX, and ωY directions. A support mechanism and switching means for alternately disabling the first and second support mechanisms are provided.

  Switch the rigidity of the leg from a support form that has a large rigidity due to contact with a fixed body to a support form that has a very small rigidity compared to the rigidity of the supported object to release the distortion inside the supported object. In addition, by returning to the support form having a large rigidity by contact with the fixed body again, the support state before the deformation without any internal distortion can be reproduced with a large support rigidity.

  For example, the three legs are each configured to switch to a 6-degree-of-freedom constrained support form (kinematic mount) from a state in which three positions in the X, Y, and Z directions of the supported object are fixed and supported with high rigidity. As a result, the distortion caused by the deformation generated inside the supported object in the support state in which the X, Y, and Z directions are fixed, and the distortion generated due to the deformation of the support base to which the three legs are fixed are generated. , And released without changing the relative positional relationship between the support base and the supported object. In such a state in which the distortion is eliminated, the shape before the deformation of the supported object is changed without changing the relative positional relationship between the supported object and the support base by switching again to the support form by the three-point fixed body contact. It is possible to restore and maintain a highly rigid and stable support form.

  As shown in FIG. 1, in a three-point support device that supports a supported object 1 with a support base 2 via three legs 3, each leg 3 is arranged in two horizontal axes by contact with a fixed body. A first support mechanism (11, 12) that restrains and supports the supported object 1 in the X and Y directions that are the directions of the X direction and the Z direction that is the direction of one vertical axis, and the X and Y directions and the horizontal direction 2 A second support mechanism (13 to 15) for supporting the supported object 1 by contact of a movable body movable in a total of four degrees of freedom in the ωX and ωY directions that are rotation directions around the axis, and the first and second And a lift mechanism 16 which is switching means for alternately switching the support form by the support mechanism.

  In the second support mechanism having four degrees of freedom, for example, by adding an X guide or the like that constrains the degree of freedom in the Y direction of the X and Y directions, 1 to 3 degrees of freedom in the four degrees of freedom. It is possible to change the configuration to arbitrarily restrict the degree.

  FIG. 1 shows a three-point support device according to a first embodiment. A supported object 1 is supported on a support base 2 through three legs 3 at three points. FIG. 2 is an enlarged view of the internal structure of each leg 3, and a leg having a spherical surface 11 a that protrudes from the bottom surface of the supported object 1 and is a part of a gentle spherical surface having a radius of, for example, 100 mm or more. 11 and a fixed support 12 that is a fixed body having a flat surface 12a that is fixed to the support base 2 and has a planar shape, the leg 11 contacts the flat surface 12a of the fixed support 12. The supported object 1 is in a very rigid support form in which it is restrained and supported in the X, Y, and Z directions with respect to the support base 2.

  The second support mechanism of each leg 3 is supported by an elastic support means 14 having a ring-shaped housing 14a on a flange 13 provided integrally with the supported object 1 so as to surround the leg 11 horizontally. The thrust bearing 15 is a bearing means, and the thrust bearing 15 is provided over the entire circumference in a form in which a sphere 15c sandwiched between two ring-shaped flat plates 15a and 15b is held by a cage 15d. . The bottom surface of the lower ring-shaped flat plate 15b is fixed to a ring-shaped housing 14a, and the bottom surface of the housing 14a is fixed to a ring-shaped bellows cylinder 16 that is a lift mechanism. The bellows cylinder 16 is formed by welding two bellows-shaped cylinders 16c and 16d having different radial dimensions between two ring-shaped flat plates 16a and 16b, and has a double tube shape in a horizontal section. The portion sandwiched between the bellows-like cylinders 16c and 16d serves as an air chamber, and the air can be expanded and contracted in the Z direction by taking air in and out from the air supply / exhaust hole 16e. The bellows cylinder 16 is fixed to the support base 2, and the housing 14a is connected to a stand 14b fixed to the support base 2 via a leaf spring 14c serving as a guide in the Z direction.

  By supplying and exhausting the bellows cylinder 16, the housing 14a and the thrust bearing 15 can be moved in the Z direction in a state where the rigidity of the leaf spring 14c is restricted in the X and Y directions and the ωZ direction that is the rotational direction around the Z axis. It becomes possible.

  When air is supplied to the bellows cylinder 16 at a predetermined pressure and the housing 14a is raised, the flat surface 15a above the thrust bearing 15 is brought into contact with the spherical portion 11a of the leg 11 from the point-contact with the flat seat 12a of the fixed column 12. Is brought into contact with the flange 13, and the supported object 1 is lifted using this surface. In the lifted state, the supported object 1 is constrained on the support base 2 by the contact of the bellows cylinder 16, the leaf spring 14 c of the Z direction guide, the movable body including the thrust bearing 15 and the like. The thrust bearing 15 rolls in the X and Y directions without springiness or exhibits very flexible springiness in a minute region. Further, since the bellows cylinder 16 is flexible in the ωX and ωY directions and the leaf spring 14c of the Z guide is also flexible in ωX and ωY, it is flexible in the X, Y, ωX, and ωY directions in the lifted state. It becomes a support form with springiness.

  Thus, in each leg 3, depending on whether air is supplied to the bellows cylinder 16 or not, the support form that restricts the degrees of freedom in the X, Y, and Z directions and the support form that has four degrees of freedom are alternately switched. It is possible.

  When the supported object 1 is supported at three points by the three legs 3 as shown in FIG. 1, the three legs 3 are generated on the supported object 1 in the support form by contact with the fixed body that is not supplying air. A deformation that cannot be released. For example, when the supported object 1 is lifted, removed, and mounted again, the position of the suspension point when it is lifted is different from the position of the support point. Due to the influence of the friction of the contact portion, the supported object 1 is deformed without returning to the original three-point supported state. Further, even when the support base 2 is deformed in a state where the supported object 1 is mounted, the force is transmitted to the supported object 1 due to the friction of the contact portion of the fixed body. It will be deformed.

  In such a case, the internal distortion of the supported object 1 can be released by supplying air to each leg 3 and switching the support at three points to support with four degrees of freedom. However, in this state, since the support rigidity is greatly reduced, the leg portions 3 are then switched to support that restricts the degrees of freedom in the X, Y, and Z directions, and the high rigidity after restoration is maintained. To do.

  By the way, in the configuration of FIG. 1, the deformation of the supported object can be arbitrarily eliminated without reducing the support rigidity, but when each leg is switched to support with 4 degrees of freedom, There are three degrees of freedom in the X, Y, and ωZ directions with respect to the support base, and the position of the supported object may be displaced. Example 2 described below solves such a problem.

  As shown in FIG. 3, the supported object 21 is supported on a support base 22 via three leg portions 23, 24 and 25 having different configurations.

  Of the three legs, the leg 25 has three degrees of freedom in the ωX and ωY directions around the two horizontal axes and the ωZ direction around the vertical axis, and the legs 24 are fixed points. Supported by a support that constrains the three degrees of freedom in the X, Y, and Z directions by contact, and a movable body that can move in one of the X and Y directions and a total of three degrees of freedom in the ωX and ωY directions. There are two types of support modes for supporting the object 21, and the leg portion 23 is a support mode for restraining three degrees of freedom in the X, Y, and Z directions by point contact of the fixed body, and X, Y By supporting the supported object 21 by a movable body that can move in a direction of four degrees of freedom in the direction and ωX and ωY directions, the support form of the supported object 21 is changed to 3 A combination of a state where each point restrains and supports three degrees of freedom in the X, Y, and Z directions and three different support forms It can be freely be switched to a state in which the overall 6 degree-of-freedom constraint support form (kinematic mount) at Align.

  The leg portion 23 has exactly the same structure as the leg portion 3 of the first embodiment, and the members constituting the inside thereof are the same and are therefore denoted by the same reference numerals and description thereof is omitted. In a state in which the supported object 21 is lifted when the legs 23 are supplied with air, the support form has four degrees of freedom with flexible spring properties in the X, Y, ωX, and ωY directions.

  The leg portion 24 has the same structure except that the thrust bearing 15 of the leg portion 3 of the first embodiment is provided with an X guide 17 that restrains the freedom degree in the Y direction among the four degrees of freedom. In other words, the plate springs 17a and 17b constituting the X guide 17 are fixed to the thrust bearing 15 between the ring-shaped flat plates 15a and 15b with the spacer 17c interposed therebetween. By comprising in this way, the rigidity with respect to the relative movement of the ring-shaped flat plates 15a and 15b of the thrust bearing 15 differs depending on the moving direction, and shows a small rigidity in the X direction, whereas in the Y direction, Shows great rigidity. In the Z direction, the rigidity is smaller than that of the sphere 15c. When the air of a predetermined pressure is supplied to the bellows cylinder 16 by adding the spring mechanism of the X guide 17, the leg portion 24 can lift the supported object 21 via the thrust bearing 15. Since the movable direction of the bearing 15 is constrained in the Y direction, in a state where the supported object 21 is lifted during supply of air, it has a flexible spring property in the X, ωX, and ωY directions and has three degrees of freedom. It becomes the support form.

  The leg portion 25 has a leg 18 that is integral with the supported object 21, and its tip has a spherical shape 18 a. The receiving seat 19 has a conical recess 19a, and by combining them, the three degrees of freedom in the X, Y, and Z directions are constrained, and constitutes a rolling element that is movable in the ωX, ωY, and ωZ directions. .

  In the state where the supported object 21 is supported on the support base 22, depending on the presence or absence of air supply to the legs 23 and 24, the support form by the contact of the three fixed bodies having high support rigidity and the support rigidity are small. It is possible to switch to a kinematic mount that is a six-degree-of-freedom constrained support configuration that can release strain inside the supported object.

  For example, when the supported object 21 is lifted, removed, and mounted again in the support form by contact with the three-point support fixed body, the lifted position is different from the position of the support point. If the deformation occurs and only the mounting is performed again, the supported object 21 is deformed without returning to the original state due to the friction of the contact support portion of the fixed body. Further, when the support base 22 is deformed in a state where the supported object 21 is mounted, the force is transmitted to the supported object 21 due to the influence of the friction of the contact support portion of the fixed body. Will also deform. In such a case, the legs 23 and 24 are supplied with air, and the distortion inside the supported object 21 is released by temporarily switching to the six-degree-of-freedom restricted support mode. After that, by switching each support portion to contact support of a fixed body with three degrees of freedom restraint of X, Y, and Z again, a highly rigid support state can be maintained. Even when air is supplied to the legs 23 and 24, the supported object 21 is in a state of being restrained by the kinematic mount with respect to the support base 22 with six degrees of freedom, so that the positional relationship of the supported object 21 is supported. There is no deviation from the base 22.

  FIG. 5 shows a three-dimensional shape measuring apparatus according to the third embodiment, which is a stylus along the measurement surface of the measurement object 103 on the measurement table 102 supported on the floor surface via the vibration absorbing member 101. The surface shape of the DUT 103 is measured by moving the probe 104 and measuring the relative distance between the three-dimensional position of the probe 104 and the reference mirrors 105a to 105c that are measurement references. The measurement table 102 on which the object to be measured 103 is mounted and the frame 106 that holds the reference mirrors 105a to 105c need to be kept in constant relative distance during measurement and must be connected in structure. However, at the same time, each of the reference mirrors 105a to 105c itself is required not to be deformed due to the influence of the deformation of the measurement table 102 that occurs when the object to be measured 103 is removed. Therefore, by using the three-point support device according to the second embodiment for the support structure of the frame 106 that supports the reference mirrors 105a to 105c, when the frame 106 is distorted, the support form is changed to a kinematic mount. By switching, the relative movement between the frame 106 and the measuring table 102 is enabled to release the distortion, and the frame 106 is returned to the original stable shape. And it switches to a highly rigid fixed body contact support again.

  During measurement, the measurement table 102 on which the object 103 to be measured 103 is mounted and the frame 106 holding the reference mirrors 105a to 105c are structurally connected, and the direction of gravity acceleration due to vibration from the floor or the inclination of the apparatus is maintained. Since the reference mirrors 105a to 105c are not easily affected by disturbance acceleration such as a change in the distance and the distance between the relative mirrors can always be kept constant, highly accurate three-dimensional shape measurement is possible.

  Similarly, using the three-point support device according to Example 2 for the support structure of the object to be measured 103, after the object 103 is placed on the measurement table 102, the support form is temporarily switched to the kinematic mount, By enabling relative movement between the object to be measured 103 and the measuring table 102, distortion generated when the object to be measured 103 is placed is released. After that, by returning the support form to the original state again, the shape is measured and supported in a support form by contact with a three-point fixed body having a large support rigidity. In this way, it is possible to support the object 103 in a state where there is no shape change, and at the same time, to perform highly accurate and stable three-dimensional shape measurement without being affected by disturbance acceleration or the like.

  The drive unit of the three-dimensional shape measuring apparatus shown in FIG. 5 has a feed screw 113 connected to a Y slide 111, a rolling guide 112, and a rotation motor (not shown) on a surface plate 110 supported on the floor surface. On the Y slide 111, an X slide 114, a rolling guide 115, a feed screw 116, and a rotation motor 117 are provided. Further, on the X slide 114, a Z slide 118, a Z slide guide 119, a feed screw 120, and a rotary motor 121 are provided. A housing 130 that supports the contact-type probe 104 is fixed to the tip of the Z slide 118.

  The contact-type probe 104 is for measuring the height of the surface of the object 103 to be measured in the Z direction, and is supported by the housing 130 so as to be movable only in the Z direction via parallel leaf springs 131a to 131d. Yes. A master ball 104a, which is a sphere whose shape accuracy is guaranteed to be high, is attached to the lower end of the probe 104, and a mirror 104b is provided on the upper part. A laser interferometer 134 is provided at a position directly above the probe 104 on the Z slide 118, and measures the distance Z1 between the Z reference mirror 105c and the mirror 104b above the probe 104. A displacement sensor 132 that detects the position of the mirror 104 b is attached to the housing 130, and detects the relative displacement of the probe 104 with respect to the housing 130. With the probe 104 in contact with the surface of the object to be measured 103, the X and Y slides 111 and 114 are driven to control the position of the Z slide 118 when scanning the surface of the object to be measured 103. Thus, the pressing pressure of the probe 104 against the object 103 to be measured can be made constant. In addition, laser interferometers 135 and 136 for measuring the distance in the X direction of the Z slide 118 are provided at the tip of the Z slide 118. The laser slide interferometers 135 and 136 are disposed between the upper and lower portions of the Z slide 118 and the X reference mirror 105a. The distances X1 and X2 are measured. A similar laser interferometer (not shown) is also provided in the Y direction, and the distances Y1 and Y2 between the two upper and lower portions of the Z slide 118 and the Y reference mirror 105b are measured. The reference mirrors 105a to 105c for X, Y, and Z are held by a frame 106 that is a single structure, and the frame 106 is the same as the legs 23 to 25 shown in FIG. It is supported by a three-point support device 107 using a supporting mechanism member having the structure. The object to be measured 103 is also supported on the measurement table 102 by a similar three-point support device 108.

  By simultaneously measuring the distance Z1 and the distances X1, X2, Y1, and Y2 when the probe 104 scans the surface of the object 103 while keeping the pressure applied to the object 103 constant, the object to be measured is measured. The relative distance from the reference mirrors 105a to 105c of the X, Y, and Z of the master ball 104a in contact with the 103 can be accurately known. This position information is caused by the natural frequency of the structure having various frequency components such as the frame 106, the measurement table 102, and the Z slide 118 in addition to the three-dimensional shape of the surface of the object 103 to be measured. The noise is mixed. However, since these noises are components having a temporal frequency, and the three-dimensional shape of the surface of the object 103 to be measured is a component having no temporal frequency, it is averaged at a predetermined time. Accordingly, it is possible to cancel only the frequency component, and it is possible to extract only the three-dimensional shape of the surface of the DUT 103.

  In this three-dimensional shape measuring apparatus, the surface shape of the DUT 103 is obtained from position information of the master ball 104 a from the reference mirrors 105 a to 105 c held by the frame 106. Therefore, deformation of the frame 106 that supports the reference mirror causes a measurement shape error of the object 103 to be measured, and therefore it is desirable that the frame 106 always maintain the same shape. In addition, since a change in relative displacement between the DUT 103 and the frame 106 during measurement also causes an error, the frame 106 and the measurement table 102 are firmly connected during measurement and the frame 106 and the measurement table 102 are connected to each other. It is desirable that the natural frequency be as high as possible. The object to be measured 103 mounted on the measuring table 102 has various shapes and weights, and the deformation state of the measuring table 102 changes each time various objects to be measured are mounted. In order to cope with this problem, in this embodiment, the frame 106 that supports the reference mirror is supported on the measurement table 102 by using the same three-point support device 107 as that in the second embodiment.

  That is, depending on the presence or absence of air supply to the legs 23 and 25, the support form of the frame 106 includes three support forms by contact with a fixed body having a large support rigidity, and three points 6 that can release distortion inside the supported object. It is possible to switch to a freedom-constrained support form (kinematic mount). After mounting the object to be measured 103 on the measurement table 102, air is supplied to the legs 23 and 24 to support the six-degree-of-freedom restraint, so that the distortion generated in the frame 106 due to the deformation of the measurement table 102 or the like. After releasing, the legs 23 and 24 are evacuated and switched to contact support of a three-point fixed body having high support rigidity at the time of shape measurement.

  Similarly, the object to be measured 103 is also supported by using the same three-point support device 108 as in the second embodiment, so that the strain at the time of placing on the measuring table 102 is released, and the support rigidity is measured at the time of shape measurement. It can be supported by a large three-point fixed body contact support.

  In this way, the reproducibility of the shape of the frame 106 that supports the reference mirrors 105a to 105c and the object 103 to be measured is improved, and at the same time, the frame 106 that is being measured as compared with the case where it is always supported by a kinematic mount, etc. Therefore, it is possible to increase the noise frequency due to the natural frequency of the structure at the time of measurement, and to reduce the amplitude. As a result, the measurement accuracy can be improved and the measurement time can be greatly reduced by reducing the data sampling time for noise averaging.

The three-point support apparatus by Example 1 is shown, (a) is the top view, (b) is an elevation view which shows each leg part in a cross section. It is sectional drawing which shows the internal structure of the leg part of FIG. The three-point support apparatus by Example 2 is shown, (a) is the top view, (b) is an elevation view which shows only each leg part in a cross section. It is a figure which shows the internal structure of each leg part of FIG. 6 is a schematic diagram illustrating a three-dimensional shape measuring apparatus according to Embodiment 3. FIG. It is a figure which shows the kinematic mount by one prior art example. It is a figure which shows another prior art example.

Explanation of symbols

1, 21 Supported object 2, 22 Support base 3, 23, 24, 25 Leg 11, 18 Leg 12 Fixed support 13 Flange 14 Elastic support means 14a Housing 14b Stand 14c Plate spring 15 Thrust bearing 15a, 15b Flat plate 15c Sphere 15d Cage 16 Bellows cylinder 17 X guide 19 Receiving seat 102 Measuring table 103 Object to be measured 104 Stylus 105a-105c Reference mirror 106 Frame 107, 108 Three-point support device 110 Surface plate 111 Y slide 114 X slide 118 Z slide 134-136 Laser interferometer

Claims (5)

  A three-point support device that supports a supported object via three legs between the support base and at least one leg is a fixed body that restrains at least the degrees of freedom in the X, Y, and Z directions. The first support mechanism, the second support mechanism by a movable body having at least one of four degrees of freedom in the X, Y, ωX, and ωY directions, and the first and second support mechanisms alternately A three-point support device comprising switching means for disabling operation.   A three-point support device for supporting a supported object via three legs between a support base and a first leg by a fixed body that restrains at least the degrees of freedom in the X, Y, and Z directions A support form and a support form by a movable body having four degrees of freedom in the X, Y, ωX, and ωY directions can be switched alternately, and the second leg portion has at least degrees of freedom in the X, Y, and Z directions. The support form by the fixed body to be constrained and the support form by the movable body having three degrees of freedom in one of the X and Y directions and in the ωX and ωY directions can be switched alternately, and the third leg portion is ωX , ΩY, ωZ direction, has a support form by rolling elements having three degrees of freedom.   The said movable body is equipped with the bearing means which has a some spherical body between two flat plates, and the elastic support means which supports the said bearing means elastically, The Claim 1 or 2 characterized by the above-mentioned. 3-point support device.   A three-point support device according to any one of claims 1 to 3, a measurement table, and a stylus, wherein the object to be measured is supported on the measurement table via the three-point support device, A three-dimensional shape measuring apparatus for measuring a three-dimensional position of the stylus while bringing the stylus into contact with a surface to be measured of a measurement object and moving the stylus along the surface to be measured.   A three-point support device according to any one of claims 1 to 3, a measurement table for supporting an object to be measured, a stylus, and a frame having a measurement reference for measuring a three-dimensional position of the stylus. The frame is supported on the measurement table via the three-point support device, the stylus is brought into contact with the surface to be measured of the object to be measured, and the touch is moved along the surface to be measured. A three-dimensional shape measuring apparatus for measuring a three-dimensional position of a needle.

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