Abstract:
A spin stand for testing a head or disk, comprising a base and a stage connected to the base through a rolling bearing. In the spin stand, the stage can be rapidly and stably fixed to the base. A fixing device is sucked to be connected to the base and the stage, and the stage is fixed to the base.

Description:
FIELD OF THE INVENTION  
       [0001]     The present invention pertains to a spin stand for testing heads or disks, and in particular, relates to a spin stand comprising a base and a stage that communicates with the base via an antifriction bearing.  
       DISCUSSION OF THE BACKGROUND ART  
       [0002]     There are spin stands that are used for testing at least one of the heads or disks that are the structural elements of hard disk drives (for instance, refer to  FIG. 1  of JP (Kohyo) [National Publication of International Application, Unexamined] 2003-515,859; page 5 of JP (Kokai) [Unexamined Japanese Patent Publication] 2001-101,853, and page 4 of JP (Kokai) [Unexamined Japanese Patent Publication] 6[1994]-150,269).  
         [0003]     The spin stand is the device that rotates the disk, or aligns the head with the disk that rotates. The preliminary structural components of the spin stand are a base, a disk-rotating means, and an alignment means. The disk-rotating means and the alignment means are fastened to the base. The alignment means comprise a stage for supporting a head, a drive means for driving the stage, and a position detection means for detecting the position of the stage. The stage is fastened to the base by a bearing.  
         [0004]     The stage is disturbed by an outside force that is different from the force of the drive means. Today the alignment precision of a head on a spin stand must be 2 to 3 nanometers or less. Therefore, in order to maintain the required alignment precision, the position of the head is stabilized by anchoring the stage to the base once the stage has been moved to the desired position. A typical means for anchoring the stage to the base is an air chuck (for instance, refer to page 9 of JP (Kohyo) [National Publication of International Application, Unexamined] 2003-515,859 and page 5 of JP (Kokai) [Unexamined Japanese Patent Publication] 2001-101,853).  
         [0005]     There are problems with the position stability of the stage after alignment when the base and the stage of a spin stand are coupled via a ball bearing or other antifriction bearing. First, a linear stage that is coupled with the base via a ball bearing is indirectly anchored to the base as a result of an air chuck fastened to the stage via a flat spring that is attached to the base. A flat spring will mainly deform in a specific direction, but will also deform, although slightly, in other directions. Therefore, the relative positional relationship between the air chuck and the stage is not stable. Moreover, there are no examples of using a rotating stage in a conventional spin stand; therefore, there is no prior art for anchoring a rotating stage to the base. In short, to date there are no means for anchoring a stage to a base with stability in a spin stand where the base and the stage are coupled via an antifriction bearing. However, the alignment precision required of spin stands increases each year. Moreover, there is also a demand for a spin stand that performs frequent, high-speed alignment.  
         [0006]     Therefore, an object of the present invention is to provide a spin stand with which it is possible to accomplish a highly stable, high-speed anchoring of a stage fastened to a base via an antifriction bearing at the base.  
       SUMMARY OF THE INVENTION  
       [0007]     The present invention is a spin stand for testing a head or a disk that comprises a base and a stage fastened to the base via an antifriction bearing, characterized in that it further comprises an anchoring device, which is integrated as one unit with the base and the stage by being attached to the base and attached to the stage and thereby anchors the stage to the base, and with which it is possible to control the attachment as one unit of the base and the stage as well as the separation of the base and the stage.  
         [0008]     The part of the anchoring device that couples the base and the stage by attachment is made from an solid unit. The phrase “solid unit” as used in this application is intended to refer to a deformable unit with no moving parts.  
         [0009]     The spin stand also comprises a means for confirming the attached state of the anchoring device and the base or the attached state of the anchoring device and the stage.  
         [0010]     The force that attaches the anchoring device and the base and the force that attaches the anchoring device and the stage are weaker once the anchoring device has been integrated with the base and the stage than before the base and the stage have been integrated.  
         [0011]     The stage comprises a first magnetic body, the base comprises a the second magnetic body, and the anchoring device comprises a magnet for attaching to the first magnetic body and second magnetic body by magnetic force.  
         [0012]     The spin stand further comprises a means for separating the magnet from the first magnetic body and the second magnetic body when the magnet is magnetically attached to the first and second magnetic bodies.  
         [0013]     The base comprises two smooth surfaces, and the anchoring device comprises an air chuck that can be attached and removed from the first and second smooth surfaces by controlling air pressure.  
         [0014]     By means of the present invention, an solid unit is attached to the base and stage; therefore, the base and stage are firmly integrated as one unit and the stage is anchored to the base. Moreover, pressure is not applied to the base and the stage and the load applied to the moving parts, such as the bearing parts related to the base and the stage is alleviated.  
         [0015]     In addition, the state of attachment with the base and the stage can be confirmed by means of the present invention; therefore, the anchoring capability of the anchoring device can be realized with stability and certainty.  
         [0016]     The present invention is such that the magnet in an attached state is pulled away under force; therefore, the anchored state of the stage can be released within a predetermined time.  
         [0017]     By means of the present invention, the force of attachment of the anchoring device weakens once the anchoring device has been attached to both the stage and the base; therefore, the necessary electricity and generation of heat are controlled. Thus, for instance, it is possible to alleviate the effect of heat on the device under test and the equipment and circuits around the magnet.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0018]      FIG. 1  is an oblique view from the top showing a spin stand  100 .  
         [0019]      FIG. 2  is an oblique view from the bottom showing the spin stand  100 .  
         [0020]      FIG. 3  is a cross section of an anchoring device  300  of the present invention.  
         [0021]      FIG. 4  is a cross section of the anchoring device  300  of the present invention.  
         [0022]      FIG. 5  is a cross section of the anchoring device  300  of the present invention.  
         [0023]      FIG. 6  is a cross section of an anchoring device  400  of the present invention.  
         [0024]      FIG. 7  is a cross section of the anchoring device  400  of the present invention.  
         [0025]      FIG. 8  is an oblique view from the top showing a spin stand  500 .  
         [0026]      FIG. 9  is a cross section of an anchoring device  700  of the present invention.  
         [0027]      FIG. 10  is a cross section of the anchoring device  700  of the present invention 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0028]     The present invention will now be described based on the preferred embodiments shown in the attached drawings. The first embodiment of the present invention is a spin stand  100  for testing at least one head or disk. Refer to  FIGS. 1 and 2 .  FIG. 1  is a drawing wherein the spin stand  100  is shown at an inclined angle viewed from the top.  FIG. 2  is a drawing wherein the spin stand  100  is shown at an inclined angle viewed from the bottom. The same reference numbers are used in  FIG. 2  for the parts that are the same as in  FIG. 1 . Spin stand  100  comprises a base  110 , a disk-rotating device  120 , a piezo stage  130 , and a rotating stage  140 . Base  110  comprises a top plate  111  and side plates  112 . Disk-rotating device  120  is the device that rotates disks, which are not illustrated. Piezo stage  130  is the device for linear fine alignment of a head  200 , and is fastened on top of a top plate  141  of rotating stage  140 . Piezo stage  130  aligns head  200  in the direction of arrow A. The direction of arrow A is the direction, or includes the direction, perpendicular to the gap center line (not illustrated) of head  200 . Rotating stage  140  is fastened to base  110  via an antifriction bearing  150 . Rotating stage  140  rotates and aligns piezo stage  130  in the direction of arrow B using a drive means and a position detecting means that are not illustrated. When piezo stage  130  is rotated and aligned, the alignment direction A of piezo stage  130  also changes.  
         [0029]     Moreover, spin stand  100  comprises an anchoring device  300 . Anchoring device  300  is the device that anchors rotating stage  140  to base  110  using a magnet  330 . Magnet  330  is magnetically attached and integrated as one unit with base  110  and rotating stage  140 ; as a result, rotating stage  140  is anchored to base  110 . Base  110  comprises a magnetic plate  220  for attaching magnet  330 . Rotating stage  140  comprises a magnetic plate  210  for attaching magnet  330 . Magnetic plates  210  and  220  are sheets made of iron.  
         [0030]     Refer to  FIGS. 2 and 3  below.  FIG. 3  is the C-C cross section of  FIG. 2 . The same reference numbers are used in  FIG. 3  for the parts that are the same as in  FIG. 2 . There is no difference in grade between a surface  211  of magnetic plate  220  and a surface  221  of magnetic plate  220 . Surfaces  211  and  221  are perpendicular to the rotating shaft of rotating stage  140 . Magnet  330  is fastened to base  110  via a flat spring  340  such that an attachment surface  331  faces surfaces  211  and  222 . Attachment surface  331  of magnet  330  is shaped such that it can simultaneously fit closely with surfaces  211  and  221 . Flat spring  340  is bridge-shaped, and ends  341  thereof are anchored to base  110 . Moreover, a magnetic plate  380  is attached to the surface of flat spring  340  at the surface opposite the surface to which magnet  330  is fastened. Magnetic plate  380  is a flat sheet made of iron. An insulator  370  is disposed in between magnetic plate  380  and flat spring  340 . Insulator  370  is made from, for instance, MC Nylon®. A magnet  350  is fastened to base  110  via a support unit  360  such that it is opposite magnetic plate  380 . A magnet  350  is not anchored to magnetic plate  380 . The magnetism produced by magnets  330  and  350  is turned on and off and the magnetic force of the magnets is controlled by control circuit C, which is not illustrated. Control circuit C (not illustrated) can be a part of spin stand  100  or it can be an external device.  
         [0031]     The operation of anchoring device  300  with the above-mentioned structure will now be described.  FIG. 3  shows the state where rotating stage  140  and base  110  are not anchored. This is the normal state. When voltage is applied to magnet  330 , magnet  330  is attached to magnetic plates  210  and  220  by the magnetic force that is generated. Refer now to  FIG. 4 .  FIG. 4  is the same C-C cross section of  FIG. 2  as in  FIG. 3 . However, it differs from  FIG. 3  in that magnet  330  is attached to magnetic plates  210  and  220 . The same reference numbers are used for the parts in  FIG. 4  that are the same as in  FIG. 3 . Magnetic plate  210  in  FIG. 4  is anchored so that it is integrated as one unit with magnetic plate  220  via magnet  330 . Magnetic plate  210  is anchored to rotating stage  140  and magnetic plate  220  is anchored to base  110 . Therefore, rotating stage  140  is anchored such that it is integrated as one unit with base  110  via magnet  330 . Magnet  330  that couples rotating stage  140  and base  110  is a single solid unit; therefore, is integrated under force with rotating stage  140  and base  110  to obtain a stable anchored state. Moreover, magnet  330  is attached to magnetic plates  210  and  220 ; as a result, force is not applied to rotating stage  140  or base  110  when the anchored state is produced. Consequently, little load is applied to the rotating shaft of rotating stage  140  (not illustrated) or antifriction bearing  150 .  
         [0032]     As previously mentioned, attachment surface  331  of magnet  330  has a shape that simultaneously fits closely with surfaces  211  and  221 . Thus, base  110  and rotating stage  140  are integrated into one unit under force. Nevertheless, if any dust or similar contamination penetrates in between surface  211  or  221  and attachment surface  331 , the contact between the surfaces will not be complete; as a result, the anchored state between rotating stage  140  and base  110  will be unstable. Moreover, if magnet  330  is not carefully controlled, the anchored state between rotating stage  140  and base  110  will also be unstable. When head  200  is aligned with piezo stage  130  in this unstable anchored state, there is a chance that rotating stage  140  will move in the direction opposite to that in which head  200  is driven, and a high-precision alignment of rotating stage  140  and head  200  will not be achieved. Therefore, anchoring device  300  of the present embodiment applies voltage to flat spring  340  and confirms the state of contact between surface  221  and attachment surface  331  by confirming the conducting state between flat spring  340  and magnetic plate  220 . Thus, it is possible to confirm the state of attachment of magnetic plate  210  and magnet  330  and also the state of attachment of magnetic plate  220  and magnet  330 ; therefore, the anchoring capability of the anchoring device can be realized with stability. In order to confirm the conducting state, magnet  330  and magnetic plate  220  are conductive. It is also possible to apply voltage to magnetic plate  210  and confirm that electricity is being conducted between magnetic plates  210  and  220 . However, attachment surface  331  has a shape such that it can simultaneously contact surfaces  211  and  221 ; therefore, it is difficult for attachment surface  331  to touch only one of surfaces  211  and  221 . Consequently, it is sufficient to confirm the state of contact between surface  211  or surface  221  and attachment surface  331  as described above.  
         [0033]      FIG. 5  shows the path of the lines of magnetic force generated by magnet  330 . Magnet  330  in the figure comprises a coil  332  and a core  333 . The magnetic force of magnet  330  is produced by coil  332 . When current flows to coil  332 , there is an S pole near the center of coil  332  and an N pole near the outside periphery. Core  333  covers all of magnet  330 , with the exception of the surfaces of magnet  330  that face magnetic plate  210  and magnetic plate  220 . When magnet  330  is attached to magnetic plates  210  and  220 , the magnetic line that is generated by coil  332  forms closed loops of magnetic flux  334  via magnetic plates  210  and  220 . Moreover, the lines of magnetic force generated by coil  332  form a closed loop of magnetic flux with core  333 . Virtually all of attachment surface  331  of magnet  330  can be covered. Consequently, when magnet  330  is attached to magnetic plates  210  and  220 , the lines of magnetic force generated by coil  332  do not leak to the outside. In addition, attachment surface  331  of magnet  330  is disposed close to magnetic plates  210  and  220 ; therefore, virtually none of the lines of magnetic force generated by coil  332  will leak to the outside, even before magnet  330  is attached to magnetic plates  210  and  220 . This is very important to devices for testing heads  200  and other magnetic elements. This is because effects from the surrounding magnetic field can influence the test results and are alleviated in this manner.  
         [0034]     Moreover, magnet  330  generates a strong magnetic force until it becomes attached to magnetic plates  210  and  220 , and once it is attached, the magnetic force that is generated weakens. For instance, just before magnet  330  is to be attached, 20 V are applied to magnet  330  and after attachment, the applied voltage is lowered to 10 V. This is because the magnetic force that is required to maintain an attached state once magnet  330  has attached to magnetic plates  210  and  220  can be reduced in comparison to the force when the magnet is to be attached. The amount of heat generated by magnet  330  can be reduced by controlling the applied voltage in this way.  
         [0035]     Next, the operation for releasing the attached state of magnet  330  will be explained, that is, the state of attachment between magnet  330  and magnetic plate  210  and the state of attachment between magnet  330  and magnetic plate  220 . The voltage applied to magnet  330  is first brought to zero in  FIG. 4 . Bringing the voltage applied to magnet  330  to zero does not mean that there is no closed loop of magnetic flux  334 ; therefore, magnet  330  is kept in an attached state. Moreover, when a voltage opposite to that applied for attachment is applied to magnet  330 , the direction of the closed loop of magnetic flux  334  in  FIG. 5  simply reverses itself. That is, the attached state of magnet  330  is maintained. Therefore, it is necessary to pull magnet  330  away from magnetic plates  210  and  220  under force in order to quickly release the attached state of magnet  330 . Specifically, magnetic plate  380  is drawn in by magnet  350  and magnet  330  is thus pulled away from magnetic plates  210  and  220 . As a result, anchoring device  300  is in the state shown in  FIG. 3 . Moreover, although not illustrated, like magnet  330 , magnet  350  comprises a core and coil. In contrast to magnet  330 , magnet  350  generates a strong magnetic force until it becomes attached to magnetic plate  380 , but the magnetic force that is generated becomes zero once the magnet is attached. Once magnet  330  is pulled away from magnetic plates  210  and  220 , anchoring device  300  comes to rest with flat spring  340  in the state shown in  FIG. 3 ; therefore, it is not necessary for magnet  350  to continuously generate magnetic force. Magnetic plate  380  has a sufficient surface area for attachment and magnet  350  is disposed next to magnetic plate  380 . Therefore, the lines of magnetic force that leak from magnet  350  can be controlled. This method with magnet  350 , for instance, makes it possible to pull magnet  330  away within a specific time and with certainty when compared to methods where the magnet is pulled away under gravity by attaching a weight to magnet  330 . Therefore, stable, high-speed release of the attached state of magnet  330  is possible.  
         [0036]     Magnets  330  and  350  generate a magnetic field. There are times when this field can be a source of errors when measuring head  200  or another magnetic element. Magnetic plate  210  and similar components are disposed in spin stand  100  between head  200  and magnets  330  and  350 ; therefore, the magnetic field is kept from affecting the measurements of head  200 .  
         [0037]     There can be a difference in grades between surfaces  211  and  221  in the first embodiment, and attachment surface  331  can be graded to match this difference in grade. Moreover, surfaces  211  and  221  and attachment surface  331  can be curved rather than flat. In other words, the shape thereof does not matter as long as simultaneous attachment is possible.  
         [0038]     Next, a second embodiment of the present invention will be described. The second embodiment of the present invention is a spin stand for testing heads or disks, and is the same as that shown in  FIGS. 1 and 2 . However, by means of the second embodiment of the present invention, an anchoring device  400  is used in place of anchoring device  300  in spin stand  100 . Moreover, this results in several elements being omitted or modified. Anchoring device  400  is characterized in that an air chuck is used in place of the magnet as an attachment means.  
         [0039]      FIG. 6  shows a cross section of anchoring device  400  here. The same reference numbers are used for the elements in  FIG. 6  that are the same as in  FIGS. 2 and 3 . Anchoring device  400  is a device for anchoring rotating stage  140  to base  110  using an attachment block  430 . Attachment block  430  is fastened and integrated as one unit with rotating stage  140  and base  110  and this results in rotating stage  140  being anchored to base  110 . Rotating stage  140  comprises a smooth plate  230  for attaching to attachment block  430 . Base  110  comprises a smooth plate  240  for attaching to attachment block  430 . Smooth plates  230  and  240  are sheets made from aluminum. Smooth plates  230  and  240  respectively comprise smooth surfaces  231  and  241  having a degree of roughness of 5 microns or less. Smooth surfaces  231  and  241  do not differ in grade. Moreover, smooth surfaces  231  and  241  are surfaces that are perpendicular to the rotating shaft of rotating stage  140 .  
         [0040]     Attachment block  430  comprises an air chuck  460  and an attachment surface  431 . Attachment block  430  is fastened to base  110  via flat spring  340  such that attachment surface  431  faces smooth surfaces  231  and  241 . Attachment surface  431  of attachment block  430  has a shape such that it can simultaneously attach to smooth surfaces  231  and  241 . Flat spring  340  is bridge-shaped, and ends  341  thereof are anchored to base  110 . The air pressure produced by air chuck  460  is turned on and off and the extent of this air pressure is controlled by an air feed-emission device P (not illustrated) connected to air chuck  460  via an air path  470 . Air feed-emission device P (not illustrated) can be part of spin stand  100 , or it can be an external device.  
         [0041]     The operation of anchoring device  400  with the above-mentioned structure will now be described.  FIG. 6  shows the state where rotating stage  140  and base  110  are not anchored. This is the normal state. Air is sucked into air chuck  460  by the effect of air feed-emission device P (not illustrated). When this is done, a negative pressure is generated at air chuck  460 . Attachment block  430  attaches to smooth plates  230  and  240  under this negative pressure that is generated. Refer now to  FIG. 7 .  FIG. 7  is a cross section showing the same anchoring device as in  FIG. 6 , but in contrast to  FIG. 6 , attachment block  430  is attached to smooth plates  230  and  240 . The same reference numbers are used for the parts in  FIG. 7  that are the same as in  FIG. 6 . Smooth plate  230  in  FIG. 7  is anchored such that it is integrated as one unit with smooth plate  240  via attachment block  430 . Smooth plate  230  is anchored to rotating stage  140  and smooth plate  240  is anchored to base  110 ; therefore, rotating stage  140  is anchored such that it is integrated as one unit with base  110  via attachment block  430 . Attachment block  430  that couples rotating stage  140  and base  110  is a single solid unit, and a stable integrated state is obtained by integrating rotating stage  140  and base  110  as one unit under force. Moreover, attachment block  430  is attached to rotating stage  140  and base  110 ; therefore, force is not applied to rotating stage  140  or base  110  as a result of anchoring. Consequently, little load is applied to the rotating shaft (not illustrated) of rotating stage  140  or antifriction bearing  150 .  
         [0042]     As previously mentioned, attachment surface  431  of attachment block  430  has a shape that simultaneously fits closely with surfaces  231  and  241 . Thus, base  110  and rotating stage  140  are integrated into one unit under force. Nevertheless, if any dust or similar contamination penetrates in between surface  231  or  241  and attachment surface  431 , the contact between the surfaces will not be complete; as a result, the anchored state between rotating stage  140  and base  110  will be unstable. Moreover, if air chuck  460  is not carefully controlled, the anchored state between rotating stage  140  and base  110  will also be unstable. When head  200  is aligned with piezo stage  130  in this unstable anchored state, there is a chance that rotating stage  140  will move in the direction opposite to that in which head  200  is driven, and a high-precision alignment of rotating stage  140  and head  200  will not be achieved. Therefore, anchoring device  400  of the present embodiment confirms the state of contact between smooth surface  231  and attachment surface  431  as well as the state of contact between smooth surface  241  and attachment surface  431  by confirming the load applied to air feed-emission device P (not illustrated). The difference between the load applied to air feed-emission device P (not illustrated) when contact between these surfaces is complete and when it is incomplete is used. As a result, it is possible to provide a stable anchoring capability of anchoring device  400 .  
         [0043]     Attachment block  430  generates a strong negative pressure until it becomes attached to smooth plates  230  and  240 , and once it does become attached, this negative pressure is greatly diminished. This is because once attachment block  430  has become attached to smooth plates  230  and  240 , the negative pressure needed to maintain the attached state can be smaller than before the block becomes attached. Of course, it is not necessary to reduce the negative force that is generated after attachment.  
         [0044]     Next, the operation for the release of the attached state of attachment block  430 , that is the attached state of smooth plate  230  and attachment block  430  and the attached state of smooth plate  240  and attachment block  430 , will be described. Air is released from air chuck  460  by the operation of air feed-emission device P (not illustrated). As a result, a positive pressure is generated at air chuck  460 . Attachment block  430  is pulled away from smooth plates  230  and  240  by the positive pressure that is generated. Anchoring device  400  wherein the attached state of attachment block  430  has been released is as shown in  FIG. 6 . Once attachment block  430  moves away from smooth plates  230  and  240 , anchoring device  400  comes to rest as shown in  FIG. 6  and there is no need for air chuck  460  to continuously generate a positive pressure. Just as when a magnet is used, it is possible to pull attachment block  430  away within a specific time and with certainty by the release method with air chuck  460 ; therefore, a stable, high-speed release of the attached state of attachment block  430  is possible. Moreover, when compared to the use of a magnet, the method that uses air chuck  460  does not require an additional means for releasing the attached state of attachment block  430 . In addition, the method that uses air chuck  460  has virtually no effect on the head test results.  
         [0045]     A third embodiment of the present invention will now be described. The third embodiment of the present invention is a spin stand  500  for testing at least one head or disk. Refer now to  FIG. 8 .  FIG. 8  is a drawing showing spin stand  500  at an inclined angle viewed from the top.  
         [0046]     Spin stand  500  comprises abase  510  and a linear stage  520 . Base  510  comprises a top plate  511  and support poles  512  and  513  standing upright on top plate  511 . Support pole  512  comprises a magnetic plate  611  at the top. Support pole  513  comprises a magnetic plate  612  at the top. A linear guide  531 , which is one example of an antifriction bearing, is fastened to the top of magnetic panel  611 . A linear guide  532 , which is an example of an antifriction bearing, is fastened to the top of magnetic plate  612 . Linear stage  520  is supported by linear guides  531  and  532 , and is aligned in the direction of arrow D by a drive source  540 . Moreover, linear stage  520  comprises a magnetic plate  620  at the bottom.  
         [0047]     Refer to  FIGS. 9 and 10  next;  FIG. 9  is the E-E cross section in  FIG. 8 .  FIG. 10  is the F-F cross section in  FIG. 9 . The same reference numbers are used for the parts in  FIG. 9  that are the same as in  FIG. 8 . The same reference numbers are used for the parts in  FIG. 10  that are the same as in  FIG. 9 . Spin stand  500  comprises an anchoring device  700 . Anchoring device  700  is the device that anchors linear stage  520  to base  510  using magnets  710  and  750 . Magnet  710  is attached to and is integrated as one unit with magnetic plates  611  and  620 , and magnet  750  is attached to and is integrated as one unit with magnetic plates  612  and  620 . Anchoring device  700  anchors rotating stage  140  to base  110  by this integration of parts.  
         [0048]     Magnet  710  is attached to base  510  via a flat spring  720 . Magnet  750  is attached to base  510  via a flat spring  760 . Magnet  710  has a shape such that it can simultaneously fasten to magnetic plates  611  and  620 . Magnet  750  has a shape such that it can simultaneously fasten to magnetic plates  612  and  620 . Flat spring  720  is bridge-shaped, and ends  721  thereof are anchored to base  510 . Magnetic plate  730  is fastened to the surface of flat spring  720  opposite the surface to which magnet  710  is attached. Magnetic plates  730  and  770  are sheets made of iron. Magnetic plate  730  and flat spring  720  are electrically insulated. Magnetic plate  770  and flat spring  760  are also electrically insulated. A magnet  740  is fastened to base  510  such that it faces magnetic plate  730 . Moreover, a magnet  780  is fastened to base  510  such that it faces magnetic plate  770 . The magnetic forces generated by magnets  710 ,  740 ,  750 , and  780  are turned on and off and the extent of these forces is controlled by a control circuit G that is not illustrated. Control circuit G (not illustrated) can be a part of spin stand  500  or it can be an external device.  
         [0049]     The operation of anchoring device  700  made as described above will now be explained.  FIGS. 9 and 10  show free-acting stage  520  and base  510  in an unanchored state. This is the normal state. When voltage is applied to magnets  710  and  750 , magnet  710  becomes magnetically attached to magnetic plates  611  and  620 , and magnet  750  becomes magnetically attached to magnetic plates  612  and  620 . Magnet  710  and magnetic plates  611 ,  612 , and  620  are conductive. Therefore, as in the first embodiment, the state of attachment between magnet  710  and magnetic plates  611  and  620 , and the state of attachment between magnet  750  and magnetic plates  612  and  620  can be electrically confirmed. Magnetic plate  620  is anchored to free-acting stage  520 , and magnetic plates  611  and  612  are anchored to base  510 . Therefore, free-acting stage  520  is anchored, integrated as one unit with base  510  via magnets  710  and  750 . Magnets  710  and  750  that couple linear stage  520  and base  510  are a single solid unit, so that linear stage  520  and base  510  therefore are integrated as one unit under force to obtain a stable state. Moreover, pressure is not applied to linear stage  520  or base  510  when they are anchored. Magnets  710  and  750  generate strong magnetic forces until they become attached to magnetic plates  620 , etc., and after they become attached, the magnetic force that is generated weakens. When the state of attachment of magnets  710  and  750  is released, the voltage applied to magnets  710  and  750  becomes zero, and magnets  710  and  750  are pulled away from magnetic plates  620 , etc., under force by magnets  740  and  780 .  
         [0050]     The magnetic plates in the first and third embodiments should be magnetic bodies such that magnets can be attached. Therefore, they are not limited to iron and can also be made of nickel, cobalt, and similar materials.  
         [0051]     In addition, the smooth plates in the second embodiment should have a smooth surface such that the attachment blocks can attach. Therefore, they are not limited to aluminum and can be made of iron, or another metal, resin, and similar materials.  
         [0052]     The means used to confirm the state of attachment in the first through third embodiments is not limited to electrical means, and optical or mechanical means can also be used.  
         [0053]     Furthermore, the shape of the attaching part in the first through third embodiments is not necessarily flat.  
         [0054]     The insulation in the first through third embodiments must be a material that provides an electrical insulation; therefore, it can be made from ceramic, rubber, and similar materials.  
         [0055]     The anchoring device in the first through third embodiments can use an attachment means other than a magnetic force or a negative pressure.