JP2002074764A - Slide table device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a slide table device which is easy in fabrication and assembly of parts, allows stable feeding without the occurrence of uneven speeds, is strong against disturbance and is excellent in static performance while a drive motor is off. SOLUTION: A table 3 is freely advanceably and retreatably installed across a static pressure direct action bearing 2 to a base 1. The base 1 is provided with a main spindle 5 which is rotationally driven by the motor. This main spindle 5 is provided with a roller 9 which comes into contact therewith at an angle of inclination therewith. The roller 9 is freely rotationally installed on a yoke 10. The yoke 10 is freely vertically movably installed by means of a linear guide 11 to the table 3. The yoke 10 is provided with a circular hole 12 through which the main spindle 5 is passed and a plurality of permanent magnets 14 for impression of prepressure to the roller 9 are disposed in this circular hole 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a precision positioning slide table device used for an optical disk mastering device, a semiconductor inspection device, and the like.

[0002]

2. Description of the Related Art Conventionally, in a device requiring a high degree of precision, such as an optical disk mastering device or a semiconductor inspection device, a table is installed via a hydrostatic linear motion bearing so as to be able to move forward and backward. An air slide type slide table device is used. A voice coil type linear motor is generally used for driving the table,
A closed-loop control system is adopted using an interferometric laser length measuring device or a linear scale as a position detector. Further, in a device such as a semiconductor inspection device which needs to maintain a stationary state in order to observe a work after positioning, a device using a ball screw for driving a table is employed.

However, an air slide type slide table device with a voice coil type linear motor is completely non-contact, and thus is easily affected by disturbance. Therefore, there is a limit in increasing the resolution. Further, in the case where the ball screw is used for driving the slide body, speed irregularities such as moving in the axial direction while slightly moving occur due to an error in the shape of the thread groove or the ball diameter. Since the positioning accuracy is limited, high-density writing cannot be performed.

As a slide table device which solves such a problem, the present applicant has provided a friction advance / retreat drive device for supporting a table with a static pressure on a base and for driving the table forward / backward with respect to the base. (Japanese Patent Laid-Open No. 11-19 / 1999)
No. 5247). The above-mentioned friction advance / retreat drive device is shown in FIG.
As shown in FIG. 1, a roller 52 that is in contact with a main shaft 51 that is driven to rotate at an inclined angle is provided on a table 50, and the rotation of the main shaft 51 gives a propulsive force to the table 50 via the roller 52. Is done. Roller 52
Are equally arranged around the main shaft 51. According to this configuration, since the static pressure support and the friction advance / retreat drive device are combined, the table 50 can be guided with high accuracy by the static pressure support, and the table 50 moves with respect to the main shaft 51 in the traveling direction.
And is mechanically supported by the contact between the roller 52 and
Compared to a completely non-contact type, it is more resistant to external disturbances and has higher staticness when the motor is off, and can compensate for the weak point of static pressure support. Further, the friction advance / retreat drive device is composed of components having a simple shape such as a round shaft-shaped main shaft 51 and a roller 52 obliquely in contact with the shaft, and can relatively relatively accurately process each component, so that the speed unevenness is increased. , And stable feeding can be performed. For these reasons, the resolution of positioning can be improved, and high-density writing can be performed.

However, the example shown in FIG.
Therefore, if the inclination of the roller 52 with respect to the main shaft 51 is different, the lead of the roller 52 will be different, which may adversely affect the feeding accuracy. Therefore, the inclination of the rollers 52 with respect to the main shaft 51 must be the same for all three rollers. This requires time and cost because it requires a high level of technology for processing accuracy and assembly accuracy of each part.

In a slide table device provided with such a frictional advance / retreat drive device, when performing feedback control, a position detector 55 of a linear scale 54 is provided on a side surface of a table 50 as shown in FIG. A scale section 56 facing the position detection section 55 is installed on a base (not shown). The table 50 is supported on a base via a hydrostatic linear motion bearing 57 so as to be able to move forward and backward.

However, when the table 50 is moved, a slight inclination θ is generated in the table 50 as shown in FIG. When such a tilt θ occurs, the position of the table 50 where the position detection unit 55 is provided has a small error because the feedback control is performed, but the accuracy is poor at a position away from the position detection unit 55. When this slide table device is used in the optical disk mastering device, the optical head 60 is mounted on the table 5 as shown in FIG.
0 is attached to the side opposite to the position detection unit 55,
Write position P on optical disk by optical head 60
Is located away from the table 50. For this reason, even if the feedback control is performed, the position detection unit 55
At a writing position away from the position, the accuracy deteriorates.

SUMMARY OF THE INVENTION An object of the present invention is to provide a slide table device capable of performing stable feeding without causing speed unevenness, being resistant to disturbances, having excellent stationary performance when the drive motor is off, and being easy to process and assemble parts. That is. Another object of the present invention is to make it possible to drive the table forward and backward without giving an error factor due to shaft runout of the spindle to the table. Still another object of the present invention is to reduce a writing error caused by a tilt of a table when used in an optical disk mastering device.

[0009]

According to the present invention, there is provided a slide table device, comprising: a main shaft which is mounted on a base and driven to rotate;
A slide table device comprising a roller contacting the main shaft at an inclined angle and a yoke rotatably supporting the roller and penetrating the main shaft and connected to a table, having the following configuration. It is. That is,
A plurality of permanent magnets are arranged on the inner peripheral surface of the yoke facing the outer diameter surface of the main shaft, and a preload is applied to the roller with respect to the main shaft by a magnetic attraction force of the permanent magnet. According to this configuration, a force for attracting the yoke to the main shaft is generated by the magnetic attraction force of the permanent magnet. Since the roller is supported by the yoke, the roller is pressed against the main shaft. When the main shaft rotates in this pressed state, the rollers rotate with a lead angle by an inclination angle with respect to the main shaft, and the table is moved in the axial direction by the frictional force of the contact portion. As described above, the roller is pre-pressed to the main shaft by the magnetic attraction force, so that the roller stably contacts the main shaft. Therefore,
As in the case of the conventional friction advance / retreat drive device, stable feeding can be performed without causing speed unevenness. In addition, since the feed is given by the frictional force of the roller, it is resistant to disturbance, improves the resolution, and is excellent in the stationary performance when the movement is stopped.
Further, in this configuration, since only one roller is used, high precision is not required for component processing and assembly as compared with a conventional configuration using three rollers, and component processing and assembly are facilitated. In addition, the number of parts is small and the configuration is simple.

In the present invention, the yoke and the table may be connected vertically via a linear guide. As described above, when the yoke and the table are connected via the linear guide, it is possible to absorb the vertical movement generated during rotation due to a processing error of the main shaft and the rollers. In addition, since there is only one roller, there is a degree of freedom in the horizontal direction in the relationship between the roller and the main shaft, so that the table can be driven without affecting the table in the horizontal direction of the main shaft. Thus, the drive can be performed without giving an influence of an error factor generated by the spindle to the table.

In the present invention, the table may be slidably supported on the base via a hydrostatic direct-acting bearing. According to the static pressure linear motion bearing, the table can be guided with high accuracy by the static pressure support. It is supported by non-contact,
Since the table is mechanically supported by the contact between the main shaft and the roller in the traveling direction, the table is more resistant to disturbance than a completely non-contact table, and can compensate for the weak point of the static pressure support.

In the present invention, the yoke may have a circular hole through which the main shaft passes, and a roller may be disposed at the upper center of the circular hole, and the permanent magnet may be disposed on both sides of the roller. good. By arranging the permanent magnets on both sides of the roller in this way, an aligning force acts to make the yoke coincide with the axis of the main shaft. Therefore, in the relationship between the roller and the main shaft, it is possible to maintain the positional relation between the roller and the main shaft while avoiding the influence of the main shaft in the horizontal direction on the table with one roller.

The slide table device of each of the above structures of the present invention may be used for an optical disk mastering device. In that case, a position detection unit or a scale unit of the linear scale is provided on the optical head side mounted on the table, and the scale unit or the position detection unit of the linear scale is opposed to the position detection unit or the scale unit. It may be installed on a base. The detection data of the linear scale is used for feedback of table movement. As described above, by providing the position detection unit or the scale unit of the linear scale on the same side as the optical head with respect to the table, it is possible to reduce a writing position error caused by the inclination of the table. Therefore, highly accurate writing can be performed.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 1, a table 3 is installed on a base 1 via a hydrostatic linear motion bearing 2 so as to be able to advance and retreat, and a spindle of a friction advance / retreat drive device 4 is provided at the center of the hydrostatic linear motion bearing 2 in the width direction. 5 are installed. Friction advance / retreat drive 4
Rotates the main shaft 5 by a motor 7 which is a rotation drive source, and controls the rotation of the main shaft 5 by a roller 9 provided on the table 3.
Is converted into an advance / retreat operation of the table 3 via the.
The roller 9 is provided so as to be in contact with the main shaft 5 with an inclination angle. The main shaft 5 includes a bearing 8 installed on the base 1.
At one end, and the other end is supported by a bearing (not shown) in the speed reducer 6. In this example, an AC servomotor is used as the motor 7, and the rotation of the motor 7 is transmitted to the main shaft 5 via the speed reducer 6.

As shown in FIG. 5, the table 3 is formed in a saddle shape by a top plate portion 3a and side plate portions 3b which fall from both side edges thereof, and straddles the rail 2a of the hydrostatic linear motion bearing 2. I have. The rail 2 a is provided on the base 1 and serves as a guide unit for guiding the table 3. In this example, rail 2
a is formed in a thick upward groove shape, and the main shaft 5 is inserted into the groove. The rail 2a and the table 3 are both made of ceramics or metal.

The hydrostatic linear motion bearing 2 forms a minute bearing gap d between the rail 2a and the table 3, and has a large number of nozzles 4 provided on the top plate 3a and the side plate 3b of the table 3.
The table 3 is supported in a non-contact manner by the static pressure of the bearing gap d by jetting compressed air from the bearing gap 3 into the bearing gap d. Each nozzle 43 communicates with a common air supply path 44 provided in the table 3.
Is connected to a compressed air supply source (not shown) by a flexible tube or the like via a supply port 45 provided at one place of the table 3. The air supply path 44 communicates with a pair of left and right main paths 44a provided in the top plate 3a of the table 3 along the forward and backward directions, a plurality of branch paths 44b branched from the main path 44a, and a branch path 44b. Side plate 3
b. Main route 4
The nozzle 43 is provided in each section of 4a and each vertical path 44c. Each of the paths 44a to 44c is composed of a linear drill hole, and two main paths 44a are connected to an external pipe 4 at one end.
6 communicate with each other. The other end of the main path 44a and the open end of the branch path 44b are both closed with plugs 47. Each nozzle 43 is formed in an orifice throttle as shown in FIG.

In the hydrostatic linear motion bearing 2 used in this embodiment, as means for restricting the lifting of the table 3, magnets 41 are provided at the lower ends of the side plates 3b on both sides of the table 3. A magnetic body 42 for generating an attraction force is provided in a rail shape along both sides of the rail 2a.

As shown in FIG. 2 and FIG.
Is rotatably mounted on the yoke 10 and the yoke 1
Numerals 0 are set up and down on the lower surface of the table 3 via the linear guide 11 on both side surfaces. More specifically, the roller 9 is rotatably supported on the outer periphery of a roller shaft 9 a having both ends fixed to the yoke 10. Note that instead of the roller 9 being rotatable with respect to the roller shaft 9a, the roller 9
a, and both ends of the roller shaft 9a may be rotatably supported by the yoke 10.

The yoke 10 has a circular hole 1 through which the main shaft 5 passes.
2 and is disposed at the upper center of the circular hole 12.
Specifically, the yoke 10 has a roller arrangement window 13 (FIG. 3) communicating with the upper center of the circular hole 12 and opening on the upper surface.
The roller 9 is arranged in the roller arrangement window 13, a part of which enters the circular hole 12, and comes into contact with the main shaft 5. York 10
As shown in the enlarged view of FIG. 4, permanent magnets 14 are disposed on both sides of the roller 9 in the circular hole 12. The material of the main shaft 5 is a magnetic material so that a magnetic attraction force is generated for the permanent magnet 14.

The yoke 10 is supported by the linear guide 11 via a pair of yoke supports 15 projecting from the lower surface of the table 3. The linear guide 11 is formed by connecting a pair of rails 16 and 17 via rolling elements so as to be able to advance and retreat in the longitudinal direction. One of the rails 16 extends vertically on the inner surface of the yoke support 15. The other track base 17 is attached to the side surface of the yoke 10 so as to extend vertically.

FIG. 6 shows an example of the linear guide 11.
The linear guide 11 is of a type called a cross roller way, and V-shaped track grooves 16a, 17a are formed on opposing surfaces of a pair of track bases 16, 17 to face each other.
A plurality of rolling elements 18 made of cylindrical rollers are interposed between the raceway grooves 16a and 17a in pairs, in a direction in which the roller axes are orthogonal to each other. Each rolling element 18 is held in each pocket of a plate-shaped retainer 19.

The linear guide 11 is not limited to the cross roller way type, but may be a ball type shown in FIG. Ball type linear guide 11
The rolling element 18 is a ball. Both way 16,
The track grooves 16a, 17a provided in the groove 17 may be grooves having an arc-shaped cross section as shown in the example of the figure, or may be grooves having a V-shape.

The operation of the above configuration will be described. The rotation of the motor 7 is transmitted to the main shaft 5 via the speed reducer 6. When the main shaft 5 rotates, the roller 9 rotates with a lead angle by an inclination angle with respect to the main shaft 5, and the table 3 moves in the axial direction due to the frictional force. In this case, the roller 9 is given a preload to the main shaft 5 by a magnetic attraction force generated between the permanent magnet 14 and the main shaft 5. Therefore, the roller 9
Makes stable contact with the main shaft 5 and can perform stable feeding without causing a problem of poor contact. Since only one roller 9 is used, high precision is not required for processing and assembling parts compared to the conventional case of using three rollers, processing and assembling are easy, the number of parts is small, and the structure is simple. It is. Further, since the yoke 10 is connected to the table 3 via the linear guide 11, it is possible to absorb the vertical movement that occurs during rotation due to a processing error of the main shaft 5 and the roller 9. Further, since there is only one roller 9, there is a degree of freedom in the horizontal direction in the relationship between the roller 9 and the main shaft 5, and the horizontal direction of the main shaft 5 does not affect the table 3.
Can be driven. Thus, the drive can be performed without giving the influence of the error factor generated by the main shaft 5 to the table 3.

The permanent magnet 14 for preloading the roller 9
Since the permanent magnets 14 are arranged on both sides, the horizontal component force Fx of the magnetic attraction force F (FIG. 4) of the permanent magnets 14 exerts an aligning force for making the yoke 10 coincide with the axis of the main shaft 5. I do. Therefore, in the relationship between the roller 9 and the main shaft 5, it is possible to maintain the positional relationship between the roller 9 and the main shaft 5 while avoiding the influence of the main shaft 5 in the horizontal direction on the table 3 with one roller 9.

Since the support of the table 3 with respect to the base 1 is performed through the static pressure linear motion bearing 2, the table 3 can be guided with high accuracy by the static pressure support. Since the table 3 is mechanically supported by the contact between the main shaft 5 and the roller 9 in the traveling direction, the table 3 is more resistant to disturbance than the completely non-contact type. It has excellent static performance when stopping, and can compensate for the weak point of static pressure support.

FIGS. 8 to 10 show an optical disc mastering device using the slide table device according to the above embodiment. The optical head 21 is attached to the table 3 so as to protrude from the side surface. The linear scale 22 for detecting the advance / retreat position of the table 3 includes a position detection unit 23
Is attached to the side surface of the table 3 on which the optical head 21 is attached, and the scale unit 2 facing the position detecting unit 23
4 is set on the base 1. It is preferable that the position detection unit 23 is further arranged such that the writing point P, which is the center of the position detection unit 23 and the optical head 21, is located on a straight line L parallel to the main axis 5. The position detection unit 23 is attached to the table 3 via an attachment stand 25 such as a bracket. The linear scale 22 may have a scale portion attached to the table 3 and a position detection portion attached to the base 1.
In that case, the scale portion and the writing point P are arranged so as to be located on the straight line L. Position detection data obtained by the position detection unit 23 of the linear scale 22 is used for feedback control in a control system that controls the motor 7.

In this configuration, since the position detector 23 of the linear scale 22 is located near the writing position P of the optical head 21, even if the table 3 is tilted as shown in FIG. The occurrence of an error in the positional relationship between the position detected by the linear scale 22 and the optical head 21 is reduced. Therefore, the table 3 is moved to the position detection unit 2.
In the case where the feedback control is performed according to the detection position of the table 3, even if the table 3 is inclined as described above, the error of the writing position P can be reduced. Therefore, highly accurate writing can be performed.

[0028]

According to the slide table apparatus of the present invention, a main shaft mounted on a base and driven to rotate, a roller in contact with the main shaft at an inclined angle, and the roller rotatably supported, In a slide table device including a yoke connected to a table through a main shaft,
A plurality of permanent magnets are arranged on the inner peripheral surface of the yoke facing the outer diameter surface of the main shaft, and a preload is applied to the roller with respect to the main shaft by a magnetic attraction force of the permanent magnet.
Stable feed can be performed without speed unevenness, it is resistant to disturbance, and it has excellent static performance when stopping.
It can be easily assembled. If the yoke and the table are connected via a linear guide so as to be vertically movable, the table can be driven forward and backward without giving an error factor due to shaft runout of the main shaft to the table. When the table is slidably supported on the base via a static pressure linear motion bearing, the table can be guided with high precision by the static pressure support, and the friction by one roller preloaded with a permanent magnet In combination with driving, more stable feeding can be performed. When the yoke has a circular hole that penetrates the main shaft, a roller is disposed in the upper center of the circular hole, and the permanent magnets are disposed on both sides of the roller, a centering action is obtained. A more stable table movement can be performed. When the slide table device of the present invention is used for an optical disc mastering device, a position detection unit or a scale unit of a linear scale is provided on the optical head mounted on the table, and the linear scale is opposed to the position detection unit or the scale unit. When the scale section or the position detecting section of the linear scale is installed on the base, errors generated due to the inclination of the table can be reduced, and highly accurate writing can be performed.

[Brief description of the drawings]

FIG. 1 is a plan view of a slide table device according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a sectional view taken along line BB of FIG. 2;

FIG. 4 is a partially enlarged view of FIG. 2;

5A is a plan view of a table in the slide table device, FIG. 5B is a cross-sectional view showing a relationship between the table and a hydrostatic linear bearing, and FIG. 5C is an enlarged cross-sectional view of a nozzle portion thereof. .

FIG. 6A is a partial perspective view of an example of a linear guide,
(B) is a sectional view thereof.

FIG. 7 is a cutaway perspective view of another example of the linear guide.

FIG. 8 is a partial plan view of an optical disc mastering device to which the slide table device according to the embodiment is applied.

FIG. 9 is an operation explanatory view showing the table inclination state in an emphasized manner.

FIG. 10 is a partial front view of a slide table device in the optical disc mastering device.

FIG. 11 is a partial cross-sectional view of a conventional example.

FIG. 12 is a plan view of another conventional example.

FIG. 13 is an operation explanatory view in the conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Base 2 ... Static pressure linear bearing 3 ... Table 4 ... Friction advance / retreat drive device 5 ... Spindle 7 ... Motor 9 ... Roller 10 ... Yoke 11 ... Linear guide 12 ... Circular hole 14 ... Permanent magnet 43 ... Nozzle

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01L 21/68 H01L 21/68 K F term (Reference) 2F078 CA08 CB05 CB09 CB12 CB13 3C029 AA33 3J102 AA02 BA05 CA10 CA16 EA02 EA07 EA13 GA20 5D121 AA02 BB21 BB38 5F031 CA01 JA45 LA02 LA12 MA33 PA02

Claims (5)

[Claims] 1. A main shaft installed on a base and driven to rotate, a roller contacting the main shaft with an inclination angle, a roller rotatably supported, and connected to a table through the main shaft. A plurality of permanent magnets are arranged on the inner peripheral surface of the yoke facing the outer diameter surface of the main shaft, and the magnetic attraction force of the permanent magnets causes the roller to be attached to the main shaft. A slide table device to which a preload is applied. 2. The slide table device according to claim 1, wherein the yoke and the table are vertically movably connected via a linear guide. 3. The slide table device according to claim 1, wherein the table is slidably supported on the base via a hydrostatic linear motion bearing. 4. The yoke has a circular hole through which the main shaft penetrates, a roller is disposed in the upper center of the circular hole, and the permanent magnets are disposed on both sides of the roller. Item 4. The slide table device according to any one of Items 3. 5. The slide table device according to claim 1, wherein the slide table device is used for an optical disk mastering device, and a position of a linear scale is detected on an optical head mounted on the table. A slide table device provided with a scale section or a scale section, and a scale section or a position detection section of a linear scale is installed on the base so as to face the position detection section or the scale section.