JPH11352265A - Stage - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a stage for accurately detecting the amount of travel for a traveling stand. SOLUTION: A stage 1 is provided with a fixed bed 3, a table 7 that is supported by the bed 3 which can travel in a straight line via bearings 5 and 5, and an ultrasonic linear motor 11 that is fixed at the bed 3 for driving the table 7. The ultrasonic linear motor 11 is provided with a ceramic spacer 11 that touches a plate 13 of the table 7 along the traveling direction with a specific press force. A linear scale 15 is arranged integrally at the plate 13 of the table 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a stage having an ultrasonic linear motor.

[0002]

2. Description of the Related Art For example, FIG.
Are described on page 75 of “Nikkei Mechanical” published by Nikkei BP, 1997.5.26 (No. 507).

In this stage 101, a fixed bed 1
A moving table 107 is supported on the reference numeral 03 via cross rollers 105, 105 so as to be able to move linearly. An ultrasonic linear motor 109 is fixed on the bed 103, and the leg (drive unit) of the elastic body of the linear motor 109 abuts on the side surface 107 a of the moving table 107, and the moving table 107 is moved in a direction perpendicular to the paper surface. Drive.

[0004] A laser scale 111 for detecting the position of the moving table 107 is mounted on the moving table 107.

[0005]

However, since the position of the moving table 107 is detected by the laser scale 111 provided on the side opposite to the driving unit of the moving table 107, the cross roller 105 is not used. If a slight backlash causes a shift angle (inclination) with respect to the moving axis (straight line) on the moving table 107 centering on the drive unit, the measurement error is enlarged at the measurement point on the opposite side surface away from the drive unit.

Accordingly, an object of the present invention is to provide a stage capable of accurately detecting the amount of movement of a movable table.

[0007]

According to one aspect of the present invention, there is provided a fixed bed, and a moving table supported on the bed via a bearing so as to be linearly movable or rotatable. An ultrasonic linear motor fixed to the bed and driving the moving table, wherein the ultrasonic linear motor includes a vibrator that abuts on a driving surface of the moving table along a moving direction with a predetermined pressing force. Wherein the scale is integrally disposed on the driving surface of the moving table.

Therefore, for example, the position detection sensor fixed to the bed can detect the amount of movement of the scale integrated with the driving surface of the moving table in the vicinity of the driving section. , The influence on the detection accuracy can be suppressed, and the amount of movement of the movable platform can be detected with high accuracy.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [First Embodiment] A first embodiment of the present invention will be described with reference to FIG. FIG. 1 is a sectional view conceptually showing the configuration of the stage 1 of the present embodiment.

As shown in FIG. 1, a stage 1 mainly includes a fixed bed 3, a table (moving table) 7, and an ultrasonic linear motor 11 (hereinafter abbreviated as a linear motor 11). It is configured.

A table (moving table) 7 is supported and guided on the fixed bed 3 via linear bearings (bearings) 5 and 5, and the table 7 can be linearly moved in a direction perpendicular to the plane of FIG. . An alumina ceramic plate or a glass plate (driving surface) 13 (hereinafter referred to as a plate) for ensuring abrasion resistance is provided on a driving side surface of the table 7 which is in contact with an ultrasonic linear motor 11 (hereinafter abbreviated as a linear motor 11) to be described later. 13) is fixed. Note that the table 7 may be rotated instead of moving linearly.

A linear scale (scale) 15 is integrated on the upper portion of the plate 13 by bonding, and faces a detection head (sensor) 25 described later. The linear scale 15 may be arranged below the plate 13 or on the driving side of the table 7 above or below the plate 13.

On the other hand, the linear motor 1 as a driving source
Numeral 1 is fixed to a bracket 17 attached to the bed 3 by a bolt (not shown). The linear motor 11 is made of a thin rectangular piezoelectric ceramic and has a box-shaped holder 21.
It is built in. A ceramic spacer (vibrator) 11a made of hard 99% alumina is adhered to the tip side (the plate 13 side of the table 7) of the piezoelectric ceramic.

The ceramic spacer 11a is pressed against the plate 13 of the table 7 with a predetermined pressing force by a set screw 23 provided on the bracket 17, and is in contact therewith. In this contact state of the ceramic spacer 11a, the linear motor 11 is fixed to the bracket 17 described above.

A detection head (sensor) 25 is fixed on the linear motor 11 and faces the linear scale 15 adhered to the plate 13 of the table 7. The detection head 25 may be fixed to another fixing member near the linear motor 11. The fixed position of the detection head 25 is
The linear scale 15 is selected so as to face one of the arrangement positions.

Next, the operation of the stage 1 will be described.

When a voltage having a frequency in the ultrasonic range is applied to a predetermined electrode attached to the piezoelectric ceramic, the piezoelectric ceramic resonates at that frequency, and a vertical resonance motion and a horizontal resonance motion are combined, and The ceramic spacer 11a in contact with 13 makes an elliptical motion. The plate 13 (table 7) is reciprocated on the bed 3 due to the friction between the two abutting members 11a and 13.

At this time, the detection head 25 detects the amount of movement of the linear scale 15, for example, the processing position of the workpiece on the table 7, and the driving by the linear motor 11 is controlled. The detection head 25 is a non-contact type, for example, a laser interferometer that irradiates the linear scale 15 with laser light to obtain interference fringes.

Thus, according to the present embodiment, the linear scale 15 is integrated with the plate 13 of the table 7,
The detection head 25 is a plate 1 which is a driving surface of the table 7.
Since the movement amount is detected by the three sections, even if the table 7 is inclined with respect to the movement axis (straight line), the influence on the detection accuracy can be suppressed, and the movement amount of the table 7 can be detected with high accuracy.

[Second Embodiment] A second embodiment of the present invention will be described with reference to FIG. FIG. 2 shows the stage 30 of the present embodiment.
FIG. 2 is a sectional view conceptually showing the configuration of FIG.

The stage 30 is a table (moving table)
The first embodiment differs from the first embodiment in that a concave portion (hollow portion) is provided on the lower surface (surface facing the bed) of the device and a linear scale (scale) is integrally arranged on a driving surface provided in the concave portion. Other configurations are the same as those of the first embodiment. Therefore, only the differences will be described, and redundant description will be omitted.

As shown in FIG. 2, a concave portion 37a is formed on the lower surface of the table 37, and a vertical wall 37b is provided at the center in the width direction of the concave portion 37a so as to extend downward along the moving direction. . An alumina ceramic plate or a glass plate (drive surface) 13 (hereinafter abbreviated as plate 13) is fixed to both surfaces of the vertical wall 37b, and is in contact with each ultrasonic linear motor 11 (hereinafter abbreviated as linear motor 11).

A linear scale (scale) 15 is integrated on the upper portion of the right plate 13 by bonding, and faces the detection head 25. In addition, linear scale 1
The arrangement position of 5 has the same degree of freedom as in the case of the first embodiment.

On the other hand, a bracket 47 for supporting the linear motor 11 is fixed on a fixed bed 33, and a pair of linear motors 11, 11 are fixed to the bracket 47 so as to face each other with the vertical wall 37b of the table 37 interposed therebetween. The ceramic spacer (vibrator) 11a is in contact with the plate 13 of the vertical wall 37b with a predetermined pressing force. Both linear motors 11, 1
1 drives the plates 13, 13 (table 37) in the same direction.

With this configuration, according to the present embodiment, the same operation and effect as those of the first embodiment can be obtained, and the linear motor 11 is disposed in the internal space between the table 37 and the bed 33. Because of this, the stage 30 is made compact, which is extremely advantageous in terms of arrangement space.

By arranging the two linear motors 11 facing each other, no bending load is applied to the vertical wall 37b by the linear motors 11.

The recess 37a may be provided on the bed 33 side.

If the driving force is sufficient, one linear motor 11 may be used.

Third Embodiment A third embodiment of the present invention will be described with reference to FIG. FIG. 3 shows a stage 50 of the present embodiment.
FIG. 2 is a plan view conceptually showing the configuration of FIG.

The stage 50 has an arrangement in which the ultrasonic linear motor 11 (hereinafter abbreviated as linear motor 11) is arranged in the first position.
Different from the first embodiment, other configurations are the same as those of the first embodiment. Therefore, only the differences will be described, and redundant description will be omitted.

As shown in FIG. 3, a table (moving table) 5
7 and one linear motor 1 facing one side surface 57a.
1 are arranged, and two linear motors 11, 11 are arranged to face the other side surface 57b. And this 2
The linear motors 11, 11 are arranged before and after the one linear motor 11 in the moving direction of the table 57, and are respectively fixed to brackets 17 attached to the bed 3 (not shown).

In this manner, the three linear motors 11 are arranged at the respective vertices of an approximately isosceles triangle when viewed from above, and the detection head 25 is fixed on the linear motor 11 facing one side surface 57a.

The ceramic spacer (vibrator) 11a of each linear motor 11 is
An alumina ceramic plate or a glass plate (driving surface) 13 (hereinafter, abbreviated as plate 13) fixed to each of 7a and 57b is in contact with a predetermined pressing force by a set screw 23. Each linear motor 11 drives the table 57 in the same direction.

The linear scale 15 is integrated with the upper part of the plate 13 on one side surface 57 a side of the table 57 by bonding, and faces the detection head 25. The arrangement position of the linear scale 15 has the same degree of freedom as in the case of the first embodiment.

With this configuration, according to the present embodiment, each linear motor 1 located at each vertex of an isosceles triangle is used.
The inclination of the table 57 with respect to the movement axis (straight line) of the table 57 is suppressed by the pressing force of 1, and the detection head 25 is arranged on one side surface 57a of the table 57, that is, substantially on the center line of the isosceles triangle. Even if a slight inclination with respect to the moving axis (straight line) occurs at 57, the measurement error is suppressed to a small value, and the position of the table 57 can be detected with high accuracy.

The same operation and effect can be obtained also in the case of the rotary drive instead of the linear drive in each of the above embodiments.

[0037]

As is apparent from the above description, according to the first aspect of the present invention, for example, the position detection sensor fixed to the bed drives the amount of movement of the scale integrated with the driving surface of the moving table. Since it is possible to detect near the part, even if the movable table is inclined with respect to the moving axis (straight line), it is possible to suppress the influence on the detection accuracy and accurately detect the moving amount of the movable table. Becomes

[Brief description of the drawings]

FIG. 1 is a sectional view conceptually showing a configuration of a first embodiment of the present invention.

FIG. 2 is a sectional view conceptually showing a configuration of a second embodiment of the present invention.

FIG. 3 is a plan view conceptually showing a configuration of a third embodiment of the present invention.

FIG. 4 is a sectional view of a conventional example.

[Explanation of symbols]

 3, 33 bed 5 linear bearing (bearing) 7, 37, 57 table (moving table) 11 linear motor (ultrasonic linear motor) 11 a ceramic spacer (vibrator) 13 plate (driving surface) 15 linear scale (scale) 17, 47 Bracket 23 Set screw 25 Detection head (sensor) 37a Recess 37b Vertical wall 57a One side of table 57b The other side of table

Claims (1)

[Claims] 1. A fixed bed, a moving table supported on the bed via a bearing so as to be linearly movable or rotatable, and an ultrasonic linear motor fixed to the bed and driving the moving table, The ultrasonic linear motor includes a vibrator that comes into contact with a driving surface of the moving table along a moving direction with a predetermined pressing force, and a scale is integrally arranged on the driving surface of the moving table. Stage to do.