JPS60145614A - Rotary finely moving mechanism - Google Patents

Abstract

PURPOSE:To increase the fine drive and the rotary stroke in length and to further prevent in advance the fluctuation upon driving by forming an arbitrary delaying time in the phase between voltage waveforms applied to drive members and applying a voltage to the drive members. CONSTITUTION:A second moving member 3 is attracted and fixed onto a base 5 by the second electrostatic chuck 12. The first drive member 7 is elongated in this state, and the second drive member 8 is contracted. Thus, the first moving member 2 finely rotates in a direction P at an elastic hinge 4 as a center. Then, the member 2 is secured onto the base 5 by the first electrostatic chuck 11, and the fixture of the second member 3 is then released by the chuck 12. The first member 7 is contracted in this state, and the second member 8 is elongated. Then, the member 3 is rotated at the hinge as a center. In this mechanism, the timings of switches 9a, 9b and 13a, 13b are displaced to provide the delaying time to drive.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical field to which the invention pertains] The present invention relates to an improvement in a fine movement mechanism that can position an object with high precision.

[Prior art and its problems]

In recent years, electron beam writing U1. +i devices, reduction projection transfer devices, X-ray transfer devices, and the like have been developed, but these types of devices require a minute drive mechanism in order to maintain submicron precision. A fine movement drive mechanism with high precision is required not only in the above-mentioned devices but also in fields where precise measurements are performed using measuring instruments.

As such a fine movement drive mechanism, the inventors have recently developed a mechanism as shown in Fig. 1 (
We devised a rotational fine movement mechanism as shown in a) and (b) (
(Japanese Patent Application No. 19328/1982). In this method, minute 0
By using a finely movable element with a step of about 0.005 μm, it is possible to rotate more than one revolution. This rotation mechanism will be explained. Figure 1 (,) is a plan view (bl is the same figure (a)
A sectional view taken along line A-A of FIG. In the figure, reference numeral 1 denotes a rotary plate, and this rotary plate 1 is constructed by connecting first and second moving members 2 and 3 in the shape of semicircular plates with an elastic hinge 4. In fact, the outer circumference 2 of the disk is symmetrical about the central axis of the disk.
The rotary disk 1 consisting of the movable member 2.degree. 3 and the elastic hinge 4 is formed by cutting out a portion of each portion and providing a notch from the notch toward the central axis. The rotary disk 1 is movably mounted on a base 5, and its center of rotation is defined by a pin 6 provided on the lower surface of an elastic hinge 4.

First and second drive members 7 and 8 are provided in the cutout portion of the rotating plate 1, respectively. These driving members 7
, 8 consists of piezoelectric elements that expand and contract according to the respective applied voltages, and the first and second moving members 2 and 3 are fixed at both ends of the piezoelectric elements in the direction of expansion and contraction (the direction of the arrow shown in the figure). There is. This fixation can be done by gluing, screwing,
It may be press-fitted or the like. Also, the first driving member 7
A variable voltage power source 10a is connected to the second drive member 8 via a switch 9a, and a variable voltage power source 10b is connected to the second drive member 8 via a switch 9b.

On the other hand, the lower part of the first moving member 2 (= means the lower part 11a
and an electrostatic chuck 11 consisting of insulators 11b and llc.
is provided, and by connecting a power source 14a between the electrode 11a and the base 5 via the switch 13a, the first movable member 2 is fixed to the base 5'' by suction. ing. Further, a second electrostatic chuck 12 similar to the electrostatic chuck 11 is provided at the bottom of the second moving member 3, and this chuck 12 allows the second moving member 3 to be moved onto the jig and table 5. It is designed to be fixed by suction.

In the rotational fine movement mechanism configured in this way, first the second
The second moving member 3 is suctioned and fixed onto the base 5 by an electrostatic chuck 12 . In this state, the first drive member 7 is expanded and the second drive member 8 is contracted. As a result, the first moving member slightly rotates in the direction of the arrow P around the elastic hinge 4, as shown in FIG. 2(,). Next, the first moving member 2 is fixed on the base 5 by the first electrostatic chuck 11, and the fixation of the second moving member 3 by the electrostatic chuck 12 of the apprentice 2 is released. In this state, the first
When the driving member 7 is retracted and the second driving member 8 is expanded, the second moving member 3 rotates around the elastic hinge as shown in FIG. 2(b).

In this way, the rotary plate 1 can be driven finely, and the rotation stroke can be made longer by this repeated operation. Furthermore, by adjusting the voltages applied to the drive members 7 and 8, coarse and ultra-fine changes in the number of rotations can be easily performed. By the way, such a mechanism (2) has the following problems. Namely, due to processing errors or assembly errors of the parts, it is difficult to make the gaps between the movable members 2 and 3 and the fixed members 11 and 12 the same. Therefore, if 11 is extended and 12 is tightened at the same time, moving member 2 will be securely fixed (or moving member 3 will be securely fixed even if drive members 7 and 8 are driven). If the drive members 7 and 8 are not sufficiently freed, the movable member 2 may move (or the movable member 3 may not move), and the rotary plate 1 may not move properly or In addition, since the natural frequency of the fixed member and the rotating plate is 5 mm, if the fixed member and the rotary plate drive section are expanded and contracted at the same time, the fixed member or the rotating plate may be affected by the applied force. It may not follow the voltage.

[Purpose of the invention]

An object of the present invention is to enable fine movement, to make the rotation stroke sufficiently long, and to reduce the noise that accompanies the drive. evening 7
- It provides an extremely reliable rotational fine movement mechanism that can prevent the occurrence of such problems.

[Summary 4a of the Invention] The gist of the present invention is that when a rotating plate is rotated over a long stroke by repeatedly applying a voltage to a drive member having a piezoelectric effect (=
, providing an arbitrary delay time in the phase between the voltage waveforms applied to each of the drive members.

That is, the present invention provides a first
and a second moving member, a driving member made of a piezoelectric element that expands and contracts according to the applied voltage, and the first and second moving members are respectively attached to both ends of the driving member in the direction of expansion and contraction; a fixing member that alternately fixes two moving members on the base and always fixes at least one of these moving members; a means for determining the center of rotation of the first and second moving members; and a drive unit. and means for applying a predetermined voltage to the members, and the first and second movable members are rotated about a single axis by the expansion and contraction action of the driving member and the fixing action of the fixed member. In the fine movement mechanism, a wind pressure is applied to the drive members by providing an arbitrary delay time in the phase between the voltage waveforms applied to each of the drive members.

〔Effect of the invention〕

According to the invention, by repeatedly applying a voltage to the drive member,
When rotating the rotary plate over a long stroke, the moving member can be securely fixed, and then the driving member can be expanded and contracted to drive other moving members. This ensures that the movement is performed reliably, and that the moving member is fixed as the moving member is switched. Unintentional movement of the moving member can be suppressed, and the reliability of the device can be improved.

It is possible to drive at the limit angular velocity that the rotational fine movement mechanism can produce. It is possible to drive in response to deformation of the material due to wear of the sliding part, etc.

[Embodiments of the invention]

FIG. 3 shows a schematic structure of the chest 1 according to the embodiment of the present invention. Note that the same parts as in FIG.

This embodiment differs from the mechanism shown in FIGS. 1(a) and 1(b) above in that
This is due to the fact that the input timing of b is staggered.

That is, as shown in Figure @4, a delay time from φ to φ is provided for driving. In the figure, τ is the rise time.

With the configuration of the present invention, after the nil residual vibration ends, the movable part IFA' 3 is reliably fixed to the fixed member 12 (after being fixed, the movable member 2 is rotated by moving the driving members 7 and 8 by 5 μ). That's Denji. Therefore, it is possible to reliably suppress unwanted movement of the movable member due to switching of the circumference of the movable member.

By appropriately setting the delay time, the rotational fine movement mechanism can be driven at the maximum angular velocity that its structure can achieve. Furthermore, even if the material is deformed due to wear of the sliding contact portion, it is possible to cope with the problem by resetting the delay time.

Note that the delay time setting is based on the specifications of the rotational fine movement mechanism (f14
100 (following speed)).

Schematic diagram for explaining the action of the above mechanism, Part 3
FIG. 4 is a configuration diagram showing a schematic configuration of a rotating fine movement mechanism according to an embodiment of the present invention, and FIG. 4 is a characteristic diagram for explaining the present invention in detail.

l... Rotating plate, 2... First moving member, 3... Second moving member, 4... Elastic hinge, 5... Base, 6
... Bin, 7, 8 ... Drive member, 9a, 9b,
13a, 13b -7, itch, 10a, 10b, 14
a, 14b-power supply, 11, 12...fixing member, 2
0a, 20b, 20c, 20d -- switching circuit, 21 -- delay time setting circuit.

(7317) Patent Attorney Kensuke Chika (1 other person) ttfl) tel) tM tb) (b) Figure 3

Claims (1)

[Claims] (1) Consisting of first and second moving members movably placed on a base and a compression element that expands and contracts according to applied voltage, with the first and second moving members located at both ends in the expansion and contraction direction. a sorbed driving member, a fixing member that alternately fixes the first and second moving members on the base and always fixes at least one of these moving members;
and a means for determining a center of rotation of the second moving member, and the rotating fine movement mechanism rotates the first and second moving members by the expansion and contraction action of the driving member and the fixing action of the fixed member. Rotary fine movement mechanism (2) characterized in that the rotational fine movement mechanism is driven by shifting the phase of the voltage waveform applied to the driving member and the voltage waveform applied to each of the fixed members by an arbitrary delay time. The rotational fine movement mechanism according to claim 1, wherein is adjustable.