JPH0481907A - Minute positioning device - Google Patents

Abstract

PURPOSE:To execute the feed control of a member to be driven with high accuracy by utilizing two piezo-elements, and executing the minute movement of a stage plate (member to be driven) and the detection of a moving amount or a moving position. CONSTITUTION:A member 4 to be driven is fed minutely by a first piezo-element 5, a second piezo-element 6 is displaced by the minutely fed member 4 to be driven, and a voltage generated in this displaced second piezo-element 6 is detected. Accordingly, the member 4 to be driven can be fed minutely with high accuracy, and an actual minute feed amount or minute feed position of the minutely fed member 4 to be driven can be detected with high accuracy, based on a generated voltage of a second piezo-element 6. In such a way, minute positioning of the member 4 to be driven can be executed with high accuracy.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a drive device such as an X-axis stage, and more particularly to a micro-positioning device that can perform positioning with high precision.

[Background Art and Problems to be Solved] In recent years, various actuators using piezo elements have been proposed. Therefore, an object of the present invention is to realize a micro-positioning device that can accurately position a driven member using this piezo element.

[Means to solve the problem]

In order to solve the above problems, in the micro-positioning device of the present invention, a first piezo element is arranged on the upstream side in the linear movement direction, sandwiching a driven member supported so as to be linearly movable in at least one direction. and a second piezo element is disposed on the downstream side, and includes voltage applying means for applying a voltage to at least the first piezo element and voltage detecting means for detecting the voltage generated in at least the second piezo element. ing. The first and second piezo elements described above are arranged so as to be displaceable in the linear movement direction, and one end is brought into contact with the driven member side, and the other end is supported in a restrained state. It is.

[Effect]

When a voltage is applied to the first piezo element in a fixed direction by the voltage applying means, the piezo element is displaced in the direction of expansion, and the driven member is pushed and moved. Therefore, this first piezo element functions as a means for minutely feeding the driven member. On the other hand, the other second piezo element side is compressed by the driven member that has moved slightly, and a voltage corresponding to the amount of compression is generated. This voltage is detected by voltage detection means. The amount of compression of the second piezo element can be calculated from this detected voltage, and therefore the amount of movement or the movement position of the driven member can be determined. In this way, the second piezo element serves as a means for detecting the position of the driven member after minute movement. function.

〔Example〕

Below, with reference to FIG.
Explain the axis stage.

In the X-axis stage 1 shown in the figure, 2 is a pedestal, and two linear guide rails 3.
3 are attached in parallel, and a rectangular stage plate 4 is supported by these rails so as to be linearly movable along the rails. First and second cylindrical piezo elements 5.6 are arranged on both sides of the stage plate 4 in the moving direction. In this example, these first and second piezo elements 5.6 have the same shape and have the same voltage-strain characteristics. The first piezo element 5 has one end 5a in contact with the side surface 4a of the stage plate 4, and the other end 5b in contact with the side surface 4a.
It is fixed to the side surface 2a of the pedestal facing the frame. Similarly, the second piezo element 6 has one side 6a in contact with the side surface 4b of the stage plate, and the other end 6b fixed to the pedestal side surface 2b.

7 is a control circuit, which applies a voltage corresponding to the target fine feed amount to the first piezo element 5 via the lead wire 8, and from the second piezo element 6, The voltage generated there is detected via the lead wire 9.

In the X-axis stage l having this configuration, when the stage plate 4 is minutely fed in the feeding direction X, under the control of the control circuit 7, the first piezo element 5 is A DC voltage of a predetermined value is applied to. By applying this voltage, the first piezo element 5 expands, pushes the stage plate 4 in the X direction, and moves it slightly. On the contrary,
The second piezo element 6 on the other side is compressed by the minute movement of the stage plate 4. A voltage corresponding to this compressive deformation is generated within this second piezo element. This generated voltage is detected by the control circuit 7. The actual amount of movement of the stage plate 4 is detected from the detected voltage value.

That is, the moving position is detected. Thereafter, the stamp voltage value applied to the first piezo element is adjusted, and feedback control is performed so that the stage plate 4 is accurately positioned at the target movement position.

In this way, in the X-axis stage 1 of this example, the first and second piezo elements are used to perform minute movements of the stage plate and to detect the amount of movement or the movement position. feed control can be performed with high precision.

Note that in the above example, the first piezo element is used only for fine movement of the table, but by applying a voltage to the second piezo element, the second piezo element can also be used for fine movement of the table. Can be used for shipping. Similarly, the first piezo element side can also be used to detect the minute feed amount or feed position of the table by detecting the voltage generated there.

Furthermore, the present invention can also be applied to an X-Y axis stage. In this case, in the X direction and Y direction,
The first and second piezo elements may be arranged respectively.

〔Effect of the invention〕

As explained above, in the micro-positioning device of the present invention, the first piezo element minutely feeds the driven member, the second piezo element is displaced by the minutely fed driven member, and the second piezo element is moved by the second piezo element. The voltage generated in the second piezo element is detected. Therefore, according to the present invention, the driven member can be minutely fed with high precision, and the actual minute feed amount or minute feed position of the minutely fed driven member can be accurately detected based on the voltage generated by the second piezo element. Therefore, minute positioning of the driven member can be performed with high precision.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram showing an X-axis stage according to an embodiment of the present invention. [Explanation of symbols] 1... X-axis stage 4... Stage plate (driven member) 5... First piezo element 6... Second piezo element 7... Control circuit (voltage application means, voltage detection means). Figure 1

Claims (1)

[Claims] A first piezo element located on one side in the linear movement direction and a second piezo element located on the other side with a driven member supported so as to be linearly movable sandwiched therebetween, and at least the first piezo element and voltage detection means for detecting the voltage generated in at least the second piezo element, and the first and second piezo elements are displaceable in the linear movement direction. arranged in
A micro-positioning device characterized in that one end is in contact with the driven member and the other end is supported in a restrained state so as to be immovable.