JPH04331452A - Linear motor type scanning stage - Google Patents

Abstract

PURPOSE:To perform the high-speed shifting and the fine operation by manual operation positively and to reproduce the stored position accurately. CONSTITUTION:A controller 18, which performs feedback control, and a linear motor 10 are connected through a changeover switch 20 which changes over the on-off of the linear motor 10. A linear encoder, which is fixed to fixed and running stages 4 and 6 and detects the position of the running stage 4 to the fixed stage 2, is connected to this controller 18. A nob shaft 12a is provided rotatably to the running stage 4, and to this kappa nob shaft 12a are fixed a friction wheel 12b, which engages with the friction member 14 fixed to the bottom of the fixed stage 2, and an operation nob 12, which operates a kappa nob shaft 12a.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a linear motor type scanning stage suitable for use in optical inspection equipment such as a microscope.

0002

[Prior Art and its Problems] In a scanning stage for optical inspection equipment, it is necessary to move the traveling stage at high speed to near the target position relative to the fixed stage, and then perform fine movement operations to accurately move it to the target position. There is. or,
When inspecting wafers and liquid crystal panels, it is necessary to memorize the locations where defects and the like have been checked and to reproduce them accurately later. Although a manual scanning stage is suitable for performing high-speed movement and fine movement to the target position, an electric scanning stage is required to accurately reproduce the memorized position.

Many conventional electric scanning stages are of the rotary motor type. This rotary motor type scanning stage is configured such that the traveling stage is movable by engaging a nut attached to the traveling stage with a feed screw rotated by a rotary motor. However, because a screw mechanism is used in which the feed screw of the rotary motor and the nut of the traveling stage are always engaged, even if the operator wants to manually move the traveling stage at high speed, it is impossible; In other words, if an attempt is made to move the object at high speed using the rotary motor, the rotary motor must have a large output, and the entire apparatus including the scanning stage becomes large and expensive.

[0004] High-speed movement and fine movement by electric power, as well as accurate reproduction of memorized positions, can be suitably performed with a linear motor type scanning stage equipped with a control means for controlling a linear motor by receiving a signal from an encoder. . However, the linear motor type does not have the concept of actively performing high-speed movement and fine movement manually.
If this is done, the control means must be powered off, so it is impossible to control according to the memorized position.

SUMMARY OF THE INVENTION An object of the present invention is to provide a linear motor type scanning stage that can actively perform manual high-speed movement and fine movement operations, and can accurately reproduce memorized positions using electric power.

[0006]

[Means for Solving the Problems] Therefore, in the linear motor type scanning stage according to the present invention, a signal from an encoder that reads the position of the traveling stage with respect to the fixed stage is obtained to perform feedback control of the linear motor that drives the traveling stage. The device is equipped with a changeover switch that turns the linear motor on and off, and a drive that manually drives the traveling stage relative to the fixed stage when the linear motor is turned off by the changeover switch. It is characterized by comprising a device.

[0007]

[Operation] First, the linear motor is turned off using a changeover switch, and the driving device manually drives the traveling stage relative to the fixed stage. The control means receives a signal from the encoder and performs feedback control of the linear motor.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of a linear motor type scanning stage according to the present invention will be described below with reference to FIGS. 1 and 2.

As shown in FIG. 1, the linear motor type scanning stage of this embodiment includes a fixed stage 2 attached to the main body of the apparatus (not shown). A traveling stage 4 that can move horizontally is provided on the fixed stage 2. Between the fixed stage 2 and the traveling stage 4, there is a linear guide 6 for guiding the travel of the traveling stage 4.
is inserted. A coil 10b fixed to a yoke 10a is buried in the upper part of the fixed stage 2. A magnet 10d fixed to a yoke 10c is embedded in the lower part of the traveling stage 6 so as to face the coil 10b. These yoke 10a, coil 10b, yoke 10c, and magnet 10d constitute a linear motor 10.

A knob shaft 12a having a vertical axis of rotation is rotatably attached to one side of the traveling stage 4. A fixed stage 2 is located in the middle of this knob shaft 12a.
A friction wheel 12 that engages with a friction member 14 fixed to the lower surface of the
b is fixed coaxially with the knob shaft 12a. Further, an operation knob 1 for rotating the knob shaft 12a is provided at the lower end of the knob shaft 12a.
2 is fixed. These operation knobs 12 and knob shafts 12
a, the friction wheel 12b, and the friction member 14 constitute a drive device that manually drives the traveling stage 4.

A linear scale 16a is fixed to the lower surface of the traveling stage 4. This linear scale 1
A head portion of a detection head 16b that reads this is located below 6a. This detection head 16b is fixed to the other side of the lower surface of the fixed stage 2. These linear scale 16a and detection head 16b constitute a linear encoder 16. This linear encoder 16 is
It is connected to the controller 18 so as to read the linear scale 16a and send a signal. This controller 1
8 is electrically connected to the linear motor 10.

This controller 18 receives a signal from the linear encoder 16, stores the position, and performs feedback control of the traveling stage 4. This controller 1
8 and the linear motor 10, the linear motor 10 is turned on and off.
The connection is made by a changeover switch 20 that turns off. This changeover switch 20 is attached to the front surface of the fixed stage 2, as shown in FIG. The changeover switch 20 is used to cut off and cut off the supply of the drive source to the linear motor 10, but not to cut off and cut off the connection between the linear encoder 16 and the controller 18.

The operation of the linear motor type scanning stage of the first embodiment constructed in this way will be explained. When manually moving the traveling stage 4 to a target position at high speed and finely moving it, storing this target position, and reproducing this position later, first, the changeover switch 20 is operated to turn off the linear motor 10. Then, the traveling stage 4 can be manually moved at high speed, and after performing the high-speed movement, the operating knob 12 is rotated to slightly move the traveling stage 4 to move it to the target position. This position is then read into the controller 18 by receiving the position signal from the linear encoder 16. Since the reading operation by the controller 18 continues as it is, changeover switch 2
By turning on 0, the position can be reproduced at any time. According to this embodiment, manual high-speed movement and fine movement operations can be performed, and position reproduction can be performed electrically.

Next, a linear motor type scanning stage according to a second embodiment of the present invention will be described with reference to FIGS. 3 to 5. Note that the same members as those in the first embodiment are indicated by the same reference numerals, and explanations thereof will be omitted.

The basic configuration of the second embodiment is almost the same as that of the first embodiment, but the difference is that a link mechanism is provided to disconnect and disengage the engagement between the friction wheel 12b and the friction member 14. be. The friction member 14 shown in FIG. 3 is attached to the fixed stage 2 so as to be movable in the X-Y plane by first and second link members 30 and 32 forming a link mechanism, as shown in FIG. ing. The base end of the first link member 30 is rotatably attached to the fixed stage 2 by a rotating shaft 30a, and the distal end is rotatably attached to one end of the friction member 14. The second link member 32 is formed in a dogleg shape, and its bent portion is rotatably attached to the fixed stage 2 by a rotating shaft 32a, and its tip portion is rotatably attached to the other end of the friction member 14. installed.

The friction member 14 is a friction wheel 1 shown in FIG.
It is biased by two leaf springs 34 so as to always engage with 2b. The base end portion of the second link member 32 is
It is connected to the solenoid 36, and this solenoid 36
By applying this force, the friction member 14 is disengaged from the friction wheel 12b against the biasing force of the two leaf springs 34. This solenoid 36 is turned on and off by a solenoid changeover switch 40. This solenoid changeover switch 40 is connected to the changeover switch 20 so that the solenoid 36 is operated when the changeover switch 20 of the linear motor 10 is turned on, and is stopped when the changeover switch 20 of the linear motor 10 is turned off. This solenoid changeover switch 40 is connected to the fixed stage 2 as shown in FIG.
is attached to the front of the

The operation of the scanning stage of the second embodiment constructed in this way will be explained below. First, when the changeover switch 20 is turned on, the linear motor 10 is turned on.
The solenoid 36 operates and the friction member 14 and the friction wheel 12b
The engagement with is released. When the changeover switch 20 is turned off, the linear motor 10 is turned off, the operation of the solenoid 36 is stopped, and the friction member 14 and the friction wheel 12b are engaged.

With the above configuration, when the linear motor is turned on and driven electrically, the engagement between the friction wheel and the friction member is always released, so no unnecessary load is applied to the linear motor. Low heat generation and low power consumption can be achieved. Next, a third embodiment will be described with reference to FIG. As in the second embodiment, the same members as in the first embodiment are designated by the same reference numerals, and their explanations will be omitted.

The linear motor type scanning stage of this embodiment has a changeover switch 20 in addition to that of the second embodiment.
A touch switch 50 that performs the same function as the above is added. This touch switch 50 is attached to the front surface of the manual operation section 4a, which is the front portion of one side of the traveling stage 4. If this touch switch 50 is not touched, the linear motor 10 is on.
When touched, the linear motor 10 is turned off. The touch switch 50 and the changeover switch 20 are connected so that if either one is operated, the linear motor 10 is turned off.

According to this embodiment, if you want to manually move at high speed, you can touch the touch switch 50 by grasping the manual operation part 4a with your hand, without having to operate the solenoid changeover switch 45 each time. linear motor 1
0 is turned off, allowing manual high-speed movement.

The present invention is not limited to the above-mentioned embodiments, and many embodiments and modifications are possible. For example, in the three examples above, the stage was a single axis,
It can also be applied to an X-Y two-axis stage.

[0022]

Effects of the Invention It is possible to provide a linear motor type scanning stage that can actively perform manual high-speed movement and fine movement operations, and can accurately reproduce memorized positions.

[Brief explanation of the drawing]

FIG. 1 is a front view showing a linear motor type scanning stage according to a first embodiment of the present invention.

FIG. 2 is a perspective view of the scanning stage in FIG. 1;

FIG. 3 is a front view of a linear motor scanning stage according to a second embodiment.

FIG. 4 is a bottom view of the scanning stage in FIG. 3;

FIG. 5 is a perspective view of the scanning stage in FIG. 3;

FIG. 6 is a perspective view of a linear motor scanning stage according to a third embodiment.

[Explanation of symbols]

2...Fixed stage, 4...Traveling stage, 10...Linear motor, 12...Operation knob, 12a...Knob shaft, 12b...Friction wheel, 14...Friction member, 16...Linear encoder, 16a
... Linear scale, 16b... Detection head, 18... Controller, 20... Changeover switch.

Claims (1)

[Claims] 1. A linear motor type scanning stage comprising a control means for obtaining a signal from an encoder that reads the position of a traveling stage with respect to a fixed stage and performing feedback control of a linear motor that drives the traveling stage. A linear motor type scanning device comprising: a changeover switch that turns on and off; and a drive device that manually drives the traveling stage relative to the fixed stage when the linear motor is turned off by the changeover switch. stage.