JPH06138395A - Positioning controller for microscope - Google Patents

Abstract

PURPOSE:To provide a controller capable of improving the positioning accuracy of the part to be driven of a revolver or a stage. CONSTITUTION:As to a microscope in which the stage 2 is constituted to freely move in a specified direction through a moving mechanism on the mirror base substance 4 of the microscope and which is provided with an electrostriction element 63 giving driving force to the stage 2; the positioning controller for the microscope equipped with an electrostatic capacity type displacement sensor 8 for detecting a relative distance between the stage 2 and a sensor supporting member 7 on the base substance 4, and a control circuit controlling and driving the element 63 in accordance with deviation between the moving target instruction optionally set to the element 63 and the relative distance detected by the sensor 8 by giving the relative distance and moving target instruction is provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a positioning control device for a microscope, which is capable of increasing the positioning accuracy when moving a stage of a microscope or a driven part of a revolver in the optical axis direction.

[0002]

2. Description of the Related Art Focusing in a conventional microscope is constructed so that a stage on which an object to be inspected (sample) is placed can be moved to a focus position of an objective lens by manually rotating a focusing handle. There is one (first conventional example).

In the first conventional example, a rotary shaft portion of a conventional focusing handle is rotatably driven by a motor and a power transmission mechanism as means for automatically moving to a focus position for the purpose of autofocus or the like. There is one configured (second conventional example). In this case, in order to control the positioning of the stage, the amount of rotational displacement of the motor is detected and this detected value is fed back to the motor control circuit, which is used as the deviation between this and the arbitrarily set movement target command (target signal). According to the control, the deviation is zero. Further, when an electrostrictive element is used as a drive source, feedback is performed by detecting the amount of displacement of the electrostrictive element itself.

[0004]

However, in the second conventional example, the error factors generated by the components of the power transmission mechanism interposed between the motor as the drive source and the stage to be finally operated are as follows. No consideration is given. The same applies to the electrostrictive element. In other words, since only the rotational displacement of the motor is detected and fed back, the position of the motor side changes due to the reaction force during the movement of the stage as a whole configuration. This is because the deformation of the mechanism may cause an error. Therefore, for example, like a scanning laser microscope,
When the relative distance between the revolver and the stage is moved by a predetermined amount to construct a stereoscopic image, the amount of movement may vary.
It is considered that the shape of the construction image may be different or the resolution may be reduced.

The present invention has been made to eliminate the above drawbacks, and an object of the present invention is to provide a positioning device for a microscope, which can improve the positioning accuracy of the driven part of the revolver or the stage.

[0006]

In order to achieve the above object, the invention according to claim 1 is such that a stage or a driven part of a revolver is movable in a predetermined direction to a fixed part of a microscope through a moving mechanism. In a microscope having a driving source configured to give a driving force to the driven portion, a relative distance detector that detects an absolute value of a mutual distance between focal positions of images obtained by the driven portion and the fixed portion. When,

A moving target command that can be arbitrarily set is given to the relative distance detected by the relative distance detector and the driving source, and the driving source is driven according to the deviation between the moving target command and the relative distance. It is a positioning control device of a microscope provided with a control circuit to be controlled.

[0008]

According to the invention corresponding to claim 1, the relative distance between the movable portion and the fixed portion of the driven portion of the stage or the revolver is detected, and the relative distance is fed back.
Since the drive source is drive-controlled according to the deviation from the movement target command, it is possible to improve the positioning accuracy of the driven part of the revolver or the stage.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a schematic configuration of the present invention, which is an upright microscope, and includes an objective lens 1 and a stage 2.
The relative distance L is measured.
Reference numeral 3 in the drawing denotes an object to be inspected (sample) and a mirror basic body 4.

FIG. 2 is a schematic configuration diagram showing only a main part (A part in FIG. 1) of the first embodiment of the present invention.
Is an optical axis direction (depth direction of the inspection object,
It is configured to be movable in the Z direction) of FIG. 2 and has a coarse movement mechanism section 5 and a fine movement mechanism section 6 as this configuration.

The coarse movement mechanism portion 5 is movably supported by a fixed side power transmission mechanism storage box 51 fixed to the mirror base body 4 and a linear movement bearing 52 on the outer peripheral portion of the storage box 51. The movable-side power transmission mechanism storage box 53, a gear and a pinion (not shown) in each of the storage boxes 51 and 53, a focusing handle that is rotated by an observer, and a rotational force from the focusing handle is a movable-side power transmission mechanism. It is adapted to be transmitted to the pinion in the storage box 53.

The fine movement mechanism portion 6 includes a stage support member 62 that allows the stage 2 to move in the Z direction via a linear movement bearing 61, and an electrostriction in which the amount of displacement of the movable piece changes depending on the voltage applied value. And element 63.

Further, a sensor support member 7 extending near the end of the surface of the stage 2 on which the object 3 to be inspected is mounted is fixed substantially horizontally to the mirror base 4, and the end of the sensor support member 7 is fixed. The capacitance type displacement sensor 8 is attached, and the second electrode 82 is attached to the end portion of the upper surface of the stage 2 that faces the first electrode 81 in parallel with the capacitance type displacement sensor 8.

The capacitance type displacement sensor 8 utilizes the principle of a capacitor, and this principle will be described below. That is, 1s arranged in parallel and facing each other
The electrostatic capacitance C between the pair of electrodes 81 and 82 is
Is S, the distance between the electrodes 81 and 82 is d, and the dielectric constant is ε.
Then, C = εS ÷ d

[0015] Therefore, if one of the electrodes 81 is the detection electrode of the sensor and the other 82 is the object to be inspected, the change in the distance d, that is, the displacement can be known from the change in the capacitance C. The change in capacitance C can be measured as a change in voltage using a capacitance-voltage conversion circuit.

FIG. 3 is a control block diagram showing the relationship between the drive circuit of the fine movement drive unit 6 and the capacitance type displacement sensor 8 described above. The drive circuit 9 arbitrarily sets a target displacement command (target signal).
, A command setting device 90 capable of setting the following, an amplifier 91 for amplifying the relative distance signal obtained by the capacitance type displacement sensor 8, and a comparator 92 for obtaining a deviation between the output signal of the amplifier 91 and the target displacement command. A control circuit 93 that inputs the deviation of the device 92 and converts it into a voltage signal of the electrostrictive element 63, and an electrostrictive element drive amplifier 94 that amplifies the voltage signal converted by the control circuit 93 and gives it to the electrostrictive element 63. ing.

The operation of the first embodiment of the microscope positioning control device thus configured will be described. When the observer observes the object 3 to be inspected, the stage 2 is moved through the coarse movement mechanism 5 by rotating the focusing handle.
Is roughly moved in the Z direction (depth method of the inspection object 3), and after moving by a predetermined amount, it stops.

After that, the stage 2 is finely moved by the fine movement mechanism section 6 as follows. That is, the setting device 9
When a target displacement command is input to the drive circuit 9 from 0, the electrostrictive element drive amplifier 9 amplifies the voltage through the comparator 92 and a predetermined voltage is applied to the electrostrictive element 63. The piece is displaced according to the voltage value, and the stage 2 is finely moved in the Z direction according to the displacement amount 10. By slightly moving the stage 2 in the Z direction, the relative distance between the stage 2 and the capacitance type displacement sensor 8 changes, and this is detected by the capacitance type displacement sensor 8. The relative distance signal detected by the capacitance displacement sensor 8 is amplified by the amplifier 91 and input to one input terminal of the comparator 92, and the target displacement command input to this and the other input terminal. Of the electrostrictive element 63 is given via the control circuit 93 and the electrostrictive element drive amplifier 94, and the movable piece of the electrostrictive element 63 is controlled to move so that the deviation becomes zero. .

As described above, according to the apparatus of the first embodiment, the relative distance between the stage 2 and the capacitance type displacement sensor 8 attached to the mirror basic body 4, that is, the stage 2
The relative distance between the objective lens 1 and the objective lens 1 (that is, the absolute value of the mutual distance between the focal positions of the obtained images) is surely detected, and this detection signal is fed back to the drive circuit 9. Since the cause of the error caused by the deformation of the transmission mechanism and the like is eliminated, the stage 2 can be positioned with high accuracy.

FIG. 4 is a schematic configuration diagram showing a second embodiment of the present invention, in which the capacitance type displacement sensor 8 is used as the relative distance detector in the first embodiment described above. Instead, the differential transformer type linear sensor 11 is attached to the end of the sensor support member 7. In this case, the probe of the linear sensor 11 is brought into contact with the stage 2 to obtain the relative distance between the stage 2 and the objective lens.

FIG. 5 is a schematic configuration diagram showing a third embodiment of the present invention, in which a glass scale 1 is used as a relative distance detector.
2 is provided on the mirror basic body 4. In this case, the slit detection head 13 of the glass scale 12 is attached to the stage 2 side. FIG. 6 shows a fourth embodiment of the present invention.
FIG. 9 is a schematic configuration diagram showing an embodiment of the present invention, in which the motor 14 is provided on the focusing rotary shaft 15 instead of the electrostrictive element 63 used as the drive source of the fine movement drive mechanism section of each of the above-mentioned embodiments.
Needless to say, the above-mentioned relative distance detector is provided in the section B,

FIG. 7 is a schematic configuration diagram showing a fifth embodiment of the present invention. Although each of the embodiments described above is intended for an upright microscope, this embodiment is an inverted microscope. FIG. 3 is a schematic configuration diagram for the above. That is, the capacitance type displacement sensor 8 is used as the relative distance detector, and
This is an example in which a part, that is, the sensor 8 is attached to the fixed-side mirror base, and the electrode 82 is attached to the movable-side revolver 16.

The present invention is not limited to the embodiment described above,
For example, the following can be done. The sensor 8 of the embodiment of FIG. 2 described above may be attached to the stage 2 side, and the electrode 82 may be attached to the sensor attachment member 7, or similarly, the sensor 8 and the electrode 82 of FIG. 7 may be attached in reverse.
A DC servo motor, an AC servo motor, or a stepping motor may be used instead of the electrostrictive element 63 described above. In the case of a stepping motor, the input may be a pulse signal instead of a voltage signal. In addition, various modifications can be made without departing from the scope of the present invention.

[0024]

According to the present invention, it is possible to provide a positioning control device for a microscope which can improve the positioning accuracy of the driven part of the revolver or the stage.

[Brief description of drawings]

FIG. 1 shows a first positioning control device for a microscope according to the present invention.
FIG. 3 is a diagram showing a schematic configuration of the embodiment of FIG.

FIG. 2 is a schematic configuration diagram showing an enlarged part A of the embodiment of FIG.

FIG. 3 is a block diagram showing a control relationship between the drive circuit and the capacitance type displacement sensor of FIG.

FIG. 4 shows a second positioning control device for a microscope according to the present invention.
FIG. 3 is a diagram showing a schematic configuration of the embodiment of FIG.

FIG. 5 is a third part of a positioning control device for a microscope according to the present invention.
FIG. 3 is a diagram showing a schematic configuration of the embodiment of FIG.

FIG. 6 is a fourth positioning control device for a microscope according to the present invention.
FIG. 3 is a diagram showing a schematic configuration of the embodiment of FIG.

FIG. 7 is a fifth part of a positioning control device for a microscope according to the present invention.
FIG. 3 is a diagram showing a schematic configuration of the embodiment of FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Objective lens, 2 ... Stage, 3 ... Inspected object, 4 ... Mirror basic body, 5 ... Coarse movement mechanism part, 6 ... Fine movement mechanism part, 63 ... Electrostrictive element, 7 ... Sensor support member, 8 ... Electrostatic Capacitive displacement sensor, 9 ... Driving circuit, 11 ... Differential transformer type linear sensor, 12 ... Glass scale.

Claims (1)

[Claims] 1. A microscope comprising a fixed part of a microscope, wherein a driven part of a stage or a revolver is movable in a predetermined direction via a moving mechanism, and a driving source for giving a driving force to the driven part. In the relative distance detector that detects the absolute value of the focal position mutual distance of the image obtained by the driven portion and the fixed portion, and the relative distance and the drive source detected by this relative distance detector Give a movement target command that can be set arbitrarily,
A positioning control device for a microscope, comprising: a control circuit that drives and controls the drive source according to a deviation between the movement target command and the relative distance.