JP3379773B2 - Scanning laser microscope - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scanning laser microscope capable of enhancing the positioning accuracy when moving the stage of a microscope or the driven part of a revolver in the optical axis direction.
Regarding the mirror.

[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 example of the prior art, as a means for automatically moving to a focus position for the purpose of autofocus, etc., a rotary shaft portion of a conventional focusing handle is rotationally driven by a motor and a power transmission mechanism. 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 constituent elements of the power transmission mechanism interposed from the motor as the drive source to 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 when the stage moves as a whole configuration, and the object to be inspected reaches the objective lens. 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 three-dimensional image, variations in the moving amount may occur. Therefore, with respect to the actual shape of the inspection object,
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 in order to eliminate the above drawbacks, and an object of the present invention is to provide a scanning laser microscope capable of improving the positioning accuracy of a driven part of a revolver or a stage. To do.

[0006]

In order to achieve the above-mentioned object, the invention corresponding to claim 1 includes a fixing part for a microscope and a front part.
Serial and movable driven part of the stage or the revolver via a moving mechanism on the fixed portion <br/> predetermined direction relative to the driven part
Drive source that provides driving force and a moving eye relative to the drive unit.
Command setting device that can set the standard signal arbitrarily, and the command setting
And relative distance detector in response to the moving target signal from vessel to detect the relative distance between the fixed part and the driven part driven,

[0007] and the relative distance signal from the relative distance detector
The deviation from the movement target signal set by the command setter is
A control circuit for driving and controlling the drive source so as to be zero ;
And a control unit for controlling the driven part.
Running characterized by driving control for each predetermined amount by a circuit
This is an inspection laser microscope .

[0008]

According to the present invention, the relative distance detector detects the relative distance between the driven portion and the fixed portion of the stage or revolver, and the relative distance signal and the movement target signal from the relative distance detector. The drive source is drive-controlled in accordance with the deviation between and, and the drive source is drive-controlled so that the deviation becomes zero, whereby the positioning accuracy of the driven part of the revolver or the stage can be improved.

[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 thus constructed will be described. When the observer observes the inspection object 3, the stage 2 is roughly moved in the Z direction (depth method of the inspection object 3) via the coarse movement mechanism section 5 by rotating the focusing handle. Then, after moving 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 the target displacement command from 0 is input to the drive circuit 9, it is amplified by the electrostrictive element drive amplifier 94 via the comparator 92 and a predetermined voltage is applied to the electrostrictive element 63, so that the electrostrictive element 63 moves. 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 to the electrostrictive element 63 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 and the objective lens 1. Relative distance (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, so that the power transmission mechanism or the like is deformed like the conventional device. Since there is no error generation factor associated with, 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 aforementioned 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, run can be enhanced revolver or positioning accuracy of the driven part of the stage,
An inspection laser microscope can be provided.

[Brief description of drawings]

FIG. 1 shows a schematic configuration of the onset Ming first embodiment.

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.

4 is a diagram showing the schematic configuration of the onset Ming second embodiment.

5 is a diagram showing a schematic configuration of the onset Ming third embodiment.

6 is a diagram showing the schematic configuration of the onset Ming fourth embodiment.

7 is a diagram showing a schematic configuration of the onset light of the fifth embodiment.

[Explanation of symbols]

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

Claims (2)

(57) [Claims] 1. A fixed part of a microscope, a driven part capable of moving a stage or a revolver in a predetermined direction via a moving mechanism to the fixed part, and a drive source for giving a driving force to the driven part. A command setting device capable of arbitrarily setting a movement target signal for the drive unit, and detecting a relative distance between the driven unit and the fixed unit driven according to the movement target signal from the command setting unit. A relative distance detector, and a control circuit that drives and controls the drive source so that the deviation between the relative distance signal from the relative distance detector and the movement target signal set by the command setting device becomes zero. And a relative position between the driven part and the fixed part are moved by a predetermined amount.
When moving and constructing a stereoscopic image,
A scanning laser microscope characterized by controlling the drive of the drive source . 2. The control circuit further comprises a comparator for comparing a relative distance signal from the relative distance detector with the movement target signal set by the command setting device. The scanning laser microscope according to 1.