JP2001051200A - Conforcal microscope device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the overshoot and hunting, enlarge a range of a measurement time and prevent the damage of a driving circuit and the collision of an objective lens to a sample. SOLUTION: This confocal microscope capable of obtaining a three- dimensional image by scanning the optical beam on a sample surface by a confocal scanner and axially scanning the optical beam by a moving mechanism, comprises a driving means for driving the moving mechanism, and the driving means outputs the driving waveform corrected on the basis of the reverse characteristic of the frequency characteristic on the displacement of the moving mechanism.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a confocal microscope apparatus for three-dimensionally displaying an object under test using a confocal microscope, and more particularly to an improvement in the performance of real-time three-dimensional driving.

[0002]

2. Description of the Related Art As a confocal microscope apparatus of this type, a "confocal microscope apparatus" filed by the present applicant (Japanese Patent Laid-Open No.
No. 174334). FIG. 5 is a configuration diagram thereof. This confocal microscope is a combination of a confocal scanner 20, a microscope 10, and a camera 30, each of which includes a condenser disk 22, a pinhole disk 23, a beam splitter 25, and a lens 26.
5, the objective lens 14 can be moved freely in the Z-axis direction.

In such a configuration, the laser light 21 is condensed on the pinhole 24 of the pinhole disk 23 by the microlens of the condensing disk 22, passes through the pinhole 24, and is conjugated with the pinhole disk 23 by the objective lens 14. At the focal point 17 on the scanning surface 16 in the sample 11 at a different position.

[0004] When the condensing disk 22 and the pinhole disk 23 rotate, the scanning surface 16 of the sample 11 is optically scanned, and the reflected light from the sample surface is again reflected by the objective lens 1
After passing through 4 and the pinhole disk 23, the light is reflected by the beam splitter 25, and forms an image on the image receiving surface of the camera 30 by the lens 26.

At this time, the objective lens 14 is moved by the moving mechanism 15
6, as shown in FIG. 6, the positions Z ₁ , Z ₂ , Z ₃ ,. . . Slice images in Z _n is photographed by the camera 30. FIG. 3A is a diagram showing each slice image in the Z-axis direction, and FIG. 3B is a diagram showing a relationship between a sample and a slice plane. The objective lens 14 is shown in FIG.
It is driven by a triangular wave as shown in FIG.

[0006]

However, even if the objective lens can be moved at a high speed, the moving mechanism cannot follow the objective lens.
At the turning point A of the triangular wave drive in FIG. 7, overshoot and hunting occur as shown in the enlarged view of FIG. (1) If the hunting is long, the net measurement time width (in other words, the linear driving range) B decreases as shown in FIG. (2) The objective lens 14 moves the sample 1 due to overshoot.
1 may collide, and the collision may damage the moving mechanism. (3) The characteristics of the moving mechanism cannot be fully utilized in the arbitrary correction.

[0007] An object of the present invention is to solve the above-mentioned problems, and it is possible to suppress overshoot and hunting, expand a measurement time range, and prevent a drive circuit from being damaged and an objective lens from colliding with a sample. A focus microscope apparatus is provided.

[0008]

In order to achieve the above object, according to the first aspect of the present invention, a sample surface is scanned with a light beam by a confocal scanner, and the light beam is scanned in the optical axis direction by a moving mechanism. A confocal microscope apparatus configured to obtain a three-dimensional image of the sample by using a driving means for driving the moving mechanism. A driving waveform corrected on the basis of the driving waveform is output.

As described above, when the moving mechanism is driven with the waveform corrected based on the inverse characteristic of the frequency characteristic of the displacement of the moving mechanism, overshoot and hunting in the vicinity of the turning point particularly during triangular wave driving are suppressed. As a result, it is possible to prevent the collision of the objective lens with the sample beforehand, and to obtain an effect that the measurement time width is widened.

[0010] In this case, it is practically acceptable to supplement the region above the frequency that can be followed by the moving mechanism with the low-pass filter characteristic.

Further, the correction in the driving means may be a correction by Fourier transform or filter processing. Further, in the case of the filter processing, claim 4
The correction may be made by using a CR passive circuit or an active filter or a digital filter.

In this case, the moving mechanism moves the objective lens as described in claim 5, or moves a relay lens provided between the objective lens and the confocal scanner as described in claim 6.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings. FIG. 1 is a main part configuration diagram of a confocal microscope apparatus according to the present invention. The figure shows a configuration of an objective lens driving portion, and includes a moving mechanism 15 and a moving mechanism 1 using a piezo element or the like.
5 includes a driver 41 for driving the driver 5 and a correction waveform generator 42 for generating a signal to be supplied to the driver 41.

The correction waveform generator 42 includes a memory for storing waveform data, waveform data processing means (for example, a microprocessor) for obtaining a correction waveform, and a digital / analog converter for converting the correction waveform data into an analog signal. . These components are not shown here.

In such a configuration, the moving mechanism 15 is driven by the output signal of the driver 41, and
4 is moved up and down. The driver 41 amplifies and outputs the output waveform of the correction waveform generator 42 as appropriate. The waveform of the signal supplied to the driver 41 is not a simple triangular wave as in the related art, but a correction waveform. Here, the driver 4
The portion consisting of 1 and the correction waveform generator 42 is referred to as driving means.

The correction waveform is created based on the inverse characteristic of the frequency characteristic of the displacement of the moving mechanism 15 measured in advance. This will be described in more detail below. The inverse characteristic H of the displacement frequency characteristic G of the moving mechanism 15 as shown in FIG.
The inverse characteristic H is a characteristic as shown in FIG.

The correction waveform E 'is created based on the following equation. E ′ = F ⁻¹ (H), H = 1 / G where F is a Fourier transform, F ⁻¹ is an inverse Fourier transform, and G
H is a displacement frequency characteristic of the moving mechanism 15, and H is an inverse characteristic of the displacement frequency characteristic G. According to the above equation, not only the gain but also the phase is corrected.

Note that the complete correction requires the moving mechanism to have an infinite band, but this is impossible, so here, the frequency is stopped at the frequency fx that the moving mechanism can follow, and the frequency band beyond that is forcibly forced by a low-pass filter. Substitute with the characteristics of

When the analog signal of the correction waveform E 'obtained in this way is supplied to the driver 41 and the moving mechanism 15 is driven, overshoot and hunting of the movement of the objective lens 14 are suppressed, and as a result, the measurement shown in FIG. The time range B becomes wider.

The present invention is not limited to the above embodiment. For example, the transform may be not only a Fourier transform but also a filter. The correction waveform generator 42
Is not limited to a configuration including a waveform data processing means (for example, a microprocessor) for obtaining a correction waveform, a digital / analog converter for converting the correction waveform data into an analog signal, and the like, as shown in FIG. And a reference waveform generator 51 for removing high frequency components of the reference wave meter.
It may be configured with a correction circuit 52 such as an R integration circuit.

An active filter or a digital filter may be used instead of the CR integrating circuit. In addition to driving the objective lens 14, a stage (not shown) on which the sample 11 is mounted is driven, or a relay lens 61 is provided between the objective lens 14 and the pinhole disk 23 as shown in FIG. Then, it may be moved up and down.

[0022]

As described above, according to the present invention, the following effects can be obtained. Driving the moving mechanism with the corrected waveform suppresses overshoot and hunting in the upper limit movement of the objective lens, thereby expanding the measurement time range as compared with the conventional one, and also causing damage to the drive circuit and the sample of the objective lens. Collision is prevented beforehand.

[Brief description of the drawings]

FIG. 1 is a main part configuration diagram showing one embodiment of a confocal microscope apparatus according to the present invention.

FIG. 2 is a diagram showing a frequency characteristic of displacement of a moving mechanism and its inverse characteristic.

FIG. 3 is a diagram showing another embodiment of the correction waveform generator.

FIG. 4 is a main part configuration diagram showing another embodiment of the present invention.

FIG. 5 is a configuration diagram illustrating an example of a conventional confocal microscope device.

FIG. 6 is a diagram showing a relationship between a slice image and a slice plane.

FIG. 7 is an explanatory diagram relating to a driving waveform of an objective lens.

FIG. 8 is a diagram showing a relationship between a driving waveform and a displacement of a moving mechanism.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Microscope 11 Sample 14 Objective lens 15 Moving mechanism 16 Scanning surface 17 Focusing point 20 Confocal scanner 21 Laser beam 22 Focusing disk 23 Pinhole disk 24 Pinhole 25 Beam splitter 30 Camera

Claims (6)

[Claims] 1. A confocal microscope apparatus configured to scan a sample surface with a light beam by a confocal scanner and scan a light beam in an optical axis direction by a moving mechanism to obtain a three-dimensional image of the sample. A driving means for driving the moving mechanism, wherein the driving means outputs a driving waveform corrected based on an inverse characteristic of a frequency characteristic of a displacement of the moving mechanism. microscope. 2. The confocal microscope according to claim 1, wherein a region of a frequency equal to or higher than a frequency which can be followed by said moving mechanism is supplemented by a low-pass filter characteristic. 3. The confocal microscope according to claim 1, wherein the correction in said driving means is correction by Fourier transform or filter processing. 4. The confocal microscope according to claim 3, wherein said drive means performs correction using a CR passive circuit, an active filter, or a digital filter when the correction is based on filter processing. 5. The confocal microscope according to claim 1, wherein the moving mechanism moves the objective lens to scan the light beam in the optical axis direction. 6. The apparatus according to claim 1, further comprising a relay lens provided between said objective lens and said confocal scanner, wherein said moving mechanism moves said relay lens to scan a light beam in an optical axis direction. Item 6. A confocal microscope according to Item 5.