JPH08101343A - Microscope - Google Patents

Abstract

PURPOSE: To automatize the luminance adjustment of a light source for illuminating a sample used for a microscope. CONSTITUTION: The image data of a sample 10 is obtained by an objective optical system 13, a video camera 16 or the like. By a CPU 26, the value of a contrast function calculated based on the image data is maximized by moving a stage 11 every luminance while the luminance of the light source is changed through a driver for adjusting luminance 100. Then, the light source is set to the luminance corresponding to the maximum value among the maximum contrast values obtained every luminance in such a way.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microscope, and more particularly to adjusting the brightness of a light source for illuminating a sample in a microscope. In addition to the ordinary microscope for obtaining a magnified image of a small sample, the microscope here is used to measure the spectrum of transmitted or reflected infrared light by focusing infrared light on a minute part of the sample. It also includes an infrared microscope.

[0002]

2. Description of the Related Art In order to make it easier to observe a sample with a microscope, it is necessary to set the brightness of a light source for illuminating the sample appropriately. Conventionally, an observer manually adjusts the brightness while looking through an eyepiece lens. Was there.

[0003]

However, it is complicated to manually adjust the brightness while looking through the eyepiece of the microscope. In addition, there is a demand for automation of operations for observing and analyzing samples with a microscope, and there are already microscopes equipped with an autofocus function (a function for automatically focusing). In addition to focusing, it is necessary to automate brightness adjustment. Further, in the conventional microscope having the autofocus function, the automatic focusing operation is performed independently of the brightness adjustment, so that the light amount for illumination is insufficient or excessive, and the contrast of the image of the sample becomes abnormally low. is there. In this case, there is a problem that the focus position cannot be detected, or the stage position (sample position) set by the focus operation deviates from the focus position.

The present invention has been made to solve such a problem, and an object thereof is to provide a microscope capable of automatically setting the brightness of a light source for illuminating a sample to an appropriate value. To provide.

[0005]

In a microscope according to the present invention made to solve the above problems, a) an optical system mounted on a stage to generate an image of a sample illuminated by a predetermined light source; b) image pickup means for outputting an image signal representing the image generated by the optical system; and c) calculation means for calculating a value indicating the contrast height of the image based on the image signal output from the image pickup means. D) brightness changing means for changing the brightness of the light source; e) moving means for moving the stage in the optical axis direction of the optical system; f) changing the brightness by the brightness changing means and the stage by the moving means. And the stage and the stage position are calculated by calculating the value for various combinations of the stage and the stage position. Seeking a combination of, and the light source to the luminance in the combination obtained and control means for setting the luminance changing unit, configured to include a.

[0006]

According to this structure, the image of the sample placed on the stage and illuminated is generated by the optical system, and the image signal representing the image is output from the image pickup means. The control means changes the brightness of the light source for illuminating the sample by the brightness changing means and moves the stage by the moving means, and the value indicating the height of the contrast of the image of the sample by the calculating means for various combinations of the brightness and the stage position. To calculate. Then, based on the calculation result, the combination of the brightness and the stage position, which has the maximum value, is obtained,
The light source is set to the brightness in the obtained combination. Here, the stage position having the maximum value calculated by the calculation means can be regarded as the in-focus position. Therefore, by the above operation, the brightness is set so that the contrast of the image of the sample in the focused state becomes the highest.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a diagram showing the construction of the essential parts of an infrared microscope which is an embodiment of the present invention. This infrared microscope is sample 1
An objective optical system 13 is provided above the stage 11 on which 0 is mounted, and a condenser optical system 12 is provided below. Both the objective optical system 13 and the condenser optical system 12 are composed of Cassegrain type reflecting mirrors, and as shown in FIG. 2, the stage 11 can be moved between these two optical systems by a stage moving mechanism 18 using a stepping motor. You can When the infrared spectrum is measured by the focusing operation described later, the stage 11 moves to the position where the infrared light is condensed (the position of Zf in FIG. 2). At this position, both the objective optical system 13 and the condenser optical system 12 are in focus. As a result, when measuring the spectrum of infrared light reflected by the sample 10 (in the case of reflection type measurement), the infrared light that has passed through the objective optical system 13 is condensed on the sample 10 and is reflected by the sample 10. After the external light passes through the objective optical system 13 again, it is guided to the detector by the infrared optical system (not shown) and detected by the detector (not shown).
On the other hand, when measuring the infrared light transmitted through the sample 10 (in the case of transmission type measurement), the infrared light passing through the condenser optical system 12 is focused on the sample 10 and the infrared light transmitted through the sample 10 is After passing through the objective optical system 13, it is similarly guided to the detector by the infrared optical system and detected by the detector.

In the infrared microscope, in order to move the stage 11 to the position where the infrared light is condensed as described above, the visible light is used for focusing prior to the measurement of the infrared spectrum. The infrared microscope of the present embodiment has an autofocus function, which allows the above focusing to be performed automatically. The configuration for realizing the autofocus function in the present embodiment is basically the same as the configuration disclosed by the applicant in Japanese Patent Laid-Open No. 6-118296.

That is, in the above focusing, the sample 10
The light from passes through the objective optical system 13, is reflected by the mirror 14, and then enters the video camera 16. The light incident on the video camera 16 is converted into an electric signal, and as a result,
A luminance signal (image signal) corresponding to the image of the sample 10 is obtained. This brightness signal is input to the electric board.

The electrical board is a video amplifier 21, A /
It is composed of a D converter 22, a static RAM 24, a DMA controller 25, a CPU 26, a motor driver 28, and a data bus connecting them. The luminance signal input from the video camera 16 to the electric board is first amplified by the video amplifier 21 and then converted into a digital signal by the A / D converter 22. The value of this digital signal is image data corresponding to the image of the sample 10. This image data is transferred from the A / D converter 22 to the static RAM 24 by the DMA controller 25 and stored therein. The CPU 26 calculates the value of the contrast function at the current position of the stage 11 (hereinafter referred to as “stage position”) from the image data for one screen. Then, the CPU 26, based on the calculation result, passes the stage moving mechanism 18 via the motor driver 28.
Control signal to the stage 11 toward the in-focus position.
To move. Here, the contrast function is a function of the stage position Zn, and in the present embodiment, the difference between the maximum value and the minimum value of the image data for one screen corresponding to the image of the sample 10 on the stage 11 is the value of the contrast function. I am trying. FIG. 4 is a diagram showing the shape of such a contrast function. As described later, the position where this contrast function is maximum (Zf in FIG. 4) is the in-focus position. Note that as the contrast function, another function indicating the height of the contrast of the image of the sample 10 may be adopted.

In the infrared microscope of this embodiment, the brightness of the light source illuminating the sample 10 (hereinafter referred to as "illumination light source") is automatically adjusted in addition to the above focusing. This point is different from the infrared microscope disclosed in JP-A-6-118296. In order to automatically adjust the brightness, in this embodiment, as shown in FIG. 1, a brightness adjusting driver 100 is connected to the data bus in the electric system board. CPU2
6 adjusts the brightness by changing the voltage supplied to the illumination light source by the brightness adjusting driver 100.

The details of the operation for adjusting the brightness performed together with the focusing in the infrared microscope of this embodiment will be described below with reference to the flowchart shown in FIG. In the flowchart shown in FIG. 3, the variable n indicates the number of times the luminance of the illumination light source is changed, and L (n) indicates the value of the luminance after changing n times. However, L (0) represents the minimum value Lmin of the brightness that can be set. In the present embodiment, the CPU 26 performs focusing at each brightness while sequentially changing the brightness L of the illumination light source from the minimum value Lmin that can be set to the maximum value Lmax that can be set at a predetermined interval as follows. .

First, in step S10, the variable n value is set to 0 (initialization), and in step S12, the brightness of the illumination light source is set to L (n). This setting is performed via the brightness adjustment driver 100 described above. After the brightness is set, focusing is performed in step S14.

In this focusing, the CPU 26 controls the stage moving mechanism 18 via the motor driver 28 to maximize the value of the above-mentioned contrast function, that is, for one screen at the brightness L (n). Of the stage 1 so that the difference between the maximum value and the minimum value of the image data of (the image data represents the image of the sample 10) becomes maximum.
Move 1 In general, the contrast of the image of the sample 10 is the highest when the position of the sample 10 is at the in-focus position, and the contrast becomes lower as the position of the sample 10 moves away from the in-focus position. Therefore, the light quantity for illumination becomes insufficient or excessive, and the sample 10
Unless an exceptional state in which the contrast of the image is abnormally low, the stage position where the value of the contrast function is maximum is the in-focus position, and after the execution of step S14, the in-focus state is normally set. Has become.

In step S16, the value of the contrast function and the position of the stage 11 after execution of step S14,
That is, the maximum value FMX of the contrast function at the current brightness L (n) and the position Zf (see FIG. 4) of the stage 11 at that time are static R together with the brightness L (n).
Store in AM24.

In the next step S18, the current luminance L
Maximum value (n) can be set (hereinafter referred to as "maximum brightness")
It is determined whether it is Lmax. If it is determined that the luminance is not the maximum luminance Lmax, the variable n is incremented by 1 in step S24, and the process returns to step S12. Thereafter, S12 → S14 → S16 → until L (n) reaches the maximum luminance Lmax.
The loop of S18 → S24 → S12 is repeatedly executed. As a result, focusing is performed at each luminance within the settable range Lmin to Lmax, and the maximum value of the contrast function (hereinafter referred to as “maximum contrast value”) FMX at each luminance and the position Zf of the stage 11 at that time are: Static RAM with corresponding brightness L (n)
It will be stored in 24.

In step S18, the current luminance L
If it is determined that (n) is the maximum luminance Lmax, the process proceeds to step S20. In step S20, the maximum contrast value FMX for each luminance stored in the static RAM 24 as described above is searched for. Then, in step S22, the stage 11 is moved to the stage position stored together with the maximum maximum contrast value, and the illumination light source is set to the brightness stored together with the maximum maximum contrast value. For example, step S20
Assuming that the relationship between the brightness L stored in the static RAM 24 and the maximum contrast value FMX at the time of proceeding to the step becomes as shown in FIG. 5, the maximum maximum contrast value is FMXmax, and the brightness corresponding to this is Lf. Is. Therefore, in this case, the luminance of the illumination light source is set to Lf in step S22. When the brightness is set in step S22 in this way, the operation for adjusting the brightness ends together with the focusing operation.

As can be seen from the above, according to this embodiment,
After the processing of the flowchart of FIG. 3 is executed, the brightness is set so that the maximum contrast value (maximum value of the contrast function) FMX is maximized at the stage position Zf where the value of the contrast function is maximized. Therefore,
The brightness is set so that the contrast of the image of the sample 10 in the focused state becomes the highest, and the set brightness can be considered as the brightness at which the sample is most easily observed, that is, the optimum brightness. Further, since the conventional automatic focusing operation is performed irrespective of the brightness adjustment, focusing may be performed in a state where the contrast of the image of the sample is abnormally low due to insufficient or excessive illumination light amount. According to the present embodiment, finally, focusing is performed at the luminance Lf where the contrast becomes highest. Therefore, the focused state can always be achieved with high accuracy.

[0019]

According to the present invention, since the brightness of the light source for illuminating the sample is automatically set to an appropriate value, observation of the sample by a microscope and infrared microscopic measurement can be performed easily and efficiently. . In addition, the automatic focusing operation is performed at the same time as the automatic adjustment of the luminance, and finally, the focusing is performed at the luminance at which the contrast of the image of the sample becomes sufficiently high, so that the focusing state is always made with high accuracy. There is also an advantage that you can.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a main part of an infrared microscope which is an embodiment of the present invention.

FIG. 2 is a diagram showing movement of a stage in the embodiment.

FIG. 3 is a flowchart showing a process for brightness adjustment in the embodiment.

FIG. 4 is a diagram showing a contrast function used in a focusing operation in the embodiment.

FIG. 5 is a diagram showing the maximum contrast value at each luminance obtained by the processing for luminance adjustment in the embodiment.

[Explanation of symbols]

 10 ... Sample 11 ... Stage 12 ... Condenser optical system (lower Cassegrain) 13 ... Objective optical system (upper Cassegrain) 16 ... Video camera 18 ... Stage moving mechanism 26 ... CPU 28 ... Motor driver 100 ... Luminance adjusting driver

Claims (1)

[Claims] 1. An a) an optical system mounted on a stage for generating an image of a sample illuminated by a predetermined light source; and b) an image pickup means for outputting an image signal representing the image generated by the optical system. c) calculating means for calculating a value indicating the height of the contrast of the image based on the image signal output from the image pickup means, d) brightness changing means for changing the brightness of the light source, and e) optical operation of the stage. F) moving means for moving in the optical axis direction of the system; f) changing the brightness by the brightness changing means and moving the stage by the moving means, and calculating the value by the calculating means for various combinations of the brightness and the stage position. By calculating, the combination of the brightness and the stage position where the value becomes the maximum is obtained, and the light source is illuminated to the brightness in the obtained combination. Microscope, characterized in that it comprises control means for setting the changing means.