JP2002174779A - Microscopic system and auxiliary method of determining magnification - Google Patents

Abstract

PROBLEM TO BE SOLVED: To change an auxiliary magnification to the necessary and sufficient magnification taking advantage of the resolution of an objective lens to the maximum extent. SOLUTION: The auxiliary magnification MSUB is calculated by the following mathematical expression (1) in accordance with the magnification MOBJ and numerical aperture NAOBJ of the objective lens and the resolution P of a photoelectric conversion element and the auxiliary magnification of the microscope is changed to the calculated auxiliary magnification. MSUB=(2×P×2NAOBJ)/ MOBJ×λ...(5).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a microscope system and a method for determining an auxiliary magnification in the system.

[0002]

2. Description of the Related Art When obtaining a magnified image by a microscope, resolution is important in addition to magnification, for efficient observation. In visual observation through an eyepiece or photography using a silver halide film, the resolution is substantially determined by the numerical aperture of the objective lens. On the other hand, a microscope system that converts an enlarged image by an optical system into electrical image information using a photoelectric conversion element such as a CCD (Charge Coupled Device) camera and outputs the electrical image information, and outputs the resolution of the final output image Is not determined only by the numerical aperture of the objective lens, but is also affected by the resolution of the photoelectric conversion element.

[0003]

Therefore, in such a microscope system, when the resolution of the CCD camera is lower than the resolution of the objective lens, the performance of the objective lens cannot be fully utilized. Therefore, in order to obtain a clear image, it is desirable to increase the total magnification of the image reaching the object plane of the photoelectric conversion element by using an auxiliary magnification device such as intermediate magnification or intermediate zoom.

However, in this case, since the total magnification increases, the field of view of the photoelectric conversion element on the object plane becomes small. Therefore, if the auxiliary magnification is set too high, the range that can be observed in one field of view is narrowed, resulting in poor efficiency. Further, since the resolution does not increase beyond the performance of the objective lens, there is no merit in increasing the auxiliary magnification more than necessary.

Accordingly, an object of the present invention is to provide a method for changing the auxiliary magnification to a necessary and sufficient magnification making the most of the resolution of the objective lens, and a microscope system for changing the auxiliary magnification using the method. And

[0006]

According to the present invention, an auxiliary magnification is calculated based on a magnification and a numerical aperture of an objective optical element (for example, an objective lens) and a resolution of a photoelectric conversion element. An auxiliary magnification determining method for changing the auxiliary magnification of the microscope to the calculated auxiliary magnification is provided.

The resolution R _OBJ of the objective optical element on the object plane can be obtained by the following equation (1). R _OBJ = λ / 2NA _OBJ (1) where λ is the wavelength of light used for observation. Also,
NA _OBJ is the numerical aperture of the objective optical element.

The objective optical element is 10 times (numerical aperture 0.3),
20 times (numerical aperture 0.5), 40 times (numerical aperture 0.75), λ is 0.55 μm, auxiliary magnification is 1 to 2 times, and total magnification is 10 to 80 times continuously. The solid line in FIG. 2 shows the relationship between the total magnification (that is, the magnification of the objective optical element × the auxiliary magnification) and the resolution R _OBJ when the magnification is enlarged. In FIG. 2, a solid line a shows a case using a 10-fold optical element, a solid line b shows a case using a 20-fold optical element, and a solid line c shows a case using a 40-fold optical element. In general, the resolution does not depend on the auxiliary magnification, but is determined only by the numerical aperture of the objective optical element. The relationship shown in FIG. 2 is merely an example, and the present invention is not limited to the case where an objective optical element having such a magnification and a numerical aperture is used.

On the other hand, the resolution on the CCD image pickup surface is substantially equal to the distance PIX between the centers of adjacent pixels in the CCD.
It can be expressed as twice the EL. Therefore, the CCD
The resolution R _CCD on the object plane is converted to the object plane and is obtained by the following equation (2). Note that M _total
Is the total magnification. R _CCD = 2 × PIXEL / M _total (2)

When PIXEL is set to 7 μm, the relationship between the total magnification and the resolution R _CCD is graphed, as shown by the dotted line in FIG.

For example, if the objective optical element is 20 times (numerical aperture 0.5) and the auxiliary magnification is 1, the total magnification is 20 times, but the resolution R _OBJ of the objective optical element is 0.5 μm. Since the resolution R _{CCD of the CCD} is 0.7 μm, the resolution of the obtained image is governed by the resolution R _CCD of the lower _CCD and is 0.7 μm.

Further, the objective optical element is increased by a factor of 20 (a numerical aperture of 0.1).
5) If the auxiliary magnification is 1.8, the total magnification is 36, but the resolution R _OBJ of the objective optical element is 0.5 μm, whereas the resolution R _CCD of the _CCD is 0.38 μm. Therefore, the resolution of the obtained image is governed by the resolution R _OBJ of the lower objective optical element, and is 0.5 μm.

Thus, the overall resolution R_totalIs the objective
Optical element resolution R_OBJAnd CCD resolution R_CCDWith low
The dotted line and the solid line in the graph shown in FIG.
There is no point in the total magnification higher than the intersection point,
Not taking full advantage of resolution. Therefore, the objective optical element
Resolution R_OBJAnd CCD resolution R_CCDLike
Using the auxiliary magnification, which is the overall magnification, is the most efficient
Resolution R of object optical element _OBJWhile maximizing the field of view
Obtainable.

For example, when the objective optical element is 20 times (numerical aperture 0.50), if the auxiliary magnification is 1.4 times, the total magnification is 28 times, and both the objective optical element and the resolution of the CCD are 0. .5 μm, the most efficient observation is possible.

Note that the method of calculating the auxiliary magnification in the present invention is not limited to the above-described method, and necessary corrections can be appropriately applied to each numerical value in accordance with an actual device or the like.

Further, according to the present invention, as a microscope system using the auxiliary magnification determining method of the present invention, an objective lens, an auxiliary magnification conversion unit for changing the size of an image, and a scaled optical image converted into electrical image information. A microscope system including a photoelectric conversion element for conversion, an auxiliary magnification determining unit, and a control signal output unit that outputs a control signal for controlling the auxiliary magnification converting unit based on the auxiliary magnification determined by the auxiliary magnification determining unit is provided. Is done. The auxiliary magnification determining unit calculates an auxiliary magnification of the auxiliary magnification conversion unit for changing the magnification of the objective lens based on the magnification and the numerical aperture of the objective lens and the resolution of the photoelectric conversion element. Means. It is preferable that the microscope system of the present invention further includes a unit for detecting an objective optical element used for observation.

The resolution of the final output image may be affected not only by the magnification and numerical aperture of the objective optical element and the resolution of the photoelectric conversion element, but also by the resolution of the aperture stop of the condenser and the output device. Therefore, the auxiliary magnification determination unit in the system of the present invention determines at least one of the aperture value of the condenser (aperture aperture value), the resolution of the photoelectric conversion element, and the resolution of the output device, and the magnification and the numerical aperture of the objective optical element. Based on this, it is desirable to have means for calculating the auxiliary magnification.

[0018]

<First Embodiment> A. First Embodiment System Configuration As shown in FIG. 1, a microscope system 100 according to the present embodiment includes a microscope 10 connected to each other by a signal line 30.
And an information processing device 20.

The microscope 10 includes an objective optical system (an optical element for enlarging an optical image (in this embodiment, an objective lens, but not limited to a lens)) 12 and a photoelectric conversion device for converting the optical image into an image signal. CCD camera 1 having conversion element
6), located between the optical element 12 and the photoelectric conversion means,
An optical system including at least one auxiliary magnification changing mechanism (auxiliary magnification optical system) 15 for changing the magnification of the optical image stepwise or continuously, and further detects the objective lens 12 inserted in the optical path. Means 47 (FIG. 4) are provided.

The microscope 10 of the present embodiment has an objective lens 12
, And by selectively inserting any one of them into the optical path, the magnification of the optical image can be changed in a stepwise manner. In the revolver of the objective lens 12,
As means 47 for detecting the objective lens 12, a sensor for recognizing which objective lens is in the optical path is mounted.

The auxiliary magnification changing mechanism 15 is provided with an electric actuator, and an auxiliary magnification (intermediate zoom magnification).
Corresponds to a control signal input via the signal line 30,
The magnification is automatically changed to a predetermined magnification indicated by the signal.

As shown in FIG. 3, the information processing device 20
Main storage device 31 and central processing unit (CPU) 32
, An interface unit 33, an external storage device 34, an input device 23, and an output device 22. In this embodiment, a keyboard is used as the input device 23 and the output device 2
Although an image display device (monitor) is used as 2, the present invention is not limited to this. The input / output device can be appropriately changed or added such as a touch sensor, a printer, a magnetic recording device, or the like.

FIG. 4 shows a functional configuration of the information processing apparatus 20 according to the present embodiment. The information processing apparatus 20 according to the present embodiment includes an apparatus configuration storage unit 40, an auxiliary magnification determining unit 44 that calculates an intermediate zoom magnification, and a control signal for changing the intermediate zoom magnification to the calculated auxiliary magnification. A control signal output unit 45 for outputting the image signal and a display unit 46 for displaying and outputting the image signal output from the photoelectric conversion element 16 are provided.

The device configuration storage unit 40 is a storage area provided in the main storage unit 31 and / or the external storage unit 34, and includes a CCD resolution storage unit 41 that holds the resolution of the CCD camera 16 in advance, and a CCD resolution storage unit 41 for each objective lens. A numerical aperture table 42 that stores the magnification and the numerical aperture in advance, and a wavelength storage unit 43 that previously stores the wavelength of light used for observation is provided. As shown in FIG. 5, the numerical aperture table 42 includes a lens number storage area 51, a magnification storage area 52, and a numerical aperture storage area 53 for each objective lens, and these areas are attached to the microscope 10. Data is stored in advance in accordance with the set objective lens 12. In the present embodiment, the data in the device configuration storage unit 40 is registered in advance, but input may be received via an input device.

Auxiliary magnification determining section 44, control signal output section 45
The display unit 46 is realized by the CPU 32 executing a program which is stored in the storage medium of the external storage device 34 in advance and a part or all of which is read into the main storage device 31 as needed. However, the present invention is not limited to such means by software, and each unit may be realized by hard wired logic or the like.

In the microscope system 100 of the present embodiment, the light applied to the sample placed on the stage 11 of the microscope 10 passes through the optical system (the objective lens 12, the lens barrel 14, the intermediate zoom 15) and the CCD camera. An optical image is formed as an optical image on a CCD imaging surface of a photoelectric conversion element built in 16. The optical image is converted into an image signal by the photoelectric conversion element 16, sent to the display unit 46 of the information processing device 20 via the signal line 30, and output as an image to the monitor 22 as an output device.

B. Auxiliary magnification calculation process In the microscope system of this embodiment, the objective inserted in the optical path
When the lens 12 is changed, the objective lens detecting the change
Detection means 47 assists the identification number of the detected objective lens
Notify the magnification determining unit 44. As shown in FIG.
The notified auxiliary magnification determining unit 44 (step 601)
Referring to the numerical aperture table 42,
The magnification M of the corresponding objective lens 12_OBJAnd numerical aperture NA_OBJ
Is read (step 602), and the CCD resolution is recorded.
Reads out the resolution on the CCD imaging surface from the storage unit 41
(Step 603), the resolution of the CCD at the object plane
R _CCDIs the resolution R of the objective lens_OBJAuxiliary magnification M that matches
_SUBIs calculated by the following equation (3) (step 60).
4).

Finally, the auxiliary magnification determining section 44 outputs a control signal to the auxiliary magnification changing mechanism 15 via the control signal output section 45 so that the auxiliary magnification becomes the calculated _MSUB (step 605).

<Embodiment 2> The microscope system 7 of the present embodiment.
0 is different from the system 100 of the first embodiment except that the microscope 10 is provided with the condenser aperture stop detecting means 71 as shown in FIG. The same is true. Here, only differences from the first embodiment will be described.

In this embodiment, the condenser 1 of the microscope 10
7 is provided with a condenser aperture stop detecting means 71.
Is connected, and the aperture value read by this potentiometer is the signal line 3
0 is notified to the auxiliary magnification determining unit 44.

When the aperture stop is stopped down, the image contrast can be increased, but the resolution is reduced. The balance between the contrast and the resolution can be adjusted by the observer by operating the aperture stop. If the aperture stop value NA _{CON of the} condenser is smaller than the numerical aperture NA _{OBJ of the} objective lens, the resolution R ′ when the aperture stop of the condenser is narrowed is obtained by the following equation (4). R ′ = λ / 2NA _CON (4) where λ is the wavelength of light used for observation (0.55 μm in this embodiment).

Therefore, the auxiliary magnification determining section 44 of this embodiment
_Receives the notification of the aperture stop value NA _CON from the condenser aperture stop detecting means 71 in addition to the identification number of the objective lens in step 601. Further, in step 604, the auxiliary magnification determining unit 44 of this embodiment calculates the auxiliary magnification M _{SUB according} to the following equation (5) if the aperture stop value NA _CON of the condenser is smaller than the numerical aperture NA _{OBJ of the} objective lens. If the numerical aperture NA _CON of the condenser is equal to or _larger than the numerical aperture NA _{OBJ of the} objective lens, the equation (3) is used in the same manner as in the first embodiment.
It is calculated by:

According to this embodiment, even when the observer operates the aperture stop of the condenser to achieve the desired contrast, the auxiliary magnification is automatically set so that the resolution and the field of view are optimally combined. can do.

<Embodiment 3> The microscope system 8 of the present embodiment.
0, a printer is connected as an output device 22 of the information processing device 20 in addition to the same image display device (monitor) as in the first embodiment. As shown in FIG. 8, the information processing apparatus 20 according to the present embodiment includes a resolution determining unit 83 that determines the resolution used for calculating the auxiliary magnification.
0 are provided with storage units 81 and 82 for holding the resolutions of the monitor and the printer, respectively. The configuration of the microscope system 80 of the present embodiment is the same as that of the system 70 of the second embodiment except that these configurations are different from the processing in the auxiliary magnification determining unit 44. Only the differences will be described. In this embodiment, the aperture value of the condenser is used for the calculation of the auxiliary magnification, as in the second embodiment, but this value may not be used as in the first embodiment.

As shown in FIG. 9, the auxiliary magnification determining unit 44 of this embodiment receives the notification of the identification number of the objective lens from the objective lens detecting means 47 (step 901). After detecting the aperture value by the aperture detecting means 71 (step 902), referring to the numerical aperture table 42, the magnification M _OBJ and the numerical aperture NA _OBJ of the objective lens 12 corresponding to the notified identification number are read out ( Step 903).
The resolution of D is read (step 904).

Next, the auxiliary magnification determining section 44 of the present embodiment
An input screen of the resolution on the output device of the monitor and the printer is displayed on the monitor 22, and an input is received via the input device 23 (step 906).

When the resolution of the monitor and / or the printer is input, the resolution is converted into the resolution on the CCD image pickup surface, and the resolution determination unit 83 determines the lowest resolution P _min among the resolutions of the CCD 16, the monitor 22, and the printer. A decision is made (step 907). If the aperture stop value NA _CON of the condenser is smaller than the numerical aperture NA _{OBJ of the} objective lens, the auxiliary magnification determining section 44 determines the aperture stop value NA of the condenser by the following equation (6).
_{If CON} is equal to or _larger than the numerical aperture NA _OBJ of the objective lens, the auxiliary magnification M _SUB is calculated by the following equation (7) (step 9).
08), a control signal indicating the calculated auxiliary magnification M _SUB is output from the control signal output unit 45 (step 909).

As a result, an image obtained using the calculated auxiliary magnification M _SUB is displayed on the screen of the monitor 22 by the display unit 46. Lastly, the auxiliary magnification determination unit 44 inquires of the user via the monitor 22 and the input device 23 whether or not re-change is necessary (step 910). If necessary, the process returns to step 906, and the process returns to step 906. If so, the process ends.

In this embodiment, since the auxiliary magnification is determined in consideration of the resolution of the output device in addition to the objective lens and the CCD camera, even if the resolution of the output device is low, the image resolution and An optimal combination with the field of view can be realized.

[0040]

According to the microscope system and the auxiliary magnification determining method of the present invention, since the necessary and sufficient auxiliary magnification utilizing the resolution of the objective lens is automatically set, it is simple, easy and efficient. Observations can be made.

[Brief description of the drawings]

FIG. 1 is an external view showing a configuration of a microscope system.

FIG. 2 is a graph showing the relationship between the total magnification and the resolution.

FIG. 3 is a hardware configuration diagram of the information processing apparatus.

FIG. 4 is a functional configuration diagram of the microscope system according to the first embodiment.

FIG. 5 is a schematic diagram showing a data structure of a numerical aperture table.

FIG. 6 is a flowchart illustrating processing of an auxiliary magnification determining unit according to the first embodiment.

FIG. 7 is a functional configuration diagram of a microscope system according to a second embodiment.

FIG. 8 is a functional configuration diagram of a microscope system according to a third embodiment.

FIG. 9 is a flowchart illustrating processing of an auxiliary magnification determining unit according to the third embodiment.

[Explanation of symbols]

Reference numeral 10: microscope, 12: objective lens, 13: revolver, 1
4 ... lens barrel, 15 ... intermediate zoom mechanism, 16 ... CCD camera, 17 ... condenser, 17A ... aperture stop mechanism, 20 ...
Information processing device, 21: Information processing device main body, 22: Image display device (monitor), 23: Input device (keyboard), 3
0: signal line, 31: main storage device, 32: central processing unit (CPU), 33: interface unit, 34: external storage device, 40: device configuration storage unit, 41: CCD resolution storage unit, 42: numerical aperture Table, 43... Wavelength storage unit, 44
... Auxiliary magnification determination unit, 45 ... Control signal output unit, 46 ... Display unit, 47 ... Objective lens magnification detection unit, 51 ... Lens number storage area, 52 ... Magnification storage area, 53 ... Numerical aperture storage area, 70 ... Microscope system 71, condenser aperture stop detecting means, 80, microscope system, 81, monitor resolution storage unit 81, printer resolution storage unit, 82, resolution determination unit, 100, microscope system.

Claims (4)

[Claims] 1. A method of forming an image of a sample on a photoelectric conversion element with an objective optical system and an auxiliary magnification optical system and converting the image into electrical image information, comprising: setting an auxiliary magnification of the auxiliary magnification optical system to A method for determining an auxiliary magnification, wherein the magnification is determined based on a magnification, a numerical aperture, and a resolution of the photoelectric conversion element. 2. An objective lens, an auxiliary magnification conversion unit for changing the size of an image, a photoelectric conversion element for converting a scaled optical image into electrical image information, and a unit for changing the magnification of the objective lens An auxiliary magnification determining unit that calculates an auxiliary magnification of the auxiliary magnification converting unit based on a magnification and a numerical aperture of the objective lens and a resolution of a photoelectric conversion element; and an auxiliary magnification determined by the auxiliary magnification determining unit. A control signal output unit for outputting a control signal for controlling the auxiliary magnification conversion unit based on the control signal. 3. The microscope system further comprises: a condenser lens provided at a position facing the objective lens; and an output device for outputting an electric signal output from the photoelectric conversion element. The unit calculates the auxiliary magnification based on at least one of an aperture value of the capacitor, a resolution of the photoelectric conversion element, and a magnification and a numerical aperture of the objective lens. 3. The microscope system according to 2. 4. The microscope system according to claim 2, wherein said microscope system further comprises a detecting means for detecting an objective lens used for observation.