JPH08234093A - Focusing device for optical instrument - Google Patents

Abstract

PURPOSE: To automatically set a parting boundary on light receiving elements at the focal position with respect to each objective lens of an optical instrument by comparing the value of a 1st output signal from a 1st light receiving part with the value of a 2nd output signal from a 2nd light receiving part at the time of focusing on a sample. CONSTITUTION: When an automatic setting start switch 30 is depressed in a focused state, information on the initial position of the parting boundary is inputted from a CPU 26 to an integrator 22, and in the integrator 22, integral signals L and L+R of the light receiving signal are generated for the parting boundary in default. A signal (R-L) generated by a 2nd subtractor 25 through a subtractor 23 and a sample/hold circuit 24 is inputted to the CPU 26. In the CPU 26, the parting boundary is moved by the amount of the prescribed number of elements of a CCD 12 in a direction R when the signal (R-L) is positive, and the parting boundary is moved by the amount of the prescribed number of elements of the CCD 12 in the direction L when the signal (R-L) is negative. Further, when the signal (R-L) is zero, the initial state is recognized by the CPU 26 as the position of the parting boundary at the focal position.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a focus adjusting device for an optical instrument, and more particularly to a focus adjusting device for a microscope device.

[0002]

2. Description of the Related Art In a conventional focus adjusting device for a microscope, there is a so-called semi-fixed method as a method of setting a dividing boundary line at a focus position. According to this semi-fixed method, first, the user visually focuses on a specific objective lens to focus the objective lens on the sample. Then, a slit image is projected on the sample through one area of the optical axis of the objective lens, and light from the slit image on the sample is received by a light receiving element such as a CCD through the other area.

Then, while looking at the screen of a measuring instrument such as an oscilloscope which displays the output of the CCD, for example, an adjusting device built in the base is manually adjusted. In this way, the division boundary line on the light receiving element at the focus position is set or changed. The adjusting device is composed of, for example, a plurality of volumes, and it is necessary to manually adjust the corresponding volume for each objective lens attached to the revolver.

[0004]

As described above, in the conventional focus adjusting device for a microscope apparatus as described above, the lens barrel of the microscope apparatus causes thermal expansion due to temperature change, and the angle of the half mirror slightly changes. When changing the objective lens of the revolver, or replacing the revolver itself,
Each time, it was necessary to set the division boundary line at the in-focus position by manually adjusting the adjusting device while looking at the screen of the measuring instrument.

The present invention has been made in view of the above problems, and automatically sets the dividing boundary line on the light receiving element at the in-focus position with respect to each objective lens of an optical apparatus such as a microscope apparatus. It is an object of the present invention to provide a focus adjusting device that can be used.

[0006]

In order to solve the above-mentioned problems, in the present invention, an irradiation means for irradiating a sample with light through one region divided into two parts with respect to the optical axis of the objective lens, and a division. A first light receiving portion and a second light receiving portion divided by a boundary line are provided, and reflected light from the sample is passed through the other region bisected with respect to the optical axis to the first light receiving portion and the second light receiving portion. In a focus adjusting device for an optical instrument, comprising a light receiving section and a light receiving section for receiving light by the light receiving section, the value of the first output signal from the first light receiving section and the second light receiving section when the sample is focused. Comparing means for comparing the value of the second output signal with the value of the first output signal based on the comparison result of the value of the first output signal with the value of the second output signal. A setting means for setting the division boundary line at a position where the value of the output signal matches Providing focusing device of the optical apparatus characterized by Rukoto.

According to a preferred aspect of the present invention, the comparison means further includes an integrator for integrating the first output signal and the second output signal, and the integrated value of the first output signal and the second output signal. The setting means compares the integrated value of the output signal and sets the dividing boundary line at a position where the integrated value of the first output signal and the integrated value of the second output signal match.

[0008]

As described above, in the present invention, the value of the first output signal from the first light receiving portion and the value of the second output signal from the second light receiving portion are compared, and the value of the first output signal The division boundary line is set at a position where the value of the second output signal matches. Specifically, in an optical instrument such as a microscope device, the objective lens is visually focused on the sample. Then, based on the output signal from the light receiving means in the focused state, the division boundary line is set at a position where the integrated value of the first output signal and the integrated value of the second output signal match. In this way, the division boundary line at the in-focus position can be automatically set for each objective lens attached to the revolver, for example.

It is preferable that the position information of the dividing boundary line obtained for each objective lens is stored in the storage means according to the type of the objective lens. In this way, when a specific objective lens is selected from the plurality of objective lenses for which the division boundary line has already been set and placed in the optical path of the microscope apparatus, the division boundary already obtained for that specific objective lens is selected. The objective lens can be automatically focused on the sample based on the position information of the line.

[0010]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a diagram schematically illustrating the configuration of a microscope device equipped with a focus adjusting device according to an embodiment of the present invention. The microscope apparatus of FIG. 1 includes an epi-illumination optical system for epi-illuminating an object plane 8 such as a sample. In the epi-illumination optical system, the illumination light emitted from the observation light source 10 illuminates the field stop 11. Illumination light that has passed through the field stop 11 is reflected by the half mirror 6 and illuminates the object plane 8 by epi-illumination through the objective lens 7. Object surface 8 with epi-illumination
The light from the above forms an intermediate image via the objective lens 7, the half mirror 6, the half mirror 5, and the half mirror 13. The light from the intermediate image reaches the image plane 15 via the eyepiece lens 14. Thus, the object plane 8 at the image plane 15
Can be magnified and observed.

The microscope apparatus shown in FIG. 1 also includes a focus adjusting device for automatically setting the division boundary line at the in-focus position. In the focus adjustment device, the infrared light emitted from the dedicated light source 1 illuminates the slit plate 2 having slits whose longitudinal direction extends in the z direction. Slit plate 2
After passing through the shield plate 3 having an edge extending in the z direction and passing through the optical axis, the light passes through the half mirror 4 and enters the half mirror 5.

The light reflected downward in the figure by the half mirror 5 is imaged as a slit image on the object plane 8 via the half mirror 6 and the objective lens 7. In this way, the slit light that has passed through the slit plate 2 reaches the object plane 8 via one of the two areas divided in the optical axis of the objective lens 7.

The light from the slit image on the object plane 8 enters the half mirror 4 via the objective lens 7, the half mirror 6 and the half mirror 5. The light reflected by the half mirror 4 reaches a light receiving element 12 such as a CCD. In this way, the light from the slit image on the object plane 8 reaches the CCD 12, which is the light receiving means, via the other region (indicated by diagonal lines in the figure) that is divided into two parts with respect to the optical axis of the objective lens 7.
The output of the CCD 12 is input to the arithmetic drive means 9 of the focus adjustment device, and the arithmetic drive means 9 automatically sets the division boundary line at the in-focus position.

FIG. 2 is a diagram showing the internal configuration of the arithmetic drive means 9 of the focus adjustment device of FIG. Arithmetic drive means 9 of FIG.
At, the output from the CCD 12 is amplified by the amplifier 21 and then input to the integrator 22. Note that CC
A light receiving signal as shown in FIG. 3A is output from D12. Then, in the integrator 22, integrated signals L and L + R of the light receiving signal as shown in FIG. 3B are generated. As shown in the figure, the integration signal L is a signal obtained by integrating the light receiving signal from the CCD scanning start point to the division boundary line (shown by the broken line in the figure), and the integration signal L + R receives light from the CCD scanning start point to the CCD scanning end point. It is a signal obtained by integrating the signal.
That is, the signal L is the integrated value of the received light signal in the area on the left side of the division boundary line.

The integrated signal L + R from the integrator 22 is input to the subtractor 23, and the integrated signal L from the integrator 22 is input to the sample hold circuit 24. The signal L sampled and held by the sample and hold circuit 24 is added to the subtractor 23.
Is input to Thus, the subtractor 23 produces the signal R. The signal R is the integrated value of the received light signal in the area on the right side of the division boundary line. Signal R from the subtractor 23
Is input to the second subtractor 25. The signal L sampled and held by the sample and hold circuit 24 is input to the second subtractor 25. Thus, the signal (RL) representing the difference between the two integrated values in the second subtractor 25.
Is generated.

The signal generated by the second subtractor 25 (R-
L) is input to the CPU 26. In the CPU 26, based on the sign of the signal (RL), the division boundary line is set to the CCD 1
2 is moved in a predetermined direction by a predetermined number of elements. In addition,
The CPU 26 includes a switch 30 for starting the automatic setting of the division boundary line, a sensor 28 for detecting the type of the objective lens arranged in the optical path of the microscope apparatus, and an objective lens 7 attached to the revolver for the optical axis. A revolver drive unit 27 for moving along and a memory 29 are connected.

The automatic setting operation of the dividing boundary line in this embodiment will be described below with reference to FIG. First, before the automatic setting of the division boundary line at the in-focus position, the observer manually focuses the microscope device. That is, the revolver is rotated and the objective lens is arranged in the optical path of the microscope apparatus. Then, the objective lens is focused on the object plane by visual focusing while moving the revolver and then the objective lens in the optical axis direction. When the automatic setting start switch 30 is pressed in this focused state, the CPU 26
The initial position information of the dividing boundary line is input to the integrator 22 from. As the initial position of the dividing boundary line, for example, the central position of the CCD 12 can be adopted.

In this way, in the integrator 22, the integrated signals L and L of the received light signal with respect to the default boundary division line are obtained.
+ R is generated. The integrated signal L + R from the integrator 22 is input to the subtractor 23, and the integrated signal L from the integrator 22 is input to the sample hold circuit 24. The signal L sampled and held by the sample and hold circuit 24 is input to the subtractor 23. Thus, the subtractor 23 produces the signal R. The signal R from the subtractor 23 is input to the second subtractor 25. The signal L sampled and held by the sample and hold circuit 24 is input to the second subtractor 25. In this way, the second subtractor 25 generates a signal (RL) representing the difference between the two integrated values.

The signal (R-
L) is input to the CPU 26. If the signal (RL) is positive, the CPU 26 moves the division boundary line in the direction R (rightward in FIG. 3) by the predetermined number of elements of the CCD 12. If the signal (RL) is negative, the dividing boundary line is moved in the L direction (leftward in FIG. 3) by the predetermined number of elements of the CCD 12. Further, if the signal (RL) is zero, the CPU 26 recognizes the initial position as the position of the dividing boundary line at the in-focus position.

Then, if the signal (RL) is non-zero,
The new position information of the moved division boundary line is input from the CPU 26 to the integrator 22. In the integrator 22, the integrated signal L of the received light signal is obtained with respect to the division boundary line moved to the new position.
And L + R. Then, the signal (RL) generated by the subtractor 25 is fed back to the CPU 26. Thus, the CPU 26 appropriately moves the division boundary line according to the sign of the signal (RL) until the signal (RL) becomes zero.

As described above, the position of the dividing boundary line at the in-focus position can be automatically determined by moving the dividing boundary line until the signal (RL) becomes zero. The position information of the division boundary line at the in-focus position thus obtained is
It is stored in the memory 29 together with the objective lens information (magnification information) detected by the sensor 28. The division boundary line at the focusing position for each objective lens attached to the revolver is set by sequentially arranging each objective lens in the optical path and visually positioning at the focusing position, and then pressing the automatic setting start switch respectively. Just done automatically.

Next, referring to FIG. 5, an automatic positioning operation (autofocus operation) of each objective lens to the in-focus position will be described. As described above, it is assumed that the revolver is rotated and a desired objective lens is selected in a state where the division boundary line at the focus position is automatically set for each objective lens. When a particular objective lens is placed in the optical path of the microscope system and switched to the autofocus mode, the sensor 28 detects the type of that objective lens. Based on the type information of the objective lens from the sensor 28, the CP
The U 26 reads out from the memory 29 the position information of the division boundary line at the in-focus position with respect to the objective lens.

The CPU 26 inputs the position information of the division boundary line at the focus position read from the memory 29 to the integrator 22. Thus, in the integrator 22, the integrated signal L of the received light signal with respect to the position of the division boundary line at the focus position is obtained.
And L + R are generated. The integrated signal L + R from the integrator 22 is input to the subtractor 23, and the integrated signal L from the integrator 22 is input to the sample hold circuit 24. Signal L sample-held by the sample-hold circuit 24
Is input to the subtractor 23. Thus, the subtractor 23 produces the signal R.

The signal R from the subtractor 23 is input to the second subtractor 25. Further, the second subtractor 25 has a signal L sampled and held by the sample and hold circuit 24.
Is entered. Thus, in the second subtractor 25, 2
A signal (RL) representing the difference between the two integrated values is generated.

The signal (R-
L) is input to the CPU 26. The CPU 26 outputs a command to the revolver drive unit 27 to move the objective lens in the predetermined direction along the optical axis according to the sign (positive or negative sign) of the signal (RL). That is, if the sign of the signal (RL) is negative, a command to move the object surface away from the objective lens is output, and if the sign of the signal (RL) is positive, the command to bring the object surface closer to the objective lens is output. Also,
If the signal (RL) is zero, the CPU 26 does not output a command to the revolver drive unit 27, and the automatic positioning operation of the objective lens to the in-focus position is completed.

Next, when the signal (RL) is not zero, the CPU
26 outputs a command to the revolver drive unit 27,
In the integrator 22, based on the output signal from the CCD 12 for the objective lens that has moved to a new position, the integration signals L and L + R with respect to the position of the division boundary line at the in-focus position.
Generate Then, the signal (R
-L) is fed back to the CPU 26. In this manner, the CPU 26 outputs a command to move the objective lens to the revolver drive unit 27 according to the sign of the signal (RL) until the signal (RL) becomes zero.

In this way, the objective lens can be moved until the signal (RL) becomes zero, and the objective lens can be automatically focused on the object plane. If you replace the objective lens for the revolver or replace the revolver itself, press the automatic setting start switch for each objective lens that was replaced or for all the objective lenses that were attached to the replaced revolver. It is necessary to automatically set the division boundary line at the focus position.

FIG. 6 is a diagram showing the relative positional relationship of the division boundary line information A, B, and C for the a-fold objective lens, the b-fold objective lens, and the c-fold objective lens having magnifications a, b, and c, respectively. is there. Thus, between the division boundary line information A of the a-times objective lens and the division boundary line information B of the b-times objective lens, the division boundary line information B of the b-times objective lens and the division boundary line information C of the c-times objective lens. There is a relative positional relationship between each of the division boundary line information C of the c-times objective lens and the division boundary line information A of the a-times objective lens.

Therefore, if these relative positional relationships are stored, the a-fold objective lens, the b-fold objective lens, and the c-fold objective lens
When the division boundary line is set again for the double objective lens, it is not necessary to automatically set the division boundary line for all magnification objective lenses. That is, the division boundary line is set again for any one magnification objective lens among the three objective lenses, and for the other magnification objective lenses, it is based on the relative positional relationship stored without being automatically set. It is possible to obtain the division boundary line information. In this way, it is possible to shorten the automatic setting time of the division boundary line after the second time.

In the above-described embodiment, the slit image on the sample is projected through one of the two areas bisected with respect to the optical axis of the objective lens. However, for example, light having another shape such as spot light is projected. It can also be projected. Further, in the above-mentioned embodiment, an example in which the focus adjusting device of the present invention is applied to a microscope is shown, but the focus adjusting device of the present invention can be applied to other suitable optical equipment for detecting an object plane through an objective lens. The device can be applied.

[0031]

As described above, according to the present invention, it is possible to focus on each objective lens of the optical device by simply pressing the automatic setting start switch without using a separately prepared measuring instrument such as an oscilloscope. The division boundary line at the position can be set automatically.

[Brief description of drawings]

FIG. 1 is a diagram schematically illustrating a configuration of a microscope device equipped with a focus adjusting device according to an embodiment of the present invention.

FIG. 2 is a diagram showing an internal configuration of a calculation driving unit of the focus adjustment device of FIG.

3A is a diagram showing a light receiving signal output from the CCD 12 of FIG. 2, and FIG. 3B is a diagram showing how the integrator 22 of FIG. 2 generates integrated signals L and L + R of the light receiving signal.

FIG. 4 is a diagram illustrating an automatic setting operation of a division boundary line.

FIG. 5 is a diagram illustrating an automatic positioning operation of each objective lens to a focus position.

FIG. 6 a-times objective with magnifications a, b and c,
It is a figure which shows the relative positional relationship of each division | segmentation boundary line information A, B, and C about a b-time objective lens and a c-time objective lens.

[Explanation of symbols]

 1 Dedicated Light Source 2 Slit Plate 3 Shielding Plate 4 Half Mirror 5 Half Mirror 6 Half Mirror 7 Objective Lens 8 Object Surface 9 Calculation Driving Means 10 Observation Light Source 11 Field Stop 12 CCD 13 Half Mirror 14 Eyepiece 15 Image Forming Surface 21 Amplifier 22 Integrator 23 Subtractor 24 Sample and hold circuit 26 CPU 27 Revolver drive unit 28 Sensor 29 Memory

Claims (3)

[Claims] 1. An irradiation means for irradiating light onto a sample through one of the two areas bisected with respect to the optical axis of the objective lens, and a first light receiving section and a second light receiving section divided by a dividing boundary line. Focus adjustment of an optical device that includes a light receiving unit that receives reflected light from the sample through the other region that is bisected with respect to the optical axis by the first light receiving unit and the second light receiving unit. In the apparatus, comparing means for comparing the value of the first output signal from the first light receiving unit and the value of the second output signal from the second light receiving unit when the sample is focused on the sample; Based on the result of comparison between the value of the first output signal and the value of the second output signal, the dividing boundary line is set at a position where the value of the first output signal and the value of the second output signal match. A focus adjusting device for an optical instrument, comprising: setting means. 2. The comparing means further includes an integrator that integrates the first output signal and the second output signal, and calculates the integrated value of the first output signal and the integrated value of the second output signal. In comparison, the setting means sets the integrated value of the first output signal and the second value.
The focus adjusting device for an optical apparatus according to claim 1, wherein the division boundary line is set at a position where the integrated value of the output signal matches. 3. A storage unit is further provided for storing the positions of the division boundary lines set for each of the plurality of objective lenses according to the type of the objective lens. 3. The focus adjusting device for an optical instrument according to 1 or 2.