JP4322992B2 - Focusing device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a focusing device used in an optical apparatus such as a microscope or an optical measuring instrument.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, an automatic focusing device that automatically focuses an object to be observed is used in optical instruments such as a microscope and an optical measuring instrument.
[0003]
As such an automatic focusing device, devices disclosed in Japanese Patent Application Laid-Open Nos. 58-217909 and 60-42725 are conventionally known.
[0004]
FIG. 5 shows an automatic focusing device disclosed in these publications. A linearly polarized measuring light beam emitted from the measuring light source 1 is regulated to a parallel light beam via a collimator lens 2 and then a polarizing beam splitter. 3. The light is transmitted through the λ / 4 plate 4 to be converted into circularly polarized light, and the dichroic mirror 5 reflects only the measurement light beam having a predetermined wavelength, and passes through the objective lens 6 to the observation object 8 on the stage 7. Irradiate. Further, the reflected light beam reflected by the surface of the observation object 8 is incident again on the dichroic mirror 5 through the objective lens 6, and a part of the reflected light beam is transmitted through the observation imaging lens 9 to form the imaging position 10. On the other hand, the remaining part is reflected by the dichroic mirror 5, and is reflected by the polarization beam splitter 3 as linearly polarized light that is transmitted through the λ / 4 plate 4 and shifted by 90 ° with respect to the first linearly polarized light. Light is received by the light receiving element 12 through the imaging lens 11. Then, the image forming state of the reflected light beam received by the light receiving element 12 is calculated by the arithmetic control device 13, and the data is input to the driving device 14, and the stage 7 or the objective lens 6 is moved in the optical axis direction. The optical system is focused.
[0005]
[Problems to be solved by the invention]
However, according to the automatic focusing apparatus configured as described above, for example, when there is a step 15 on the surface of the observation object 8 as shown in FIGS. When the light beam 16 a is condensed, two reflected light beams 16 b are generated from the step portion 15, and two light beam points may be formed on the light receiving element 12.
[0006]
Therefore, in such a case as well, a method of combining two reflected light beams 16b is used as a focusing method so as to obtain in-focus. In the normal case, there is a problem that the in-focus position is shifted.
[0007]
In addition, when there is a curved portion 17 on the surface of the observation object 8 as shown in FIG. 6C, when the measurement light beam 16 a is condensed on the curved portion 17, two or more reflected light beams from the curved portion 17. 16b may occur, and two or more light flux points may be formed on the light receiving element 12. In such a case, there is a problem that the in-focus position is completely deviated.
[0008]
Furthermore, when the observation object 8 moves, there is a problem that if the focusing operation is automatically performed in accordance with this movement, an accurate focusing cannot be obtained.
[0009]
Therefore, when it is difficult to obtain the focus by the automatic operation in this way, it is possible to forcibly switch from the automatic focus mode to the manual focus mode by manual operation. Since the mode changeover switch must be operated to switch to the manual focusing mode, there arises a problem that the usability is poor.
[0010]
The present invention has been made in view of the above circumstances, and an object thereof is to provide a focusing device capable of always performing good focusing.
[0011]
[Means for Solving the Problems]
According to the first aspect of the present invention, in the focusing device that performs focusing control on the observation object on the stage by moving the objective lens or the stage in the optical axis direction, the objective lens or the stage is moved in the optical axis direction. A drive unit for causing the objective lens or the stage to be moved in the optical axis direction by the drive, a light receiving element that forms an image of light from the observation object, and the drive unit by an operation of an operator An operation instruction unit for outputting an operation direction and an operation command signal, and driving the drive unit based on output information from the light receiving element to switch to an automatic focusing mode to control focusing, and the operation instruction unit A control unit that drives the driving unit based on a signal from the control unit to switch to a manual focusing mode and controls focusing, and a detection unit that detects a continuous operation state of the operation instruction unit. When the unit determines that the operation instruction unit has been operated continuously for a predetermined time from the output of the detection unit while being switched to the automatic focusing mode, the unit stops the automatic focusing mode and performs the manual operation. It is characterized by forcibly switching to the operation mode .
[0012]
According to a second aspect of the present invention, in the first aspect of the invention, the detection unit is configured to determine whether the operation instruction unit has been operated continuously for a predetermined time based on the operation time of the operation instruction unit or the number of pulses of the operation instruction unit. The feature is to detect .
[0013]
According to a third aspect of the invention, in the first aspect of the invention, the stage has stage position detecting means for detecting movement in the XY directions, and the control unit is given a signal associated with movement of the stage. And control for returning from the manual focusing mode to the automatic focusing mode is performed .
According to a fourth aspect of the present invention, in the first aspect of the present invention, the operation instruction unit includes a mode switching switch for switching to an automatic focusing mode, and the control unit is forcibly switched to the manual operation mode. Thereafter, the automatic focus mode is restored by operating the mode changeover switch.
[0014]
As a result, according to the present invention, even when it is difficult to focus the observation image due to the state of the surface of the observation object, the mode changeover switch or the like is operated to switch directly to the focusing operation by the manual focusing operation means. By operating the manual focusing operation means, it is possible to switch to manual focusing operation by the manual focusing operation means.
[0015]
Further, according to the present invention, even after switching to the manual focusing mode by the manual focusing operation means, it is possible to return to the automatic focusing mode by the automatic focusing operation means again by moving the stage.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0017]
(First embodiment)
FIG. 1 shows a schematic configuration of an epi-illumination microscope to which the focusing device of the present invention is applied. In the figure, reference numeral 21 denotes a focus optical system, and the focus optical system 21 has the same configuration as described in FIG. 5 described above, and the same reference numerals are given to the same parts as those in FIG.
[0018]
A display unit 22 is connected to such a focal optical system 21. The display unit 22 includes a CCD camera 22a and a monitor 22b. The CCD camera 22a is arranged at an image forming position 10 through the observation image forming lens 9 of the focus optical system 21, and the observation object 8 is imaged. At the same time, the captured image of the observation object 8 is displayed on the monitor 22b.
[0019]
A control unit 23 is connected to the focal optical system 21, and an operation instruction unit 24 is connected to the control unit 23. Here, the control unit 23 controls the driving device 25 based on an instruction signal from the operation instruction unit 24. As shown in FIG. 2, the operation instructing unit 24 includes an encoder 24a for outputting an operation direction and an operation command signal for the driving device 25, an automatic focusing mode (AF) for automatically focusing, and a manual focusing for manually. A mode changeover switch 24b for selectively changing over the focus mode (MF) is provided.
[0020]
The control unit 23 includes an A / D converter 23a, a focus determination numerical value memory unit 23b, a timer 23c, and a CPU 23d.
[0021]
Here, the A / D converter 23a converts an electric signal corresponding to the reflected light beam 16b collected by the light receiving element 12 of the focus optical system 21 into a digital signal, and inputs the digital signal to the CPU 23d. I have to.
[0022]
The focus determination numerical value memory unit 23b stores a focus determination value set in advance.
[0023]
The timer 23c has a continuous operation time (for example, 1 second) that can be determined that the operator has not operated the encoder 24a by mistake in a state where the changeover switch 24b is switched to the automatic focusing mode (AF). It is to be measured, and the set time can be arbitrarily adjusted.
[0024]
When the changeover switch 24b is switched to the autofocus mode (AF), the CPU 23d and the digital signal from the A / D converter 23a and the focus determination value set in the focus determination value memory unit 23b. To determine whether or not the focusing operation is possible, and outputs the determination result to the driving device 25, and the stage 7 or the objective lens 6 is moved in the optical axis direction to automatically focus the optical system. To do. Further, when the changeover switch 24b is switched to the manual focusing mode (MF), the CPU 23d directly controls the driving device 25 based on the operation direction and the operation command signal for the driving device 25 by the encoder 24a, and the stage 7 Alternatively, manual focusing of the optical system is performed by moving the objective lens 6 in the optical axis direction. Further, the CPU 23d operates the encoder 24a for some reason from the state in which the changeover switch 24b is switched to the automatic focusing mode (AF), and the operation of the encoder 24a continues for a predetermined time from the output of the timer 23c. If the determination is made, the automatic focusing mode (AF) is stopped regardless of the current switching state (automatic focusing mode) of the changeover switch 24b, and the drive device 25 is directly controlled by the output of the encoder 24a. The mode is forcibly switched to the manual focusing mode (MF).
[0025]
The focus determination numerical value stored in the focus determination numerical value memory unit 23b can be arbitrarily set, and the best value can be set according to the observation object being observed, the observation magnification, or the observation method. it can. Further, the observation object 8 is a transparent body and is effective for the purpose of use for observing the inside.
[0026]
Next, the operation of the embodiment configured as described above will be described.
[0027]
First, the observation object 8 is placed on the stage 7, and the changeover switch 24b is switched to the automatic focusing mode (AF) side.
[0028]
From this state, when the focusing optical system 21 irradiates the observation object 8 on the stage 7 with the measurement light beam 16a and the reflected light beam 16b reflected by the surface of the observation object 8 is received by the light receiving element 12, The electric signal output from the light receiving element 12 is converted into a digital signal by the A / D converter 23a and input to the CPU 23d.
[0029]
Then, the CPU 23d compares the digital signal from the A / D converter 23a with the in-focus determination value set in the in-focus determination value memory unit 23b to determine whether or not the in-focus operation is possible. . Based on the determination result, the stage 7 or the objective lens 6 is moved in the optical axis direction by the driving device 25, and automatic focusing is performed. Then, an observation image of the observation object 8 obtained by such an automatic focusing operation (AF) is obtained by a CCD camera 22 a disposed at the image formation position 10 via the observation image formation lens 9 of the focus optical system 21. The image is captured and displayed on the monitor 22b.
[0030]
By the way, in such an automatic focusing mode (AF), as shown in FIG. 6 mentioned above, the observation displayed on the monitor 22b due to the stepped portion 15 and the curved portion 17 existing on the surface of the observation object 8 is observed. When it is difficult to focus the image, the observer operates the encoder 24a of the operation instruction unit 24. Then, the timer 23c starts measuring the continuous operation time of the encoder 24a. When the CPU 23d detects from the output of the timer 23c that the operation of the encoder 24a has been continuously performed for a predetermined time, the automatic focusing mode (AF) is stopped without waiting for the switching operation of the changeover switch 24b. It is forcibly switched to a manual focusing mode (MF) in which the drive device 25 is directly controlled by the output from the encoder 24a.
[0031]
Thereafter, by switching the changeover switch 24b to the automatic focusing mode (AF) side again, it is possible to switch from the manual focusing mode (MF) to the above-described automatic focusing mode (AF) again.
[0032]
Therefore, in this way, even when it is difficult to focus the observation image displayed on the monitor 22b due to the step portion 15 or the curved portion 17 on the surface of the observation object 8, the changeover switch of the operation instruction portion 24 is used. Since it is possible to switch to the manual focusing mode (MF) by directly operating the encoder 24a without switching the 24b to the manual focusing mode (MF), there is no switching error of the mode switching switch 24b, and the object to be observed Thus, it is possible to always achieve good focusing without being affected by the viewing conditions of 8. Further, since the automatic focusing mode can be automatically switched from the manual focusing mode to the manual focusing mode only by operating the encoder 24a, the mode switching switch 24b is searched for or the hand is switched from the mode switching switch 24b to the encoder 24a. There is no need to move it, improving operability.
[0033]
(Second Embodiment)
FIG. 3 shows a schematic configuration of the second embodiment of the present invention, and the same parts as those in FIG.
[0034]
In this case, the stage position detector 26 is connected to the driving device 25. The stage position detection unit 26 converts the absolute position or operation direction and operation signal associated with the movement of the stage 7 into a digital signal and outputs it to the CPU 23d. Further, when a digital signal is given from the stage position detector 26, the CPU 23d returns the manual focus mode (MF) that has been forcibly switched to the automatic focus mode (AF) again.
[0035]
Even in such a configuration, the focusing optical system 21 irradiates the observation object 8 on the stage 7 with the measurement light beam 16a, and the reflected light beam 16b reflected by the surface of the observation object 8 is received by the light receiving element 12. When the electrical signal output from the light receiving element 12 is input to the CPU 23d via the A / D converter 23a, the CPU 23d performs a comparison operation between the digital signal and the focus determination value of the focus determination value memory unit 23b. From this result, the stage 7 or the objective lens 6 is moved in the direction of the optical axis by the driving device 25 to perform automatic focusing, and an observation image of the observation object 8 is picked up by the CCD camera 22a and displayed on the monitor 22b. Is done.
[0036]
In such an automatic focusing mode (AF), when the observation image 8 becomes difficult to be focused due to the state of the surface of the observation object 8, and the observer operates the encoder 24a of the operation instruction unit 24, the CPU 23d When it is detected from the output of 23c that the operation of the encoder 24a is continuously performed for a predetermined time, the automatic focusing mode (AF) is stopped, and the manual focusing mode in which the driving device 25 is directly controlled by the output from the encoder 24a. Forcibly switched to (MF).
[0037]
Thereafter, when in-focus is obtained by the manual focusing operation, the observer stops the operation of the encoder 24a and performs observation. When the observation is finished, the observer moves the stage 7 in order to observe the next observation site. When the stage 7 is moved in the X and Y directions for the next observation in this way, a digital signal associated with the movement of the stage 7 from the stage position detector 26 is input to the CPU 23d, and the automatic focusing is resumed from the manual focusing mode (MF). It is automatically switched to the focus mode (AF).
[0038]
Therefore, even in this case, the same effect as that of the first embodiment can be expected, and further, by detecting the movement of the stage 7 even after forcibly switching to the manual focusing mode (MF). Since it is possible to return to the automatic mode (AF) again, usability can be further improved.
[0039]
In the first and second embodiments, the example applied to the epi-illumination microscope has been described. However, the present invention is not limited to this and can be applied to an optical instrument such as a transmission illumination microscope or a measuring instrument. In the first and second embodiments, the encoder 24a is used as the manual operation instructing means. However, as shown in FIG. 4, switching for instructing UP or DOWN in the optical axis direction of the stage 7 or the objective lens 6 is performed. The switch 27 may be used. Furthermore, in the first and second embodiments, the continuous operation time of the encoder 24a is measured by the timer 23c. However, the encoder 24a generates pulses at a predetermined interval and counts the number of pulses. The continuous operation state may be monitored. Furthermore, in the first and second embodiments, AF and MF are switched using another changeover switch, but an illumination type switch may be used as AF during illumination and as MF during extinction.
[0040]
【The invention's effect】
As described above, according to the present invention, even when it is difficult to focus the observation image due to the state of the surface of the observation object, it is possible to directly operate the manual focusing operation means without operating the mode switch. Since it is possible to automatically switch to the manual focusing mode, the usability is improved and good focusing can always be performed without being influenced by the observation condition of the observation object.
[0041]
Further, even after switching to the manual focusing mode by the manual focusing operation, it is possible to automatically return to the automatic focusing mode again by moving the stage, so that the usability can be further improved.
[Brief description of the drawings]
FIG. 1 is a diagram showing a schematic configuration of a first embodiment of the present invention.
FIG. 2 is a diagram showing a schematic configuration of an operation instruction unit used in the first embodiment.
FIG. 3 is a diagram showing a schematic configuration of a second embodiment of the present invention.
FIG. 4 is a diagram showing a schematic configuration of a modified example of the present invention.
FIG. 5 is a diagram showing a schematic configuration of an example of a conventional focusing device.
FIG. 6 is a diagram for explaining a conventional focusing device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Measuring light source 2 ... Collimator lens 3 ... Polarizing beam splitter 4 ... (lambda) / 4 board 5 ... Dichroic mirror 6 ... Objective lens 7 ... Stage 8 ... Observation object 9 ... Observation imaging lens 10 ... Imaging position 11 ... Connection Image lens 12 ... Light receiving element 15 ... Step 16a ... Measurement light beam 16b ... Reflected light beam 17 ... Bending part 21 ... Focusing optical system 22 ... Display part 22a ... CCD camera 22b ... Monitor 23 ... Control part 23a ... D converter 23b ... Focus determination value memory unit 23c ... Timer 23d ... CPU
24 ... Operation instruction unit 24a ... Encoder 24b ... Mode changeover switch 25 ... Drive device 26 ... Stage position detector 27 ... Changeover switch

Claims (4)

In a focusing apparatus that moves the objective lens or the stage in the optical axis direction and performs focusing control on the observation object on the stage
A drive unit for moving the objective lens or the stage in the optical axis direction;
A light receiving element that forms an image of light from the object to be observed when the objective lens or the stage is moved in the optical axis direction by the driving;
An operation instruction unit that outputs an operation direction and an operation command signal to the drive unit by an operation of an operator;
Based on the output information from the light receiving element, the driving unit is driven to switch to an automatic focusing mode to perform focusing control, and the driving unit is driven based on a signal from the operation instruction unit to manually focus. A control unit for controlling focus by switching to a mode;
A detection unit for detecting a continuous operation state of the operation instruction unit,
When the control unit determines that the operation instruction unit has been operated continuously for a predetermined time from the output of the detection unit while being switched to the automatic focusing mode, the control unit stops the automatic focusing mode. A focusing device forcibly switching to the manual operation mode . 2. The condition according to claim 1 , wherein the detection unit detects whether the operation instruction unit is operated continuously for a predetermined time based on an operation time of the operation instruction unit or a pulse number of the operation instruction unit. Charcoal device. The stage includes a stage position detecting means for detecting a movement of the XY directions, the control by the control unit, to return from the signal with the movement of the stage is given the manual focusing mode to the automatic focusing mode The focusing device according to claim 1, wherein: The operation instruction unit has a mode switching switch for switching to the automatic focusing mode, and the control unit is switched to the automatic focusing mode by operating the mode switching switch after being forcibly switched to the manual operation mode. The focusing apparatus according to claim 1, wherein the focusing apparatus is returned.

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