JPH10197784A - Automatic focusing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain an automatic focusing device which is convenient for a person who is inexperienced in image processing, microscopic and picture photographing, etc., and also who can not spare a plenty of time for microscopic photographing, such as a person who engages in medical care and a research worker, etc. SOLUTION: As for the automatic focusing device 4, in the case that a CCD camera 51 is not appropriately connected to the device main body 400, the state is automatically detected by a camera connection state detection circuit 90 based on the potential level (video signal) of a detection result inputting terminal 50 to which a signal from the CCD camera 51 is inputted, then, an error display lamp 44 is lighted so as to give an alarm as for the effect, and also, an operation 903 of stopping a focus motor 27 is executed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an autofocus apparatus for automatically and accurately performing a focus operation for photographing in a microphotographing system for photographing an enlarged image of a subject.

[0002]

2. Description of the Related Art As a system for taking a microscopic photograph, there is known a system provided with an autofocusing device using a CCD camera in order to automate a focusing operation of a photographing device attached to an optical microscope. By using the autofocus device, the focus operation of the photographing device can be performed more accurately than in the case of visual observation, and photographing without blur can be performed.

[0003] The focus operation by the autofocus device is convenient when, for example, photographing a pathological specimen or the like with an optical microscope. That is, in this case, a low-magnification (low-magnification) photograph for grasping the entire specimen image and a high-magnification (high-magnification) photograph for closely examining the lesion are often taken. Focusing is difficult in low-magnification photography,
Even when clearly visible when observed visually, the photographed image is often blurred and unfit for practical use. The difficulty in focusing when using a low-magnification objective lens is due to the fact that the depth of focus of the optical system of the photographing device is shallower than the visual depth of focus.

[0004] In view of this point, the present applicant has previously disclosed
In the specification of Japanese Patent No. 25478, there is proposed a microscope photographic apparatus provided with an autofocus apparatus for easily performing autofocus of photographing even when the magnification of an objective lens in a microscope is about 1 to 4 times. ing.

[0005] The above auto-focusing apparatus is of a contrast detection type. An outline of the operation will be described with reference to FIG. In the autofocus device, an image of the subject 7 formed through an optical microscope and a lens optical system of a photographing device can be captured via an image sensor 51 such as a CCD camera. While moving the stage of the optical microscope, a video signal is taken in at a certain timing, its high frequency component is detected, and the contrast of the video signal is calculated. The stage scans the lens optical system between its far point side and its near point side. By this scanning, a contrast curve as shown by a curve C is obtained. It is determined that the position where the value P having the highest contrast is obtained is the focus point.

[0006]

A system provided with such a contrast detection type autofocus device is disclosed in US Pat.
It is used at medical sites, universities and the like to take biological micrographs. Therefore, users of such a system are generally novice and busy with respect to image processing, microscopes, photography, and the like. Also,
In many cases, it is not possible to retake a photograph of a pathological specimen or the like.
Therefore, such a system must be capable of ensuring that a layman can perform a focusing operation in a short time, but such consideration is not sufficient in the above-mentioned autofocus apparatus.

[0007] For example, as described above, since a person who handles a living tissue takes a picture while he is busy, he or she cannot save much time for this photographing. Even if the user has forgotten to connect the image sensor, no care is taken to prevent the unnecessary autofocus operation from being repeated without knowing it.

Further, if the autofocus device is limited to taking a micrograph of a living tissue, the need for such a device is limited, and the device becomes expensive. Therefore, the autofocus device may be configured to be compatible with both a microscope for handling biological tissue and a microscope for handling so-called industrial materials. While photography is performed with a light transmission type microscope, industrial microscope photography is often performed with a light reflection type microscope. However, in these methods, the conditions for the autofocus operation and the conditions for determining whether or not the illumination level is appropriate are considerably different.
After fully understanding this difference, it is necessary to adjust each condition with effort each time. Therefore, if the autofocus device is of a general-purpose type, it is inconvenient for busy medical staff and researchers. That is, a microscope generally used for industrial materials is a light reflection type, and a video signal obtained from the imaging device at that time is shown in FIG.
As schematically shown in FIG. 5A, the level of the video signal is high and the contrast (clarity) is high. However, the difference between the bright part and the dark part is small. In contrast, living tissue is photographed with a light transmission type microscope.
In the case of a relatively thick sample such as a brain slice, the image signal obtained from the image sensor has a low image signal level and a contrast (clearness) as schematically shown in FIG. Is also small. However, the difference between the bright part and the dark part is large. Further, even though a photograph of a living tissue is taken with a light transmission type microscope, in the case of a relatively thin sample such as a cancer pathological sample, an image signal obtained from the imaging device is as shown in FIG.
As schematically shown in (C), the level of the video signal is high, but the contrast (clarity) is low. Further, the difference between the bright part and the dark part is small. Note that FIG. 15D shows the relationship between the content of microscopic photography and the characteristics of video signals. As described above, since the video signal obtained from the image sensor changes depending on the contents of the microscopic photographing and the subject, only the video signal obtained from the image sensor is actually obtained even though the image signal is not in an appropriate state for photographing. As a result, it is determined that the camera is in an appropriate state, and a photograph that cannot be used is taken.

[0009] The object of the present invention is to solve the above problems.
Realized an autofocus device convenient for those who have little experience in image processing, microscopy, photography, etc. and who can not spend much time taking micrographs like medical professionals and researchers Is to do.

[0010]

In order to solve the above-mentioned problems, according to the present invention, a light image of a subject is input to a main body of a device via a video signal input terminal and input through a lens optical system of a microscope. When each of the image sensor and the lens optical system and the object are relatively scanned by a motor drive, each image is obtained from a high frequency component included in the image signal of the object input in time series through the image sensor. In a contrast detection unit that detects a contrast value of a signal, and an autofocus apparatus that determines a focus point based on a result of the contrast value detection by the contrast detection unit and performs an autofocus operation, a potential level at the video signal input terminal Connection state detecting means for detecting whether or not the image sensor is properly connected to the apparatus body based on A focus operation automatic stop unit for automatically stopping an autofocus operation when the connection state detecting unit detects that the image sensor is not properly connected to a body; and the image sensor is appropriate for the apparatus main body. And a warning means for issuing a warning when the connection state detecting means detects that the connection is not established.

[0011] In the autofocus device according to the present invention,
If the image sensor is not properly connected to the main body of the apparatus, the connection state detecting means automatically detects this based on the potential level at the video signal input terminal, and the automatic focus operation stopping means performs auto focus. Stop the operation automatically. Therefore, it is possible to save time for performing unnecessary focus operation. When the image sensor is not connected to the apparatus main body, the warning unit issues a warning to that effect. Therefore, it is immediately noticed that the user has forgotten to connect the image sensor to the apparatus main body, so that time loss can be saved. Therefore, it is convenient for those who have little experience in image processing, microscopy, photography, and the like, and who cannot spend much time taking micrographs, such as medical professionals and researchers.

It is preferable that the focus operation stopping means is configured to automatically stop the motor drive for the auto focus operation. With this configuration, the lens optical system and the object are not scanned in vain over time, so that the time spent in unnecessary autofocus operation can be effectively saved.

According to the present invention, an illumination level detecting means for detecting whether or not an object has an illumination level suitable for taking a microphotograph of the object based on the video signal, and photographing the object with a light transmission type microscope. At this time, a first parameter group including a contrast detection parameter necessary for performing an autofocus operation and an illumination level detection parameter required for detection performed by the illumination level detection unit, and a subject are reflected by a light reflection microscope. A second parameter group including a contrast detection parameter necessary for performing an autofocus operation and an illumination level detection parameter required for detection performed by the illumination level detection unit when taking a photograph; Is preferred. With this configuration, since the parameter groups for performing the typical two types of microscopic photographing have already been configured, simply selecting the first parameter group allows the biological tissue to be transmitted through the light transmission type microscope. The auto-focus operation and the appropriateness of the illumination level can be detected under the conditions suitable for taking a photo.

In the present invention, since the autofocus device is configured so as to be particularly suitable for taking a micrograph of a living tissue, the first parameter group is used when taking a photograph of the living tissue with a light transmission type microscope. It is preferable that a parameter group is provided, and initialization is performed so as to detect the suitability of the autofocus operation and the illumination based on the parameter group.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings.

(Overall Configuration) FIG. 1A shows the overall configuration of a microphotographing system having an autofocus apparatus to which the present invention is applied. The microphotographing system 1 is a system in which the use conditions are limited to a low magnification (1 to 10 times) objective lens of a biological system, and the autofocus operation is optimized. Further, the operation is simplified by using only four auto focus start switches corresponding to the magnification of the objective lens. Further, the weakly magnifying objective lens has a very large depth of focus, and it is necessary to widen a scanning width for detecting a contrast in order to perform accurate focusing. Therefore, focusing can be performed in a short time even if the scanning width is wide. Furthermore, focusing can be performed with high accuracy even when the scanning width is wide.

As shown in FIG. 1A, a microscope photographing system 1 includes a biological microscope 2, a photographing device 3 attached thereto, and an autofocus device 4 for focusing the photographing device 3. It is basically composed of The autofocus device 4 is electrically connected to the photographing device 3 via a signal line 5 schematically indicated by a dotted line, and captures a video signal of the subject 7 obtained here. In addition, the autofocus device 4 is also connected to the stage 2 of the biological microscope 2 via a signal line 6 schematically indicated by a dotted line.
The first driving mechanism 22 is connected to the first driving mechanism 22 and drives the driving mechanism 22 to move the focusing stage 21 up and down.

The device body 400 of the autofocus device 4
The front panel 40 is formed obliquely upward and a scanning panel 41 is formed therein. This scanning panel 41 has 4
Auto focus activation switches 42 (42 (×
1), 42 (× 2), 42 (× 4) and 42 (× 1
0)) are arranged. In addition, on the operation panel 41,
A focus display lamp group 43 (43a, 43b) for displaying whether or not a focus point has been properly detected by an autofocus operation, when a video signal detection error occurs, or when the CCD camera 51 An error display lamp 44 (warning means) that lights up when not properly connected to the main body 400, and a gain display lamp group 45 (45a, 45b, 45a, 45b, 45b) for displaying whether or not the illumination level of the subject 7 is appropriate. 45
c) is also arranged. When these switches or lamps are operated or turned on will be described later. Reference numeral 461 denotes a power supply lamp.
2 is a main switch.

As shown in FIG. 1B, a detection result input terminal 50 (video signal) for connecting the signal line 5 to the photographing device 3 and the CCD camera 51 is provided on the back of the autofocusing device 4. An input terminal) and a drive signal output terminal 60 to which the signal line 6 of the drive mechanism 22 of the stage 21 of the biological microscope 2 is connected. In addition, an inlet 471 for AC100V and a fuse 472 are also configured therein.

Further, in the present embodiment, a part of the rear surface of the autofocus device 4 is opened with a window, and scanning conditions corresponding to each optical parameter of a plurality of built-in objective lenses 23 are set therein as described later. A scanning condition input terminal 48 for external setting is configured.

A video monitor terminal 61 for monitoring the result of autofocus is provided. The scanning condition input terminal 48 and the video monitor terminal 61 are covered by a terminal cover 49 that is screwed to the back of the autofocus device 4 after the external input of the scanning condition is completed.

Using this microscope photographing system 1,
When taking a photograph, a sample as the subject 7 is placed on the stage 21, and one of four low-magnification objective lenses (1, 2, 4, and 10 ×) is selected as the objective lens 23. Focusing and visual field determination are performed visually using the eyepiece 25. Next, remove the focusing viewer in advance and attach the CCD
The autofocus device 4 including the camera 51 is activated. For this activation, the one corresponding to the objective lens used among the four auto focus activation switches 42 may be operated. As a result, the autofocus device 4 performs the autofocus operation by driving the focusing knob fine movement shaft that constitutes the drive mechanism 22 of the stage 21. After focusing, the film camera 31 of the photographing device 3 is operated to take a microphotograph.

FIG. 2 shows a schematic configuration of a lens optical system and a control system of the microscope photographing system 1 of the present embodiment. As shown in this figure, the lens optical system includes four types of objective lenses 23, a half mirror 24, an eyepiece 25, and a half mirror 34 for guiding light to a photographing lens 32 and a CCD camera 51 incorporated in the optical microscope 2. It has. An enlarged image of the subject sample 7 obtained through the objective lens 23 passes through the half mirror 24 and passes through the photographing device 3.
, And is reflected here to the eyepiece lens 25 side. The enlarged image directed to the photographing lens 32 forms an image on the photographic film 33 through the enlarged image. A half mirror 34 is also arranged on the optical path between the taking lens 32 and the photographic film 33. The subject image reflected by the half mirror 33 is received by the image sensor 52 of the CCD camera 51 of the autofocus device 4.

An illumination light source 26 is arranged on the back side of the focusing stage 21, that is, on the lower side in the figure. The subject sample 7 placed on the stage 21 is illuminated by an illumination light source 26, and a photograph of the subject sample 7 is taken by a light transmission method.

On the other hand, a video signal of the subject sample 7 received by the CCD camera 51 is input to the autofocus device 4 via the signal line 5 and the detection result input terminal 50 as an NTSC video signal, for example. The main function of the drive control circuit 8 of the autofocus device 4 is a function realized by a microcomputer. Under the control of the CPU 84, the control program stored in the ROM 87 is executed using the RAM 88 as a working area. It is achieved by doing.

The drive control circuit 8 includes a buffer 81 for converting the impedance and level of a video signal, and a contrast detection circuit 82 (contrast detection unit) for receiving the video signal and detecting the contrast thereof.
And an illumination level detection circuit 83 (illumination level detection unit) that receives an image signal and detects whether or not the illumination level of the illumination light source 26 is appropriate.
A camera connection state detection circuit 90 (connection state detection means) for detecting whether or not the camera is properly connected to the camera, and a CPU 84 for controlling the driving of these parts. The driving of these parts is performed based on the timing signal supplied from the timing controller 85 based on the synchronization signal of the video signal. An operation unit 86 is provided. The operation unit 86 includes an operation panel 41 including various switches 42 and lamps 43 to 46 shown in FIG. Control circuit 8 of autofocus device 4 having this configuration
Are connected to the motor driver 9 via an input / output interface 89. It can also be connected to a host computer (not shown).

The motor driver 9 drives a focus motor 27 which is a driving source of a driving mechanism 22 of the focusing stage 21 of the optical microscope 2. A stepping motor is used as the focus motor 27.

(Outline of Control System and Operation) FIG. 3 shows a control system of the microphotographing system 1 of this embodiment together with control function blocks realized mainly by the CPU 84 of the drive control circuit 8 of the autofocus device 4. It is. With reference to this figure, the control system of the system 1 of the present example will be described in more detail.

First, when the autofocus device 4 is started, that is, when one of the autofocus start switches 42 is operated, the control parameters (scanning conditions) of the autofocus operation stored in the memory are stored. The corresponding control parameter is output from the parameter storage unit 9188 that performs the control. In this example, as described later,
It is configured to perform a step autofocus operation. Therefore, a coarse parameter group 92 (first pulse number J1 for defining the minimum unit of stage movement to be described later) and data number S1 for defining the contrast data sampling number for the coarse focus operation performed first.
Etc.) and a fine parameter group 93 for a fine focus operation to be performed subsequent to the coarse focus operation (the number of pulses J2 for specifying the minimum movement unit of the stage movement, which will be described later, and the sampling number of contrast data). Is output.

The control parameters (coarse parameter group 92 and dense parameter group 93) are set for each of the objective lenses 23 according to their optical characteristics. In addition, when setting the control parameters in the parameter storage unit 9188, the control parameters can be set via the scanning condition input terminal 48 described with reference to FIG.
There is no need to change unless the type of the objective lens 23 is changed.

The CPU 84 of the autofocus device 4
A motor control operation 94 for controlling the driving of the focus motor 27 is executed based on these control parameter groups.
The drive signal output by the motor control operation 94 causes the focus motor 27 via the motor driver 9.
Is driven, and the focusing stage 21 of the microscope 2 is driven.
Reciprocates along the optical axis of the optical system.

The video signal obtained via the CCD camera 51 while moving the focusing stage 21 is stored in the buffer 81 in the control parameters 92 and 93 described above.
Are sampled frame by frame at the sampling timings included in. The sampled video signal is supplied to a contrast detection circuit 82 via a buffer 81.

The contrast detection circuit 82 extracts high frequency components from the video signal and detects the contrast. The contrast of the video signal detected by the movement of the stage 21 (that is, scanning of the optical system) at the time of the first coarse focus operation is stored in the coarse focus operation contrast memory 96 developed in the RAM in time series. Will be retained. The contrast of the video signal detected at the time of the fine focus operation performed after the coarse focus operation is stored and held in the fine focus operation contrast memory 97 developed in the RAM in a time series.
Since there is a temporal difference in the timing of these storages, a common memory can be used.

A contrast curve creating operation 98 is executed based on the contents of these memories 96 and 97, and the contrast curve 9 of the video signal by the coarse focusing operation is obtained.
6C and a contrast curve 97C of the video signal by the fine focus operation are obtained. Shape determination 99 of these contrast curves 96C and 97C is executed. In this shape determination, the peak position, the quality of the result, and the like are detected.

In the shape determination operation 99A based on the contrast curve 96C obtained by the coarse focusing operation, the coarse peak position of the contrast curve 96C is determined. If the peak cannot be determined, a determination operation 101 for determining whether or not to perform an auto-focus restart described later is performed based on the determined pattern. This determination operation 10
1 determines whether or not to perform the coarse focus operation again based on the pattern, and when performing the coarse focus operation again, sets the scanning range. If restart is not possible, the focus indicator lamp group 43 blinks to warn and stop the operation.

When performing the coarse focus operation again,
The motor control operation 94 is executed, and the coarse focus operation in the newly set scanning range is executed.

When a clear focus point is detected by one coarse focus operation, a scan range setting operation 102 for a fine focus operation is executed. The motor control operation 9 is performed so that the fine focus operation is performed in the scan range set by the scan range setting operation 102.
4 is performed.

The shape determination operation 99B is also performed on the contrast curve 97C obtained by the fine focus operation. The shape determination operation 99B also determines a dense peak position and calculates a difference between the maximum value and the minimum value of the contrast. A focus point position detection operation 103 is performed based on the shape determination 99B. When the focus point is detected, a motor control operation 94 is executed to drive the focus motor 27, move the focus stage 21 toward the focus point, and stop at the position.

Depending on the respective conditions, there is a case where a sufficient function can be achieved only by the dense autofocus operation. In such a case, the coarse autofocus operation is omitted.

The result of the shape determination operation 99B of the contrast curve 97C obtained by the fine focus operation is displayed via the focus display lamp group 43.

Here, in the autofocus device 4 of the present embodiment, the drive control circuit 8 is provided with an illumination level detection circuit 83 described later. The illumination level detection circuit 83 performs a video signal level detection operation 833, performs a level (amplitude) detection operation 832 of a high-frequency component extracted from the video signal, and performs an addition operation 834 of these levels. Then, based on the addition result, a level comparison operation 835 is performed to determine whether the illumination level is within an appropriate range, or is higher or lower than that range. The gain display lamp group 45 is driven based on the comparison result.

(Camera Connection State Detection Circuit and Auto Focus Stop Function) The drive control circuit 8 includes a camera connection state detection circuit 90. In the camera connection state detection circuit 90, after the synchronization separation circuit 901 separates the video signal input from the detection result input terminal 50 (potential level of the detection result input terminal 50) into a synchronization signal, the presence or absence of a signal is determined. The detection circuit 902 detects whether or not the CCD camera 51 is properly connected to the device main body 400 of the autofocus device 4 based on the level of the video signal. When it is determined from the detection result that the CCD camera 51 is properly connected, the focusing operation is performed as it is.

On the other hand, the camera connection state detection circuit 9
If it is detected that the CCD camera 51 is not connected or the connection state is abnormal at 0, a scan stop operation 903 of the focus motor 27 is executed to forcibly stop the auto focus operation and display an error. The lamp 44 is turned on to give a warning to that effect. Therefore, even if the CCD camera 51 is forgotten to be connected to the apparatus main body 400, it is possible to eliminate a time loss in which the autofocus operation is repeatedly performed. Also,
Since the user immediately notices that he has forgotten to connect the CCD camera 51 to the apparatus main body 400, it is convenient for a person who cannot spend much time taking a micrograph, such as a medical worker or a researcher. In particular, when the autofocus operation is forcibly stopped, the focus motor 27
Since the scanning itself is stopped, the focusing stage 21 of the microscope 2 does not needlessly scan for a relatively long time, so that the time spent for useless autofocus operation can be effectively saved.

As such a camera connection state detection circuit 90, for example, one having the configuration shown in FIG. 4 can be used. The camera connection state detection circuit 90 shown in FIG. 4 uses a synchronization separation circuit 901 and a signal presence / absence detection circuit 902. Further, a focus operation continuation / stop determination circuit 904 (focus operation automatic stop means) is configured at a stage subsequent to the camera connection state detection circuit 90.

In the camera connection state detection circuit 90, the synchronization separation circuit 901 includes a resistor R15 and a capacitor C5. The signal presence / absence detection circuit 902 is a comparator C
OM3, a variable resistor VR5, and a resistor R16 are provided. In the camera connection state detection circuit 90 having this configuration, a signal obtained by separating a synchronization signal from a video signal (potential level of the detection result input terminal 50) input from the detection result input terminal 50 is input to the comparator COM3. Therefore, when the CCD camera 51 is not connected, the output from the comparator COM3 is “L” (low level in the binary signal). When the CCD camera 51 is properly connected, the output from the comparator COM3 is “H” (high level in the binary signal). Therefore, whether or not the CCD camera 51 is properly connected to the apparatus main body 400 can be detected based on the output from the comparator COM3.

In this embodiment, the comparator COM3
Is input to a focus operation continuation / stop determination circuit 904 provided at a subsequent stage. In this determination circuit, when one of the start switches 42 corresponding to the 1 × to 10 × objective lenses 23 is pressed, an “L” level signal (“L” level signal) is sent to the corresponding inverters INV1N to INV4 via the resistors R21 to R24. (Ground potential) is input. Here, the inverters INV1N to INV4
Is input to each of the AND gate circuits AND1 to AND4, and the output of the comparator COM3 is also input to these AND gate circuits AND1 to AND4. Therefore, if one of the start switches 42 is pressed and the output from the comparator COM3 is “H”, that is, if the CCD camera 51 is properly connected to the apparatus main body 400, the pressed start switch 42 Corresponding AND gate circuits AND1 to AND
Since the output of No. 4 becomes "H", the autofocus operation is performed under conditions corresponding to the output. For example, as shown in FIG. 4, when the start switch 42 corresponding to the 4 × objective lens 23 is pressed, the output signal from the inverter INV3 to the AND gate circuit AND3 switches from “L” to “H”. CCD camera 51 for body 400
Are properly connected, the AND gate circuit AND3
Is switched from "L" to "H", the autofocus operation is started under the conditions corresponding to the 4 × objective lens 23.

However, in this embodiment, when the CCD camera 51 is not properly connected to the apparatus main body 400, the output of the comparator COM3 is "L".
Start switch 4 corresponding to 4 × objective lens 23
Even if 2 is pressed, the output signal of the AND gate circuit AND3 does not switch to "H" because the output signal of the AND gate circuit AND3 remains "L". Other start switch 42
The same is true when is pressed. Therefore, unless the CCD camera 51 is properly connected, the autofocus operation (motor drive for the focus operation) is not started. When the outputs from all the AND gate circuits AND1 to AND4 are "L", the error display lamp 44 is turned on to warn that the CCD camera 51 is not properly connected. Further, when the connection state of the CCD camera 51 becomes abnormal during the autofocus operation, the output of any one of the AND gate circuits AND1 to AND4 is “H” until all the AND gate circuits AND1 to AND4 are changed to “H”.
The output from the D gate circuits AND1 to AND4 is "L"
, The auto focus operation is forcibly interrupted, and the error display lamp 44 is turned on.
A warning is given that the CCD camera 51 is not properly connected.

(Parameter Group) The auto-focusing device 4 configured as described above is used for photographing a microscopic photograph of a living tissue.
In order to be able to use it for any of the so-called industrial photomicrographs, it is necessary to provide a configuration that can perform an autofocus operation and a determination of an illumination level under conditions suitable for each. That is, as described with reference to FIG. 15, when the microscopic photographing is performed by the light transmission method and when the microscopic photographing is performed by the light reflecting method,
Since the level of the video signal, the contrast (clarity), and the difference between the bright part and the dark part are remarkably different, if the autofocus operation or the illumination level is determined under common conditions, the focus operation and the illumination suitable for the subject sample 7 are performed. This is because it cannot be determined whether the level is appropriate.

Therefore, in this embodiment, as shown in FIG.
A first parameter group 95A used when photographing a subject sample 7 such as a living tissue with a light transmission type microscope.
And a second parameter group 95D used when photographing a subject sample such as an industrial material with a light reflection type microscope.
Are configured in the RAM 88. As such a parameter group, in the present embodiment, an autofocus operation is performed based on the contrast value of a video signal. Therefore, the first parameter group 95A includes an autofocus operation when a photograph is taken with a light transmission type microscope. A contrast detection parameter 951A for properly performing the focus operation and an illumination level detection parameter 952A for the illumination level detection circuit 83 to appropriately determine whether the illumination level is appropriate are configured. The second parameter group 95D includes contrast detection parameters 95 for appropriately performing an autofocus operation when photographing with a light reflection type microscope.
1D and an illumination level detection parameter 9 for the illumination level detection circuit 83 to properly determine whether the illumination level is appropriate.
52D. Therefore, since the parameter groups corresponding to the typical two-type microscopes have already been configured, simply selecting the first parameter group 95A under the conditions suitable for observing the living tissue by the light transmission method. Contrast detection for the autofocus operation and detection of appropriateness of the illumination level can be performed, which is convenient.

Here, the autofocus device 4 can be used for any type of microscope of the light reflection type and the light transmission type. In this embodiment, however, the autofocus device 4 is used for weakly expanding a biological system (1). Since it is mainly intended to be used in the light transmission type microphotographing system 1 in which the use conditions are limited to the objective lens, it is initially set to use the first parameter group 95A at the time of shipment. .

Here, the level and contrast (clarity) of a video signal can be obtained even between a relatively thick sample such as a slice of a brain and a relatively thin sample such as a pathological sample of cancer, even if the same biological tissue is used. The difference between the light and dark areas is different. Therefore, the first parameter group 95A includes, as the contrast detection parameter 951A, a contrast detection parameter 951B used when photographing a thick sample.
And a contrast detection parameter 951C used when photographing a thin sample. The first parameter group 95A includes illumination level detection parameters 952B used for photographing a thick sample as illumination level detection parameters 952A.
And an illumination level detection parameter 952C used for photographing a thin sample.

Here, even if a photograph of a living tissue is taken with a light transmission type microscope, any of the contrast detection parameters 951B and 952B for a thick sample and the contrast detection parameters 951C and 952C for a thin sample can be used. A switch is configured in the apparatus main body 400 to determine whether or not the medical worker or the researcher himself specifies this switch. However, for a thick sample and a thin sample, for example, the difference between the level of the video signal obtained from the CCD camera 51 and the difference in brightness is automatically used to automatically determine which sample is used. The configuration may be such that the parameter group is automatically selected. However, since the contrast and the like of a living tissue are substantially at the same level, some parameters may be shared between the contrast detection parameters 951B and 951C.

In the following description of the focus operation, the first parameter group 95A (contrast detection parameter 9) for photographing a living tissue with a light transmission type microscope, regardless of whether the sample is thick or thin.
51A) is used.

(Basic Operation of Contrast Detection Processing) Next, the configuration and operation of the main part of the microscope photographing system 1 of the present embodiment will be described.

FIG. 5 shows the contrast detection circuit 8 of this embodiment.
2 is shown. Since the basic procedure of the contrast detection process is generally known,
Only the outline of the basic procedure will be described.

In this embodiment, the contrast detection of the video signal is performed by the contrast detection circuit 82 composed of an analog circuit. The contrast detection method performed by the contrast detection circuit 82 is to obtain a contrast for one screen by performing peak detection processing of a contrast component for each scanning line of a video signal.

As shown in FIG. 5A, the video signal is supplied to a gate 822 via a buffer amplifier 821, and then supplied to a high-pass filter 824 via the gate 822 and an amplifier 823. Only the components are extracted. The extracted high frequency component is supplied to a peak detection circuit 825. The peak value of the high frequency component detected by the peak detection circuit 825 is
The signal is converted into a digital signal by an A / D converter 827 via the input terminal 6. Thereafter, it is supplied to the CPU 84 as a contrast signal for each scanning line. The CPU 84 calculates the contrast value for one screen of the video signal by adding the contrast signals for each scanning line. The calculated contrast value for one screen is stored in the contrast memory 96 or 97 developed in the RAM 88.

FIG. 5B shows an example of a video signal waveform for one horizontal scanning line whose front and rear are defined by the horizontal synchronization signal among the video signals supplied from the CCD camera 51 side. As shown in FIG. 5B, only high frequency components are extracted from this video signal via the high-pass filter 824. Then, in the peak detection circuit 825, the difference between the maximum value and the minimum value of the extracted high-frequency component, and in the figure, the difference between the point and the point is output as a contrast value. This contrast value is converted into a digital value and supplied to the CPU 84.

As a contrast detection method, an integration process may be performed to integrate a high frequency component from a video signal for one scanning line to obtain a contrast.

(First Usage of Parameter Group for Living Body Tissue) In this embodiment, a coarse focus operation is performed when performing a focus operation while performing a peak detection process of a contrast component on a video signal in this manner. At this time, as shown in FIG.
When the peak value of the high-frequency component is converted into a digital signal by the A / D converter 827 in step 2, a comparison operation 828 is performed to determine whether the peak value is equal to or greater than a predetermined value. In this comparison operation 828, if the peak value of the contrast component is equal to or higher than the predetermined level, the contrast value for one screen of the video signal calculated by the CPU 84 is stored in the contrast memory 96 or 97 stored in the RAM 88 as described above. To be stored. On the contrary,
If the peak value of the contrast component is less than the predetermined level, the CPU 84 determines that the coarse focus operation is malfunctioning.
The contrast value for one screen of the video signal calculated by
Without storing in the contrast memory 96 or 97 developed in 88, the subsequent autofocus operation is stopped, and the focus display lamp group 43 is turned on to warn that the coarse focus operation is malfunctioning.

In performing such a comparison operation 828, the level to be a reference for the peak value of the contrast component is, as described with reference to FIG. 15, the case where the living tissue is photographed with a light transmission type microscope. And a case where an industrial material is photographed with a light reflection type microscope. For this reason, in a focus operation for photographing a living tissue with a light transmission type microscope, when an industrial material is determined based on a level to be used for taking a photograph with a light reflection type microscope, it is actually an appropriate level. In spite of the state, the peak value of the contrast component is determined to be too low and the focus operation is erroneously detected as being out of order. However, in the present embodiment, as described with reference to FIG. 3, a contrast detection parameter 951A for performing an appropriate focusing operation when photographing a living tissue with a light transmission type microscope is set to the first parameter group 95A. Since the parameter group is initially set to use this parameter group, the peak value of the contrast component is set based on a level (contrast detection parameter 951A) suitable for photographing a living tissue with a light transmission type microscope. Can be compared. Therefore, it is possible to accurately determine whether or not the coarse focus operation by the current scan is appropriate.

(Two-Step Autofocus Operation) As described above, the microphotographing system 1 of the present embodiment limits the conditions of use to a low magnification (1 to 10 times) objective lens of a biological example. The weakly magnifying objective lens has a very large depth of focus, and in order to perform an accurate focusing operation, it is necessary to widen a scanning range for the above-described contrast detection. For this reason, in a normal auto focus operation, the number of contrast sampling points increases, and it takes time until a focus point is obtained.

In the autofocus device 4 of this embodiment, as described above, the two-stage autofocus operation including the coarse focus operation and the fine focus operation is performed to reduce the time required for the autofocus operation. That is, first, a rough focus operation is performed, and a broad scan range is roughly scanned to detect an approximate focus point. Next, a fine focus operation is performed, and a narrow scanning range including an approximate focus point is densely sampled to detect an accurate focus point. When such a two-step autofocus operation is performed, the number of contrast sampling points required for the autofocus operation can be reduced as a whole, and a quick autofocus operation can be realized.

Hereinafter, the two-stage autofocus operation of the present embodiment will be described mainly with reference to FIG.

First, when any one of the auto-focus activation switches 42 arranged on the operation panel 41 of the auto-focus device 4 is operated, a control parameter group corresponding thereto is set.

Thereafter, the autofocus device 4 executes a coarse focus operation.

That is, as shown in FIG. 6 (A), after returning the stage 21 of the microscope 2 to the initial position a, one end (initial position) defining the first scanning width W1 set in advance. Move from a to the position of the other end b. The operation parameter group for stage movement control includes the minimum unit J of stage movement and the number S of contrast data samples. These values J and S are set by the number of drive pulses of the stepping motor 27. Therefore, the first scanning width W1 is J1 × S1
Is set by the number of pulses determined by. At the time of the coarse focus operation, the operation of sampling contrast data is performed every time the stage 21 moves by the minimum unit J1.
Repeated times.

FIG. 6B shows an example of a contrast curve 96C obtained by this coarse focusing operation. The case where the peak value P1 of the contrast value appears substantially at the center of the scanning width W1 is a typical and ideal example. In this case, the stage 21 is first set to the peak value P
The stage position F1 at which 1 is obtained is determined as a temporary focus point, and a range of the second scanning width W2 having a preset width is set so as to include this position F1. In the illustrated example, the second scanning width W2 is set as a range from the point d to the point e including the peak value P1 of the contrast. Further, as operation parameters for executing the fine focus operation, the minimum unit of stage movement is set to J2, and the number of contrast data sampling points is set to S2. Therefore, the second scanning width W2 is J
The number of pulses is determined by 2 × S2.

Here, the minimum unit of the stage movement, that is, the stage movement pitch J2, is １ ／ to １ ／ of the depth of focus of the optical system in order to perform the focusing operation with high accuracy.
It is necessary to set it to 10 or less. In this example, an optimal value J2 is set according to the magnification of each objective lens. Further, these values J2 are set to values smaller than the value J1 set at the time of the coarse focusing operation. Specifically, the second scanning width W2 is equal to 2 of the depth of focus of the CCD.
The stage scanning pitch J2, ie, the sampling pitch is 1/10, and the first scanning width W1 is the second scanning width W2.
The stage movement pitch J1, that is, the sampling pitch is set to about 1/4, that is, about 1/4, but is not limited thereto.

As can be seen by comparing FIGS. 6D and 6E, the scanning width W2 in the fine focus operation is
Although much smaller than 1, the minimum unit J2 of the stage movement is smaller than the value J1 at the time of the coarse focusing operation. Therefore, sampling of contrast data can be performed densely in a narrow range. When the fine focus operation is performed, for example, a contrast curve 97C shown in FIG. 6C is obtained. As shown in this figure, a case where a contrast peak value P2 appears at the center of the obtained contrast curve 97C is a typical and ideal example.
In this case, it is determined that the position where the peach value P2 is obtained is the focus point F2. And stage 2
1 is moved to the focus point F2 and stopped.

After focusing in this way, the photographing device 3 is operated to take a microscopic photograph.

In the contrast curve 97C obtained by the fine focus operation, when the difference between the minimum and the maximum of the contrast is small, the fact that the autofocus operation has failed is displayed on the focus display lamp group 43. When the operator learns from the lighting state of the lamp 43 that the autofocus operation has ended abnormally, he or she looks through the eyepiece lens again, performs a rough focus operation visually, and performs the autofocus operation again. Just start it.

As described above, the autofocus device 4 of the microscope photographing system 1 of the present embodiment executes a two-step autofocus operation. Therefore, the focus point F2 can be detected in an extremely short time as compared with a method of detecting the focus point by densely sampling contrast data over a wide scanning width W1.

(Second Usage of Parameter Group for Living Body Tissue) As described above, in this embodiment, when performing the fine focus operation, the level of the difference between the minimum and the maximum of the contrast is determined, and the normal auto focus operation is performed. It is determined whether or not it has ended. As described with reference to FIG. 15, the level serving as a criterion for this determination is, as described with reference to FIG. There is a great difference between them. For this reason, in a focus operation for photographing a living tissue with a light transmission type microscope, when an industrial material is determined based on a level to be used for taking a photograph with a light reflection type microscope, it is actually an appropriate level. In spite of the state, the level of the difference between the minimum and the maximum of the contrast is too small, and the erroneous detection that the focus operation is malfunctioning is performed. However, in this embodiment, FIG.
As described with reference to the above, the contrast detection parameter 951A for performing an appropriate focusing operation when photographing a living tissue with a light transmission type microscope is set to the first.
Since the parameter group is initially set so as to use this parameter group, the contrast is adjusted based on a level (contrast detection parameter 951A) suitable for photographing a living tissue with a light transmission type microscope. You can compare the minimum and maximum difference levels of. Therefore, it is possible to accurately determine whether or not the fine focus operation by the current scan is appropriate.

(Automatic focus restart function) Here, as the contrast curve 96C obtained by the coarse focusing operation as described above, there is a case where the peak value P1 of the contrast does not appear in the scanning range of the scanning width W1. That is, as described above, when taking a micrograph, first, an operator looks into the eyepiece and performs framing manually. As described above, since the focus operation is first performed visually, the actual focus point may not be within the scanning range for the coarse focus operation as described above.

Therefore, as shown in FIG. 7 and FIG. 8, the autofocus device 4 of this embodiment
The scanning range is shifted, and the coarse focus operation is executed again.

First, the example shown in FIG. 7 shows a contrast curve 96C obtained by the first coarse focusing operation.
No. 1 has a shape that monotonically increases from a position b at one end to a position a at the other end. In this case, the scanning range (the range from the point a to the point a1) for the autofocus operation is set again by approaching the point a where the large contrast value is obtained. The scanning width of this scanning range is also the same as the first scanning width W in the first coarse focusing operation.
Set to 1.

In the re-autofocus operation, first, the stage 21 is moved from the point b to the point a1, and the contrast data is sampled while the stage 21 is moved at a pitch J1 in the opposite direction. The number of sampling points is S1. By the re-autofocus operation, for example, a contrast curve 96C2 is obtained.
In the contrast curve 96C2, peak values P1 appear at points other than both ends.

Therefore, thereafter, as described above, 2
The fine focus operation in the step auto focus operation is executed. In this case, the scanning range (the range from the point d1 to the point e1) of the second scanning width W2 including the first focus point position F1 where the peak value P1 appears is set. Is moved at the pitch J2 to sample contrast data. Therefore, the number of sampling points in this case is S2.

As a result, for example, the contrast curve 9
7C2 is obtained. Since the peak value P2 appears at points other than both ends of the contrast curve 97C2, it is determined that the point at which this value P2 appears is the focus point F2. Then, the stage 21 is moved toward the point F2 and stopped at that position. Thus, the focus operation ends.

When the difference between the minimum and maximum contrast is small in the contrast curve 97C2 obtained by the fine focus operation, the display lamp 43 indicates that the autofocus operation has failed.
When the operator knows from the lighting state of the run 43 that the autofocus operation has ended abnormally, he or she looks through the eyepiece lens again, performs a rough focus operation visually, and performs the autofocus operation again. Just start it.

On the other hand, FIG. 8 shows a contrast curve 97 obtained by the coarse focusing operation, contrary to the above example.
This is a case where C3 is a curve that monotonically increases from the point a to the point b. In this case, a scanning range (a range from point b to point b1) for restarting autofocus is set adjacent to the point b having a large contrast value. Also in this case, the scanning width is the first scanning width W1.

Thereafter, the second coarse focusing operation is performed in the same manner as described with reference to FIG. Thus, when the contrast curve 96C4 is obtained, the second scanning width W2 including the focus position F1 is obtained.
(The range from point d2 to point e2) is set as the scanning range of the fine focus operation. When the contrast curve 97C3 is obtained by the fine focus operation, the position F2 where the peak value P2 appears is determined as the focus point, the stage 21 moves toward it, and stops at that position.

Also in this case, in the contrast curve 97C3 obtained by the fine focus operation,
If the difference between the minimum and the maximum of the contrast is small, the lamp 43 indicates that the autofocus operation has failed.
To be displayed.

Next, as a modified example of the auto focus restart function of the present embodiment, the following operation modes can be mentioned. In this example, the coarse focus operation is repeatedly performed. Alternatively or together with this, the fine focus operation can be repeatedly performed by similarly shifting the scanning range.

As a modified example of the auto focus restart function, the number of repetitions of the coarse focus operation and the fine focus operation is set to three or more, or
One in which the scanning widths of the coarse focusing operation and the fine focusing operation at the first and subsequent times are set to different scanning widths can be exemplified.

As described above, the operation parameters such as the scan width and the number of scans associated with the autofocus restart function are operated in accordance with the operation of the autofocus start switch 42 so that a value corresponding to the magnification of the objective lens used can be used. Thus, it is also possible to set a corresponding operation parameter.

(Auto Focus Stop Function) Next, an auto focus stop function executed by the auto focus device 4 of this embodiment will be described.

First, the autofocus device 4 of the present embodiment
The autofocus restart function shown in FIGS. 7 and 8 is not activated in the following cases, and the autofocus operation is stopped. That is, the contrast curve 96C1 or 9 obtained by the first coarse focusing operation.
In 6C3, if the difference Δ between the maximum value and the minimum value does not exceed a preset value (the contrast detection parameter 951A included in the first parameter group 95A), the autofocus restart is not performed. In this case, it is determined that the actual focus point F2 is significantly outside the scanning range of the coarse focus operation, and the auto focus operation is stopped.

In this case, the operator is notified via the display lamp 43 (see FIG. 1A) that the autofocus operation has been stopped. When the operator learns from the lighting state of the lamp 43 that the autofocus operation has ended abnormally, he or she looks through the eyepiece lens again, performs a rough focus operation visually, and performs the autofocus operation again. Just start it.

As described above, in this example, when there is almost no change in the obtained contrast, the autofocus operation is stopped.

Further, in this example, even when a peak value does not appear at any point other than both ends of the contrast curve obtained by executing the second coarse focus operation, the auto focus restart function is activated, The focus operation has stopped. Explaining with reference to FIG.
It is assumed that the first rough focus operation is performed from point b to point b to obtain a contrast curve 96C4. In this case, the difference Δ between the maximum value and the minimum value of the contrast
Exceeds the preset value (the contrast detection parameter 951A included in the first parameter group 95A), the auto focus restart function described above is activated. As a result, a rough focusing operation in the scanning range from point b to point b1 is performed. The contrast curve 96C5 obtained by the second coarse focusing operation
In the case where no peak value appears at any point other than the end positions b and b1, the auto focus operation is stopped,
The stage 21 is returned to its initial position, point a.

As described above, in this example, the contrast curve obtained when the stage 21 is moved in one direction is a monotonically decreasing curve or a monotonically increasing curve.
If no peak value appears at any point other than the start position or end position of the scanning range, it is determined that no focus point exists in that direction. Therefore, according to this example, useless autofocus operation can be avoided.

Such an autofocus stop operation is particularly effective when the moving direction of the stage 21 is a direction approaching the objective lens 23 of the microscope 2. That is, assuming that the direction from point a to point b1 is the approaching direction to the objective lens 23 in the case of FIG. 9, if such movement of the stage 21 is continued, the sample 7 of the stage 21 There is a possibility that these may be damaged by colliding with the. However, in the present embodiment, since such a movement of the stage 21 in one direction is limited, such an adverse effect can be avoided.

Here, as described above, the fine focus operation is executed when a peak value appears at a position other than both ends of the contrast curve due to the coarse focus operation performed before this. Therefore, in general, a peak value appears at the center of the contrast curve obtained by the fine focus operation. The determination as to whether or not a focus point has been detected in the fine focus operation can be performed as follows.

More specifically, referring to FIG. 7B, the difference Δ2 between the maximum value and the minimum value of the contrast curve 97C2 is set to a predetermined value Δ0 (first parameter group 9
Contrast detection parameter 951 included in 5A
If the value exceeds A), it may be determined that the focus point has been detected.

(Focus Operation Display Function) Next, the focus operation display function executed by the autofocus device 4 of this embodiment will be described. Autofocus device 4
Display lamps are arranged on the front of the device. Among these, the display lamp group 43 is a lamp group for displaying the state of the focus operation. In this example, as can be seen from FIG. 1A, a lamp 43a is displayed when a focus point is detected, and a lamp 43b is displayed when a focus point is not detected. In order to inform the meaning of the lamp display, a character "JUST" is printed below the lamp 43a, meaning that an appropriate focus operation has been performed. In addition, a character “OUT” is printed below the lamp 43b, meaning that an appropriate focus operation has not been performed.

FIG. 10 shows the correspondence between the contrast curve and the suitability of the focus operation. In this figure, when a curve corresponding to "JUST" is obtained, the lamp 43a is turned on. When a curve corresponding to “OUT” is obtained, the lamp 43b is turned on. FIG.
As shown in (A), when a peak value appears at a point other than both ends in the contrast curve, it is determined that the focus point has been detected. In other words, an indication that an appropriate focus operation has been performed is displayed.

However, as shown in FIG. 10B, even when a contrast curve in which a peak value appears at a point other than both ends is obtained, when the difference Δ between the peak value and the minimum value is not a value exceeding a certain difference. , It is determined that the focus point has not been detected. Also, FIGS. 10 (C) and (D)
As shown in (2), even when the obtained contrast curve is monotonically increasing or monotonically decreasing, it is determined that the focus point has not been detected. In the cases of FIGS. 10B to 10D, a display indicating that the focus operation has ended abnormally is displayed.

As described above, in the autofocus device 4 of this embodiment, the lamps 43 (43a, 43a)
Using b), the operator is notified of whether or not the focus operation has been properly performed, thereby notifying the operator. Therefore, the operator can easily understand the operation state from the lamp display, which is convenient. In particular, unlike a metal microscope with a monitor in general, such a display is extremely effective in a system like this example.

Of course, as the notification mode, an auditory notification system for driving a buzzer or the like may be employed in addition to the visual notification of a lamp or the like. In this case, there is an advantage that the operator who is observing can recognize the state of the focus operation with the posture as it is.

(Illumination level detection circuit 83) Next, the illumination level detection circuit 83 provided in the autofocus device 4 of this embodiment will be described.

When the density of the target sample subject 7 is relatively low, the video signal is as shown in FIG. When the sample concentration is relatively high, the video signal
(B). Therefore, when the brightness level of the subject is detected based on the average level or the peak level of the video signal, the result is “OK” in the former case and “NG” in the former case.

In order to avoid such adverse effects, FIG.
As shown in FIGS. 2A and 2B, the sum of the peak hold value of the video signal and its high-frequency component is used as the sample object 7.
And the light amount of the illumination light source 26 may be adjusted so that the brightness level is always within the set range.

Therefore, in this embodiment, the illumination level detection circuit 83 is configured as shown in FIG. In this figure, 831 is a clamp circuit, 832 is a high frequency component detection circuit, 833 is a peak hold circuit, 834 is an addition circuit,
835 is a comparison circuit, and 45 is a display lamp group. The peak hold circuit 833 includes a diode D and a capacitor C
1, a resistor R1, and an operational amplifier OP1. The adding circuit 834 includes resistors R2 to R4, a capacitor C2, an operational amplifier OP2, and resistors R5 and R6. The comparison circuit 835 includes comparators COM1, COM2, a resistor V
R1, VR2, R7 to R13, and switches SW1 to SW4 are provided. The display lamp group 45 is shown in FIG.
As shown in (A), “UNDER”, “GOOD”,
It has lamps 45a, 45b and 45c on which "OVER" is printed.

In the illumination level detection circuit 83 having this configuration,
The video signal is clamped by the clamp circuit 831. The clamped video signal is input to a peak hold circuit 833 to obtain a peak hold output. Also, the high frequency component of the video signal is obtained from the high frequency component detection circuit 832 and added to the peak hold output at a predetermined ratio in the addition circuit 834. This added output (light detection level) is compared with a comparison circuit 83
In step 5, it is compared with a preset upper limit value and lower limit value to determine whether or not it is within a range defined by these. If it is within the range, the lamp 45b is turned on to display that the illumination level is appropriate. However, when the value exceeds the setting range or when the value falls below the setting range, the lamps 45a and 45c are turned on, respectively, to indicate the fact.

If the illumination level is inappropriate, the auto focus function is not activated. The operator can know whether or not the light amount of the illumination light source 26 is appropriate based on the display of the lamp 45, and manually adjust the light amount of the illumination light source 26 based on this display. Of course, the light amount of the illumination light source 26 may be automatically adjusted based on the result of the automatic determination of the illumination level.

(Third Usage Mode of Biological Tissue Parameter Group) As described above, in this embodiment, the sample object 7 is obtained by adding the high-frequency component to the peak hold value of the video signal.
It is determined that the illumination level is appropriate based on whether this brightness level is within the set range. As described with reference to FIG. 15, the range used as a criterion for this determination is, as described with reference to FIG. There is a great difference between them. For this reason, when taking a photograph of a living tissue with a light transmission type microscope, the range to be used as a reference for the illumination level is determined based on the range to be used for taking a picture of an industrial material with a light reflection type microscope. Then, in spite of the fact that it is actually in an appropriate state, an erroneous determination is made that the illumination level is too low. However, in the present embodiment, as described with reference to FIG. 3, the illumination level detection parameter 952A for appropriately determining whether the illumination level is appropriate when taking a photograph of a living tissue with a light transmission type microscope is used. Parameter group 95 of 1
A, and the parameter is initially set to use this parameter group. Therefore, the illumination level is set based on a level (illumination level detection parameter 952A) suitable for photographing a living tissue with a light transmission type microscope. Suitability can be accurately determined.

Such an illumination level detection parameter 9
In making the determination based on 52A, the switches SW1 to SW4 are opened and closed corresponding to the illumination level detection parameter 952A, and the reference potentials of the comparators COM1 and COM2 are switched using the resistors 9, R10, R12, and R13. I just need.

Here, each of the comparators COM1, COM1,
2 for each of two switches SW1 to S
W4 is configured, and resistors 9, R10, R12, and R13 are configured for each of the switches SW1 to SW4.
Therefore, regarding this switching circuit, the level of the video signal is different between a relatively thick sample such as a brain slice and a relatively thin sample such as a cancer pathological sample even if the same living tissue is used. As a result, it can be used to solve the problem that the required illumination levels are also different. That is, as described with reference to FIG. 3, the first parameter group 95A includes the illumination level detection parameter 952A as the illumination level detection parameter 952B used for photographing a thick sample and the thin sample as the illumination level detection parameter 952B. Since the illumination level detection parameters 952C used for imaging are respectively configured, the illumination level detection parameters 952B and 952C may be properly used depending on which biological tissue is to be photomicrographed.

[0111]

As described above, in the auto-focusing device according to the present invention, when the image pickup device is not properly connected to the device main body, the connection state detecting means automatically detects that, and Focusing operation automatic stopping means automatically stops the autofocusing operation. Therefore,
It is possible to save time loss for performing unnecessary autofocus operation. If the image sensor is not properly connected to the apparatus main body, the warning unit issues a warning to that effect.
Therefore, it is possible to immediately notice that the user has forgotten to connect the image sensor to the apparatus main body, thereby saving time loss. Therefore, experience in image processing, microscope, photography, etc. is poor,
Moreover, it is convenient for those who cannot spend much time taking micrographs, such as medical staff and researchers.

[Brief description of the drawings]

FIG. 1A is a configuration diagram showing an entire configuration of a microphotographing system to which the present invention is applied, and FIG. 1B is a perspective view showing a plane of an autofocus device used in the system.

FIG. 2 is a schematic block diagram showing an optical system and a control system of the system of FIG.

FIG. 3 is a schematic block diagram showing a control system of the system shown in FIG. 1 together with a functional block group realized by software.

FIG. 4 is a circuit diagram showing an example of a circuit for realizing a camera connection state detection circuit and an auto focus stop function.

FIG. 5A is a schematic block diagram of a contrast detection circuit, and FIGS. 5B to 5D are signal diagrams showing the contrast detection processing.

FIG. 6 is an explanatory diagram showing a two-step focus operation.

FIG. 7 is an explanatory diagram showing an auto focus restart function.

FIG. 8 is an explanatory diagram showing another mode of the auto focus restart function.

FIG. 9 is an explanatory diagram showing an auto focus stop function.

FIG. 10 is an explanatory diagram showing a relationship between a contrast curve and whether or not a focus operation is appropriate.

FIG. 11 is an explanatory diagram showing a difference in signal level of a video signal caused by shading of a subject sample.

FIG. 12 is an explanatory diagram showing an operation of the illumination level detection circuit.

FIG. 13 is a circuit diagram showing a circuit example of an illumination level detection circuit.

FIG. 14 is an explanatory diagram showing an operation of a contrast detection type autofocus device.

FIG. 15A is an explanatory diagram of a video signal obtained from an image sensor when a light reflection microscope generally used for industrial materials is used, and FIG. FIG. 3C is an explanatory diagram of a video signal obtained from an image sensor when a relatively thick sample is photographed with a light transmission microscope. FIG. 4C is a photograph of a relatively thin sample such as a cancer pathological sample photographed with a light transmission microscope. FIG. 4D is an explanatory diagram of a video signal obtained from the image sensor at the time of performing the operation. FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Microscope photography system 2 Optical microscope 21 Stage 22 Stage drive mechanism 23 Objective lens (Objective lens system) 26 Illumination light source 27 Focus motor (Step motor) 3 Photographing device 31 Film camera 33 Film 4 Contrast detection type autofocus device 41 Operation Panel 42 Auto focus start switch (selection switch) 43 Indication lamp group of focus operation appropriateness 44 Sensor error display lamp (warning means) 45 Illumination level appropriateness indicator lamp group 400 Main unit 50 Detection result input terminal (video signal input terminal) 51 CCD camera 7 Sample 8 Drive control circuit of autofocus device 82 Contrast detection circuit 83 Illumination level detection circuit (illumination level detection means) 84 CPU 90 Camera connection state detection circuit (connection state detection) Means) 901 Sync separation circuit 902 Signal presence / absence detection circuit 904 Focus operation continuation / stop determination circuit 95A First parameter group for living tissue 95B First parameter group for thick living tissue 95C First parameter for thin living tissue Group 95D First parameter group for industrial materials 951A, 951B, 951C Contrast detection parameters for living tissue 952A, 952B, 952C Illumination level detection parameters for living tissue 951D Contrast detection parameters for industrial materials 952D Industrial materials For illumination level detection 96C, 96C1 to 96C5 Contrast curve at coarse focus 97C 97C1 to 97C5 Contrast curve at fine focus 9188 Parameter storage unit P1 Contrast by coarse focus operation F2 Focus peak value by coarse focus operation F1 Focus point by coarse focus operation F2 Focus point by fine focus operation W1 Scan width of coarse focus operation W2 Scan width of fine focus operation

Claims (4)

[Claims] 1. An image pickup device connected to a main body of a device via a video signal input terminal, to which a light image of a subject is input via a lens optical system of a microscope, and the lens optical system and the subject are driven by a motor. A contrast detection unit that detects a contrast value of each video signal from a high frequency component included in the video signal of the subject that is input in a time series manner through the imaging device when relatively scanned, and the contrast detection unit An auto-focusing device that determines a focus point based on a detection result of a contrast value according to the above and performs an auto-focusing operation, based on a potential level of the video signal input terminal, whether the imaging device is properly connected to the device body Connection state detecting means for detecting whether or not the imaging device is not properly connected to the apparatus main body. A focus operation automatic stop means for automatically stopping an auto focus operation when the connection state detection means detects, and when the connection state detection means detects that the imaging device is not properly connected to the apparatus main body. An autofocusing device having a warning unit for issuing a warning to that effect. 2. An autofocus apparatus according to claim 1, wherein said focus operation stopping means is configured to automatically stop driving of a motor for an autofocus operation. 3. An illumination level detecting means according to claim 1, wherein said illumination level detecting means detects whether or not the illumination level is suitable for taking a microscopic photograph of the object based on said video signal. When taking a photo with a microscope,
A first parameter group including a contrast detection parameter required for performing an autofocus operation and an illumination level detection parameter required for detection performed by the illumination level detection unit, and photographing the subject with a light reflection microscope. A second parameter group including a contrast detection parameter required for performing an autofocus operation and an illumination level detection parameter required for detection performed by the illumination level detection unit. Autofocus device. 4. The apparatus according to claim 3, further comprising a parameter group for photographing a living tissue with a light transmission type microscope as the first parameter group, and determining whether autofocus operation and illumination are appropriate based on the parameter group. An autofocus device, which is set to detect.