JP2001059936A - Automatic focus detector, automatic focus detecting method and automatic focus detecting program-recorded recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten acting time taken till focusing by fetching luminance in accordance with reflected light from a sample surface in a specified sampling cycle while relatively consecutively moving a sample and an objective lens. SOLUTION: Spot light from a light source 1 is radiated to the sample 4 through the objective lens 3 and the reflected light from the sample 4 is detected as a luminance signal by a photodetector 11. The lens 3 is consecutively moved at constant speed along a Z-axis in a direction where it is separated from the sample 4 or a direction where it approaches to the sample 4 by a moving and driving part 8. The luminance detected by the photodetector 11 is increased with the movement of the lens 3 and decreased from the point of time when it exceeds a maximum luminance value, and fetched in a luminance detection means 701 in the fixed sampling cycle. The means 701 outputs a signal for stopping the movement of the lens 3 when luminance change at this time, that means, the number of times that the luminance is consecutively decreased and the decreased luminance value coincide with a previously set condition.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic focus detecting device, an automatic focus detecting method, and a recording medium on which an automatic focus detecting program is recorded, which is applied to optical equipment such as a microscope.

[0002]

2. Description of the Related Art Conventionally, various types of automatic focus detection devices applied to microscopes and the like have been considered, and for example, luminance data obtained by detecting light reflected on a sample surface by a light receiving element. Is treated as a contrast amount, and the stage or the objective lens is set to Z so that the contrast amount becomes the maximum value.
2. Description of the Related Art There has been known an apparatus that performs autofocus (hereinafter, abbreviated as AF) control by a so-called hill-climbing servo system that moves in the axial direction to focus.

FIG. 29 illustrates an example of an automatic focus detection device employing such a hill-climbing servo system. First, a first pitch (indicated by a white circle in the figure) is used to move an objective lens (not shown) away from the sample in the Z direction. ), The luminance data of the reflected light from the sample surface is obtained while moving, and it is checked whether the luminance at this time is equal to or greater than the shresh hold TH. Thereafter, when a luminance exceeding the shresh hold TH is detected, a maximum luminance value H is searched for at the second pitch (black triangular mark in the drawing) finer than the first pitch while moving the objective lens in the Z direction in which the luminance increases. . Then, after detecting the maximum luminance value H, the objective lens is moved in the same direction while maintaining the second pitch, and a point M at which the luminance becomes 50% of the maximum luminance value H is searched. Pause. Next, the moving direction of the objective lens is reversed, and the moving direction of the objective lens is further shifted at a third pitch finer than the second pitch (white triangle mark in the drawing) until the maximum brightness value is passed. If a point smaller than the captured luminance is found, it is determined that the focal point has passed the true maximum luminance, and the objective lens is moved to the maximum luminance position F to complete the focusing.

[0004]

However, according to such a method, the objective lens is moved in pitch over the entire Z movement range, and every time the objective lens is moved at a predetermined pitch, the objective lens is temporarily stopped and the luminance data is moved. If the moving range of the objective lens is large or there are many pitch moving points, the moving time due to the stop of the objective lens becomes long, and it takes time to capture the luminance data. This requires a large amount of time to determine the focal point, and there is a problem that the working efficiency of sample observation using a microscope is greatly reduced.

The present invention has been made in view of the above circumstances, and provides an automatic focus detection device, an automatic focus detection method, and a recording medium in which an automatic focus detection program is recorded, which can shorten the operation time until focusing. The purpose is to do.

[0006]

According to the first aspect of the present invention,
Irradiating a spot light on the sample surface via an objective lens, and detecting a luminance according to the reflected light from the sample surface,
In an automatic focus detection device configured to detect a focal point from a change in luminance value, a moving unit that relatively continuously moves the sample and the objective lens, and simultaneously with the relative continuous movement of the sample and the objective lens. A luminance detecting means for detecting a luminance according to the reflected light from the sample surface at a predetermined sampling cycle, and a focus determining means for determining a position of a maximum value of the luminance detected by the luminance detecting means as a focal point. It is characterized by having.

According to a second aspect of the present invention, in the first aspect of the present invention, the in-focus determination means detects that the sample or the objective lens is continuously moved in one direction and the luminance decreases beyond a maximum value. Then, by detecting that the sample or the objective lens is continuously moved in the other direction and the luminance decreases beyond the maximum value, the position of the maximum value of the luminance is determined to be the focal point. .

According to a third aspect of the present invention, there is provided a moving means for moving at least one of the sample and the objective lens on the optical axis of the spot light applied to the sample surface, and a luminance according to the reflected light from the sample surface. And a luminance detecting means for detecting at a predetermined sampling period, the moving means continuously moves the position of the objective lens or the sample, and moves the position of the objective lens or the sample. And a judgment control means for judging that the position where the luminance detected by the luminance detecting means becomes maximum is near the focal point.

According to a fourth aspect of the present invention, in the third aspect of the present invention, the determination control means is arranged to move the sample on the optical axis closer to the objective lens or to separate the sample and the objective lens on the optical axis. Continuously moving in any one of the directions, during which the luminance detected by the luminance detecting means at a predetermined sampling cycle is detected to decrease beyond a maximum value, and the luminance is detected in a direction opposite to the continuous movement. The moving means is continuously moved, during which the luminance detected by the luminance detecting means at a predetermined sampling cycle is detected to decrease beyond the maximum value, and the position where the luminance is highest is near the focal point. The feature is to judge.

According to a fifth aspect of the present invention, there is provided a moving means for moving at least one of the sample and the objective lens on the optical axis of the spot light applied to the sample surface, and a luminance according to the reflected light from the sample surface. An automatic focus detection device for performing focus detection, wherein the sample is detected at a predetermined sampling period at the same time as the relative continuous movement of the sample and the objective lens. Detecting the luminance in accordance with the light reflected from the surface to detect the vicinity of the focal point,
After detecting the vicinity of the focal point, the sample or the objective lens is intermittently moved at regular intervals, and each time the sample or the objective lens moves at regular intervals, the luminance according to the reflected light from the sample surface and the sample or objective lens at that time Characterized in that it is provided with a judgment control means for performing control for detecting a position of the focus and detecting a focal point.

According to a sixth aspect of the present invention, in the fifth aspect of the present invention, the judgment control means is configured to detect reflected light from the sample surface when at least one of the sample and the objective lens is continuously moved. Brightness saturation detecting means for detecting whether the corresponding brightness value is saturated, and detection sensitivity adjusting means for adjusting the detection sensitivity of the brightness detecting means when the saturation of the brightness value is detected by the brightness saturation detecting means. And the following.

According to a seventh aspect of the present invention, in the invention of the fifth or sixth aspect, the judgment control means has the maximum number of times that the luminance value detected in a predetermined sampling period continuously decreases and the luminance is the highest. It is characterized by comprising recording means for recording the luminance value at the time.

According to an eighth aspect of the present invention, in the sixth aspect of the invention, the luminance saturation detecting means compares a luminance value detected by the luminance detecting means with a preset saturation value of luminance. It is characterized by having comparison means and setting means for setting the result of comparison by the comparison means to a variable in the main memory.

According to a ninth aspect of the present invention, in the invention according to the sixth aspect, the detection sensitivity adjusting means is configured to detect the luminance when the luminance value detected by the luminance saturation detecting means is determined to be saturated. It is characterized in that the detection sensitivity of the means is adjusted to a sensitivity at which the luminance value is not saturated.

According to a tenth aspect of the present invention, at least one of the sample and the objective lens is continuously moved, and the sample surface is irradiated with a spot light through the objective lens, and the luminance according to the reflected light from the sample surface is obtained. And an automatic focus detection method for detecting a focal point from a change in luminance value, wherein the reflection from the sample surface at a predetermined sampling cycle is performed simultaneously with the relative continuous movement of the sample and the objective lens. A first step of detecting the vicinity of the focal point by detecting the luminance according to the light, and after detecting the vicinity of the focal point in the first step, the sample or the objective lens is intermittently moved at regular intervals to obtain the sample or A second step of detecting the luminance according to the reflected light from the sample surface and the position of the sample or the objective lens at that time every time the objective lens moves at a constant interval to detect a focal point; It is characterized by comprising.

According to an eleventh aspect of the present invention, in the invention of the tenth aspect, the second step includes the step of intermittently moving the sample or the objective lens in one direction and reducing the luminance beyond the maximum value. After the detection, it is detected that the sample or the objective lens is intermittently moved in the other direction and the luminance is reduced beyond the maximum value, and thereafter, the position of the maximum value of the luminance is determined as the focal point. I have.

According to a twelfth aspect of the present invention, at least one of the sample and the objective lens is moved on the optical axis of the spot light applied to the sample surface, and the brightness according to the reflected light from the sample surface is detected. In the automatic focus detection method for detecting by means and detecting the focal point from a change in luminance value, the sample surface is irradiated with spot light, and the position of the objective lens or the sample is continuously moved, and A position where the luminance detected while the position of the objective lens or the sample is moving is maximized is determined to be near the focal point.

According to a thirteenth aspect of the present invention, in the twelfth aspect of the present invention, the automatic focus detection method is arranged so that the automatic focus detection method is performed in one of a direction in which the sample approaches the objective lens and a direction in which the sample separates from the objective lens. Continuously move, during which the brightness detected by the brightness detection means at a predetermined sampling cycle is detected to decrease beyond a maximum value, and then the objective lens or the sample is moved in a direction opposite to the continuous movement. Moving the position continuously, detecting that the luminance detected by the luminance detecting means in a predetermined sampling cycle decreases beyond the maximum value during that time, and judging the position having the maximum luminance as the vicinity of the focal point; It is characterized by.

According to a fourteenth aspect of the present invention, at least one of the sample and the objective lens is continuously moved, and the sample surface is irradiated with spot light through the objective lens, and the luminance according to the reflected light from the sample surface is obtained. And a recording medium that records an automatic focus detection program that is processed by a computer configured to detect a focal point from a change in the luminance value, and that a simultaneous continuous movement of the sample and the objective lens is performed. A first step of detecting a luminance in accordance with light reflected from the sample surface at a predetermined sampling period to detect a vicinity of a focal point; The lens is intermittently moved at regular intervals, and each time the sample or objective lens moves at regular intervals, the luminance according to the reflected light from the specimen surface and the specimen or objective at that time Is characterized by comprising a second step of detecting a focus by detecting the position of the lens, the.

According to a fifteenth aspect of the present invention, in the method of the fourteenth aspect, after detecting that the sample or the objective lens is continuously moved in one direction and the brightness decreases beyond a maximum value, the sample or the objective lens is detected. By detecting that the objective lens is continuously moved in the other direction and the luminance decreases beyond the maximum value, the position of the maximum luminance value is determined to be near the focal point.

According to a sixteenth aspect of the present invention, the objective lens or the sample is moved on the optical axis of the spot light applied to the sample surface to detect the luminance according to the reflected light from the sample surface and to obtain the luminance value. A recording medium that records an automatic focus detection program that is processed by a computer configured to detect a focal point from a change in spot light, irradiates a spot light to a sample surface, and the position of an objective lens or a sample is positioned on the optical axis. The position where the luminance detected during the movement is the highest is determined to be near the focal point.

According to a seventeenth aspect of the present invention, in the recording medium storing the automatic focus detection program according to the fifteenth aspect, the sample is irradiated with a spot light, and the objective lens or the sample is fixed on the optical axis thereof. The intermittent movement is performed at every interval, and the luminance detected every time the objective lens or the sample intermittently moves during the interval is detected to decrease beyond the maximum value, and then the objective lens or the sample is moved in the opposite direction to the intermittent movement. The position of the sample is intermittently operated, during which the brightness detected every time the objective lens or the sample intermittently moves is detected to decrease beyond the maximum value, and the position where the brightness becomes the highest is determined as the focal point. It is characterized by:

As a result, according to the present invention, the luminance caused by the reflected light from the sample surface is acquired at a predetermined sampling period while relatively continuously moving between the sample and the objective lens. Luminance data can be more efficiently captured as compared with a configuration in which luminance data is captured while the pitch of the objective lens is moved throughout the Z movement range, and the operation time until focusing is greatly reduced. be able to.

Also, by always focusing on the sample or the objective lens from one direction, it is possible to avoid the hysteresis characteristic of the moving means, and to perform focusing with high precision.

Further, when the luminance value is saturated during the rough operation, the sensitivity of the luminance detection is reduced to a sensitivity at which the luminance is not saturated,
By performing the rough operation again, the operation time until focusing can be shortened without interruption of the focus detection operation.

[0026]

Embodiments of the present invention will be described below with reference to the drawings.

(First Embodiment) FIG. 1 shows a schematic configuration of a confocal scanning microscope to which the present invention is applied.
In the figure, reference numeral 1 denotes a light source, which comprises a point light source such as a laser beam. The spot light from the light source 1 is guided to the two-dimensional scanning scanner 2. The two-dimensional scanning scanner 2 is for performing two-dimensional scanning of the spot light from the light source 1 on the sample 4, and includes, for example, a resonant scanner or a galvanometer mirror for scanning in the X-axis direction and a galvanometer mirror for scanning in the Y-axis direction. By oscillating the X scanner and the Y scanner in the X axis direction and the Y axis direction, the spot light is caused to oscillate on the sample 4 in the XY directions.

The two-dimensionally scanned spot light transmitted through the objective lens 3 is applied to the sample 4 on the stage 5. In this case, the objective lens 3 can be continuously moved in the optical axis direction of the spot light, that is, in the Z-axis direction, by the movement driving unit 8 such as a servomotor.

The reflected light from the sample 4 returns to the two-dimensional scanning scanner 2 through the objective lens 3, and the reflected light from the two-dimensional scanning scanner 2 is guided to the photodetector 11. The photodetector 11 has a pinhole (not shown) on the front surface of the light receiving surface, receives light information obtained through the pinhole, and outputs a luminance signal corresponding to the light amount.

The CPU 7 is connected to the photodetector 11 via the A / D converter 6. A display unit 10 is connected to the CPU 7 via a frame memory 9 in addition to the two-dimensional scanning scanner 2 and the movement driving unit 8.

The CPU 7 sets the continuous moving speed of the objective lens 3 in the Z-axis direction, instructs the start and stop of the movement, reads the stop position, and the like for the movement driving unit 8, and also executes the Z-axis direction of the objective lens 3. Along with the continuous movement, a luminance detecting unit 701 for detecting a luminance signal from the photodetector 11 at a predetermined sampling period, for example, 1 KHz, and a focal point judging from a change in the luminance value detected by the luminance detecting unit 701. A focus judging means 702, and further instructs the two-dimensional scanning scanner 2 to scan a spot light, and generates a confocal observation image based on a luminance signal of the photodetector 11 obtained by the spot light scanning. I do.

The display section 10 displays the observation image generated by the CPU 7 via the frame memory 9.

Next, the operation of the embodiment configured as described above will be described.

First, an operation until a rough focus position is detected by the coarse operation will be described with reference to FIG.

First, the objective lens 3 is positioned at a point A sufficiently close to the sample 4, and the spot light from the light source 1 is
Irradiation is performed on the sample 4 through the objective lens 3, and setting is made so that the light reflected from the sample 4 is detected as a luminance signal by the photodetector 11.

From this state, the objective lens 3 is continuously moved at a constant speed along the Z-axis in a direction away from the sample 4 by moving the objective lens 3 from the point A to the point B. The continuous movement in the Z direction due to the coarse operation is set to a low speed when the objective lens 3 has a high magnification and a high speed when the objective lens 3 has a low magnification. When the objective lens 3 is continuously moved by coarse movement, the luminance detected by the photodetector 11 increases with the movement of the objective lens 3 and decreases from the time when the maximum luminance value is exceeded.

The luminance signal detected by the photodetector 11 is
For example, it is taken into the luminance detecting means 701 at a constant sampling cycle such as 1 KHz. The luminance detecting means 701 outputs a signal for stopping the movement of the objective lens 3 when the change in luminance at this time coincides with the number of times the luminance continuously decreases and the decreased luminance value matches a preset condition.
In this case, in the illustrated period T1 after exceeding the maximum luminance value, when the luminance continuously decreases, for example, three times, and when it is detected that the luminance value during this period decreases by a predetermined value, the point B decreased three times Then, a stop command of the objective lens 3 is output to the movement drive unit 8, and the movement of the objective lens 3 is decelerated and stopped at the point C.

Next, the objective lens 3 is moved to the point D by the movement drive unit 8. The movement of the objective lens 3 to the point D is to secure an acceleration distance when the objective lens 3 moves.

Then, the objective lens 3 is continuously moved at a constant speed in a direction approaching the sample 4 from the point D to the point A by the movement driving unit 8. Also at this time, the luminance detected by the photodetector 11 increases with the movement of the objective lens 3 and decreases from the time when the maximum luminance value is exceeded. The luminance signal detected by the photodetector 11 is 1
It is taken into the luminance detecting means 701 at a sampling cycle of KHz. Then, also in this case, by the luminance detecting means 701,
When the change in luminance at this time is such that the number of times the luminance continuously decreases and the decreased luminance value match a preset condition, a signal for stopping the movement of the objective lens 3 is output from the luminance detecting means 701. In this case, when it is detected that the luminance continuously decreases three times during the illustrated period T2 and that the luminance value during this period decreases by a predetermined value, a stop command of the objective lens 3 is output to the movement driving unit 8 at point E. Then, the movement of the objective lens 3 is reduced and stopped at the point F.

In this embodiment, the stop position of the objective lens 3 during the coarse operation is accurately determined in consideration of the restriction that the CPU 7 cannot read the position of the objective lens 3 at a certain point during the movement. As shown in FIG. 3A, it is necessary to predict a stop position when a stop command is input during each of the acceleration period 21, the constant speed period 22, and the deceleration period 23 from the continuous movement pattern of the objective lens 3. is there. For example,
When a deceleration stop command is input during the acceleration period 21 as shown in FIG. 4B, the vehicle stops after the deceleration period 23, which is the same as the acceleration time. In addition, as shown in FIG. 3C, when a deceleration stop command is input after the transition to the constant speed period 22, the vehicle stops after the deceleration period 23. Further, as shown in FIG. 11D, in the case where a deceleration stop command is input during the deceleration period 23, the vehicle is stopped ignoring the deceleration stop command at this time. This deceleration distance is different for each of the following patterns: movement start, constant speed movement, acceleration movement, and deceleration. For example, if a stop command is received during the acceleration period, half of the movement amount is the deceleration distance, and if a stop command is received during the constant speed period, the distance required for deceleration is the deceleration distance. . As described above, the deceleration distance from the stop command during the acceleration period or the constant speed period except for the stop command during the deceleration period to the stop position is predicted, and the movement start position of the objective lens 3 is accurately obtained. In particular, by accurately obtaining the start position of the intermittent movement in the fine operation, the number of unnecessary intermittent operations can be reduced, and the time until focusing can be reduced.

Thereafter, the operation shifts to a fine operation for detecting the in-focus position. This fine operation is started from the point F ′, in which the objective lens 3 is moved by the deceleration distance from the point E to the point F. By moving the objective lens 3 to this point F ',
The number of intermittent operations by a fine operation to be described later is reduced, and the time until focusing is shortened.

Such a fine operation will be described with reference to FIG.

In this case, when the objective lens 3 is moved to the point F ′, the objective lens 3 is intermittently moved by the moving drive unit 8 at regular intervals in a direction away from the sample 4 (point B in FIG. 2). Move. At this time, the interval of the intermittent movement is set to be narrow when the objective lens 3 has a high magnification and wide when the objective lens 3 has a low magnification. In addition, the movement interval is narrow in the confocal operation and large in the non-confocal operation. You have set.

Each time the objective lens 3 is intermittently moved at a constant interval, the luminance value of the photodetector 11 is detected by the luminance detecting means 7.
01 is detected, and the maximum luminance value is stored in the focus determination unit 702 while updating the luminance value at this time to a higher one.

In this case as well, the luminance that increases with the movement of the objective lens 3 starts decreasing after exceeding the maximum luminance value, but changes continuously in the illustrated period T3 after exceeding the maximum luminance value. When the number of times of decrease and the decreased luminance value match a preset condition, for example, three consecutive decreases, and when it is detected that the luminance value has decreased by a predetermined value, the objective lens 3 is positioned at point G in FIG. Is stopped.

Then, after returning the objective lens 3 from the position I of the highest luminance value to a predetermined distance in the direction of the sample (F 'direction), the position of the highest luminance value determined to be in focus by the focus determination means 702. Then, the focal point is moved to I and the in-focus detection is completed.

Next, the case where the automatic focus detection operation described in the first embodiment is realized by a computer program will be described.

FIG. 5 shows a schematic configuration when a computer is used, and the same parts as those in FIG. 1 are denoted by the same reference numerals.

In this case, the computer 70 in place of the CPU 7 includes an A / D converter 70 for converting analog luminance data output from the photodetector 11 into digital data.
a, main memory 70b, frame memory 70d, CPU 7
0e, a storage medium 70c electronically storing a control program for an automatic focus detection operation for controlling autofocus,
It has an I / F board 70f which is connected to the two-dimensional scanning scanner 2 and the movement drive unit 8 and controls them,
They are connected by a PU bus.

The program for controlling the focus detection is as follows.
The program is loaded into the main memory 70b and executed by the CPU 70e. Such a program is stored in the computer 7
It can also be downloaded from a server computer at a remote location and executed via a communication medium such as a network connectable to the Internet.

In this case, the control program for the automatic focus detection operation stored in the storage medium 70c sets the continuous movement speed of the objective lens 3 in the Z-axis direction and stops the movement start and stop for the movement drive unit 8. An objective lens control process 70c1 for reading an instruction and a stop position, and a brightness detection process 70c2 for detecting a brightness signal from the photodetector 11 at a predetermined sampling period, for example, 1 KHz, with the continuous movement of the objective lens 3 in the Z-axis direction. And luminance detection processing 70c
2 has a focusing point determination process 70c3 for determining the focusing point based on the change in the luminance value detected in Step 2. Further, it has a process of instructing the two-dimensional scanning scanner 2 to scan a spot light, and generating a confocal observation image based on a luminance signal of the photodetector 11 obtained by the spot light scanning.

Next, the operation according to such a control program will be described.

First, an operation until a rough focus position is detected by the coarse operation will be described with reference to a flowchart shown in FIG.

Now, with the start of the rough operation in step S701, the objective lens 3 is moved to the sample 4 in step S702.
2, the spot light from the light source 1 is irradiated onto the sample 4 via the objective lens 3, and the reflected light from the sample 4 is illuminated by the photodetector 11. Set to detect as a signal.

In this state, the objective lens 3 is moved from the point A in FIG.
The robot is continuously moved at a constant speed along the Z axis in a direction away from the sample 4 toward a point, and a flag MoveUp indicating upward movement is set to TRUE. The continuous movement in the Z direction due to the coarse operation is set to a low speed when the objective lens 3 has a high magnification and a high speed when the objective lens 3 has a low magnification. When the objective lens 3 is continuously moved by coarse movement, the luminance detected by the photodetector 8 increases with the movement of the objective lens 3 and decreases from the time when the maximum luminance value is exceeded.

The luminance signal detected by the photodetector 11 is
For example, the brightness is detected by the A / D converter 70a of the computer 70 at a constant sampling cycle such as 1 KHz, and the brightness detection processing 70c2 is performed by a program stored in the storage medium 70c.

In step S704, the computer 7
The CPU 70e of 0 outputs a command to start taking in luminance data. In step S705, the first luminance data is set to a variable IMax in the main memory 70b. Subsequent luminance data is sequentially read in step S706 and subjected to luminance detection processing 70c2.

Here, the brightness detection processing 70c2 of step S706 when the objective lens 3 approaches the sample 4 will be described with reference to the flowchart of FIG.

In this case, the luminance data converted by the A / D converter 70a from the photodetector 11 is obtained in step S8.
02, the variable IBuff is set to the variable IBuff, and step S8
Go to 03.

In step S 803, the luminance data stored in IMax is compared with the luminance data set in IBuff, and if IBuff> IMax, that is, the luminance that has been captured from the luminance data that was read immediately before is compared. If the data value is larger, step S8
Go to 04.

In step S804, it is determined whether or not a counter ICount indicating the number of times the luminance has been continuously reduced is 0. If ICount = 0, step S80 is performed.
Go to 5. If ICount is not 0, step S80
At step 9, ICount is cleared, and the process proceeds to step S805.

In step S805, the luminance value in IBuff is set to IMax, and the flow advances to step S806.

In step S803, IBu
If ff> IMax is not satisfied, that is, if the current luminance value is smaller than the immediately preceding luminance value, the process proceeds to step S810.

In step S810, ICount
= 0, and if ICount = 0, IM
ax is the highest luminance value, and step S811
The luminance value stored in IMax at IDiff
The value is set to 1 and the process proceeds to step S812.

In step S812, ICount is counted up, and the flow advances to step S813.

In step S813, the luminance value stored in the IBuff is set to IMax, and in step S8
Proceed to 06.

In step S806, conditional expression ICo
It is determined whether the brightness value has continuously decreased by the predetermined number of times or more, and if ICount> = the predetermined number of times, the process proceeds to step S807. ICount>
= If the predetermined number of times is not satisfied, the process returns to step S802.

In step S807, conditional expression IDi
ff1-IBuff> = predetermined value, it is determined whether the luminance value has decreased by a predetermined value, and IDiff1-IBuff is determined.
If f> = predetermined value, the process proceeds to step S808, and the brightness detection processing ends. If IDiff1-IBuff> = predetermined value is not satisfied, the process returns to step S802.

The above processing is repeated at a constant sampling cycle, for example, 1 KHz. When the change in the luminance coincides with the preset number of times that the luminance continuously decreases and the decreased luminance value, a condition that ICount> = predetermined is satisfied. Number of times, ID
If both conditions of if-IBuff> = predetermined value are satisfied,
Proceeding to step S707 in the flowchart of FIG. 6, the CPU 70e of the computer 70 outputs a command to stop the movement of the objective lens 3 to the I / F board 70f, and the movement drive unit 8 stops the movement of the objective lens 3. In this case, in the illustrated period T1 in FIG. 2 after exceeding the maximum luminance value, the luminance decreases continuously, for example, three times, and when it is detected that the luminance value during this period decreases by a predetermined value, the luminance decreases three times. At the point B shown in FIG.
0e is output to the I / F board 70f, and the movement drive unit 8 decelerates the movement of the objective lens 3 and stops at the point C in FIG. 2, and proceeds to step S708.

In step S708, the objective lens 3
Is determined based on the value of MoveUp, and if MoveUp = TRUE, the process proceeds to step S709.

In step S709, the CPU 70e of the computer 70 outputs a command to the I / F board 70f to move the objective lens 3 to the point D in FIG.
The movement drive unit 6 moves the objective lens 3 to the point D in FIG. 2, and proceeds to step S710. This objective lens 3
The movement to the point D is to secure an acceleration distance when the objective lens 3 moves.

In step S710, the CPU 70e of the computer 70 instructs the I / F board 70f to continuously move the objective lens 3 from the point D in FIG. Is output. The movement drive unit 6 continuously moves the objective lens 3 at a constant speed in a direction approaching the sample 4, and MoveUp = F
Set to ALSE and return to step S704.

In step S704, the computer 7
The CPU 70e of 0 outputs an instruction to start taking in luminance data. In step S705, the first luminance data is set to a variable IMax in the main memory 702. Subsequent luminance data is sequentially read in step S706 and subjected to luminance detection processing 70c2.

Here, the brightness detection processing 70c2 of step S706 will be described with reference to the flowchart of FIG.

The luminance data converted by the A / D converter 70a from the photodetector 11 is set to a variable IBuff in step S802, and the flow advances to step S803.

In step S803, the luminance data set in IMax is compared with the luminance data stored in IBuff. If IBuff> IMax, the flow advances to step S804.

In step S804, it is determined whether or not a counter ICount indicating the number of times the luminance has decreased is 0. If ICount = 0, the flow advances to step S805. If ICount is not 0, ICount is cleared in step S809 and the process proceeds to step S805.

In step S805, the luminance value in IBuff is set to IMax, and the flow advances to step S806.

In step S803, IBu
If ff> IMax is not satisfied, that is, if the current luminance value is smaller than the immediately preceding luminance value, the process proceeds to step S810.

In step S810, ICount
= 0, and if ICount = 0, IM
ax is the highest luminance value, and step S811
The luminance value stored in IMax at IDiff
The value is set to 1 and the process proceeds to step S812.

In step S812, ICount is counted up, and the flow advances to step S813.

In step S813, the luminance value stored in the IBuff is set to IMax, and in step S8
Proceed to 06.

In step S806, conditional expression ICo
It is determined whether the brightness value has continuously decreased by the predetermined number of times or more, and if ICount> = the predetermined number of times, the process proceeds to step S807. ICount>
= If the predetermined number of times is not satisfied, the process returns to step S802.

In step S807, conditional expression IDi
ff1-IBuff> = predetermined value, it is determined whether the luminance value has decreased by a predetermined value, and IDiff1-IBuff is determined.
If f> = predetermined value, the process proceeds to step S808, and the brightness detection processing ends. If IDiff1-IBuff> = predetermined value is not satisfied, the process returns to step S802.

The above processing is repeated at a constant sampling cycle, for example, 1 KHz. When the change in the luminance coincides with the number of times the luminance continuously decreases and the decreased luminance value satisfy a preset condition, that is, ICount> = predetermined Number of times, ID
If both of the conditional expressions are satisfied, the process proceeds to step S707 in the flowchart of FIG.
The CPU 70e of the computer 70 is an I / F board 70f
, An instruction to stop the movement of the objective lens 3 is output, and the movement driving unit 8 stops the movement of the objective lens 3. In this case, the illustrated period T2 in FIG. 2 after exceeding the maximum luminance value
When it is detected that the luminance has continuously decreased, for example, three times, and that the luminance value during this period has decreased by a predetermined value, a stop instruction of the objective lens 3 is issued from the CPU 70e to the point E at which the luminance has decreased three times.
/ F board 70f, and the movement of the objective lens 3 is decelerated by the movement drive unit 8, stopped at the point F in FIG. 2, and proceeds to step S708.

In step S708, the conditional expression Mov
It is checked whether or not the objective lens is moving in the upward direction by eUp = TRUE. In this case, since MoveUp = FALSE, the conditional expression is not satisfied, so the process proceeds to step S711 to complete the rough operation, that is, end the detection of the vicinity of the focal point. .

Thereafter, the operation shifts to a fine operation for detecting the in-focus position. This fine operation causes the objective lens 3 to move as shown in FIG.
From the point F 'returned in the direction of the point B by the deceleration distance of.

By moving the objective lens 3 to the point F ', the number of intermittent operations by a fine operation to be described later is reduced, and the time until the focal point is shortened.

Such a fine operation will be described with reference to the flowcharts of FIGS. 8 and 9 and FIG.

Step S902 in the flowchart of FIG.
, The CPU 70e of the computer 70 moves the objective lens 3 to the I / F board 70f by using the in-focus determination processing 7
An instruction is issued to move to the point F 'which is the start position of 0c3. The movement drive unit 8 moves the objective lens 3 to the point F ', and proceeds to step S903.

In step S903, the computer 70 outputs a command to start taking in luminance data.
In 904, the first luminance data is set in a variable IMax2 in the main memory 70b, and the position data of the objective lens 3 at that time is set in a variable PosMax in the main memory 70b, and the flow advances to step S905.

In step S905, the CPU 70e of the computer 70 outputs an instruction to the I / F board 70f to move the objective lens 3 at a predetermined interval in a direction away from the sample 4. At this time, the moving interval is set to be narrow when the objective lens 3 has a high magnification and wide when the objective lens 3 is low, and the moving interval is set to be narrow in the confocal operation and large in the non-confocal operation. . Step S is performed when the objective lens 3 has been moved by the moving drive unit 8 at a fixed interval.
Proceed to 906.

Here, the in-focus point judgment processing 70c3 of step S906 will be described with reference to the flowchart of FIG.

When the in-focus point determination processing 70c3 is started (step S100), in step S101, the luminance data converted from the photodetector 11 by the A / D converter 70a is stored in a variable IBuff2 and the objective lens 1 at that time.
The position data of No. 3 is set in the variable Pos, respectively, and the process proceeds to step S102.

In step S102, the luminance data set in IMax2 is compared with the luminance data set in IBuff2, and IBuff2> IMax2
If so, the process proceeds to step S103.

In step S103, it is determined whether or not a counter ICount2 indicating the number of times the luminance has continuously decreased is 0. If ICount2 = 0, step S103 is executed.
Proceed to 104. If ICount2 is not 0, ICount2 is cleared in step S110 and step S1
Go to 04.

In step S104, IBuff2
To the IMax2, and the position data in Pos to P
osMax is set, and the process proceeds to step S105.

Also, in step S102, IBu
If ff2> IMax2 is not satisfied, that is, if the current luminance value is smaller than the immediately preceding luminance value, the process proceeds to step S111.

In step S111, ICount
It is determined whether or not 2 = 0, and if ICount2 = 0, IMax2 is the highest luminance value, and step S
At 112, the luminance value stored in IMax2 is
Diff2, the position data P of the objective lens 3 at that time
osMax is set to PosFix, respectively, and the process proceeds to step S113.

In step S113, ICount2
Is counted up and the process proceeds to step S114.

In step S114, IBuff2
Is set to IMax2, and the position data Pos at that time is set to PosMax, and the process proceeds to step S105.

In step S105, conditional expression ICo
It is determined whether the luminance value has continuously decreased by a predetermined number of times or more according to a predetermined number of times.
If it is the predetermined number, the process proceeds to step S106. ICount
If t2> = predetermined number of times is not satisfied, the process proceeds to step S107.

In step S106, conditional expression IDi
ff2-IBuff2> = predetermined value, it is determined whether the luminance value has decreased by a predetermined value, and IDiff2-IBu2 is determined.
If ff2> = predetermined value, the process proceeds to step S108. I
If Diff2-IBuff2> = predetermined value is not satisfied, the process proceeds to step S107.

In step S107, the CPU 70e of the computer 70 outputs an instruction to the I / F board 70f to move the objective lens 3 in a direction away from the sample 4 by a constant distance. At this time, the moving interval is set to be narrow when the objective lens 3 has a high magnification and wide when the objective lens 3 is low, and the moving interval is set to be narrow in the confocal operation and large in the non-confocal operation. . Step S is performed when the objective lens 3 has been moved by the moving drive unit 8 at a fixed interval.
Return to 101.

At the stage where the condition in step S106 is true, the period T3 shown in FIG.
Thus, the number of times that the change in luminance continuously decreases and the decreased luminance value match the preset condition. That is, ICou
nt2> = predetermined number of times, IDiff2-IBuff2> =
Since both conditions of a predetermined value (for example, the luminance value continuously decreases three times and the luminance value during this period decreases by a predetermined value) are satisfied, G in FIG. 4 is satisfied.
At this point, the movement of the objective lens 3 is stopped.

In step S108, the CPU 70e of the computer 70 reads the PosFix data stored in the main memory 70b, and reads the data of the I / F board 70f.
Then, a command to move the objective lens 3 to the position of the highest luminance value, ie, I in FIG. 4 is output, and the movement drive unit 8 moves the objective lens 3 to the position I. Then, the process proceeds to step S109,
The in-focus point determination processing 70c3 is completed, and the process proceeds to step S907 of the flowchart in FIG. 8, where the fine operation is completed, that is, the in-focus point is detected and the processing ends.

Therefore, in this way, during the rough operation,
The objective lens 3 was continuously moved with respect to the sample 4, and the luminance according to the reflected light from the surface of the sample 4 was detected at a predetermined sampling cycle, and it was determined from the detected luminance data that there was a position of the highest value. Later, normal A by fine operation
F, so that the objective lens 3 is positioned at the focal point, so that the luminance data is compared with the conventional one in which the Z position of the objective lens is moved in all process pitches and the luminance data is acquired. Efficiency can be obtained efficiently, the operation time until focusing can be greatly reduced, and the work efficiency of sample observation using a microscope can be greatly improved.

After confirming the position of the highest luminance value by the coarse operation, the objective lens 3 is moved backward from the position of the highest luminance value to a predetermined position, and is again moved to the focal point. Is moved to the focal point, backlash and hysteresis characteristics of the moving mechanism of the objective lens 3 can be avoided, and highly accurate focus detection can be realized.

In the coarse operation described in FIG. 2 of the above embodiment, the deceleration stop command is output to the objective lens 3 by continuously decreasing the luminance a plurality of times. If non-luminance information due to the reflected light from the sample 4 is mixed, such as a secondary peak due to the characteristics of the lens 3 or black level noise from the photodetector 11 and the amplifier, the luminance will continue due to the secondary peak and black level noise. As a result, it may be erroneously determined that the number has decreased a plurality of times, and a deceleration stop command of the objective lens 3 may be output. Therefore, in order to solve such inconvenience, for example, a threshold including an absolute value of luminance is added to a condition for outputting a deceleration stop command, and a secondary peak or black level noise below the threshold is ignored. Thus, malfunctions due to these secondary peaks and black level noise can be prevented. In this case, the same effect can be obtained even if the threshold value is set to a value larger than the average value of the difference between the maximum value and the minimum value of the black level noise and a small peak of the black level noise is not detected.

Further, even in the fine operation described with reference to FIG. 4, there is a possibility that a secondary peak or a peak due to black level noise may be erroneously detected. In this case, an area having only 70% or more of the maximum luminance value detected in the coarse operation is used. Is used for fine operation, malfunctions due to these secondary peaks and black level noise can be prevented.

(Second Embodiment) By the way, when the luminance value is saturated in the focus position detecting operation for moving the objective lens with respect to the sample, there are countless positions where the luminance value becomes maximum. May be interrupted. Therefore, in the second embodiment, the focus detection operation can be continuously performed by adjusting the sensitivity so that the luminance value is not saturated.

FIG. 10 shows a schematic configuration of the second embodiment of the present invention, and the same parts as those in FIG. 1 are denoted by the same reference numerals.

In this case, the CPU 7 sets the moving speed of the objective lens 3 in the Z-axis direction, instructs the movement driving unit 8 to start and stop the movement, reads the stop position, and the like.
Along with the continuous movement of the objective lens 3 in the Z-axis direction, a luminance detection unit 701 that detects a luminance signal from the photodetector 11 at a predetermined sampling period, for example, 1 KHz, and a detection sensitivity of the luminance detection unit 701 based on the luminance value. A detection sensitivity adjusting means 703 for adjusting, a luminance saturation detecting means 704 for detecting that the luminance value is saturated, and a luminance detecting means 70
And a focus light judging means 702 for judging a focus from a change in the luminance value detected by the control unit 1. A confocal observation image is also generated based on the luminance signal of the photodetector 11.

Next, the operation of the embodiment configured as described above will be described with reference to the flowchart shown in FIG.

First, in step S1, the objective lens 3 is positioned at a point A in FIG. 14, which is sufficiently close to the sample 4, and the spot light from the light source 1 is irradiated onto the sample 4 via the objective lens 3. At the same time, it is set so that the reflected light from the sample 4 is detected by the photodetector 11 as a luminance signal.

In step S2, from the above state,
The objective lens 3 is continuously moved at a constant speed along the Z-axis in a direction away from the sample 4 (from point A to point B in FIG. 14) by the movement drive unit 8. When the objective lens 3 is continuously moved by coarse movement, the luminance detected by the photodetector 11 increases with the movement of the objective lens 3 and decreases from the time when the maximum luminance value is exceeded.

In step S3, the luminance signal detected by the photodetector 11 is taken into the luminance detecting means 701 at a constant sampling cycle, for example, 1 KHz.

In step S4, the luminance saturation detecting means 704 determines that the luminance value taken in by the luminance detecting means 701 is equal to the upper limit of detection of the luminance detecting means 701 (Ilimit in FIG. 14).
t) is detected.

If it is determined in step S5 that the luminance saturation detecting means 704 has not exceeded the detection upper limit (Ilimit in FIG. 14), the flow advances to step S7.

In step S7, the luminance detecting means 70
1 sets the number of times the luminance at this time continuously decreases and the amount of decrease in the decreased luminance value.

In step S8, it is determined whether or not the objective lens 3 has moved within a predetermined moving range. If the movement has not been completed, the flow advances to step S9. If the movement has been completed, the process proceeds to step S11.

In step S9, if the number of times the luminance continuously decreases and the amount of decrease in the luminance value obtained in step S7 match the preset condition, it is determined that the maximum luminance has been detected, and step S10 The CPU 7 outputs a signal to the movement driving unit 8 to stop the movement of the objective lens 3. In FIG. 14, FIG.
In the T1 period of 4, when it is detected that the luminance has continuously decreased, for example, three times, and that the luminance value during this period has decreased by a predetermined value, the movement of the objective lens 3 is stopped at the point B in FIG. A command is output from the CPU 7 to the movement drive unit 8, and the movement of the objective lens 3 is reduced and stopped at the point C in FIG.

Next, the objective lens 3 is moved to the point D in FIG. FIG. 14 of this objective lens 3
The movement to the point D is to secure an acceleration distance when the objective lens 3 moves.

In step S11, it is determined whether the objective lens 3 is moving in a direction approaching the sample 4, that is, whether the moving direction is downward. If the objective lens 3 is moving in a direction away from the sample 4, that is, if the moving direction is upward, the process proceeds to step S12.

In step S12, the CPU 7 issues an instruction to the movement drive unit 8 to move the objective lens 3 downward, and the movement drive unit 8 moves the objective lens 3 from point D in FIG. 14 to point A in FIG. Toward the sample 4 at a constant speed, and return to step S3.

The luminance detected by the photodetector 11 in step S3 increases with the movement of the objective lens 3 even when the objective lens 3 is continuously moved in a direction approaching the sample 4, and decreases from the time when the maximum luminance value is exceeded. become. Photodetector 11
Is detected by the luminance detecting means 701 at a sampling frequency of 1 KHz.

In step S4, the luminance saturation detecting means 704 determines that the luminance value taken in by the luminance detecting means 701 is equal to the upper limit value of the luminance detecting means 701 (Ilimit in FIG. 14).
t) is detected.

If it is determined in step S5 that the luminance saturation detecting means 704 has not exceeded the detection upper limit value (Ilimit in FIG. 14), the process proceeds to step S7.

In step S7, the luminance detecting means 70
1 sets the number of times the luminance at this time continuously decreases and the amount of decrease in the decreased luminance value.

In step S8, it is determined whether or not the objective lens 3 has moved within a predetermined moving range. If the movement has not been completed, the flow advances to step S9. If the movement has been completed, the process proceeds to step S11.

In step S9, if the number of times the luminance continuously decreases obtained in step S7 and the decreased luminance value matches a preset condition, it is determined that the maximum luminance has been detected, and in step S10, the CPU 7 determines that the maximum luminance has been detected. A signal for stopping the movement of the objective lens 3 is output to the movement driving unit 8. In FIG. 14, T2 of FIG.
During the period, the brightness has decreased continuously, for example, three times,
When it is detected that the luminance value has decreased by a predetermined value during this time, a stop command for the objective lens 3 is issued at point E in FIG.
The signal is output from U7 to the movement drive unit 8, and the movement of the objective lens 3 is reduced and stopped at the point F in FIG.

In step S11, if the direction in which the objective lens 3 is currently approaching the sample 4, that is, the moving direction is downward,
Proceeding to step S13, the coarse movement operation, that is, the detection of the vicinity of the focal point is ended.

If it is determined in step S5 in FIG. 11 that the luminance is saturated, a contrast adjustment process (step S6 in FIG. 11) is performed. This processing will be described in detail with reference to the drawings.

When the luminance saturation detecting means 704 detects the saturation of the luminance value in step S4 of FIG. 11 during the process of detecting the maximum luminance in the direction in which the objective lens 3 moves away from the sample 4, the luminance saturation detecting means 704 Determines that the detection sensitivity of the luminance detecting means 701 is too high, and proceeds to step S5.

In step S5, when the luminance saturation detecting means 704 determines that the luminance value taken into the luminance detecting means 701 is saturated, the process proceeds to step S6. The flowchart of the operation in step S6 is shown in FIG.
And the processing from step S21 is started.

In step S22, a luminance saturation counter ICount indicating the number of times that the saturation of the luminance value is detected is counted up, and the flow advances to step S23.

In step S23, it is determined whether or not the luminance value has been saturated a predetermined number of times n or more. For example, in the situation shown in FIG. If n, the process proceeds to step S24.

In step S24, the detection sensitivity of the luminance detecting means 702 is reduced by the luminance detecting sensitivity adjusting means 703 to a sensitivity which does not saturate, and the flow advances to step S25.

In step S23, if the brightness is not saturated a predetermined number of times n or more, that is, if ICount <n, the process proceeds to step S26.

In step S25, the luminance saturation counter ICount is cleared, and the flow advances to step S26 to complete the contrast adjustment processing.
Is returned to the initial position for starting the coarse operation, an instruction to move the objective lens 3 upward is issued, and the process is continued from step S3 in FIG.

After the rough operation is completed, the operation shifts to a fine operation for detecting a focus position.

This fine operation will be further described.

In this fine operation, the objective lens 3 is located at the point F in FIG.
Deceleration distance when coarsely moving in the direction approaching
4. Start from point F ′. By moving the objective lens 3 to the point F 'in FIG. 14, the number of intermittent operations due to fine operations to be described later is reduced, and the time until focusing is shortened.

In this case, when the objective lens 3 is moved to the point F 'in FIG. 14, the flowchart of FIG. 13 is executed. In this case, with the start of the fine operation in step S31, in step S32, the objective lens 3 is intermittently moved at regular intervals in the direction away from the sample 4 (point B direction in FIG. 14) by the movement driving unit 8.

In step S33, every time the objective lens 3 is intermittently moved at a constant interval, the luminance value of the photodetector 11 is detected by the luminance detecting means 701, and the luminance value at this time is updated to a large value, and step S34 is performed. In step (5), the maximum luminance value is set by the focusing point determination unit 702.

Also in this case, the luminance that increases with the movement of the objective lens 3 starts decreasing when the luminance exceeds the maximum luminance value.

In the period after the maximum luminance value is exceeded, that is, at T3 in FIG. 15, when the number of times that the change in luminance continuously decreases and the decreased luminance value match a preset condition, for example, Then, when it is detected that the luminance value has decreased by a predetermined value during this period, it is determined in step S35 that the maximum luminance has been passed, and the movement of the objective lens 3 is stopped at point G in FIG. Proceed to S38.

In step S38, the objective lens 3
Is moved to the position of the highest luminance value determined to be in focus by the focus determination means 702, that is, I in FIG. 15, and the detection of the focus is completed.

If it is determined in step S35 that the condition that does not hold the maximum luminance can not be detected, the process proceeds to step S36. In step S36, it is determined whether or not the movement of the movable range of the objective lens 3 has been completed. If the movement has not been completed, the process returns to step S32. If the movement has been completed, the process proceeds to step S37 to perform error processing.

Therefore, by doing so, the first
The same effect as that of the embodiment can be expected. Further, when the luminance value is saturated during the coarse operation, the luminance detection sensitivity adjusting means 70
3, the detection sensitivity of the luminance detection means 702 is reduced to a level at which the luminance is not saturated, and the coarse operation is performed again.
The focus detection operation is not interrupted as in the related art, and the operation time until focusing can be further reduced.

(Third Embodiment) In the second embodiment, when the luminance value is saturated during the coarse operation, the sensitivity is reduced to a level at which the luminance is not saturated, and the coarse operation is performed again. In the embodiment, by performing the process of resetting the luminance value, the coarse operation is not performed again.

FIG. 17 shows a schematic configuration of the third embodiment of the present invention. The same parts as those in FIG. 10 are denoted by the same reference numerals.

In this case, the CPU 7 sets the moving speed of the objective lens 3 in the Z-axis direction, instructs the moving drive unit 8 to stop moving, reads the stop position, and the like.
Along with the continuous movement of the objective lens 3 in the Z-axis direction, a luminance detection unit 701 for detecting a luminance signal from the photodetector 11 at a predetermined sampling period, for example, 1 KHz, a luminance value storage unit 705 for setting a luminance value, a luminance value Detection sensitivity adjustment means 703 for adjusting the detection sensitivity of the luminance detection means 701 from
It has a luminance saturation detecting means 704 for detecting that the luminance value is saturated, a focusing focus determining means 702 for determining a focal point from a change in the luminance value detected by the luminance detecting means 701, and further has a two-dimensional focus. The scanning scanner 2 is instructed to scan a spot light, and a confocal observation image is generated based on a luminance signal of the photodetector 11 obtained by the scanning of the spot light.

Next, the operation of the embodiment configured as described above will be described with reference to the flowchart shown in FIG. In FIG. 18, the same portions as those in FIG. 11 described above are denoted by the same reference numerals, and detailed description of the steps denoted by the same reference numerals is omitted.

Also in this case, when the luminance value is read in step S3, the process proceeds to step S3 '.

In step S3 ', the read luminance value and the position of the objective lens 3 at that time are stored in the luminance value storage means 70.
Set to 5.

Then, in step S4, the same luminance saturation detection processing as described above is performed, and the flow advances to step S5.

In step S5, it is determined whether or not the luminance value is saturated. If it is determined that the luminance value is not saturated, the flow advances to step S7 to continue the processing. When it is determined in step S5 that the luminance value is saturated, the process proceeds to step S6.

In step S6, the same contrast adjustment processing as described above is performed, and the flow advances to step S6 '.

In step S6 ', the luminance value set in the luminance value storage means 705 is reset, and the luminance value before contrast adjustment is recalculated according to the characteristics of the photodetector 11. In this case, if a photomultiplier is used as the photodetector 11, for example, the brightness value can be calculated by the following equation.

G = (V1 / V2) αn where α is a constant unique to the photomultiplier, n is the number of dynodes of the photomultiplier, V1 is the result of the contrast adjustment processing, and the photomultiplier is adjusted by the brightness detection sensitivity adjusting means. The detection sensitivity setting voltage set to
V2 is a detection sensitivity setting voltage set in the photomultiplier before the contrast adjustment processing.

Using this formula, the brightness value set in the brightness value storage means 705 is calculated, and the brightness value storage means 7 is again calculated.
Set the luminance value to 05. In this case, the luminance detecting means 70
Since the luminance value after the detection sensitivity adjustment is lower than the luminance value before the detection sensitivity adjustment of No. 1, it is possible to detect the number of times the luminance required for the peak detection process in step S7 continuously decreases.

Then, the process proceeds to step S8 and thereafter, and the rough operation for focus detection is continued as in the case of FIG.

Therefore, in this way, the same effect as in the first embodiment can be expected. Further, when the luminance value is saturated during the rough operation, the detection sensitivity of the luminance detecting means 702 is reduced. In addition to lowering the sensitivity to not perform, the peak detection processing was enabled by resetting the already detected luminance value based on the above formula, so it is necessary to continuously perform the fine movement operation without performing the coarse operation again. Therefore, the operation time until focusing can be further reduced.

In the first and second embodiments, the luminance sensitivity of the luminance detecting means 702 is adjusted when the luminance is saturated during automatic focus detection, but the luminance level is determined to be noise. Even when the brightness is low, the brightness sensitivity of the brightness detection means 702 may be adjusted to enable coarse operation.

Next, a case in which the automatic focus detection operation described in the second and third embodiments is realized by a computer program will be described.

FIG. 19 shows a schematic configuration when a computer is used, and the same parts as those in FIG. 5 are denoted by the same reference numerals.

In this case, the computer 70 in place of the CPU 7 includes an A / D converter 70 for converting analog luminance data output from the photodetector 11 into digital data.
a, main memory 70b, frame memory 70d, CPU 7
0e, a storage medium 70c electronically storing a control program for an automatic focus detection operation for controlling autofocus,
It has an I / F port 70f that is connected to the two-dimensional scanning scanner 2 and the movement drive unit 8 and controls them.
They are connected by a PU bus.

The program for controlling the focus detection is as follows.
The program is loaded into the main memory 70b and executed by the CPU 70e. Such a program is stored in the computer 7
It can also be downloaded from a server computer located at a remote location and executed via a communication medium such as a network connectable to the Internet.

In this case, the control program for the automatic focusing detection operation stored in the storage medium 70c is to set the continuous movement speed of the objective lens 3 in the Z-axis direction and to stop the movement start and stop for the movement drive unit 8. An objective lens control process 70c1 for reading an instruction and a stop position, and a brightness detection process 70c2 for detecting a brightness signal from the photodetector 11 at a predetermined sampling period, for example, 1 KHz, with the continuous movement of the objective lens 3 in the Z-axis direction. , This luminance detection processing 70c
2, a peak detection process 70c4 for determining whether or not a focal point exists based on the change in the luminance value detected in Step 2, an in-focus determination process 70c5 for determining a focal point from the change in the luminance value detected by the luminance detection process 70c2, A brightness saturation detection process 70c6 for detecting that the brightness value obtained in the brightness detection process is saturated, and a detection sensitivity for adjusting the detection sensitivity of the photodetector 8 when the brightness value is detected by the brightness saturation detection process 70c6. An adjustment process 70c3 is provided. Further, it has a process of instructing the two-dimensional scanning scanner 2 to scan a spot light, and generating a confocal observation image based on a luminance signal of the photodetector 11 obtained by the spot light scanning.

The display section 9 displays an observation image generated by the computer 70 and stored in the frame memory 70c.

Next, the operation according to such a control program will be described.

First, the operation until the rough focus position is detected by the coarse operation will be described with reference to the flowchart shown in FIG.

First, in step S111, the objective lens 3 is positioned at the point A in FIG. 14 which is sufficiently close to the sample 4, and the spot light from the light source 1 is irradiated onto the sample 4 via the objective lens 3. At the same time, it is set so that the reflected light from the sample 4 is detected by the photodetector 11 as a luminance signal. From this state, in step S112, the objective lens 3 is moved from the point A in FIG.
Toward the point, the sample is continuously moved at a constant speed along the Z-axis in a direction away from the sample 4, and TRUE is set to a flag MoveUp indicating an upward movement.

The continuous movement in the Z direction due to the coarse operation is set to a low speed when the objective lens 3 has a high magnification and a high speed when the objective lens 3 has a low magnification. When the objective lens 3 is continuously moved by coarse movement, the luminance detected by the photodetector 8 increases with the movement of the objective lens 3 and decreases from the time when the maximum luminance value is exceeded. The luminance signal detected by the photodetector 11 is converted by the A / D converter 70a of the computer 70 at a constant sampling cycle such as 1 KHz, and the luminance detection processing 70c2 is performed by a program stored in the recording medium 70c. Is applied. In step S113, the first luminance data is stored in the main memory 702.
Is set to the variable IMax in the above, and the process proceeds to step S114. The subsequent luminance data is sequentially read in step S114 and subjected to luminance detection processing.

Here, the brightness detection processing 70c2 in step S114 when the objective lens 3 approaches the sample 4 will be described with reference to the flowchart in FIG. The luminance data converted by the A / D converter 70a from the photodetector 11 is set to a variable IBuff in step S121, and the process proceeds to step S122. The luminance data set in IMax in step S122 and IBuf
fBuff is compared with the luminance data set in f.
If> IMax, that is, if the value of the currently captured luminance data is larger than the luminance data read immediately before, the process proceeds to step S123. Step S123
In step, it is determined whether or not a counter IDec indicating the number of times the luminance has continuously decreased is 0. If IDec = 0, the process proceeds to step S124. If IDec is not 0, the IDec is cleared in step S125 and step S124
Proceed to. In step S124, the luminance value in the IBuff is set to IMax, the luminance detection processing 70c2 ends, and the flow advances to step S115 in FIG.

In step S122, IBu
If ff> IMax is not satisfied, that is, if the current luminance value is smaller than the immediately preceding luminance value, the process proceeds to step S126.

In step S126, IDec = 0
Then, if IDec = 0, IMax is the maximum luminance value. In step S127, the luminance value stored in IMax is set to IDiff1, and the process proceeds to step S128.

In step S128, IDec is counted up, and the flow advances to step S129.

In step S129, the luminance value stored in IBuff is set to IMax, and the luminance detection processing 70c2 ends. Then, the flow advances to step S115 in FIG.

In step S115, the process enters a brightness saturation detection process 70c5 for determining whether or not the captured brightness data is saturated. Here, the luminance saturation detection processing 70c5 in step S115 will be described with reference to the flowchart in FIG.

In step S131, the luminance data stored in IMax and a preset saturation value (for example, full count 65535 of a 16-bit A / D converter)
Is set to the saturated state), and if IMax> saturated value, the process proceeds to step S132 and the flag Iover indicating that the luminance is saturated is set to TRUE.

If IMax> saturation value does not hold in step S131, the process proceeds to step S133 and Iove
Let r be FALSE. When the setting of the flag Iover is completed in step S132 or step S133, the luminance saturation detection processing 70c5 ends, and the process proceeds to step S116 in FIG.

In step S116, Iover =
If it is TRUE and the detected luminance value is saturated, the process proceeds to step S117, where the detection sensitivity adjustment processing 70
Enter c6.

Here, the detection sensitivity adjustment processing 70c6 in step S117 will be described with reference to the flowchart of FIG.

In this case, along with the start of the processing in step S21, in step S22, a luminance saturation counter ICount indicating the number of times of luminance saturation is counted up, and the flow advances to step S23.

In step S23, conditional expression ICou
It is determined whether or not the luminance value has been saturated a predetermined number of times or more by nt> = n, and if ICount> = n, step S24 is performed.
Proceed to.

In step S24, the computer 7
The CPU 70e of 0 outputs a command to the photodetector 11 to lower the detection sensitivity to a sensitivity at which the luminance is not saturated, and adjusts the contrast.

In step S25, the luminance saturation counter ICount is cleared, and the detection sensitivity adjustment processing 70c6 is performed.
And returns to step S114 in FIG.

In step S116, Iover =
If the detected luminance value is not saturated in FALSE,
The process proceeds to step S118 to enter the peak detection process 70c4.

Here, the peak detection processing in step S118 will be described with reference to the flowchart in FIG.

At the step S142, the conditional expression IDe
c> predetermined number of times, IBuff-IMax> predetermined value,
It is determined whether the luminance value continuously decreases by a predetermined number of times or more and the amount of the decrease is equal to or more than a predetermined value. With these two conditions, it is possible to avoid erroneous recognition of invalid data such as noise. If both of the above conditions are satisfied, TRUE is set to the flag Peak indicating that a peak has been detected in step S143. If both conditions are not satisfied, the flag Peak is set to F in step S144.
Set ALSE.

Step S143 or step S1
When the setting of the flag is completed in 44, the process proceeds to step S119 in FIG.

In step S119, the objective lens 3
Judge whether has finished moving the predetermined moving range,
If the movement has not been completed, the process proceeds to step S1110.
If the movement has been completed, the process proceeds to step S1112.

In step S1110, a flag Peak indicating that a peak has been detected is referenced, and Peak =
If TRUE, the process proceeds to step S1111. In step S1111, the CPU 70e of the computer 70
Outputs a signal to stop the objective lens 3 to the I / F board 70f, and the movement drive unit 8 stops the movement of the objective lens 3. In this case, in the illustrated period T1 in FIG. 14 after the maximum luminance value is exceeded, the luminance continuously decreases, for example, three times. When it is detected that the luminance value during this period has decreased by a predetermined value or more, three times. At the reduced point B in FIG. 14, a command to stop the movement of the objective lens 3 is issued from the CPU 70e of the computer 70 via the I / F.
Output to the board 70f, the movement drive unit 8 slows down the movement of the objective lens 3 and stops it at the point C in FIG. 14, and proceeds to step S1112.

In step S1112, it is determined by referring to the variable MoveUp whether the objective lens 3 is moving in a direction away from the sample 4, that is, whether the moving direction is upward. If the objective lens 3 is moving in the direction away from the sample 4, that is, if MoveUp = TRUE, step S1
Proceed to 113.

In step S1113, the CPU 70e of the computer 70 sends a signal to the I / F board 70f.
A command is issued to move the objective lens 3 downward. The movement drive unit 8 moves the objective lens 3 from the point D in FIG.
A flag Mov indicating upward movement is continuously moved at a constant speed toward a point, that is, in a direction approaching the sample 4.
FALSE is set in eUp, and the process returns to step S113. The continuous movement in the Z direction due to the coarse operation is set to a low speed when the objective lens 3 has a high magnification and a high speed when the objective lens 3 has a low magnification. When the objective lens 3 is continuously moved by coarse movement, the luminance detected by the photodetector 11 increases with the movement of the objective lens 3 and decreases from the time when the maximum luminance value is exceeded. The luminance signal detected by the photodetector 11 is converted by the A / D converter 70a of the computer 70 at a constant sampling cycle such as 1 KHz, and the luminance detection processing 70c2 is performed by a program stored in the recording medium 70c. Is applied.

In step S113, the first luminance data is set in a variable IMax in the main memory 70b, and the flow advances to step S114. Subsequent luminance data is stored in step S
At 114, the image data is sequentially read and subjected to the luminance detection processing 70c2.

Here, the brightness detection processing 70c2 in step S114 when the objective lens 3 approaches the sample 4 will be described with reference to the flowchart in FIG.

The luminance data converted by the A / D converter 70a from the photodetector 11 is set to a variable IBuff in step S121, and the flow advances to step S122.

In step S122, the luminance data set to IMax is compared with the luminance data set to IBuff, and if IBuff> IMax,
In other words, if the value of the currently captured luminance data is greater than the previously read luminance data, step S
Go to 123.

In step S123, it is determined whether or not a counter IDec indicating the number of times the luminance has continuously decreased is 0. If IDec = 0, the flow advances to step S124. If IDec is not 0, the ID is set in step S125.
ec is cleared and the process proceeds to step S124.

In step S124, the luminance value in the IBuff is set to IMax, the luminance detection processing 70c2 ends, and the flow advances to step S115 in FIG.

In step S122, IBu
If ff> IMax is not satisfied, that is, if the current luminance value is smaller than the immediately preceding luminance value, the process proceeds to step S126.

In step S126, IDec = 0
It is determined whether or not IDec = 0, IMax is the highest luminance value. In step S127, the luminance value stored in IMax is set to IDiff1, and the process proceeds to step S128.

In step S128, IDec is counted up, and the flow advances to step S129.

In step S129, the luminance value stored in IBuff is set to IMax, and the luminance detection processing 70c2 ends. Then, the flow advances to step S115 in FIG.

In step S115, the process enters a brightness saturation detection process 70c5 for determining whether or not the captured brightness data is saturated.

Here, the luminance saturation detection processing 70c5 in step S115 will be described with reference to the flowchart in FIG.

In step S131, the luminance data stored in IMax is compared with a preset saturation value. If IMax> saturation value, the flow advances to step S132 to set a flag Iover indicating that the luminance is saturated to TRU.
E.

If IMax> saturation value does not hold in step S131, the process proceeds to step S133 and Iove
Let r be FALSE. When the setting of the flag Iover is completed in step S132 or step S133, the luminance saturation detection processing 70c5 ends, and the process proceeds to step S116 in FIG.

In step S116, Iover =
If it is TRUE and the detected luminance value is saturated, the process proceeds to step S117, where the detection sensitivity adjustment processing 70
Enter c6.

Here, the detection sensitivity adjustment processing 70c6 in step S117 will be described with reference to the flowchart in FIG.

In this case, along with the start of the processing in step S21, in step S22, a luminance saturation counter ICount indicating the number of times of luminance saturation is counted up, and the flow advances to step S23.

At step S23, conditional expression ICou
It is determined whether or not the luminance value has been saturated a predetermined number of times or more by nt> = n, and if ICount> = n, step S24
Proceed to.

In step S24, the computer 7
The CPU 70e of 0 outputs a command to the photodetector 11 to lower the detection sensitivity to a sensitivity at which the luminance value is not saturated, and adjusts the contrast.

In step S65, the luminance saturation counter ICount is cleared, and the detection sensitivity adjustment processing 70c6 is performed.
And returns to step S114 in FIG.

At step S116, Iover =
If the detected luminance value is not saturated in FALSE,
The process proceeds to step S118 to enter the peak detection process 70c4.

Here, the peak detection processing 70c4 in step S118 will be described with reference to the flowchart in FIG.

In step S142, conditional expression IDe
c> predetermined number of times, IBuff-IMax> predetermined value,
It is determined whether the luminance value continuously decreases by a predetermined number of times or more and the amount of the decrease is equal to or more than a predetermined value. If both of the above conditions are satisfied, TRUE is set to the flag Peak indicating that a peak has been detected in step S143. If both conditions are not satisfied, the flag Peak is set to FALSE in step S144.

Step S143 or step S1
When the setting of the flag is completed in 44, the process proceeds to step S119 in FIG. In step S119, it is determined whether or not the objective lens 3 has moved within the predetermined moving range. If the movement has not been completed, step S1110 is performed.
Proceed to. If the movement has been completed, the process proceeds to step S1112.

In step S1110, a flag Peak indicating that a peak has been detected is referenced, and Peak =
If TRUE, the process proceeds to step S1111.

In step S1111, the CPU 70e of the computer 70 outputs a signal for stopping the objective lens 3 to the I / F board 70f, and the movement driving unit 8 stops the movement of the objective lens 3. In this case, in the period T2 in FIG. 14 after the maximum luminance value is exceeded, the luminance continuously decreases, for example, three times. At the point E shown in FIG.
The signal is output from 70e to the I / F board 70f, and the movement driving unit 6 decelerates the movement of the objective lens 3 and stops at the point F in FIG. 14, and proceeds to step S1112. Step S111
In 2, it is checked whether or not the objective lens 3 is moving upward by the conditional expression MoveUp = TRUE.
Since OVEUP = FALSE, the conditional expression does not hold, so the process proceeds to step S1114, and the rough operation is completed.
After the above rough operation is completed, the operation shifts to a fine operation for detecting a focus position. This fine operation causes the objective lens 3 to move as shown in FIG.
From the point F 'moved by the deceleration distance from the point E to the point F. By moving the objective lens 3 between the points F ′, the number of intermittent operations due to the fine operation described later is reduced, and the time until focusing is shortened.

Next, the fine operation will be described.

In this case, the fine operation starts from step S151 in the flowchart shown in FIG. Step S1
At 52, the CPU 70e of the computer 70
An instruction is issued to the F board 70f to move the objective lens 3 to a point F 'in FIG. 14, which is the start position of the focus determination processing 70c3. The movement drive unit 8 moves the objective lens 3 to the point F ', and proceeds to step S153.

In step S153, the computer 70 outputs a command to start the acquisition of luminance data.
In 154, the first luminance data is set in a variable IMax2 in the main memory 70b, and the position data of the objective lens 3 at that time is set in a variable PosMax in the main memory 70b, and the flow advances to step S155.

In step S155, the CPU 70e of the computer 70 outputs a command to the I / F board 70f to move the objective lens 3 in a direction away from the sample 4 at a constant interval. At this time, the moving interval is set to be narrow when the objective lens 3 has a high magnification and wide when the objective lens 3 is low, and the moving interval is set to be narrow in the confocal operation and large in the non-confocal operation. . Step S is performed when the objective lens 3 has been moved by the moving drive unit 8 at a fixed interval.
Proceed to 156.

Here, the in-focus point determination processing 70c2 of step S156 will be described with reference to the flowchart of FIG.

At step S161, the photodetector 11
Is set to a variable IBuff2, and the position data of the objective lens 3 at that time is set to a variable Pos.
Go to 62.

In step S162, the luminance data set in IMax2 is compared with the luminance data set in IBuff2, and IBuff2> IMax2
If so, the process proceeds to step S163.

In step S163, it is determined whether or not a counter IDec2 indicating the number of times the luminance has continuously decreased is 0. If IDec2 = 0, the flow advances to step S164. If IDec2 is not 0, step S1610
Clears IDec2 and proceeds to step S164.

In step S164, IBuff2
To the IMax2, and the position data in Pos to P
osMax are set, and the process proceeds to step S165.

In step S162, IBu
If ff2> IMax2 is not satisfied, that is, if the current luminance value is smaller than the immediately preceding luminance value, the process advances to step S1611.

In step S1611, IDec2
= 0, and if IDec2 = 0, IMa
x2 is the highest luminance value, and step S161
2 is the luminance value stored in IMax2 as IDi
ff2, the position data Pos of the objective lens 3 at that time
Max is set to PosFix, respectively, and step S1
Proceed to 613.

In step S1613, IDec2 is counted up, and the flow advances to step S1614.

In step S1614, IBuff
2 is set to IMax2, and the position data Pos at that time is set to PosMax, and the process proceeds to step S165.

In step S165, conditional expression IDe
It is determined whether the luminance value has continuously decreased by the predetermined number of times or more according to c2> = the predetermined number of times. If IDec2> = the predetermined number of times, the process proceeds to step S166. If IDec2> = predetermined number of times is not satisfied, the process proceeds to step S167.

In step S166, conditional expression IDi
ff2-IBuff2 <= predetermined value, it is determined whether or not the luminance value has decreased by a predetermined value, and IDiff2-IBu2 is determined.
If ff2> = predetermined value, the process proceeds to step S168. ID
If not, the process proceeds to step S167.

[0239] In step S167, the CPU 70e of the computer 70 outputs an instruction to the I / F board 70f to move the objective lens 3 in a direction away from the sample by a constant distance. The movement interval at this time is determined by the objective lens 3
Is small when the magnification is high, wide when the magnification is low,
In the confocal operation, the moving interval is set narrow, and in the non-confocal operation, the moving interval is set large. Step S16 is performed when the objective lens 3 has been moved by the moving drive unit 8 at a constant interval.
Return to 1.

At the stage where the condition in step S166 is true, the period T shown in FIG.
In 3, the number of times the change in luminance continuously decreases and the decreased luminance value match the preset condition. That is, IDe
Since both conditions of c2> = predetermined number of times and IDiff2-IBuff2> = predetermined value (for example, the luminance value continuously decreases three times and the luminance value during this period decreases from the predetermined value) are satisfied, FIG.
At the point G, the movement of the objective lens 3 is stopped. Step S
At 168, the CPU 70e of the computer 70 reads the PosFix data stored in the main memory 70b, and outputs a command to the I / F board 70f to move the objective lens 3 to the position of the highest luminance value, to I in FIG. The movement drive unit 8 moves the objective lens 3 to the position I. Then, the process proceeds to step S169 to complete the in-focus point determination process, and proceeds to step S157 in the flowchart of FIG. 24 to complete the fine operation.

Next, the procedure for controlling the autofocus operation by a computer program will be described with reference to the drawings.

In this case, the flow of the rough operation when the luminance is not saturated is the same as described above. Next, the brightness detection processing in step S174 of FIG. 26 will be described with reference to the flowchart of FIG. A / A
The luminance data converted by the D converter 70a is set to a variable IBuff in step S181, and the process proceeds to step S182. In step S182, the detected luminance data is sequentially stored in the detected luminance storage array IAlay [i] secured in the main memory 70b of the computer 70, and the process proceeds to step S183. In step S183, the luminance data set to IMax is compared with the luminance data set to IBuff,
If IBuff> IMax, that is, if the value of the currently captured luminance data is greater than the previously read luminance data, the process proceeds to step S184. In step S184, it is determined whether or not a counter IDec indicating the number of times that the luminance has continuously decreased is 0, and IDec =
If it is 0, the process proceeds to step S185. If IDec is not 0, the IDec is cleared in step S186 and the process proceeds to step S185.

[0243] In step S185, the luminance value in IBuff is set to IMax, and the flow advances to step S187.

Also, in step S183, IBu
If ff> IMax is not satisfied, that is, if the current luminance value is smaller than the immediately preceding luminance value, the process proceeds to step S188.

In step S188, IDec = 0
Then, if IDec = 0, IMax is the highest luminance value. In step S189, the luminance value stored in IMax is set to IDiff1, and the process proceeds to step S1810.

In step S1810, IDec is counted up, and the flow advances to step S1811. Step S
In 1811, the luminance value stored in IBuff is copied to IMax, and the flow advances to step S187. In step S187, the detected brightness storage array IAlay
Is counted up, and the brightness detection processing 70
c2 ends, and the flow proceeds to step S175 in FIG.

After step S175, step 176,
Step 177 and steps 116 and 1 in FIG.
The same processing as in step 17 is continued, and in step S177,
After performing the detection sensitivity adjustment processing 70c6, step S17 is performed.
Go to 7 '. In step S177 ', step S1
In the brightness detection processing 70c2 of 74, the brightness resetting processing is performed on the brightness value stored in the IAlay.

Here, the brightness resetting process in step S177 'will be described with reference to FIG.

In step S191, the subsequent steps S192 and S193 are looped up to the set number i of luminance data. In step S192, the luminance value set in the detected luminance storage array IAlay is multiplied by a constant G to overwrite the luminance value. When a photomultiplier is used for the photodetector, for example, the constant G is obtained by the following equation.

G = (V1 / V2) αn where α is a constant specific to the photomultiplier, n is the number of dynodes of the photomultiplier, and V1 is the detection set in the photomultiplier as a result of the detection sensitivity adjustment processing 70c6. The sensitivity setting voltage V2 is the detection sensitivity adjustment processing 7
This is the detection sensitivity setting voltage set in the photomultiplier before 0c6.

Using this equation, the detected luminance storage array IAl
By calculating and resetting the brightness value set to the value ay, the brightness value after the detection sensitivity adjustment of the photodetector 11 is lower than the brightness value before the detection sensitivity adjustment, so that step S17 is performed.
8, it is possible to avoid inconsistency in counting the number of times the luminance continuously decreases in the peak detection process.
Even when c6 is performed, step S17 is continued.
8, the peak detection processing 70c4 can be performed, and it is not necessary to interrupt the flow of the coarse operation.

At step S193, the counter is counted up. At step S194, after the loop process has been completed the specified number of times, the flow advances to step S195.

In step S195, the array IAla
The last luminance value set to y is copied to IMax, the luminance resetting process is completed, and step S1 in FIG.
The process proceeds to 78 and the same processing as described above is performed to complete the focus detection operation.

In the first to third embodiments, the sample 4 and the objective lens 3 are relatively continuously moved, and the brightness value corresponding to the relative position is synchronized with the movement. Although input is made, the sample 4 and the objective lens 3
May be used in a stepwise manner, and a luminance value is input for each step movement. Further, in the above-described embodiment, only the movement of the objective lens is described. However, the present invention is not limited to this, and only the stage may be used because the movement may be relatively performed. In the above-described first to third embodiments, the automatic focus detection is performed by the two operations of the coarse operation and the fine operation. However, the automatic focus detection is performed by any one of the operations. Can also.

The above embodiments include the following inventions.

(1) The automatic focus detecting device according to claim 3 or 4, wherein said automatic focus detecting device comprises: a luminance saturation detecting means for detecting that the luminance detected by said luminance detecting means is saturated; When the luminance saturation detecting means detects the saturation of the luminance detected by the luminance detecting means, a luminance detection sensitivity adjusting means for adjusting the detection sensitivity of the luminance detecting means is provided.

(2) In the automatic focus detection device according to the third or fourth aspect, the automatic focus detection device may include a luminance data detected by the luminance detection means and a sample or objective lens moved by the movement means. It is characterized by having storage means for storing position data.

(3) In the automatic focus detecting device according to the fifth aspect, the judgment control means includes a judgment means for judging whether or not the vicinity of the in-focus position has been detected.

(4) In the automatic focus detecting device according to the fifth aspect, the judgment control means continuously moves the position of the objective lens or the sample by the moving means, and moves the object lens or the sample from the sample surface at a predetermined sampling cycle. It is characterized by detecting the luminance according to the reflected light.

(5) In the automatic focus detecting device described in (4), the judgment control means continuously decreases the luminance value detected in a predetermined sampling cycle by a predetermined number of times, and the amount of decrease when the luminance value decreases is reduced. At a point in time when a predetermined value or more is reached, the presence of a focal point is determined, and only luminance information is detected at a predetermined sampling period to detect the vicinity of the focal position.

(6) In the automatic focus detecting device according to the fifth aspect, the judgment control means intermittently moves the position of the sample or the objective lens at predetermined intervals by the moving means, and the sample or the objective lens is intermittently moved. The method is characterized in that the luminance according to the reflected light from the sample surface is detected every time the light is reflected.

(7) In the automatic focus detecting device as set forth in (6), each time the sample or the objective lens is intermittently moved, the judgment control means continuously decreases the detected luminance value by a predetermined number of times or more. When the amount of decrease at the time of the above becomes equal to or more than a predetermined value set in advance, the movement of the position of the sample or the objective lens by the moving means is stopped, and the position having the highest luminance value is detected as the focal point. It is characterized by.

(8) In the automatic focus detecting device according to (3), the determining means determines the number of times the luminance value recorded by the luminance detecting process has continuously decreased, and the luminance when the luminance becomes maximum. And a main memory having a variable for setting based on the result after the comparison by the comparing means, and comparing the value with a predetermined number of times and a predetermined value set in advance. I have.

(9) In the twelfth or thirteenth aspect, the automatic focus detecting method detects that the luminance detected by the luminance detecting means is saturated, and detects the saturation of the luminance detected by the luminance detecting means. When saturation is detected, the detection sensitivity of the luminance detecting means is adjusted.

(10) In the twelfth aspect or the thirteenth aspect, in the automatic focus detection method, the automatic focus detection method includes a step of transmitting the brightness data detected by the brightness detection means and the position data of the sample or the objective lens. It is characterized by memorizing.

(11) Moving means for moving at least one of the sample and the objective lens on the optical axis, and luminance detecting means for detecting the luminance according to the light reflected from the sample surface at a predetermined sampling cycle. An automatic focus detection method for detecting the in-focus point, comprising a step of performing coarse movement control of the moving means for detecting the vicinity of the in-focus point, and a step of performing fine movement control of the moving means for detecting the in-focus point. An automatic focus detection method.

(12) In the automatic focus detection method described in (11), the step of performing the coarse movement control includes a determination step of determining whether the vicinity of the focal point has been detected.

(13) In the automatic focus detection method according to (11), the step of performing the coarse movement control includes moving the objective lens or the sample continuously by the moving means, and moving the object lens or the sample from the sample surface at a predetermined sampling cycle. And a luminance detecting step of detecting a luminance according to the reflected light of the image.

(14) In the automatic focus detection method described in (13), the luminance detecting step in the coarse movement control includes a step of detecting luminance at a predetermined sampling cycle and a step of detecting the luminance value continuously for a predetermined number of times. At the time when the amount of decrease becomes equal to or more than a predetermined value set in advance,
Determining the presence of the focal point, and detecting only the luminance information at a predetermined sampling period to detect the vicinity of the focal point.

(15) In the automatic focus detection method according to (11), in the step of performing the fine movement control, the position of the objective lens or the sample is intermittently moved at a predetermined interval by the moving means, so that the objective lens or the sample is intermittently moved. It is characterized by comprising a luminance detecting step of detecting luminance every time the image is moved.

(16) In the automatic focus detection method described in (15), the luminance detection step in the fine movement control includes a step of detecting luminance each time the objective lens or the sample moves intermittently, and a step of continuously detecting the detected luminance value. And decrease more than a predetermined number of times,
And stopping the movement of the position of the objective lens or the sample when the amount of decrease when the amount of decrease becomes equal to or greater than a predetermined value set in advance, and setting the position where the luminance value becomes the highest as the focal point. It is characterized by detecting.

(17) In the automatic focus detection method according to (11), in the coarse movement control step, the sample or the objective lens is continuously moved, and in accordance with the reflected light from the sample surface at a predetermined sampling cycle. A luminance detecting step for detecting the detected luminance, a luminance saturation detecting step for detecting whether the detected luminance value is saturated, and a luminance detecting means when the luminance value is detected by the luminance saturation detecting step. And a detection sensitivity adjusting step of adjusting the detection sensitivity of the above.

(18) In the automatic focus detection method described in (17), in the luminance detection step in the coarse movement control, the number of times that the luminance value detected in a predetermined sampling period continuously decreases and the luminance is the highest. The method is characterized in that the method includes a step of recording a luminance value at the time of occurrence.

(19) In the automatic focus detection method described in (17), the luminance saturation detecting step includes a comparing step of comparing a luminance value detected by the luminance detecting step with a preset saturation value of luminance. And a setting step of setting the result of the comparison in the main memory as a variable in the main memory, wherein it is determined whether or not the luminance detected in the luminance detecting step is saturated.

(20) In the automatic focus detection method described in (17), in the detection sensitivity adjusting step, when it is judged that the luminance value detected in the luminance saturation detecting step is saturated, the detection sensitivity adjusting step is performed by the luminance detecting means. It is characterized in that the detection sensitivity is adjusted to a sensitivity at which the luminance value does not saturate.

(21) In the automatic focus detection method according to (11), the determining step includes the number of times the luminance value recorded by the luminance detection processing has continuously decreased, and the luminance when the luminance becomes maximum. The method is characterized by comprising a step of comparing the value with a predetermined number of times and a predetermined value which are set in advance, and a step of setting the result of the comparison to a variable in the main memory.

(22) The recording medium according to claim 16 or 17, wherein the recording medium on which the automatic focus detection program is recorded detects that the luminance detected by the luminance detecting means for detecting luminance is saturated, and performs the luminance detection. When the saturation of the luminance detected by the means is detected, the detection sensitivity of the luminance detecting means is adjusted.

(23) The recording medium according to claim 16 or 17, wherein the recording medium on which the automatic focus detection program is recorded comprises: luminance data detected by luminance detecting means for detecting luminance; and position data of the sample or the objective lens at that time. Is stored.

(24) A moving means for moving at least one of the sample and the objective lens on the optical axis, and a luminance detecting means for detecting a luminance according to the reflected light from the sample surface at a predetermined sampling period. A recording medium on which the in-focus point detection program is recorded, comprising: a step of performing coarse movement control of the moving means for detecting the vicinity of the in-focus point; and a step of performing fine movement control of the moving means for detecting the in-focus point. It is characterized by having.

(25) In the recording medium on which the automatic focus detection program according to (24) is recorded, the step of performing the coarse movement control includes a determining step of determining whether the vicinity of the focal point has been detected. It is characterized by.

(26) In the recording medium on which the automatic focus detection program according to (24) is recorded, the step of performing the coarse movement control is performed by continuously moving the position of the objective lens or the sample by the moving means. The method further comprises a luminance detecting step of detecting a luminance according to light reflected from the sample surface at a sampling cycle.

(27) In the recording medium on which the automatic focus detection program described in (26) is recorded, the luminance detecting step in the coarse movement control includes a step of detecting luminance at a predetermined sampling cycle, and a step of detecting the luminance value. Determining the presence of a focal point when the amount of decrease is equal to or greater than a predetermined value. Only the focus is detected and the vicinity of the focal point is detected.

(28) In the recording medium on which the automatic focus detection program described in (24) is recorded, the step of performing the fine movement control is performed by intermittently moving a position of an objective lens or a sample at a predetermined interval by the moving means. The method further comprises a luminance detecting step of detecting a luminance according to light reflected from the sample surface each time the lens or the sample moves intermittently.

(29) In the recording medium on which the automatic focus detection program according to (28) is recorded, the luminance detecting step in the fine movement control includes a step of detecting a luminance every time the objective lens or the sample moves intermittently. Stopping the movement of the position of the objective lens or the sample by the moving means when the reduced brightness value continuously decreases by a predetermined number of times or more, and when the amount of the reduction decreases to a predetermined value or more. And detecting the position where the luminance value is the highest as the focal point.

(30) In the recording medium on which the automatic focus detection program described in (24) is recorded, in the coarse movement control step, the sample or the objective lens is continuously moved so that the sample or the objective lens is moved from the sample surface at a predetermined sampling cycle. A luminance detection step of detecting luminance according to the reflected light of the light, a luminance saturation detection step of detecting whether the detected luminance value is saturated, and a case where saturation of the luminance value is detected by the luminance saturation detection step. And a detection sensitivity adjusting step of adjusting the detection sensitivity of the luminance detecting means.

(31) In the recording medium on which the automatic focus detection program according to (24) is recorded, the luminance detecting step in the coarse movement control includes the number of times that the luminance value detected at a predetermined sampling period continuously decreases. And a step of recording a luminance value when the luminance becomes maximum.

(32) In the recording medium on which the automatic focus detection program according to (30) is recorded, the luminance saturation detecting step includes a step of comparing the luminance value detected by the luminance detecting step with a preset luminance saturation value. And a setting step of setting a result of comparison in the comparison step to a variable in the main memory, and determining whether or not the luminance detected in the luminance detection step is saturated. Features.

(33) In the recording medium on which the automatic focus detection program according to (30) is recorded, the detecting sensitivity adjusting step is performed when it is determined that the luminance value detected in the luminance saturation detecting step is saturated. It is characterized in that the detection sensitivity of the luminance detecting means is adjusted to a sensitivity at which the luminance value is not saturated.

(34) In the recording medium on which the automatic focus detection program according to (24) is recorded, the judging step comprises:
The number of times the luminance value recorded by the luminance detection process has continuously decreased, and the luminance value when the luminance is the highest,
Comparing with a predetermined number of times and a predetermined value set in advance;
Setting the result after comparison to a variable in the main memory.

[0290]

As described above, according to the present invention, it is possible to shorten the operation time until focusing, and to realize an automatic focus detection apparatus, an automatic focus detection method, and an automatic focus detection method capable of realizing highly accurate focus detection. A recording medium on which an automatic focus detection program is recorded can be provided.

[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 for explaining a coarse movement operation according to the first embodiment;

FIG. 3 is a diagram illustrating a continuous movement pattern of the objective lens according to the first embodiment.

FIG. 4 is a diagram illustrating a fine operation according to the first embodiment;

FIG. 5 is a diagram illustrating a schematic configuration when the first embodiment is realized by a computer program;

FIG. 6 is a flowchart for explaining the operation by the computer program of FIG. 5;

FIG. 7 is a flowchart for explaining an operation according to the computer program of FIG. 5;

FIG. 8 is a flowchart for explaining an operation according to the computer program of FIG. 5;

FIG. 9 is a flowchart for explaining the operation according to the computer program of FIG. 5;

FIG. 10 is a diagram showing a schematic configuration of a second embodiment of the present invention.

FIG. 11 is a flowchart for explaining the operation of the second embodiment.

FIG. 12 is a flowchart illustrating the operation of the second embodiment.

FIG. 13 is a flowchart illustrating the operation of the second embodiment.

FIG. 14 is a diagram for explaining a continuous movement pattern of the objective lens according to the second embodiment.

FIG. 15 is a diagram illustrating a continuous movement pattern of an objective lens according to the second embodiment.

FIG. 16 is a diagram illustrating a continuous movement pattern of an objective lens according to the second embodiment.

FIG. 17 is a diagram showing a schematic configuration of a third embodiment of the present invention.

FIG. 18 is a flowchart illustrating the operation of the third embodiment.

FIG. 19 is a diagram showing a schematic configuration in a case where the second and third embodiments are realized by a computer program.

FIG. 20 is a flowchart for explaining the operation according to the computer program of FIG. 19;

FIG. 21 is a flowchart for explaining the operation according to the computer program of FIG. 19;

FIG. 22 is a flowchart for explaining the operation by the computer program of FIG. 19;

FIG. 23 is a flowchart for explaining the operation according to the computer program of FIG. 19;

FIG. 24 is a flowchart for explaining the operation by the computer program of FIG. 19;

FIG. 25 is a flowchart for explaining the operation by the computer program of FIG. 19;

FIG. 26 is a flowchart for explaining the operation by the computer program of FIG. 19;

FIG. 27 is a flowchart for explaining the operation by the computer program of FIG. 19;

FIG. 28 is a flowchart illustrating the operation of the computer program of FIG. 19;

FIG. 29 is a view for explaining an example of a conventional automatic focus detection device.

[Description of Signs] 1 ... Light source 2 ... Scanner for two-dimensional scanning 3 ... Objective lens 4 ... Sample 5 ... Stage 6 ... A / D converter 7 ... CPU 701 ... Brightness detection means 702 ... In-focus judgment means 703 ... Detection sensitivity Adjusting means 704 Brightness saturation detecting means 705 Brightness value storing means 70 Computer 70a A / D converter 70b Main memory 70c Storage medium 70d Frame memory 70e CPU 70f I / F port 8 Moving drive unit 9 Frame memory 10 Display unit 11 Photodetector 21 Acceleration period 22 Constant speed period 23 Deceleration period

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G02B 7/11 J (72) Inventor Nobuhiro Takamizawa 2-43-2 Hatagaya, Shibuya-ku, Tokyo Olympus Optics (72) Inventor Masahiro Oba 2-43-2 Hatagaya, Shibuya-ku, Tokyo Inside Olympus Optical Co., Ltd.

Claims (17)

[Claims] 1. An automatic focus system which irradiates a sample surface with spot light via an objective lens, detects a luminance according to light reflected from the sample surface, and detects a focal point from a change in the luminance value. In the detection device, moving means for relatively continuously moving the sample and the objective lens, and simultaneously with the relative continuous movement of the sample and the objective lens,
Brightness detection means for detecting a brightness corresponding to the reflected light from the sample surface at a predetermined sampling period; and focus determination means for determining the position of the highest value of the brightness detected by the brightness detection means as a focus. An automatic focus detection device, comprising: 2. The in-focus judging means detects that the sample or the objective lens is continuously moved in one direction and the luminance decreases beyond a maximum value, and then the sample or the objective lens is continuously moved in the other direction. 2. The automatic focus detection device according to claim 1, wherein the position of the highest value of the luminance is determined to be in focus by detecting that the luminance decreases beyond the maximum value. A moving means for moving at least one of the sample and the objective lens on the optical axis of the spot light applied to the sample surface; and a luminance corresponding to the reflected light from the sample surface at a predetermined sampling period. An automatic focus detection device comprising: a luminance detecting means for detecting; and a moving means for continuously moving the position of the objective lens or the sample, and the moving means moving the position of the objective lens or the sample. An automatic focus detection device comprising: a determination control unit configured to determine a position at which the luminance detected by the luminance detection unit is highest to be in the vicinity of the focal point. 4. The determination control means, wherein the moving means continuously moves the sample and the objective lens on the optical axis in one of a direction in which the sample and the objective lens approach or a direction in which the sample and the objective lens separate from each other. Detecting that the luminance detected at a predetermined sampling cycle by the luminance detecting means decreases beyond the maximum value, continuously moving the moving means in a direction opposite to the continuous movement, during which the luminance detecting means 4. The automatic focusing apparatus according to claim 3, wherein a luminance detected at a predetermined sampling period is detected to decrease beyond a maximum value, and a position having the maximum luminance is determined to be near a focal point. Detection device. 5. A moving means for moving at least one of a sample and an objective lens on an optical axis of a spot light applied to a sample surface, and a luminance corresponding to light reflected from the sample surface at a predetermined sampling period. An automatic focus detection device comprising: a luminance detection means for detecting, and an automatic focus detection device that performs focus detection, at the same time as the relative continuous movement between the sample and the objective lens,
At a predetermined sampling cycle, the luminance corresponding to the reflected light from the sample surface is detected, the vicinity of the focal point is detected, and the vicinity of the focal point is detected. Each time the objective lens moves at a constant interval, a judgment control means for controlling the luminance according to the reflected light from the sample surface and the position of the sample or the objective lens at that time to detect the focal point is provided. Automatic focus detection device. 6. The determination control means detects whether or not a luminance value corresponding to light reflected from the sample surface detected when at least one of the sample and the objective lens is continuously moved is saturated. 6. A luminance saturation detecting means, comprising: a luminance saturation detecting means; and a detection sensitivity adjusting means for adjusting a detection sensitivity of the luminance detecting means when the luminance saturation is detected by the luminance saturation detecting means. Automatic focus detection device. 7. The judgment control means includes a recording means for recording the number of times the luminance value detected in a predetermined sampling cycle continuously decreases and the luminance value when the luminance becomes maximum. Claim 5 or 6
The automatic focus detection device as described in the above. 8. A luminance saturation detecting means, a comparing means for comparing a luminance value detected by the luminance detecting means with a preset saturation value of luminance, and a main memory for comparing a result of the comparison by the comparing means. 7. Setting means for setting a variable within
The automatic focus detection device as described in the above. 9. The detection sensitivity adjusting means adjusts the detection sensitivity of the luminance detecting means to a sensitivity at which the luminance value is not saturated when it is determined that the luminance value detected by the luminance saturation detecting means is saturated. 7. The automatic focus detection device according to claim 6, wherein: 10. While continuously moving at least one of the sample and the objective lens, irradiating the sample surface with spot light through the objective lens, detecting a luminance according to the reflected light from the sample surface, and In an automatic focus detection method for detecting a focal point from a change in value, at the same time as the relative continuous movement of the sample and the objective lens,
A first step of detecting a luminance corresponding to light reflected from the sample surface at a predetermined sampling period to detect a vicinity of a focal point; Is intermittently moved at regular intervals, and each time the sample or objective lens moves at regular intervals, the luminance according to the reflected light from the specimen surface and the position of the specimen or objective lens at that time are detected to detect the focal point. 2. An automatic focus detection method, comprising: 11. The method according to claim 11, wherein the detecting step detects that the sample or the objective lens is intermittently moved in one direction and the luminance decreases beyond a maximum value, and then the sample or the objective lens is intermittently moved in the other direction. 11. The automatic focus detection method according to claim 10, further comprising: detecting that the pixel is moved to decrease the luminance beyond a maximum value, and thereafter determining a position of the maximum value of the luminance as a focal point. 12. At least one of the sample and the objective lens is moved on the optical axis of the spot light applied to the sample surface,
In an automatic focus detection method in which a luminance according to light reflected from the sample surface is detected by a luminance detecting unit, and a focal point is detected from a change in a luminance value, the sample surface is irradiated with spot light, The position of the lens or the sample is continuously moved, and the position where the luminance detected while the position of the objective lens or the sample is moving is determined to be near the focal point is determined. Automatic focus detection method. 13. The automatic focus detection method, comprising: continuously moving a sample and an objective lens in one of a direction in which the sample approaches the objective lens and a direction in which the sample and the objective lens separate from each other;
In the meantime, it is detected that the luminance detected at a predetermined sampling period by the luminance detecting means decreases beyond the maximum value, and then the position of the objective lens or the sample is continuously moved in a direction opposite to the continuous movement. In the meantime, it is detected that the luminance detected at a predetermined sampling cycle by the luminance detecting means decreases beyond the maximum value, and the position where the luminance becomes maximum is determined to be near the focal point. An automatic focus detection method according to claim 12. 14. A method for continuously moving at least one of a sample and an objective lens, irradiating a spot light to the sample surface via the objective lens, detecting a luminance corresponding to light reflected from the sample surface, and A recording medium that records an automatic focus detection program that is processed by a computer to detect a focal point from a change in value, at the same time as the relative continuous movement of the sample and the objective lens,
A first step of detecting a luminance corresponding to light reflected from the sample surface at a predetermined sampling period to detect a vicinity of a focal point; Is intermittently moved at regular intervals, and each time the sample or objective lens moves at regular intervals, the luminance according to the reflected light from the specimen surface and the position of the specimen or objective lens at that time are detected to detect the focal point. Two steps,
A recording medium having recorded thereon an automatic focus detection program. 15. After detecting that the sample or the objective lens is continuously moved in one direction and the brightness decreases beyond a maximum value, the sample or the objective lens is continuously moved in the other direction and the brightness is maximized. 15. The recording medium according to claim 14, wherein the position of the highest luminance value is determined to be in the vicinity of the in-focus position by detecting a decrease beyond the range. 16. An object lens or a sample is moved on an optical axis of a spot light irradiated on a sample surface to detect a luminance according to light reflected from the sample surface, and to focus on a focal point based on a change in the luminance value. A recording medium that records an automatic focus detection program that is processed by a computer that is configured to detect the spot, irradiates a spot light onto the sample surface, and moves the position of the objective lens or the sample on the optical axis thereof. A recording medium in which an automatic focus detection program is recorded, wherein a position at which the detected luminance is highest is determined to be near a focal point. 17. A recording medium on which the automatic focus detection program is recorded, irradiates a sample with spot light, and intermittently moves an objective lens or a sample at regular intervals on the optical axis, during which the objective lens or the sample is moved. It is detected that the luminance detected every time the intermittent movement decreases beyond the maximum value, and then the position of the objective lens or the sample is intermittently operated in a direction opposite to the intermittent movement, during which the objective lens or the sample is operated. 16. The automatic focus detection program according to claim 15, wherein the detected luminance is detected to decrease beyond a maximum value each time the light beam intermittently moves, and a position where the luminance is the highest is determined as a focal point. Recording medium on which is recorded.