JP2003021789A - Focus stabilizer of microscope and controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a microscope which reduces an image blurring arising from the deformation of the microscope by various kinds of the heat propagating to the microscopic body, such as a heat from generating sources varying with respective observation methods, a heat from environmental temperature, etc., maintains the stability of the stage of the microscope and has a simple and inexpensive constitution. SOLUTION: The degree of the influence of the image unsharpness by the heat of a lamp or a power source supplying electric power to the lamp is previously measured by experiment and a focusing section is so controlled as to negate the amount of the image unsharpness at all times by calculating the amount of the image unsharpness from this degree and the use conditions of the microscope.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microscope capable of electrically driving a focus section.

[0002]

2. Description of the Related Art In recent years, microscopes have been used as a base of a microscope in order to place an arm on a desk for observation in a comfortable posture and to secure a space for an observer to take notes on the desk. The width is narrow. For this reason, a power source that supplies power to a lamp that is turned on for observing a sample with transmitted illumination is often built in the back of the microscope body.

In such a microscope, the heat from the lamp and the heat from the power source are transmitted to the microscope body during transmission observation, and the microscope body expands. Therefore, the distance between the stage supporting the sample and the objective lens changes by several μm. Because the depth of focus range of the microscope is extremely small,
This has a great influence on the observation of the specimen, and the focusing position once adjusted is lost, resulting in an undesired result of image blurring in the optical axis direction.

Even during epi-illumination observation, the heat from the lamp is transferred from the epi-illumination device to the microscope body, so that the microscope body expands. Therefore, the distance between the stage supporting the sample and the objective lens changes, causing image blurring in the optical axis direction. For such problems, 2
Two technologies will be explained.

The first is disclosed in Japanese Patent Laid-Open No. 9-120030. Two rods, which are mutually coupled and show different thermal expansions, are provided between a rack and a stage of a microscope. By making the expansions occur in opposite directions, image blurring in the optical axis direction due to thermal expansion of the microscope is reduced.

In the second technique, an arm portion of a microscope, in which materials of different thermal expansion coefficients are sprayed onto the arm portion of the microscope, and the arm portion is formed by fastening two kinds of materials having different thermal expansion coefficients to each other. By sandwiching members with different coefficients of thermal expansion between the frame parts, changing the area of the fastening part between the arm part of the microscope and the frame part on the front side and the rear side, etc., arm in the direction to cancel the expansion of the frame part during thermal expansion. This is a technique for reducing image blur in the optical axis direction by configuring the portion to bend.

[0007]

In the above-mentioned first technique, the rack and the stage are connected by two rods in order to suppress thermal deformation, but these spans become considerably long, so that the microscope There is a problem that the stage becomes very fragile, that is, the sample is greatly shaken when a load or force is applied to the stage.

Further, in the above-mentioned second technique, since the arm and the frame are constructed separately, the rigidity of the microscope itself becomes low, and the configuration becomes complicated, so that it becomes expensive. Also, with these technologies, it is not possible to completely correct the difference in the amount of image blur caused by differences in observation methods such as transmission observation and epi-illumination observation, and it is possible to reduce each image blur to some extent, but it is infinitely zero. There is a problem that they cannot be brought close together.

In view of these problems, the present invention provides an image blur caused by deformation of the microscope due to each heat propagating to the microscope main body, such as heat having a different generation source depending on each observation method, heat from ambient temperature, and the like. It is an object of the present invention to provide a microscope having a simple and inexpensive structure that reduces the above-mentioned problem and maintains the stability of the microscope stage.

[0010]

A microscope having a focus stabilizing device according to the present invention is a microscope for electrically focusing a part or all of the focus, and is linked to a parameter of heat transmitted to the microscope body from inside and outside. Recording means for recording the measurement data representing the time transition of the image blur amount of the specimen that changes with each observation condition of the microscope, the observation condition of the microscope and the value of the heat parameter acquired during the observation with the microscope. Based on the calculation result, a calculation unit that calculates the image blur amount based on the measurement data and a drive unit that changes the relative position of the sample and an objective lens used for observing the sample based on the calculation result. And a control unit for electrically controlling so as to cancel the image blur amount.

Further, the control device of the microscope of the present invention is a device for controlling the microscope in which a part or all of the focus is electrically driven, and changes in association with a parameter of heat transmitted to the microscope main body from inside and outside. Recording means for recording the measurement data representing the time transition of the image blur amount of the sample, the observation data of the microscope and the heat acquired during the observation with the microscope from the measurement data read from the recording means. Calculation means for calculating the image blur amount corresponding to the value of the parameter, and the sample and an objective lens used for observing the sample so as to cancel the image blur amount of the microscope from the result of the calculation means. And a control unit that controls the drive unit that changes the relative position of the.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION A first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view when an example of the microscope of the present invention is viewed from the side. Each number given in FIG. 1 indicates one example of parts constituting the microscope according to the present invention.

Reference numeral 1 denotes a base having a built-in illumination system for illuminating the sample 2, and a lamp house 17 having a built-in lamp 3 for illumination is connected to an end of the base 1. The light emitted from the lamp 3 is reflected upward by a mirror 16 incorporated in the base 1 and then focused on the sample 2. Base 1
A frame 5 is formed above the lamp house 17. The stage guide 6 is supported so as to be vertically movable with respect to the frame 5. A power supply 4 for turning on the lamp 3 is built in the back of the frame 5. A stepping motor 15 controlled by a control unit 20 such as a control box or a personal computer is fixed to the frame 5, and an output shaft thereof is connected with a ball screw 11 via a shaft connecting member 10 such as a coupling. . The nut member 12 connected to the ball screw 11 is connected to the stage guide 6 and, in response to the rotation of the stepping motor 15,
The stage guide 6 moves up and down.
An arm 13 is formed above the frame 5, and an objective lens 7 for observing the sample 2 is attached to the arm 13 via a revolver 14. Further, an epi-illumination device 9 for illuminating the specimen 2 from above is attached above the arm 13. A lamp house 18 incorporating a lamp 8 for epi-illumination is connected to the rear end of the epi-illumination device 9. Furthermore, the epi-illumination device 9
An observation lens barrel 19 is attached above the.

Next, how the heat is propagated in the microscope shown in FIG. 1 will be described with reference to FIG. As shown in FIG. 2, when the transmitted illumination lamp 3 is turned on,
The heat from the lamp and the power source is transferred to the frame 5, the frame 5 expands, the relative position of the sample 2 and the objective lens 7 changes, and image blur occurs.

Also, when the epi-illumination lamp 8 is turned on, the heat is transmitted from the epi-illumination device 9 to the frame 5, the frame 5 expands, and the relative positions of the sample 2 and the objective lens 15 change. , Cause image blur. FIG. 3 is a graph showing the time transition of image blur caused by each observation method. This graph shows, for each observation method, the amount of image blur from the time the lamp is turned on, that is, the change in the relative position between the sample and the objective lens over time, when the voltage applied to each lamp is maximized. Is. In FIG. 3, a is a case where transmissive illumination is used, b is a case where epi-illumination is used, and c is a case where transmissive illumination and epi-illumination are used at the same time. In FIG. 3, the plus direction indicates the direction in which the sample and the objective lens move away from each other.

FIG. 4 is a graph showing the time transition of the image blur caused by the difference in the voltage applied to the lamp in the transmitted illumination. In FIG. 4, d is 12V
Is applied, e is applied 9V, and f is applied 6V. In FIG. 4, the plus direction indicates the direction in which the sample and the objective lens move away from each other.

FIGS. 3 and 4 show different graphs depending on the observation method and the applied voltage to the lamp. However, if the conditions of the observation method and the applied voltage to the lamp are determined from these figures. It can be read that the image blur amount of the microscope shows a nearly fixed value. The above-described measurement data shown in FIGS. 3 and 4 are recorded in a control unit composed of a control panel, a PC or the like.

FIG. 5 is a diagram showing the details of the processing performed by the electric focus control unit for correcting the image blur amount during observation according to the first embodiment. In the process, after turning on the power of the microscope shown in FIG. 1 (S101), the presence / absence of lighting of the transillumination lamp 3 and the epi-illumination lamp 8 is read (S102), and is applied to the lit lamp. What voltage is read in V (S103). Further, the amount of image blur is calculated based on the read value and the measurement data shown in FIGS. 3 and 4 which have been measured in advance (S104), and the stepping motor 15 is controlled so as to cancel the amount of image blur. 6 is moved (S105). In addition, this (S1
The operations from (02) to (S105) are repeated during the observation, and the power of the microscope is turned off at the end of the observation.
The operations from 2) to (S105) are ended (S106).
Further, control is performed so as not to affect the normal focus operation performed during this processing.

FIG. 6 shows a measurement example when the control shown in FIG. 5 is performed. In this example, the voltage applied to the epi-illumination lamp 8 is set to 12 V (maximum) for 30 minutes after the power is turned on. Then, during 30 to 60 minutes, the epi-illumination is kept as it is and the applied voltage to the lamp 3 for transmissive illumination is set to 6 V, and the lamp is turned on at the same time. Further, after 60 minutes, the epi-illumination was left as it was, the voltage applied to the lamp 3 for transillumination was changed to 9 V, and the lighting was performed simultaneously. In FIG. 6, A represents the temporal transition of the actual image blur amount due to the heat of these lamps, and B is the reciprocal of the image blur amount derived from the above conditions and FIGS. Is the correction amount for image blur. That is, by canceling out these, an image that is always in focus without an image blur as shown by C is obtained as an actual observation image.

Although the heat source causing the image blur is used as the illumination lamp and the power source for the transmissive illumination here, the heat source causing the image blur is not limited thereto, and may cause the image blur. If applicable, it can be adapted to other heat sources. In addition, in the configuration of the microscope of the present embodiment,
The position controlled to cancel the image blur amount is not limited to the stage, and may be any position as long as it changes the relative position between the sample and the objective lens.

Further, the mechanism is not limited to the mechanism using the stepping motor and the ball screw as in the present embodiment as long as it can electrically drive the portion to be controlled to cancel the image blur amount. Further, if the portion to be controlled for canceling the image blur amount has an electrically driven mechanism, it can be applied to an inverted microscope or the like.

Next, a second embodiment will be described. Second
As shown in FIG. 7, the configuration of the first embodiment is the same as the configuration of the first embodiment, that is, the temperature sensor 2 for measuring the environmental temperature.
1 is added and attached. The position of the temperature sensor 21 is preferably a position where the heat from the lamps 3 and 8 is not directly received as much as possible. In FIG. 7, the base 1
Temperature sensor 2 at the position opposite to the transillumination lamp 3
However, the vicinity of the observation lens barrel 19 is also desirable.

In the microscope of this configuration, if the environmental temperature (room temperature) in which the microscope is installed rises, the frame 5 of the microscope itself expands and the relative position between the sample 2 and the objective lens 7 expands. It is a well-known fact. On the contrary, if the room temperature is lowered, the relative position is reduced due to the contraction of the frame 5 of the microscope, and in any case, the image blur occurs.

FIG. 8 shows a change in image blur in the microscope when the environmental temperature rises. This is because the environmental temperature during microscopic observation in a thermostat is 2 ° C from 2 ° C.
It is a graph obtained by measuring the time transition of the image blur at each temperature when changed to 1 ° C, 23 ° C or 25 ° C. In FIG. 8, g shows the case where the temperature is raised from 20 ° C. to 25 ° C. by 5 ° C., h shows the case where the temperature is raised from 20 ° C. to 23 ° C. by 3 ° C., and i shows 1 ° C. from 20 ° C. to 21 ° C. It shows the case where it is made. Although different graphs are shown depending on the difference in temperature rise as described above, it can be read that the image blur amount of the microscope shows a substantially fixed value as long as the conditions of the temperature rise are determined. The above measurement data shown in FIG. 8 is stored in the control unit composed of a control panel, a PC, or the like.

FIG. 9 is a diagram showing the contents of processing performed by the electric focus control unit according to the second embodiment. In this process, the microscope of FIG. 7 is turned on (S201).
Then, the presence / absence of lighting of the transillumination lamp 3 and the epi-illumination lamp 8 is read (S202), and what voltage is applied to the lit lamp is read (S203). In parallel with the processes of (S202) and (S203), the ambient temperature around the microscope is measured by the temperature sensor 21 and the temperature is read (S204). After that, these read values and the previously measured values shown in FIG.
The image blur amount is calculated from the measurement data shown in 4 and 8 (S
205), the stepping motor 15 is controlled so as to cancel the image blur amount, and the stage 6 is moved (S20).
6). The operations from (S202) to (S206) are repeatedly performed during the observation, the power of the microscope is turned off at the end of the observation, and the operations from (S202) to (S206) are terminated (S207). Further, control is performed so as not to affect the normal focus operation performed during this processing.

In the second embodiment, in addition to canceling out the amount of image blur due to heat of each illumination lamp in the first embodiment, canceling out the amount of image blur due to an increase in environmental temperature will be described. However, the same can be applied to canceling out the amount of image blur caused by a decrease in environmental temperature.

Although the heat sources that cause image blur are the illumination lamps, the power source for transmitted illumination, and the ambient temperature here, the heat sources that cause image blur are not limited to these and cause image blur. If it is the cause, it can be adapted to other heat sources. Further, in the configuration of the microscope of the present embodiment, the position to be controlled for canceling the image blur amount is not limited to the stage, and may be any position as long as it changes the relative position between the sample and the objective lens.

Further, as long as the position to be controlled for canceling the image blur amount can be driven electrically, the mechanism is not limited to the mechanism using the stepping motor and the ball screw as in this embodiment. Further, if the portion to be controlled for canceling the image blur amount has an electrically driven mechanism, it can be applied to an inverted microscope or the like.

Further, a third embodiment will be described. In the configuration of the microscope shown in the first embodiment, the microscope shown in FIG. 1 is configured by combining materials having different thermal expansion coefficients and thermal conductivities, or is different in shape from the heat source compared to the microscope. FIG. 10 shows an example of the measurement data showing the time transition of the image blur caused by each observation method when the parts having different distances are used. In this microscope, it can be seen from FIG. 10 that the image blur once swings in the minus direction.

As shown in FIG. 10, the control of the relative position between the sample and the objective lens in the configuration of such a microscope is such that the value of the image blur temporarily fluctuates in the negative direction immediately after the power is turned on, that is, The rear surface of the frame closer to the lamp expands first, so that the frame itself bows and the relative position between the sample and the objective lens shrinks. During this period, the control unit controls the stage 6 in a direction to widen the relative positions of the sample and the objective lens to cancel these image blurs. After that, the displacement of the image blur value changes from the minus direction to the plus direction due to the overall expansion of the frame over time. At this time, the control unit changes the moving direction of the stage 6 so as to reduce the relative position. Then, at the point where the image blur value becomes 0, the relative position returns to the original position. After that, the stage 6 is controlled in the direction of reducing the relative position to cancel the image blur amount.

In the configuration of the microscope shown in the second embodiment, the microscope is configured by combining materials having different thermal expansion coefficients and thermal conductivities, or is different in shape from the heat source as compared with the microscope. Fig. 11 shows the time transition of image blur due to temperature change when parts with different distances are used.
As shown. The control of the relative position between the sample and the objective lens in response to this is also the same as that described above.

In the first embodiment, the correspondence between the image blur and the heat source that causes the image blur is recorded in the control unit in advance, and the image blur can be prevented from the use condition such as the observation method and the voltage applied to the lamp. Although the correction amount is calculated, it may be slightly different from the curve of the correction amount by the electric focus shown in FIG. 6 of the first embodiment due to a combination of lighting devices which is not a standard combination, a variation in used lamps, a lifespan, and the like. There may be an error. For such a case, FIG.
As shown in 2, a curve obtained by shifting the curve in the standard combination by several steps in the plus and minus directions is set and recorded in the controller. As a result, even if the above error occurs during observation, the error is eliminated by calculating the image blur amount from the above curve immediately after turning on the microscope power, and the image blur amount is further reduced to zero. It is possible to bring them closer. By doing this, fine adjustment is possible even when the configuration of the microscope or the shape or material of the components is different, or when the heat parameter is displaced independently of heat due to some factor, and the accuracy of adjusting the image blur is improved. Further increase. In FIG. 12, two steps are shifted in plus and minus directions, but the invention is not limited to this, and any number of steps may be set according to accuracy. Further, this can be applied to the correction of image blur caused by the environmental temperature shown in the second embodiment.

Further, with respect to the motorized focus mechanism of the microscope, a mechanism for normal focusing of a specimen can be manually performed, and a mechanism for electrically correcting the image blur caused by thermal deformation of the microscope is provided as a separate system. The present invention can be carried out even if it is provided with, and its control may be performed in the same manner as that shown in the first and second embodiments.

In addition, the motorized focus mechanism of the microscope is a mechanism that can normally focus a specimen electrically, and a mechanism that electrically corrects image blur due to thermal deformation of the microscope in a system different from that. The present invention can be carried out even if it is provided with, and its control may be performed in the same manner as that shown in the first and second embodiments.

In this case, since the image blur can be corrected by the control unit, the microscope having the mechanism for electrically correcting
It is not necessary to adopt a structure that reduces the rigidity of the structure or complicates the structure of the microscope. In addition, since the measurement data is recorded in the control unit and the image blur amount can be calculated by a heat parameter that can be easily obtained, such as the voltage applied to the illumination device and the environmental temperature, it can be easily used for the microscope.

Further, the amount of image blur is calculated from the thermal parameter and the measurement data, and the calculation result is compared with that of the microscope sample and the objective lens used for observing the sample so as to correct the image blur. Since the image is output to the drive unit that changes the position, the image blur in the microscope can always be corrected accurately.

[0037]

As described above in detail, according to the microscope stabilizer and control device of the present invention, the microscope stage is not weakened and the structure of the microscope itself is not complicated. It becomes possible to reduce the image blur of the microscope due to the heat such as the lamp and the environmental temperature by each observation method at low cost.

[Brief description of drawings]

FIG. 1 is a perspective view of a microscope according to a first embodiment when viewed from the side.

FIG. 2 is a diagram showing heat transfer of the microscope according to the first embodiment.

FIG. 3 is a graph showing the time transition of image blur for each observation method.

FIG. 4 is a graph showing a time transition of image blur with respect to a voltage for transmitted illumination.

FIG. 5 is a diagram showing the content of processing performed by a control unit according to the first embodiment.

FIG. 6 shows a comparison between an image blur amount and an electric focus correction amount.

FIG. 7 is a perspective view of the microscope according to the second embodiment when viewed from the side.

FIG. 8 is a graph showing a temporal transition of image blur with respect to displacement of environmental temperature.

FIG. 9 is a diagram showing the contents of processing performed by a control unit according to the second embodiment.

FIG. 10 is a graph showing the time transition of image blur for each observation method in the third embodiment.

FIG. 11 is a graph showing a time transition of image blur with respect to a displacement of environmental temperature in the third embodiment.

FIG. 12 is a graph in which a curve is gradually shifted from a correction amount of electric focus.

FIG. 13 is a perspective view when a microscope having a general configuration is viewed from the side.

[Explanation of symbols]

1 base 2 specimens 3 Transmitted illumination lamp 4 Power supply that supplies power to the transillumination lamp 5 frames 6 stages 7 Objective lens 8 Epi-illumination lamp 9 Epi-illumination device 10 axis connecting member 11 ball screw 12 Nut member 13 arms 14 Revolver 15 Stepping motor 16 mirror 17,18 Lamp House 19 Observation barrel 20 Control unit 21 Temperature sensor

Claims (5)

[Claims] 1. A microscope in which a part or all of the focus is electrically driven, and measurement data representing a time transition of an image blur amount of a sample which changes in association with a parameter of heat transmitted from inside and outside of the microscope body. Recording means for recording the observation conditions of the microscope, and a calculation for calculating the image blur amount based on the measurement data from the observation conditions of the microscope and the values of heat parameters acquired during observation with the microscope. A control unit that electrically controls a driving unit that changes the relative position of the sample and an objective lens used for observing the sample based on the calculation result so as to cancel the image blur amount. A microscope characterized by having. 2. The microscope according to claim 1, wherein the parameter of the heat is a voltage applied to the illumination device for illuminating the specimen. 3. The microscope according to claim 1, wherein the thermal parameter is an ambient temperature around which the microscope is placed. 4. The microscope according to claim 1, wherein the calculation means performs the calculation based on different measurement data depending on the configuration of the microscope. 5. An apparatus for controlling a microscope, which electrically controls a part or all of the focus, wherein a time transition of an image blur amount of a sample that changes in association with a parameter of heat transmitted to the microscope main body from inside and outside. Recording means for recording the measurement data represented, from the measurement data read from the recording means, the image corresponding to the observation conditions of the microscope and the value of the parameter of heat acquired during observation with the microscope A calculation unit that calculates the amount of blur, and a drive unit that changes the relative position of the sample and the objective lens used for observing the sample so as to cancel the image blur amount of the microscope from the result of the calculation unit. And a control unit for controlling the control unit.