Image acquisition apparatus and image acquisition method

An image acquisition apparatus includes: an imaging device on which an image of a small area allocated to an area to be imaged is formed; a detection section detecting intensity of light irradiated on the small area from a light source; an integration section integrating the intensity of light detected by the detection section; if an integration value of the intensity of light integrated by the integration section from a point in time when light is emitted from the light source is greater than a predetermined threshold value, a light-source control section terminates light emission; an exposure control section starting exposure of the imaging device before light is emitted from the light source and terminating exposure of the imaging device after emission of light from the light source is terminated; and an image acquisition section acquiring the image of the small area as a divided image from the imaging device.

CROSS REFERENCES TO RELATED APPLICATIONS

The present application claims priority to Japanese Priority Patent Application JP 2009-188776 filed in the Japan Patent Office on Aug. 17, 2009, the entire content of which is hereby incorporated by reference.

BACKGROUND

The present application relates to an image acquisition apparatus and method for acquiring an image. The present application is preferably applied to a field of observation of a tissue section, for example.

To date, a biological sample, such as a tissue section, etc., used in a pathological field has been fixed on a microscope slide, and predetermined staining has been applied on the biological sample. In general, if a retention period of a biological sample becomes long, the biological sample itself deteriorates, and color fading, etc., occurs in the staining applied on the biological sample. Thereby, noticeability on the biological sample by a microscope deteriorates. Also, a biological sample is sometimes used for a diagnosis at a facility other than a facility such as a hospital, etc., where the biological sample is created. In that case, the biological sample is generally sent and received by mail, and thus it takes a certain time for the transfer.

Under these circumstances, a proposal has been made for an apparatus storing a biological sample as image data (for example, refer to Japanese Unexamined Patent Application Publication No. 2003-222801).

Also, in pathological diagnoses, high-precision biological sample images produced by enlarging biological samples at a predetermined magnification are used. Accordingly, the following proposal has been made of a microscope apparatus producing high-precision biological sample images (for example, refer to Japanese Unexamined Patent Application Publication No. 2009-63656). In the microscope apparatus, an area including a biological sample is divided into a plurality of small areas, the small areas are enlarged at a predetermined magnification, images of the small areas are captured, and a plurality of the divided small images are combined into a high-precision biological sample image.

SUMMARY

Incidentally, in the above-described microscope apparatuses, in general, exposure time periods when a plurality of the divided images are obtained, respectively, are kept at constant in order not to make large luminance differences.

However, even if a constant current is applied to a light source irradiating light on a biological sample, intensity of emitted light varies in accordance with a temperature of the light source itself. For example, as shown inFIG. 1, a halogen lamp used for a light source outputs a higher intensity immediately after starting light emission because of a low temperature of the halogen lamp itself, lowers the intensity with time as the temperature of the lamp increases, and goes into a thermal equilibrium state after passage of a predetermined time, outputting a constant intensity.

In such a case, in a microscope apparatus, intensity of light emitted from a light source varies with time, and thus even if an exposure time is kept constant, an exposure quantity on an imaging device changes for each divided image.

As a result, for example, as shown inFIG. 2, in a microscope apparatus, it is difficult to keep luminance values of divided images DP at constant. Thus, in a biological sample image SP produced by connecting divided images DP, joints of the divided images DP become conspicuous. In particular, a joint between an upper and a lower divided images DP becomes more conspicuous because the images are captured at greatly different time.

Thus, as shown inFIG. 3A, in general, in a microscope apparatus, exposure on an imaging device is started at time Ts when a light source has reaches a thermal equilibrium state after passage of a predetermined time from the light source starting light emission, and the exposure is terminated at time Te when a certain time has passed in order to capture divided images. Here, inFIG. 3A, a CCD (Charge Coupled Device) sensor is used as an imaging device. In a CCD sensor, it is possible to start and end exposure for all the pixels at the same time.

Accordingly, it is possible to reduce luminance differences among a plurality of divided images using this method. However, in this method, it takes time until the light source reaches a thermal equilibrium state, and thus the imaging time period becomes disadvantageously long.

Also, in the case of using a CMOS (Complementary Metal Oxide Semiconductor) image sensor as an imaging device, the CMOS image sensor starts and ends exposure in sequence for each line along an array of pixels, and thus, as shown inFIG. 3B, there has been a problem in that an imaging time period becomes further long. In this regard, inFIG. 3B, time Ts1indicates exposure start time of a line on which exposure is started first, and time Ts2indicates exposure start time of a line on which exposure is started last. Also, time Te1indicates exposure end time of the line corresponding to time Ts1, and time Te2indicates exposure end time of the line corresponding to time Ts2.

The present application has been made in consideration of the above-described points. It is desirable to propose an image acquisition apparatus and method for acquiring an image, which is capable of shortening an imaging time period, and reducing luminance differences among images of small areas allocated to an imaging object.

According to an embodiment, there is provided an image acquisition apparatus including: an imaging device on which an image of a small area allocated to an area to be imaged is formed; a detection section detecting intensity of light irradiated on the small area from a light source; an integration section integrating the intensity of light detected by the detection section; if an integration value of the intensity of light integrated by the integration section from a point in time when light is emitted from the light source is greater than a predetermined threshold value, a light-source control section terminates emission of light from the light source; an exposure control section starting exposure of the imaging device before light is emitted from the light source and terminating exposure of the imaging device after emission of light from the light source is terminated; and an image acquisition section acquiring the image of the small area as a divided image from the imaging device.

Also, according to another embodiment, there is provided a method of acquiring an image, the method including the steps of: detecting intensity of light irradiated from a light source on a small area allocated to an area to be imaged; integrating the intensity of light detected by the step of detecting; if an integration value of the intensity of light integrated by the step of integrating from a point in time when light is emitted from the light source is greater than a predetermined threshold value, controlling the light source so as to terminate emission of light from the light source; controlling exposure so as to start exposure of the imaging device on which an image of the small area is formed before light is emitted from the light source and to terminate exposure of the imaging device after emission of light from the light source is terminated; and acquiring the image of the small area as a divided image from the imaging device.

Thereby, a certain amount of light can be emitted from the light source while the imaging device is exposed so that it is possible to keep an exposure quantity of the imaging device constant when a plurality of divided images are obtained.

Also, according to another embodiment, there is provided an image acquisition apparatus including: an imaging device on which an image of a small area allocated to an area to be imaged is formed; a detection section detecting intensity of light irradiated on the small area from a light source; an integration section integrating the intensity of light detected by the detection section; a light-source control section emitting light from the light source such that a time interval between start and end of emission becomes constant; an exposure control section starting exposure of the imaging device before light is emitted from the light source by the light-source control section and terminating exposure of the imaging device after emission of light from the light source is terminated by the light-source control section; an image acquisition section acquiring the image of the small area as a divided image from the imaging device; a correction section correcting a luminance value of the divided image such that an integration value of intensity of light integrated by the integration section at the time when the divided image is captured becomes the same; and an image generation section generating one image by combining the divided images corrected by the correction section.

Also, according to another embodiment, there is provided a method of acquiring an image, the method including the steps of: detecting intensity of light irradiated from a light source on a small area allocated to an area to be imaged; integrating the intensity of light detected by the step of detecting; controlling the light source to emit light such that a time interval between start and end of emission becomes constant; controlling exposure so as to start exposure of the imaging device before light is emitted from the light source by the step of controlling the light source and terminating exposure of the imaging device after emission of light from the light source is terminated by the step of controlling the light source; acquiring the image of the small area as a divided image from the imaging device; correcting a luminance value of the divided image such that an integration value of intensity of light integrated by the step of integrating at the time when the divided image is captured becomes the same; and generating one image by combining the divided images corrected by the step of correcting.

Thereby, the luminance values of the divided images are corrected such that the integration values of intensities of light emitted from the light source while the imaging device is exposed become the same, and thus the luminance differences among divided images can be reduced.

As described above, by the present application, a certain amount of light can be emitted from the light source while the imaging device is exposed so that it is possible to keep exposure quantities of the imaging device at constant when a plurality of divided images are obtained. Thereby, it is possible to achieve an image acquisition apparatus and method for acquiring an image, which is capable of shortening an imaging time period, and reducing luminance differences among images of small areas allocated to an imaging object.

Also, by the present application, the luminance values of the divided images are corrected such that the integration values of intensities of light emitted from the light source while the imaging device is exposed become the same so that it is possible to keep exposure quantities of the imaging device at constant when a plurality of divided images are obtained. Thereby, it is possible to achieve an image acquisition apparatus and method for acquiring an image, which is capable of shortening an imaging time period, and reducing luminance differences among images of small areas allocated to an imaging object.

DETAILED DESCRIPTION

The present application is described below in detail with reference to the drawings according to an embodiment. The detailed description is provided as follows:

1. First embodiment

2. Second embodiment

3. Other embodiments

1. First Embodiment

1.1 Configuration of Biological-Sample-Image Acquisition Apparatus

FIG. 4illustrates a biological-sample-image acquisition apparatus1according to an embodiment. The biological-sample-image acquisition apparatus1includes a microscope10and a data processing section20.

The microscope10has a plane on which a biological sample SPL including a biomacromolecule, such as a tissue section, or a cell, or a chromosome, etc., can be placed, and has a stage (in the following, referred to as a movable stage)11movable in a parallel direction and in a perpendicular direction to that plane (in the x-, y-, and z-axis directions).

In this embodiment, the biological sample SPL is fixed on a microscope slide SG by a predetermined fixing method, and staining is applied to the biological sample SPL as necessary. The staining includes not only general staining as typified by HE (Hematoxylin-Eosin) staining, Giemsa stain or Papanicolaou stain, etc., but also fluorescence staining such as FISH (Fluorescence In-Situ Hybridization), an immunoenzymatic technique, etc.

An optical system12is disposed on one side of the plane of the movable stage11in the microscope10, and a light-source unit13is disposed on the other side of the plane of the movable stage11. The microscope10captures an image of a biological sample SPL either in a bright-field mode or a dark-field mode by changing the modes.

In the bright-field mode, the light-source unit13emits light under the control of the light-source control section30(FIG. 5), irradiates the light on the biological sample SPL disposed on one side of the plane of the movable stage11through an opening formed on the movable stage11as illumination light.

The microscope10enlarges a part of an image of the biological sample SPL obtained by the illumination light by an objective lens12A and an imaging lens12B of the optical system12at a predetermined magnification. And the microscope10forms an image enlarged by the objective lens12A and the imaging lens12B on an imaging surface of a CMOS image sensor14.

In this regard, in the bright-field mode, in the microscope10, a dichroic mirror12C and an emission filter12D can be removed from a light path between the objective lens12A and the imaging lens12B.

Incidentally, an excitation-light-source system15and an excitation filter16are disposed at a predetermined position of the microscope10. In the dark-field mode, in the microscope10, when an excitation-light-source system15emits light, excitation light, which is produced by transmitting only light having an excitation wavelength for fluorescence staining among the emitted light by the excitation filter16is reflected by a dichroic mirror12C disposed between the objective lens12A and the imaging lens12B, and is led to the objective lens12A. And, in the microscope10, the excitation light is focussed by the objective lens12A on the biological sample SPL disposed on the movable stage11.

If fluorescence staining has been applied on the biological sample SPL fixed on the microscope slide SG, the fluorescent dye emit light by the excitation light. Light (in the following, also referred to as color development light) obtained by the emission is transmitted through the dichroic mirror12C via the objective lens12A. And the color development light reaches the imaging lens12B through an emission filter12D disposed between the dichroic mirror12C and the imaging lens12B.

The microscope10enlarges an image of the color development light by the objective lens12A, and absorbs light other than the color development light (in the following, also referred to as the other light) by the emission filter12D. And the microscope10enlarges an image of the color development light having lost the other light by the imaging lens12B, and forms the image on the imaging surface of the CMOS image sensor14.

On the other hand, the data processing section20generates the entire image of the biological sample SPL (in the following, also referred to as a biological sample image) using the CMOS image sensor14, and stores the image as predetermined-format data (in the following, also referred to as sample data).

In this manner, the biological-sample-image acquisition apparatus1can store a biological sample SPL disposed on the microscope slide SG as an image in a microscopic state. Accordingly, it becomes possible for the biological-sample-image acquisition apparatus1to store the biological sample SPL over a long period of time without deteriorating states, such as fixing, staining, etc., compared with a case of storing the microscope slide SG itself.

1.2 Configurations of Light-Source Unit and Light-Source Control Section

Next, a description will be given of the light-source unit13and the light-source control section30controlling the light-source unit13usingFIG. 5.

The light-source unit13has a configuration including a white LED (Light Emitting Diode)13A outputting white light, a condenser13B converting light emitted from the white LED13A into substantially parallel light rays, and a photodetector13C measuring intensity of light emitted from the white LED13A.

As shown inFIG. 6, the white LED13A has a characteristic in which if a constant current is applied, the LED outputs a higher intensity immediately after starting light emission because of a low temperature of the LED itself, lowers the intensity with time as the temperature of the LED increases, and goes into a thermal equilibrium state after passage of a predetermined time, outputting a constant intensity.

When the LED driver35supplies a current to the white LED13A, the white LED13A emits light diffused in a certain range. The condenser13B converts light irradiated on itself among the diffused light emitted from the white LED13A into parallel light rays, and irradiates the biological sample SPL.

The photodetector13C is disposed at a position where part of the diffused light emitted from the white LED13A is irradiated among diffused light emitted from the white LED13A without blocking a light path of light irradiated on the condenser13B.

And when the photodetector13C receives part of diffused light emitted from the white LED13A, the photodetector13C detects the intensity of the irradiated light, and sends a light-intensity signal S1in accordance with the light intensity to an integrator32.

On the other hand, the light-source control section30(FIG. 5) includes a system controller31, the integrator32, a comparator33, an AND circuit34, and an LED driver35.

The system controller31has a computer configuration including a CPU, a ROM storing various programs, etc., and a RAM functioning as a work memory of the CPU, and totally controls individual sections31to35of the light-source control section30.

When the data processing section20supplies an electronic flash instruction SS to the light-source control section30, the light-source control section30controls light aimed at the biological sample SPL in accordance with a timing chart shown inFIG. 7.

Specifically, when the data processing section20supplies the electronic flash instruction SS to the system controller31, the system controller31sends a reset signal S2to the integrator32.

Also, the system controller31sends a threshold-value signal S4indicating a predetermined threshold value to the comparator33.

Further, the system controller31outputs a light-emission instruction S6for instructing the white LED13A to output light to the AND circuit34. The light-emission instruction S6is output for a time period longer than a time period while the white LED13A should output light, and shorter than a time period at which the next reset signal S2is output.

When the integrator32receives the reset signal S2, the integrator32resets an integration value having been integrated up to that time in response to the reset signal S2. And the integrator32starts integrating the light intensity in accordance with the light-intensity signal51supplied from the photodetector13C from a point in time of the reset, and sends an integration-value signal S3indicating the integration value to the comparator33.

The comparator33compares a threshold value indicated by a threshold-value signal S4supplied from the system controller31and an integration value indicated by an integration-value signal S3supplied from the integrator32. If the integration value is less than the threshold value, the comparator33sends an output signal S5, which causes the white LED13A to output light, to the AND circuit34. If the integration value is not less than the threshold value, the comparator33does not send an output signal S5, which causes the white LED13A to output light, to the AND circuit34.

If the AND circuit34is supplied with an output signal S5from the comparator33, and a light-emission instruction signal S6from the system controller31, the AND circuit34sends a light-emission instruction signal S7for causing the white LED13A to emit light to the LED driver35.

If the AND circuit34supplies the LED driver35with a light-emission instruction signal S7, the LED driver35applies a constant current to the white LED13A so that the white LED13A emits light.

In this manner, when the light-source control section30is supplied with an electronic flash instruction SS from the data processing section20, the light-source control section30controls the white LED13A to emit light until the integration value of the intensity of light measured by the photodetector13C reaches the threshold value.

And the light-source control section30stops the current to be supplied to the white LED13A in order to cause the white LED13A to stop light emission at a point in time when the integration value of the intensity of light measured by the photodetector13C has reached the threshold value.

Thereby, it is possible for the light-source control section30to keep the light quantity emitted from the white LED13A onto the CMOS image sensor14through the condenser13B for each time the electronic flash instruction SS is supplied from the data processing section20.

Incidentally, the system controller31is allowed to obtain the light-emission instruction signal S7output from the AND circuit34, and to output a light-emission-end signal indicating that supplying electricity to the white LED13A has ended to the data processing section20on the basis of the light-emission instruction signal S7.

1.3 Configuration of Data Processing Section

Next, a description will be given of a configuration of the data processing section20. As shown inFIG. 8, the data processing section20has a configuration in which various kinds of hardware are connected to a CPU (Central Processing Unit)21performing control.

Specifically, a ROM (Read Only Memory)22, a RAM (Random Access Memory)23to be a work memory for the CPU21, an operation input section24to which an instruction in accordance with a user's operation is input, an interface section25, a display section26, and a storage section27are connected through a bus28.

The ROM22stores programs for executing various kinds of processing. The microscope10(FIG. 4) is connected to the interface section25.

A liquid-crystal display, or an EL (Electro Luminescence) display or a plasma display, etc., is employed for the display section26. Also, a magnetic disk typified by a (Hard Disk), or a semiconductor memory, or an optical disc, etc., is employed for the storage section27. A portable memory, such as a USB (Universal Serial Bus) memory, or a CF (Compact Flash) memory, etc., may be employed.

The CPU21loads a program corresponding to an instruction given from the operation input section23among a plurality of programs stored in the ROM22into the RAM23, and suitably controls the display section26and the storage section27in accordance with the loaded program. Also, the CPU21suitably controls individual sections of the microscope10through the interface section25.

1.4 Specific Contents of Biological-Sample-Image Acquisition Processing

When the CPU21receives an acquisition instruction of an image of a biological sample SPL from the operation input section24, the CPU21loads a program corresponding to the obtained instruction into the RAM23.

As shown inFIG. 9, the CPU21functions as a movement control section41, an exposure control section42, an electronic-flash control section43, an image acquisition section44, an image generation section45, and a data recording section46in accordance with the program corresponding to the acquisition instruction of the image of the biological sample SPL.

For example, as shown inFIG. 10, the movement control section41allocates an area of a biological sample SPL to be imaged (in the following, also referred to as a sample area) PR to a plurality of small areas AR to match magnifications of the objective lens12A and the imaging lens12B. In this regard, inFIG. 10, small areas AR are not overlapped one another. However, part of adjacent areas may be overlapped.

And the movement control section41moves the movable stage11such that an area to be imaged by the CMOS image sensor14becomes, for example, a small area AR on the upper-left corner among a plurality of small areas AR.

After the movement control section41performed movement so that the upper-left small area AR became an area to be imaged, the exposure control section42starts the CMOS image sensor14to be exposed.

After the exposure control section42started the exposure of the CMOS image sensor14, preferably at a point in time when the exposure is started, the electronic-flash control section43outputs the electronic flash instruction SS to the light-source control section30. When the electronic flash instruction SS is supplied by the electronic-flash control section43, the light-source control section30causes the white LED13A to emit a certain amount of light as described above.

After the electronic-flash control section43outputs the electronic flash instruction SS, and the system controller31supplied the light-emission-end signal, preferably at a point in time when a light-emission-end signal is supplied, the exposure control section42stops the exposure of the CMOS image sensor14.

The image acquisition section44reads out an electronic signal of each pixel of the CMOS image sensor14in sequence for each scanning line, and obtains an image of the biological-sample SPL member of the small area AR obtained as a result as a divided image.

Accordingly, as shown inFIG. 11, after exposure of all the pixels of the CMOS image sensor14has been started, the exposure control section42and the electronic-flash control section43cause the white LED13A to emit light. And after the exposure control section42and the electronic-flash control section43have caused the white LED13A to emit a certain amount of light, the exposure control section42and the electronic-flash control section43terminate the exposure of all the pixels of the CMOS image sensor14.

In this regard, inFIG. 11, time Ts3indicates exposure start time of a scanning line on which exposure is started first, and time Ts4indicates exposure start time of a scanning line on which exposure is started last. Also, time Te3indicates exposure end time of the scanning line corresponding to time Ts3, and time Te4indicates exposure end time of the scanning line corresponding to time Ts4.

The movement control section41causes the image acquisition section44to read out an electronic signal of the CMOS image sensor14, and at the same time, moves the movable stage11such that the next area to be imaged by the CMOS image sensor14becomes, for example, a small area AR on the right of the upper-left small area AR.

The exposure control section42and the electronic-flash control section43cause the CMOS image sensor14to start being exposed, and outputs the electronic flash instruction SS to the light-source control section30to cause the white LED13A to emit a certain amount of light. After that, the exposure control section42and the electronic-flash control section43ends the exposure of the CMOS image sensor14. Also, the image acquisition section44obtains the divided images from the CMOS image sensor14.

In this manner, the movement control section41moves an area to be imaged by the CMOS image sensor14in sequence from a small area AR of the uppermost left end to that of the right end. Next, the movement control section41moves downward by one row, and moves in sequence from the right end to the left end. In this manner, the movement control section41moves the area to be imaged in the opposite direction alternately for each row until the divided images corresponding to all the small areas AR are obtained.

And the exposure control section42, the electronic-flash control section43, and the image acquisition section44function in the same manner as described above, and obtain the divided image in the small area AR each time the area to be imaged is moved to one of the small areas AR by the movement control section41.

The image generation section45combines a plurality of divided images obtained by the image acquisition section44to generate a biological sample image.

When the biological sample image is generated, the data recording section46generates sample data including image information indicating the entire biological sample image or a part of the image that can restore the biological sample image.

And the data recording section46adds data indicating identification information on the biological sample image to the sample data, and records the sample data with that data into the storage section27.

The identification information includes information such as, an examinee name, an examinee gender, an examinee age, and an acquisition date, etc., of the biological sample SPL, for example. The data recording section46informs that the identification information should be input at predetermined timing, such as at the timing when a data storage instruction of the biological sample SPL is given, at the timing when the microscope slide SG should be set, etc.

Also, if identification information has not been obtained at the time when biological sample data is created, the data recording section46gives a warning that the identification information should be input. In this regard, a notification or a warning that the identification information should be input is given, for example, by sound or through a GUI (Graphical User Interface) screen, etc.

Next, a description will be given the above-described biological-sample-image acquisition processing procedure in accordance with a flowchart shown inFIG. 12.

Actually, the CPU21enters a routine RT1from a start step, and proceeds to the next step SP1. In step SP1, the CPU21allocates a sample area PR to a plurality of small areas AR, and moves the movable stage11such that an area to be imaged by the CMOS image sensor14is a first (upper left) small area AR, and the processing proceeds to the next step SP2.

In step SP2, the CPU21starts exposure of the CMOS image sensor14, and the processing proceeds to the next step SP3.

In step SP3, the CPU21outputs an electronic flash instruction SS to the light-source control section30to cause the white LED13A to emit light, then in the next step SP4, obtains an integration value of the intensity of light emitted from the white LED13A, and the processing proceeds to the next step SP5.

In step SP5, at the point in time when the integration value becomes a threshold value or higher, the CPU21causes the light-source control section30to end light emission from the white LED13A, and the processing proceeds to the next step SP6.

In step SP6, the CPU21ends the exposure on the CMOS image sensor14, and processing proceeds to the next step SP7.

In step SP7, the CPU21reads out an electronic signal of each pixel of the CMOS image sensor14in sequence for each line, obtains a divided image as a result, and the processing proceeds to the next step SP8.

In step SP8, the CPU21determines whether all the small areas AR have been imaged. If a negative result is obtained, it means that there is a small area AR yet to be imaged, and thus the processing proceeds to the next step SP9.

In step SP9, the CPU21moves the movable stage11such that an area to be imaged by the CMOS image sensor14becomes the next small area AR, and the processing returns to step SP2.

The CPU21repeats from step SP2to step SP9until an affirmative result is obtained in step SP8. When the affirmative result is obtained, it means that divided images corresponding to all the small areas AR have been obtained, and the processing proceeds to step SP10.

In step SP10, the CPU21combines the divided images to generate a biological sample image, then in the next step SP11, stores the sample data including the biological sample image into the storage section27, and the processing proceeds to the next step to end the processing.

1.6 Operation and Advantages

In the above-described configuration of the biological-sample-image acquisition apparatus1, light from the white LED13A is irradiated on small areas AR individually allocated to sample area PR including a biological sample SPL to be imaged.

In the biological-sample-image acquisition apparatus1, the photodetector13C detects intensity of light emitted from the white LED13A, the light intensity is integrated by the integrator32, and light emission from the white LED13A is ended at the time when the integration value becomes a threshold value or higher.

In the biological-sample-image acquisition apparatus1, exposure on the CMOS image sensor14is started before the white LED13A emits light, and exposure on the CMOS image sensor14is ended after light emission from the white LED13A is ended.

And in the biological-sample-image acquisition apparatus1, an image of a small area AR is obtained from the CMOS image sensor14as a divided image.

Thereby, in the biological-sample-image acquisition apparatus1, when all the divided images are individually obtained, the amount of light emitted from the white LED13A can be kept constant. Thus, it is possible to keep an exposure quantity on the CMOS image sensor14constant when each of the small areas AR is imaged.

Accordingly, in the biological-sample-image acquisition apparatus1, when divided images of all the small area AR are obtained, and these divided images are combined into one piece of a biological sample image, even if the intensity of light of the white LED13A varies, luminance differences among all the divided images can be reduced.

Also, in the biological-sample-image acquisition apparatus1, it is not necessary to start imaging after the white LED13A goes into a thermal equilibrium state, and thus the imaging period can be shortened by that amount of time.

Incidentally, in the case of employing an imaging device which performs starting exposure, ending exposure, and reading out an electronic signal for each line, such as a CMOS image sensor14, a time difference arises for each line in starting exposure, ending exposure, and reading out the electronic signal.

However, in the biological-sample-image acquisition apparatus1, exposure of all the pixels of the CMOS image sensor14is started before the white LED13A emits light, and exposure of all the pixels of the CMOS image sensor14is ended after the white LED13A has ended light emission.

Thereby, in the biological-sample-image acquisition apparatus1, in the case of employing an imaging device which performs starting exposure, ending exposure, and reading out an electronic signal for each line, such as a CMOS image sensor14, it is possible to obtain divided images without having luminance difference for each line.

Incidentally, in the biological-sample-image acquisition apparatus1, a method is considered in which the white LED13A emits light all the time, and exposure quantity of the CMOS image sensor14is kept constant by opening and closing a mechanical shutter disposed on a light path of the light.

In this method, in general, since a life span of a mechanical shutter is from 100 thousand times to one million times, if this method is employed in the biological-sample-image acquisition apparatus1capturing hundreds of divided images in one minute, the mechanical shutter reaches the life span in about three days.

In contrast, in the biological-sample-image acquisition apparatus1, exposure quantity of the CMOS image sensor14is kept constant by the emission control of the white LED13A, and thus it is more advantageous in maintainability and in economical efficiency than the case of disposing a mechanical shutter.

Also, for another method, a method is considered in which the white LED13A is controlled at a constant intensity by so-called APC (Auto Power Control) in order to keep the exposure quantity of the CMOS image sensor14constant.

By this method, it is possible to keep the light intensity constant in a shorter time than the time period in which the white LED13A goes into a thermal equilibrium state. However, it is necessary to design a control band to be a high band so that the APC can sufficiently respond in an electronic-flash emission time in this method. In particular, in the case of using an LED driver having a high-efficiency output format, such as a PWM (Pulse Width Modulation) method, etc., a control band of an LED current is restricted by a PWM carrier frequency, and thus it is difficult to achieve APC having a high response speed.

In contrast, in the biological-sample-image acquisition apparatus1, the amount of light emitted from the white LED13A is kept constant. Accordingly, it is not necessary to wait for intensity of light emitted from the white LED13A to become constant, and the imaging period can be shortened by that period. Also, even if an LED current pulsates by the PWM method, the amount of light can be correctly kept constant.

With the above arrangement, in the biological-sample-image acquisition apparatus1, exposure of the CMOS image sensor14on a small area AR allocated on a sample area PR is started before the white LED13A emits light. Also, in the biological-sample-image acquisition apparatus1, exposure of the CMOS image sensor14is ended to obtain a divided image after the white LED13A has emitted a certain amount of light.

Thereby, in the biological-sample-image acquisition apparatus1, it is possible to keep the exposure quantity of the CMOS image sensor14constant without waiting for the white LED13A to go into a thermal equilibrium state. Thus, it is possible to shorten an imaging period, and to reduce luminance differences among the divided images.

2. Second Embodiment

In a second embodiment, the functional configurations of the light-source control section and the CPU are different from those of the first embodiment. In this regard, the configurations of the biological-sample-image acquisition apparatus1and the data processing section20are the same as those of the first embodiment, and the descriptions thereof will be omitted.

2.1 Configurations of Light-Source Unit and Light-Source Control Section

As shown inFIG. 13, in which the same reference letters and numerals are given as the corresponding parts ofFIG. 5, a light-source control section60includes a system controller31, an integrator32, and an LED driver35. The system controller31suitably controls the integrator32and the LED driver35.

When the LED driver35supplies a current to the white LED13A, the white LED13A emits light diffused in a certain range. When part of diffused light emitted from the white LED13A is irradiated on the photodetector13C, the photodetector13C measures the intensity of the irradiated light, and sends the light-intensity signal51in accordance with the light intensity to the integrator32.

When the data processing section20supplies the electronic flash instruction SS to the system controller31, the system controller31sends the reset signal S2to the integrator32.

When the integrator32receives the reset signal S2, the integrator32resets an integration value having been integrated up to that time in response to the reset signal S2. And the integrator32integrates the light intensity in accordance with the light-intensity signal51supplied from the photodetector13C from a point in time of the reset.

After the system controller31sends the reset signal S2to the integrator32, the system controller31outputs a light-emission instruction signal S11for causing the white LED13A to emit light to the LED driver35during a certain time period set to be a same interval all the time from an emission start to an emission end.

When the system controller31supplies the LED driver35with the light-emission instruction signal S11, the LED driver35applies a constant current to the white LED13A for a certain time period so that the white LED13A emits light for a certain time period.

The integrator32integrates the intensity of light emitted from the white LED13A for a certain time period from a point in time of reset, and sends an integration-value signal S3indicating the integration value obtained as a result to the system controller31.

In this manner, when the light-source control section30is supplied with an electronic flash instruction SS from the data processing section20, the light-source control section controls the white LED13A to emit light for a certain time period, and the light-source control section30obtains the integration value of the intensity of light emitted from the white LED31A during that time.

2.2 Specific Contents of Biological-Sample-Image Acquisition Processing

When the CPU21receives an acquisition instruction of an image of a biological sample SPL from the operation input section24, the CPU21loads a program corresponding to the obtained instruction into the RAM23.

As shown inFIG. 14, the CPU21functions as the movement control section41, the exposure control section42, the electronic-flash control section43, the image acquisition section44, the image correction section47, the image generation section45, and the data recording section46in accordance with the program corresponding to the acquisition instruction of the image of the biological sample SPL.

The movement control section41allocates a sample area PR to a plurality of small areas AR, and moves the movable stage11such that an area to be imaged by the CMOS image sensor14becomes, for example, a small area AR on the upper-left corner among a plurality of small areas AR.

After the movement control section41performed movement so that the upper-left small area AR became an area to be imaged, the exposure control section42starts the CMOS image sensor14to be exposed.

After the exposure control section42started the exposure of the CMOS image sensor14, preferably at a point in time when the exposure of the CMOS image sensor14is started, the electronic-flash control section43outputs the flash instruction SS to the light-source control section60. When the electronic flash instruction SS is supplied by the electronic-flash control section43, the light-source control section60causes the white LED13A to emit light for a certain time period.

After the light emission from the white LED13A is ended by the light-source control section60, the exposure control section42ends exposure of the CMOS image sensor14preferably at a point in time when light emission is ended.

The image acquisition section44reads out an electronic signal of each pixel of the CMOS image sensor14in sequence for each line, and obtains an image of the biological-sample SPL member of the upper-left small area AR obtained as a result as a divided image.

At this time image, when the acquisition section44obtains the divided image of the upper-left small area AR, the acquisition section44obtains the integration-value signal S3indicating the integration value of the intensity of the light irradiated by the white LED13A for a certain time period.

When a divided image is obtained, the movement control section41moves the movable stage11to the next small area AR. And the exposure control section42, the electronic-flash control section43, and the image acquisition section44obtain a divided image and an integration-value signal S3of the small area AR by functioning in the same manner as described above each time the movement control section41moves the movable stage11to any small area AR.

The image correction section47calculates a magnification for matching the integration value indicated by the integration-value signal S3with a predetermined value, and multiplies the calculated magnification and the luminance value of the divided image corresponding to the integration value so as to correct the luminance value of the divided image.

The image correction section47corrects the luminance values for all the divided images in the same manner. Also, the image correction section47performs distortion correction that corrects distortions of all the divided images.

The image generation section45combines the divided images corrected by the image correction section47to generate a biological sample image. When the biological sample image is generated, the data recording section46generates sample data including image information indicating the entire biological sample image or a part of the image that can restore the biological sample image.

Next, a description will be given the above-described biological-sample-image acquisition processing procedure in accordance with a flowchart shown inFIG. 15.

Actually, the CPU21enters a routine RT2from a start step, and proceeds to the next step SP21. In step SP21, the CPU21allocates a sample area PR to a plurality of small areas AR, and moves the movable stage11such that an area to be imaged by the CMOS image sensor14is a first imaging area AR, and the processing proceeds to the next step SP22.

In step SP22, the CPU21starts exposure of the CMOS image sensor14, and the processing proceeds to the next step SP23.

In step SP23, the CPU21outputs an electronic flash instruction SS to the light-source control section60to cause the white LED13A to emit light for a certain time period and by a constant current, and the processing proceeds to the next step SP24.

In step SP24, the CPU21ends the exposure on the CMOS image sensor14, and processing proceeds to the next step SP25.

In step SP25, the CPU21reads out an electronic signal of each pixel of the CMOS image sensor14in sequence for each line, obtains a divided image as a result, also obtains an integration value signal S3corresponding to the divided image, and the processing proceeds to the next step SP26.

In step SP26, the CPU21determines whether all the small areas AR have been imaged. If a negative result is obtained, it means that there is a small area AR yet to be imaged, and thus the processing proceeds to the next step SP27.

In step SP27, the CPU21moves the movable stage11such that an area to be imaged by the CMOS image sensor14becomes the next small area AR, and the processing returns to step SP22.

The CPU21repeats from step SP22to step SP27until an affirmative result is obtained in step SP26. When the affirmative is obtained, it means that divided images and the integration value signals S3, which correspond to all the small areas AR, have been obtained, and the processing proceeds to step SP28.

In step SP28, the CPU21calculates magnifications for matching the integration values indicated by the integration-value signals S3individually corresponding to all the divided images with a predetermined value set in advance, multiplies the magnifications and the luminance values of the divided images so as to correct the luminance values of the divided images, respectively, and the processing proceeds to the next step SP29.

In step SP29, the CPU21performs distortion correction on the divided images having been subjected to the luminance-value correction. In the next step SP30, the CPU21combines the divided images into a biological sample image, and the processing proceeds to the next step SP31.

In step SP31, the CPU21stores the sample data including the biological sample image into the storage section27, and the processing proceeds to the next step to end the processing.

2.4 Operation and Advantages

In the above-described configuration of the biological-sample-image acquisition apparatus1, light from the white LED13A is irradiated for a certain time period on small areas AR individually allocated to sample area PR including a biological sample SPL to be imaged.

In the biological-sample-image acquisition apparatus1, the photodetector13C detects intensity of light emitted from the white LED13A, and the light intensity is integrated by the integrator32from a point in time when light is emitted.

In the biological-sample-image acquisition apparatus1, exposure on the CMOS image sensor14is started before the white LED13A emits light, and exposure on the CMOS image sensor14is ended after light emission from the white LED13A is ended.

And in the biological-sample-image acquisition apparatus1, an image of a small area AR is obtained from the CMOS image sensor14as a divided image, and an integration value corresponding to each of the divided images is obtained.

And in the biological-sample-image acquisition apparatus1, luminance values of the divided images are corrected so that the integration values become constant, and the corrected divided images are combined into a biological sample image.

Thereby, in the biological-sample-image acquisition apparatus1, it is possible to keep exposure time of the CMOS image sensor14constant when a small area AR is imaged, and to correct the luminance value of a divided image using the integration value corresponding to the exposure quantity at that time. Thus, it is possible to reduce the luminance differences among the divided images.

Also, in the biological-sample-image acquisition apparatus1, it is not necessary to start imaging after the white LED13A goes into a thermal equilibrium state, and thus the imaging period can be shortened by that amount of time.

Further, in the biological-sample-image acquisition apparatus1, even in the case of employing an imaging device which performs starting exposure, ending exposure, and reading out an electronic signal for each line, such as a CMOS image sensor14, it is possible to obtain divided images without having a difference in the luminance value for each line.

Also, in the biological-sample-image acquisition apparatus1, light emission time from the white LED13A is kept constant, and thus it is possible to keep the emission time of the white LED13A and the exposure time of the CMOS image sensor14constant all the time.

Accordingly, in the biological-sample-image acquisition apparatus1, the timings of the movement control of the movable stage11, the emission control of the white LED13A, and the exposure control of the CMOS image sensor14are not changed for each small area AR compared with controlling the exposure quantity at a certain amount as in the case of the first embodiment. Thus, in the biological-sample-image acquisition apparatus1, the timings for the movement control, the emission control, and the exposure control can be made easily.

Incidentally, as a method for correcting the luminance values, a method is considered in which the average values of the luminance values of a plurality of divided images are individually calculated, and the luminance values of the plurality of divided images are corrected so that the average values become the same. However, by this method, the average values of the luminance values of all the divided images become the same.

Accordingly, by this method, there are cases where it is difficult to correct the luminance value in the same manner as the case of capturing a plurality of divided images with the same exposure quantity. For example, there are cases where the luminance values become the same as to a part including a biological sample SPL and as to a part not including the biological sample SPL, etc. Accordingly, by this method, there arises a problem in which joints of the divided images DP become conspicuous.

In contrast, in the biological-sample-image acquisition apparatus1, the luminance values of the divided image are corrected so that the integration values become constant. Accordingly, it is possible to correct the luminance value in the same manner as the case of capturing a plurality of divided images with the same exposure quantity, and thus joints of the divided images become inconspicuous.

With the above arrangement, in the biological-sample-image acquisition apparatus1, exposure of the CMOS image sensor14on a small area AR allocated on a sample area PR is started before the white LED13A emits light. Also, in the biological-sample-image acquisition apparatus1, exposure of the CMOS image sensor14is ended to obtain a divided image after the white LED13A has emitted light for a certain time period.

And in the biological-sample-image acquisition apparatus1, the luminance values of the divided images are corrected such that the integration value of the intensities of light emitted from the white LED13A become the same, and then the divided images are combined into a biological sample image. Thereby, it is possible for the biological-sample-image acquisition apparatus1to shorten the imaging time period, and to reduce the luminance differences among the divided images.

3. Other Embodiments

In this regard, in the above-described first embodiment, a description has been given of the case where the amount of light emitted from the light-source unit13, in the bright-field mode, onto all the small areas AR is made constant. However, the present application is not limited to this, and the amount of excitation light emitted in the dark-field mode may be made constant.

In this case, the biological-sample-image acquisition apparatus in the dark-field mode is provided with a photodetector measuring the intensity of excitation light emitted from a excitation-light-source system, and a light-source control section receiving the light-intensity signal sent from the photodetector and controlling the excitation-light-source system.

Also, the excitation-light-source system may include a case of disposing one excitation light source emitting excitation light having a plurality of wavelengths, or a case of disposing a plurality of excitation light sources each of which emits one excitation wavelength.

For one example, a description will be given of the case of disposing a plurality of excitation light sources. The biological-sample-image acquisition apparatus100(FIG. 4) is provided with, for example, an excitation-light-source system80and a light-source-control section90as shown inFIG. 16in place of the excitation-light source system15and the light-source control section30. In this regard, in this case, it is assumed that a biological sample SPL has been subjected to fluorescence staining.

The light-source control section90includes a system controller91, an integrator92, a comparator93, an AND circuit94, an LED driver95, an integrator96, a comparator97, an AND circuit98, and an LED driver99. The system controller91totally controls individual sections91to99of the light-source control section90.

When the LED driver95supplies a current to the excitation-light source LED81A, the excitation-light source LED81A emits light diffused in a certain range. The condenser81B converts light irradiated on itself among the diffused light emitted from the excitation-light source LED81A into parallel light rays, and the parallel light is reflected on a reflecting mirror83. The light reflected from the reflecting mirror83is transmitted through a dichroic mirror84, and is irradiated on the biological sample SPL through the excitation filter16, the dichroic mirror12C, and the objective lens12A.

When the LED driver99supplies a current to the excitation-light source LED82A, the excitation-light source LED82A emits light diffused in a certain range. The condenser82B converts light irradiated on itself among the diffused light emitted from the excitation-light source LED82A into parallel light rays, and the parallel light is reflected on a dichroic mirror84. The light reflected from the dichroic mirror84is irradiated on the biological sample SPL through the excitation filter16, the dichroic mirror12C, and the objective lens12A.

When the photodetectors81C and82C receive part of diffused light emitted from the excitation-light source LEDs81A and82A, respectively, the photodetectors81C and82C detect the intensities of the irradiated light, and send light-intensity signals S21and S31in accordance with the light intensities to the integrators integrator92and96, respectively.

When the data processing section20supplies an electronic flash instruction SS to the system controller91, the system controller91sends reset signals S22and S32to the integrators92and96, respectively. Also, the system controller91sends threshold-value signals S24and S34indicating predetermined threshold values to the comparators93and97, respectively.

Further, the system controller91sends reset signals S22and S32to the integrators92and96, respectively, and then outputs the light-emission instructions S26and S36for instructing the excitation light source LEDs81A and82A to output light. The light-emission instructions S26and S36are set for a time period longer than a time period while the excitation light source LEDs81A and82A should outputs light.

When the integrator92receives the reset signal S22, the integrator92resets an integration value, the integrator92starts integrating the light intensity in accordance with the light-intensity signal S21supplied from the photodetector81C from a point in time of the reset, and sends an integration-value signal S23indicating the integration value to the comparator93.

The comparator93compares a threshold value indicated by a threshold-value signal S24and an integration value indicated by an integration-value signal S23. If the integration value is less than the threshold value, the comparator93sends an output signal S25, which causes the excitation light source LED81A to output light, to the AND circuit94.

If the AND circuit94is supplied with an output signal S25from the comparator93, and a light-emission instruction signal S26from the system controller91, the AND circuit94sends a light-emission instruction signal S27for causing the excitation light source LED81A to emit light to the LED driver95.

If the AND circuit94supplies the LED driver95with a light-emission instruction signal S27, the LED driver95applies a constant current to the excitation light source LED81A so that the excitation light source LED81A emits light.

On the other hand, when the integrator96receives the reset signal S32, the integrator96resets an integration value, the integrator96starts integrating the light intensity in accordance with the light-intensity signal S31supplied from the photodetector82C from a point in time of the reset, and sends an integration-value signal S33indicating the integration value to the comparator97.

The comparator97compares a threshold value indicated by a threshold-value signal S34and an integration value indicated by an integration-value signal S33. If the integration value is less than the threshold value, the comparator97sends an output signal S35, which causes the excitation light source LED82A to output light, to the AND circuit98.

If the AND circuit98is supplied with an output signal S35from the comparator97, and a light-emission instruction signal S36from the system controller91, the AND circuit98sends a light-emission instruction signal S37for causing the excitation light source LED82A to emit light to the LED driver98.

If the AND circuit97supplies the LED driver99with a light-emission instruction signal S37, the LED driver99applies a constant current to the excitation light source LED82A so that the excitation light source LED82A emits light.

When the CPU21receives an acquisition instruction of an image of a biological sample SPL from the operation input section24, the CPU21loads a program corresponding to the obtained instruction into the RAM23, and performs processing in accordance with a flowchart shown inFIG. 17.

Actually, the CPU21enters a routine RT3from a start step, and proceeds to the next step SP41. In step SP41, the CPU21allocates a sample area PR to a plurality of small areas AR, and moves the movable stage11such that an area to be imaged by the CMOS image sensor14is a first area AR to be imaged, and the processing proceeds to the next step SP42.

In step SP42, the CPU21starts exposure of the CMOS image sensor14, and the processing proceeds to the next step SP43.

In step SP43, the CPU21outputs an electronic flash instruction SS to the light-source control section90to cause the excitation light source LEDs81A and82A to emit light, and the processing proceeds to the next step SP44.

In step SP44, the CPU21causes the light-source control section90to obtain integration values of the intensities of light emitted from the excitation light source LEDs81A and82A, respectively, and the processing proceeds to the next step SP45.

In step SP45, at the point in time when the integration values become threshold values or higher, the CPU21causes the light-source control section90to end light emission in sequence from the excitation light source LEDs81A and82A, and the processing proceeds to the next step SP46.

In step SP46, after all the excitation light source LEDs81A and82A end light emission, the CPU21ends the exposure on the CMOS image sensor14, and processing proceeds to the next step SP47.

In step SP47, the CPU21reads out an electronic signal of each pixel of the CMOS image sensor14in sequence for each line, obtains a divided image as a result, and the processing proceeds to the next step SP48.

In step SP48, the CPU21determines whether all the small areas AR have been imaged. If a negative result is obtained, it means that there is a small area AR yet to be imaged, and thus the processing proceeds to the next step SP49.

In step SP49, the CPU21moves the movable stage11such that an area to be imaged by the CMOS image sensor14becomes the next small area AR, and the processing returns to step SP42.

The CPU21repeats from step SP42to step SP49until an affirmative result is obtained in step SP48. When the affirmative is obtained, it means that divided images corresponding to all the small areas AR have been obtained, and the processing proceeds to step SP50.

In step SP50, the CPU21combines the divided images into a biological sample image, then in the next step SP51, stores the sample data including the biological sample image into the storage section27, and the processing proceeds to the next step to end the processing.

In this manner, as shown inFIG. 18, in the biological-sample-image acquisition apparatus100, before the excitation light source LEDs81A and82A emit light, exposure of the CMOS image sensor14is started. And in the biological-sample-image acquisition apparatus100, after both of the excitation light source LEDs81A and82A end light emission, exposure of the CMOS image sensor14is ended.

In this regard, inFIG. 18, time Ts5indicates exposure start time of a line on which exposure is started first, and time Ts6indicates exposure start time of a line on which exposure is started last. Also, time Te5indicates exposure end time of the line corresponding to time Ts5, and time Te6indicates exposure end time of the scanning line corresponding to time Ts6. Also, inFIG. 18, a solid line and a dash-single-dot line indicate light intensities emitted from different excitation light source LEDs81A and82A, respectively.

Thereby, in the biological-sample-image acquisition apparatus100, in the case where a plurality of excitation light source LEDs are disposed, it is possible for the excitation light source LEDs to emit light having a constant amount of light with individual wavelengths.

Also, in the biological-sample-image acquisition apparatus100, it is possible to keep the exposure quantity of the CMOS image sensor14constant without waiting for the excitation light source LED to go into a thermal equilibrium state. Thus, it is possible to shorten an imaging period, and to reduce luminance differences in the biological sample image.

Also, in the biological sample image acquisition apparatus100, the biological sample SPL is not kept on being exposed to the excitation light as in the case of waiting until the excitation light source LED goes into a thermal equilibrium state, and thus it is possible to restrain color fading of the fluorescent dye stained on the biological sample SPL.

Also, in the above-described second embodiment, a description has been given of the case where the light emission time from the light-source unit13, in the bright-field mode, onto all the small areas AR is made constant. However, the present application is not limited to this, and the emission time of excitation light, in the dark-field mode, onto all the small areas AR may be made constant.

Further, in the above-described first and second embodiments, a description has been given of the case of using an LED as a light source. However, the present application is not limited, and a mercury lamp or a halogen lamp may be used as a light source.

Further, in the above-described first and second embodiments, a description has been given of the case where a CMOS image sensor14is used as an imaging device. The present application is not limited to this, and a CCD may be used as an imaging device.

If a CCD is employed in place of the CMOS image sensor14in the first embodiment, as shown inFIG. 19, exposure of the CCD is started before the white LED13A emits light, and exposure of the CCD ends after the white LED13A has ended light emission. Thereby, even in the case of employing a CCD, it is possible to shorten an imaging period, and to reduce luminance differences among the divided images. In this regard, inFIG. 19, time Ts7indicates exposure start time, and time Te7indicates exposure end time.

Further, in the above-described first embodiment, a description has been given of the case where exposure of the CMOS image sensor14ends after the white LED13A has ended light emission. The present application is not limited to this. If an emission time period, for which the amount of light emitted from the white LED13A becomes constant, is given, an exposure time which is further longer than the emission time is set, and the CMOS image sensor14may be exposed for the exposure time.

Specifically, if the emission time period, for which the amount of light emitted from the white LED13A becomes constant, is given as a value, for example, between 30 [ms] and 50 [ms], the exposure time for which all the lines of the CMOS image sensor14are exposed is set to 70 [ms], for example.

In this case, in the biological sample image acquisition apparatus1, it becomes easier to control the CMOS image sensor14compared with the case of changing the exposure time of the CMOS image sensor14. Accordingly, in the biological sample image acquisition apparatus1, it becomes possible to control the movable stage11, the white LED13A, and the CMOS image sensor14at a determined timing, and thus it becomes possible to perform total control.

Further, a description has been given that in the above-described first embodiment, the system controller31, the integrator32, the comparator33, the AND circuit34, and the LED driver35of the light-source control section30are implemented by hardware. The present application is not limited to this. The integrator32, the comparator33, the AND circuit34, and the LED driver35may be implemented by software in the system controller31or the CPU21.

Also, a description has been given that in the above-described second embodiment, the system controller31, the integrator32, and the LED driver35of the light-source control section60are implemented by hardware. The present application is not limited to this. The integrator32and the LED driver35may be implemented by software in the system controller31or the CPU21.

Also, a description has been given that in the above-described light-source control section90, the system controller91, the integrator92, the comparator93, the AND circuit94, the LED driver95, the integrator96, the comparator97, the AND circuit98, and the LED driver99are implemented by hardware. The present application is not limited to this. The integrator92, the comparator93, the AND circuit94, the LED driver95, the integrator96, the comparator97, the AND circuit98, and the LED driver99may be implemented by software in the system controller31or the CPU21.

Further, a description has been given that in the above-described first and second embodiments, the objective lens12A and the imaging lens12B are disposed. The present application is not limited to this. Only the objective lens12A may be disposed. Also, a revolving nose-piece, etc., may be employed to the objective lens12A in order to allow the magnification to be changed.

Further, in the above-described first and second embodiments, the sample data obtained by the biological-sample-image acquisition processing is stored in the storage section27. The storage section27is not limited to the case of being disposed in the data processing section20, and may be disposed outside of the data processing section20. Also, the data communication medium for the storage section27is not limited to the bus28, and for example, a wired or wireless communication medium, such as a local area network, the Internet, digital satellite broadcasting, etc., may be used.

Further, a description has been given that in the above-described first embodiment, the CMOS image sensor14is disposed as an imaging device, the photodetector13C is disposed as a detection section, the integrator32is disposed as an integration section, the light-source control section30is disposed as a light-source control section, the exposure control section42is disposed as an exposure control section, and the image acquisition section44is disposed as an image acquisition section. However, in the present application, an imaging device, a detection section, an integrator, a light-source control section, an exposure control section, and an image acquisition section, which have different configurations, may be disposed.

Further, a description has been given that in the above-described second embodiment, the CMOS image sensor14is disposed as an imaging device, the photodetector13C is disposed as a detection section, the integrator32is disposed as an integration section, the light-source control section30is disposed as a light-source control section, the exposure control section42is disposed as an exposure control section, the image acquisition section44is disposed as an image acquisition section, the image correction section47is disposed as a correction section, and the image generation section45is disposed as an image generation section. However, in the present application, an imaging device, a detection section, an integrator, a light-source control section, an exposure control section, an image acquisition section, a correction section, a generation section, which have different configurations, may be disposed.