JP2010197251A - Image capturing apparatus, method and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image capturing apparatus, method and program, capable of reducing the number of background images which are used to remove noise from a sample image. <P>SOLUTION: A background image memory section stores one background image for each pattern class so as to correspond to the pattern class being a class of a location pattern of a well in the background image, among background images which are captured images of a microarray chip where no sample is disposed. A removing section acquires a background image from the background image memory, which is stored so as to correspond to the pattern class of a sample image being a captured image of the microarray chip where a sample is disposed, and removes the noise contained in the sample image by using the acquired background image. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a photographing apparatus, a photographing method, and a photographing program.

  In the fields of biotechnology, biochemistry, and molecular biology, genes are incorporated into samples such as cells and bacteria, and the relationship between the sequence of the incorporated gene and the protein produced by the sample is investigated. The influence on the sample is being investigated. In such an investigation, a sample is sorted using a screening device to determine whether or not a protein is produced or to determine the degree of influence of a chemical substance on the sample.

  A sample sorting method using a conventional screening apparatus will be described with reference to FIGS. First, a microarray chip onto which a sample is dropped will be described. FIG. 28 shows an overview of the microarray chip. As shown in FIG. 28, the microarray chip has a plurality of wells in which samples are arranged. In the example shown in FIG. 28, the microarray chip has 10,000 to several hundred thousand wells. In the example shown in FIG. 28, the diameter of the well is 20 [μm (micrometer)], and the distance between the centers of the wells is 50 [μm].

  The screening apparatus irradiates the microarray chip with excitation light and images the microarray chip within a predetermined imaging range. FIG. 29 shows an example of an imaging range in a conventional screening apparatus. In the example shown in FIG. 29, the screening apparatus images a maximum of nine wells (3 vertical × 3 horizontal) at a time. Then, the screening apparatus photographs all the wells of the microarray chip by photographing the microarray chip in nine times while moving the photographing position. Then, the screening apparatus sorts the sample based on the fluorescence or luminescence intensity (luminance) of the sample obtained from the captured image.

  By the way, the captured image of the microarray chip includes the noise of the image sensor and the fluorescence of the microarray chip itself in addition to the fluorescence and light emission of the sample. For this reason, the screening apparatus cannot calculate only the fluorescence or emission luminance of the sample itself from the captured image. In the present application, the noise of the image sensor and the fluorescence of the microarray chip itself are collectively referred to as “background noise”.

  Background noise will be described with reference to FIGS. 30 and 31. FIG. FIG. 30 is a diagram for explaining noise of the image sensor. Note that the image shown in FIG. 30 is an image of a microarray chip taken in a state where excitation light is not irradiated. As shown in FIG. 30, even when excitation light is not irradiated, the brightness of the captured image does not become “0” but becomes a minute value due to noise of the image sensor. The luminance that appears due to such noise of the image sensor is generally non-uniform within the imaging range. For example, in the example illustrated in FIG. 30, the luminance at Y coordinates “0” to “300” is smaller than the luminance at Y coordinates “300” to “630”.

  FIG. 31 is a diagram for explaining the fluorescence of the microarray chip itself. Note that the image shown in FIG. 31 is an image of the microarray chip taken in a state where the excitation light is irradiated and the sample is not dropped. As shown in FIG. 31, even if the sample is not dropped, the microarray chip emits light when irradiated with excitation light. In particular, as in the example shown in FIG. 31, the edge of the well often emits light. Note that since the image shown in FIG. 31 is taken by the photographing apparatus, noise of the image sensor is also included. That is, the captured image includes the noise of the image sensor as shown in FIG. 31 and the fluorescence of the microarray chip itself in addition to the fluorescence and light emission of the sample.

  In recent years, a screening apparatus that removes background noise from a captured image is known for the purpose of calculating the luminance of fluorescence or light emission of the sample itself. Specifically, such a screening apparatus images in advance a microarray chip on which no sample is dropped, and generates an image including background noise (hereinafter referred to as “background image”) for each imaging position. Such a screening apparatus photographs a microarray chip in which a sample is placed in a well, and generates a fluorescent image of the sample (hereinafter referred to as “sample image”). And this screening apparatus removes the background noise of this sample image using the background image whose imaging position is the same as the imaging position of the sample image.

JP 2004-184379 A

  However, the conventional technique described above has a problem that the number of background images is enormous. Specifically, as described above, the screening apparatus images the microarray chip a plurality of times while moving the imaging position, and thus generates a huge number of background images for one microarray chip. When the number of background images becomes enormous, the problem of pressing the storage capacity and the time taken for generating the background image become longer.

  For example, in the case of the current imaging magnification, the screening apparatus shoots the microarray chip by dividing it into about 500 times. In such a case, the screening apparatus generates about 500 background images for one microarray chip. In addition, since the number of wells per microarray chip is increasing year by year, it is conceivable that the screening apparatus will generate about 5000 background images in the future.

  The disclosed technology has been made in view of the above, and an object thereof is to provide an imaging device, an imaging method, and an imaging program that can reduce the number of background images used for removing noise from a sample image. To do.

  An imaging apparatus disclosed in the present application is, in one aspect, an imaging apparatus that images a microarray chip having a well in which a sample is arranged in a predetermined imaging range while moving an imaging position, wherein the sample is arranged. A background image storage unit that stores one background image for each pattern type, which is a type of the arrangement pattern of wells in the background image, among background images that are photographed images of no microarray chip; A background image stored in association with a pattern type of a sample image that is a captured image of a microarray chip on which the sample is arranged is acquired from the background image storage unit, and the sample is acquired using the acquired background image. It is a requirement to include a removal unit that removes noise included in the image.

  In addition, what applied the component of the imaging device disclosed by this application, the expression, or arbitrary combinations of a component to a method, an apparatus, a system, a computer program, a recording medium, a data structure etc. is effective as another aspect. .

  According to one aspect of the photographing apparatus disclosed in the present application, there is an effect that the number of background images used for removing noise from a sample image can be reduced.

FIG. 1 is a diagram illustrating an example of an imaging range in the screening apparatus according to the first embodiment. FIG. 2 is a diagram illustrating an example of a background image generated by the screening apparatus according to the first embodiment. FIG. 3 is a diagram illustrating an example of a sample image generated by the screening apparatus according to the first embodiment. FIG. 4 is a diagram illustrating an example of a sample image from which background noise has been removed. FIG. 5 is a diagram illustrating the configuration of the screening apparatus according to the first embodiment. FIG. 6 is a diagram illustrating an example of the pattern correspondence storage unit. FIG. 7 is a diagram illustrating an example of the background image storage unit. FIG. 8 is a diagram showing the relationship between the brightness of the sample image and the exposure time. FIG. 9 is a diagram for explaining an example of background removal processing by the removal unit. FIG. 10 is a diagram for explaining shading. FIG. 11A is a diagram for explaining a shading coefficient calculation method. FIG. 11B is a diagram for explaining a shading coefficient calculation method. FIG. 11C is a diagram for explaining a shading coefficient calculation method. FIG. 11D is a diagram for explaining a shading coefficient calculation method. FIG. 12A is a diagram for explaining an example of a sorting process by the sorting unit. FIG. 12-2 is a diagram for explaining an example of the sorting process by the sorting unit. FIG. 13 is a flowchart illustrating a procedure of sample separation processing by the screening apparatus according to the first embodiment. FIG. 14 is a flowchart illustrating a procedure of background photographing processing by the photographing control unit. FIG. 15 is a flowchart illustrating a procedure of background removal processing by the removal unit. FIG. 16 is a diagram showing an example of a microarray chip having a well arrangement pattern of a staggered pattern. FIG. 17 is a diagram for explaining sample separation processing by the screening apparatus according to the second embodiment. FIG. 18A is a diagram illustrating an example of a dark noise image. FIG. 18-2 is a diagram illustrating an example of a well background image. FIG. 19 is a diagram for explaining background image generation processing performed by the screening apparatus according to the second embodiment. FIG. 20 is a diagram for explaining the background image generation processing by the screening apparatus according to the second embodiment. FIG. 21 is a diagram illustrating the configuration of the information processing apparatus according to the second embodiment. FIG. 22 is a flowchart illustrating a procedure of sample separation processing by the screening apparatus according to the second embodiment. FIG. 23 is a flowchart illustrating a procedure of well background photographing processing by the photographing control unit. FIG. 24 is a flowchart illustrating a procedure of background image generation processing and background removal processing by the removal unit. FIG. 25A is a diagram illustrating a distribution example of luminance that appears due to noise of the image sensor. FIG. 25B is a diagram of an example of luminance distribution of background noise. FIG. 25C is a diagram illustrating a distribution example of fluorescence luminance of the microarray chip itself. FIG. 26 is a flowchart illustrating the shading coefficient calculation processing procedure performed by the screening apparatus according to the third embodiment. FIG. 27 is a diagram illustrating a computer that executes an imaging program. FIG. 28 is a diagram showing an overview of the microarray chip. FIG. 29 is a diagram illustrating an example of an imaging range in a conventional screening apparatus. FIG. 30 is a diagram for explaining noise of the image sensor. FIG. 31 is a diagram for explaining the fluorescence of the microarray chip itself.

  Embodiments of a photographing apparatus, a photographing method, and a photographing program disclosed in the present application will be described below in detail with reference to the drawings. In addition, the imaging device, the imaging method, and the imaging program disclosed in the present application are not limited by this embodiment. For example, in the following embodiment, an example in which the imaging apparatus disclosed in the present application is applied to a screening apparatus will be described. However, the imaging apparatus disclosed in the present application can also be applied to a microscope apparatus that does not separate samples.

[Sample Separation Processing by Screening Apparatus According to Example 1]
First, the sample separation process by the screening apparatus 100 according to the first embodiment will be described. The screening apparatus 100 according to the first embodiment images a microarray chip only at a specific imaging position when generating a background image. Specifically, when there are a plurality of imaging positions where the well arrangement pattern is the same in the imaging range, the screening apparatus 100 images the microarray chip at only one imaging position among the plurality of imaging positions. Generate an image.

  Then, the screening apparatus 100 selects a background image in which the well arrangement pattern matches the well arrangement pattern in the sample image from the generated background images. Subsequently, the screening apparatus 100 removes the background noise of the sample image by subtracting the luminance of the selected background image for each pixel from the luminance of the sample image. And the screening apparatus 100 calculates the brightness | luminance of a sample using the sample image from which background noise was removed, and classifies a sample based on the calculated brightness | luminance.

  Here, the reason why only one background image with the same well arrangement pattern is generated will be described. As described above, the background image is used to remove background noise from the sample image. Among the background noises, the luminance that appears due to the noise of the image sensor is the same even if the shooting position is different if the size of the shooting range is the same.

  In addition, among the background noise, the fluorescence of the microarray chip itself is the same even if the imaging position is different if the well arrangement pattern in the imaging range is the same. That is, when the size of the imaging range is the same and the well arrangement pattern in the sample image matches the well arrangement pattern in the background image, the screening apparatus 100 uses the background image to use the background of the sample image. Noise can be removed. Therefore, when there is an imaging position where the well arrangement pattern is the same, the screening apparatus 100 generates a background image by imaging the microarray chip at one of the imaging positions.

  The sample separation process described above will be specifically described with reference to FIGS. FIG. 1 is a diagram illustrating an example of an imaging range in the screening apparatus 100 according to the first embodiment. In the example shown in FIG. 1, the screening apparatus 100 images the microarray chip C10 at the imaging positions H11 to H13, H21 to H23, and H31 to H33.

  In the first embodiment, it is assumed that the photographing position of the screening apparatus 100 is determined in advance. Further, it is assumed that the screening apparatus 100 recognizes in advance the arrangement pattern of wells at each imaging position. That is, in the example shown in FIG. 1, in the screening apparatus 100, the photographing positions for photographing the microarray chip C10 are determined in advance as photographing positions H11 to H13, H21 to H23, and H31 to H33. The screening apparatus 100 recognizes in advance the arrangement pattern of wells at the imaging positions H11 to H13, H21 to H23, and H31 to H33.

  In the example shown in FIG. 1, the well arrangement patterns at the photographing positions H11, H12, H21, and H22 are the same. Accordingly, the screening apparatus 100 shoots the microarray chip C10 at any one of the shooting positions H11, H12, H21, or H22 to generate a background image.

  Also, since the well arrangement patterns at the photographing positions H13 and H23 are the same, the screening apparatus 100 photographs the microarray chip C10 at one of the photographing positions H13 or H23 to generate a background image. Similarly, the screening apparatus 100 shoots the microarray chip C10 at one of the shooting positions H31 or H32 to generate a background image. In addition, the screening apparatus 100 captures the microarray chip C10 at the capturing position H33 and generates a background image. That is, in the example illustrated in FIG. 1, the screening apparatus 100 generates a total of four background images. Hereinafter, a well arrangement pattern that can be taken at each imaging position is referred to as a “basic pattern”.

  FIG. 2 shows an example of a background image generated by the screening apparatus 100 according to the first embodiment. In the example illustrated in FIG. 2, the screening apparatus 100 captures the microarray chip C10 at the capturing positions H11, H13, H31, and H33 illustrated in FIG. 1, and generates background images B11, B13, B31, and B33. .

  In the first embodiment, it is assumed that the screening apparatus 100 determines in advance at which imaging position the microarray chip C10 is to be imaged when generating a background image. That is, in the example shown in FIG. 2, when the background image is generated, the screening apparatus 100 is predetermined to photograph the microarray chip C10 at the photographing positions H11, H13, H31, and H33.

  Subsequently, the screening apparatus 100 images the microarray chip C10 in which the sample is arranged in the well at all imaging positions, and generates a sample image for each imaging position. FIG. 3 shows an example of a sample image generated by the screening apparatus 100 according to the first embodiment. In the example shown in FIG. 3, the screening apparatus 100 images the microarray chip C10 at the imaging positions H11 to H13, H21 to H23, and H31 to H33, and generates sample images S11 to S13, S21 to S23, and S31 to S33. is doing.

  Specifically, the screening apparatus 100 generates the sample image S11 by shooting the microarray chip C10 in which the sample C11 is placed in the well W11-6 at the shooting position H11. Similarly, the screening apparatus 100 generates a sample image S12 including the sample C12, a sample image S22 including the samples C22a and C22b, a sample image S31 including the sample C31, and a sample image S33 including the sample C33. . The screening apparatus 100 also generates sample images S13, S21, S23, and S32 that do not include a sample.

  Subsequently, the screening apparatus 100 selects a background image in which the well arrangement pattern matches the well arrangement pattern in the sample image from the background images generated in advance. Subsequently, the screening apparatus 100 removes background noise from the sample image using the selected background image.

  This will be described using the example shown in FIGS. For example, when removing the background noise of the sample image S11 shown in FIG. 3, the screening apparatus 100 selects the background image B11 from the background images B11, B13, B31, and B33 shown in FIG. This is because the well arrangement pattern in the sample image S11 and the well arrangement pattern in the background image B11 are the same. Subsequently, the screening apparatus 100 removes background noise from the sample image S11 by subtracting the luminance of the background image B11 for each pixel from the luminance of the sample image S11.

  Similarly, the screening apparatus 100 uses the background image B11 to remove background noise from the sample images S12, S21, and S22. Moreover, the screening apparatus 100 removes the background noise of the sample images S13 and S23 using the background image B13. Moreover, the screening apparatus 100 removes the background noise of the sample images S31 and S32 using the background image B31. Moreover, the screening apparatus 100 removes the background noise of the sample image S33 using the background image B33.

  FIG. 4 shows an example of a sample image from which background noise has been removed. The sample image shown in FIG. 4 is an image obtained by removing background noise from the sample images S11 to S13, S21 to S23, and S31 to S33 shown in FIG. As shown in FIG. 4, the fluorescence or luminescence of the samples C11, C12, C22a, C22b, C31, and C33 themselves appears in the sample image from which background noise has been removed. The screening apparatus 100 sorts the samples C11, C12, C22a, C22b, C31, and C33 based on the sample image shown in FIG.

  As described above, the screening apparatus 100 according to the first embodiment generates background images with the same well arrangement pattern without overlapping. Then, the screening apparatus 100 selects a background image whose well arrangement pattern is the same as the well arrangement pattern in the sample image, and removes background noise from the sample image using the selected background image. Thereby, the screening apparatus 100 according to the first embodiment can reduce the number of background images used for removing noise from the sample image. As a result, the screening apparatus 100 can shorten the photographing time for generating the background image without squeezing the storage capacity.

  For example, since a conventional screening apparatus shoots a microarray chip having 10,000 to several hundred thousand wells in about 500 times, it generates about 500 background images. On the other hand, the screening apparatus 100 according to the first embodiment generates the background images by the number of the basic patterns even when the microarray chip is imaged about 500 times. It can be less than a screening device.

  Although not described above, the screening apparatus 100 according to the first embodiment images the microarray chip a plurality of times while changing the time for irradiating the excitation light (hereinafter referred to as “exposure time”), A plurality of background images having different exposure times for each photographing position are generated. Hereinafter, the screening apparatus 100 according to the first embodiment will be described in detail including processing for generating a plurality of background images having different exposure times.

[Configuration of Screening Apparatus 100 According to Embodiment 1]
Next, the configuration of the screening apparatus 100 according to the first embodiment will be described. FIG. 5 is a diagram illustrating a configuration of the screening apparatus 100 according to the first embodiment.

  As shown in FIG. 5, the screening apparatus 100 includes a stage 101, a culture dish 102, an LED (Light Emitting Diode) 103, a pipette 104, a manipulator 105, an objective lens 106, a fluorescent lamp 107, and a shutter 108. , Fluorescent filter 109, reflecting mirror 110, reflecting mirror 111, CCD (Charge Coupled Device) camera 112, objective lens drive motor 113, LED controller 114, stage controller 115, shutter controller 116, focus Controller 117, RS (Recommended Standard) 232C converter 118, DIO (Digital Input Output) 119, RS232C converter 120, AIO (Analog Input Output) 121, USB (Universal Serial Bus) 122, and amplifier 123 And information And a management device 130.

  The stage 101 is an XY stage that can move in the horizontal direction, and is equipped with a culture dish 102 and a microarray chip C10. The screening apparatus 100 changes the imaging position by moving the stage 101. The culture dish 102 is a dish for culturing samples such as cells and bacteria.

  The LED 103 irradiates light to the microarray chip C10 from above. The pipette 104 is a hollow glass needle whose tip is miniaturized, and injects an object such as a gene into cells on the microarray chip C10. The manipulator 105 moves the pipette 104. The objective lens 106 includes a plurality of lenses having different magnifications and enlarges a part of the microarray chip C10.

  The fluorescent lamp 107 irradiates the microarray chip C10 with excitation light. The shutter 108 opens and closes the optical path of the excitation light emitted by the fluorescent lamp 107. The fluorescent filter 109 extracts light having a wavelength used for excitation of the sample from the excitation light irradiated by the fluorescent lamp 107. The reflecting mirror 110 reflects the excitation light irradiated by the fluorescent lamp 107 toward the microarray chip C10.

  The reflecting mirror 111 reflects the image of the microarray chip C10 enlarged by the objective lens 106 toward the CCD camera 112. The CCD camera 112 captures a part of the microarray chip C10 reflected by the reflecting mirror 111 and generates a captured image. The objective lens driving motor 113 drives the objective lens 106.

  The LED controller 114 controls whether or not the LED 103 is irradiated with light. The stage controller 115 controls the movement of the stage 101. The shutter controller 116 controls the time (exposure time) during which the microarray chip C10 is irradiated with excitation light by controlling the opening and closing of the shutter 108. The focus controller 117 changes the enlargement magnification by controlling the objective lens driving motor 113.

  The RS232C conversion unit 118, the DIO119, the RS232C conversion unit 120, and the AIO 121 are interfaces, and are connected to the information processing apparatus 130 via the USB 122. Specifically, the RS232C conversion unit 118 connects the stage controller 115 and the information processing apparatus 130. The DIO 119 connects the shutter controller 116 and the information processing apparatus 130. The RS232C conversion unit 120 connects the focus controller 117 and the information processing apparatus 130. The AIO 121 connects the LED controller 114 and the information processing apparatus 130.

  The amplifier 123 amplifies a control signal input from a servo controller 134, which will be described later, and outputs the amplified control signal to the pipette 104 or the manipulator 105.

  As shown in FIG. 5, the information processing apparatus 130 includes a display unit 131, an input unit 132, a storage unit 133, a servo controller 134, a CCD controller 135, a shooting control unit 136, a removal unit 137, and shading. A correction unit 138 and a sorting unit 139 are provided.

  The display unit 131 is a display device that displays various types of information, and is, for example, a liquid crystal display. The input unit 132 is an input device for inputting various information and operation instructions, and is, for example, a keyboard or a mouse.

  The storage unit 133 is a storage device that stores various types of information, and is, for example, a memory or a hard disk. The storage unit 133 in the first embodiment includes a pattern correspondence storage unit 133a and a background image storage unit 133b.

  The pattern correspondence storage unit 133a stores the type of the well arrangement pattern at the photographing position in association with the photographing position. FIG. 6 shows an example of the pattern correspondence storage unit 133a. As illustrated in FIG. 6, the pattern correspondence storage unit 133 a includes items such as “photographing position” and “pattern type”.

  The “imaging position” indicates an imaging position when the screening apparatus 100 images the microarray chip C10. The information stored in the “shooting position” shown in FIG. 6 corresponds to the symbols H11 to H13, H21 to H23, and H31 to H33 attached to the shooting positions in FIG. “Pattern type” indicates the type of the basic pattern.

  That is, the first row of the pattern correspondence storage unit 133a illustrated in FIG. 6 indicates that the well arrangement pattern at the imaging position H11 is the basic pattern PT1. Further, the second row of the pattern correspondence storage unit 133a illustrated in FIG. 6 indicates that the well arrangement pattern at the imaging position H12 is the basic pattern PT1. As described above, the pattern correspondence storage unit 133a illustrated in FIG. 6 indicates that the well arrangement patterns at the photographing positions H11, H12, H21, and H22 are the same. Similarly, the pattern correspondence storage unit 133a illustrated in FIG. 6 indicates that the well arrangement patterns at the photographing positions H13 and H23 are the same, and the well arrangement patterns at the photographing positions H31 and H32 are the same.

  The background image storage unit 133b stores a background image for each exposure time in association with the pattern type. In the background image storage unit 133b, various types of information are stored by a shooting control unit 136 described later. FIG. 7 shows an example of the background image storage unit 133b. As illustrated in FIG. 7, the background image storage unit 133 b includes items such as “pattern type”, “exposure time”, and “background image”.

  The “pattern type” corresponds to the “pattern type” shown in FIG. The “exposure time” indicates the time during which excitation light is applied to the microarray chip C10 when the background image is taken. “Background image” indicates the file name (including device name, directory name, folder name, etc.) of the background image.

  That is, in the first row of the background image storage unit 133b shown in FIG. 7, the background image whose well arrangement pattern is the basic pattern PT1 and whose exposure time is 1 [ms] is the background image B1 (1). It is shown that. In the second row of the background image storage unit 133b shown in FIG. 7, the background image whose well arrangement pattern is the basic pattern PT1 and whose exposure time is 2 [ms] is the background image B1 (2). It is shown that.

  The servo controller 134 outputs a predetermined control signal to the pipette 104 or the manipulator 105 via the amplifier 123, thereby dropping the culture solution or sample onto the microarray chip C10. The CCD controller 135 controls the CCD camera 112 in accordance with instructions from a shooting control unit 136 described later.

  The imaging control unit 136 instructs the CCD controller 135 to image the microarray chip C10, and acquires a sample image and a background image from the CCD controller 135. Hereinafter, the processing by the imaging control unit 136 will be specifically described by dividing it into a sample imaging process and a background imaging process.

  First, the sample photographing process by the photographing control unit 136 will be described. When acquiring a sample image, the imaging control unit 136 instructs the stage controller 115 to move the stage 101. For example, it is assumed that the imaging positions of the screening apparatus 100 are determined as the imaging positions H11 to H13, H21 to H23, and H31 to H33 shown in FIG. In addition, it is assumed that the screening apparatus 100 is configured to capture images in the order of the imaging positions H11, H12, H13, H21,..., H32, and H33 when acquiring a sample image. In such a case, the imaging control unit 136 instructs the stage 101 to move so that the imaging position becomes the imaging position H11.

  The stage controller 115 that has received such an instruction moves the stage 101. Subsequently, the photographing control unit 136 sets the exposure time at the time of photographing to a predetermined initial value. Then, the photographing control unit 136 instructs the CCD controller 135 to photograph the microarray chip C10 when the exposure time has elapsed. The CCD controller 135 controls the CCD camera 112 to take a picture according to such an instruction. Then, when a predetermined exposure time has elapsed, the CCD camera 112 shoots the microarray chip C10 to generate a sample image, and transmits the generated sample image to the shooting control unit 136 via the CCD controller 135.

  Subsequently, the imaging control unit 136 determines whether the sample image received from the CCD camera 112 is saturated. For example, when the specification of the CCD camera 112 defines that the luminance of the image is represented by 12 bits, the imaging control unit 136 determines whether or not the sample image includes a pixel of luminance “4095”. Then, when the sample image includes a pixel with luminance “4095”, the imaging control unit 136 determines that the sample image is saturated.

  The reason for determining whether or not the sample image is saturated is that if the luminance of the sample image is saturated, the magnitude relationship of the luminance of each sample cannot be accurately grasped. For example, even when the brightness of the sample image B is larger than the brightness of the sample image A, if the exposure time is too long, the brightness of the sample image A and the sample image B is the maximum value (in the above example, the brightness “ 4095 "), they look the same. Therefore, the screening apparatus 100 makes it possible to accurately grasp the magnitude relationship of the brightness of each sample by using a sample image whose brightness is not saturated.

  When the sample image is saturated, the imaging control unit 136 sets the exposure time to be shorter than when the previous instruction was given. Then, the imaging control unit 136 instructs the CCD controller 135 to image the microarray chip C10 when the exposure time has elapsed. The imaging control unit 136 instructs the CCD controller 135 to image the microarray chip C10 while gradually shortening the exposure time until the sample image is no longer saturated.

  If the sample image is not saturated, the imaging control unit 136 instructs the stage controller 115 to move the stage 101 to another imaging position. Similarly to the above example, when it is determined that the shooting positions H11, H12,..., H32, and H33 are shot in this order, the shooting control unit 136 causes the stage 101 to set the shooting position to the shooting position H12. To move.

  Then, the photographing control unit 136 sets the exposure time to an initial value, and instructs the CCD controller 135 to photograph the microarray chip C10 when the exposure time has elapsed. Subsequently, the imaging control unit 136 performs processing for determining whether or not the above-described sample image is saturated. The imaging control unit 136 repeatedly performs the stage movement process, the process for setting the exposure time, and the process for determining whether or not it is saturated until the microarray chip C10 is imaged at all imaging positions.

  Next, background photographing processing by the photographing control unit 136 will be described. When acquiring the background image, the imaging control unit 136 instructs the stage controller 115 to move the stage 101 so that the arrangement pattern of the wells in the imaging range becomes the basic pattern. For example, as in the example illustrated in FIG. 2, when the screening apparatus 100 generates a background image, it is determined in advance that the microarray chip C10 is imaged at the imaging positions H11, H13, H31, and H33. To do. Further, it is assumed that the screening apparatus 100 is determined to shoot in the order of the shooting positions H11, H13, H31, and H33 when acquiring the background image. In such a case, the imaging control unit 136 instructs the stage 101 to move so that the imaging position becomes the imaging position H11.

  The stage controller 115 that has received such an instruction moves the stage 101. Subsequently, the imaging control unit 136 instructs the CCD controller 135 to image the microarray chip C10 when a predetermined exposure time has elapsed. At this time, the photographing control unit 136 designates a plurality of exposure times (for example, 1, 2, 4,... 1024 [ms]), and photographs the microarray chip C10 every time the designated exposure time elapses. To instruct.

  Each time the designated exposure time elapses, the CCD camera 112 captures the microarray chip C10 to generate a background image, and transmits the generated background image to the imaging control unit 136. Then, the imaging control unit 136 associates the background image received from the CCD camera 112, the exposure time of the background image, and the pattern type indicating the well arrangement pattern of the background image, and stores them in the background image storage unit 133b. Let

  Subsequently, the imaging control unit 136 instructs the stage controller 115 to move the stage 101 so that the well arrangement pattern in the imaging range becomes an unphotographed basic pattern. Similarly to the above example, when it is determined that the shooting positions H11, H13, H31, and H33 are shot in this order, the shooting control unit 136 moves the stage 101 so that the shooting position becomes the shooting position H13. To instruct. The imaging control unit 136 instructs the CCD controller 135 to image the microarray chip C10 until background images are acquired for all basic patterns.

  The background photographing process by the photographing control unit 136 will be described using the example shown in FIG. Here, first, it is assumed that the background image is acquired by photographing the microarray chip C10 at the photographing position H11. First, the imaging control unit 136 instructs the stage controller 115 to move the stage 101 so that the imaging position becomes the imaging position H11.

  After the stage 101 has moved, the imaging control unit 136 has passed an exposure time of 1 [ms], 2 [ms], 4 [ms],..., 1024 [ms] with respect to the CCD controller 135, for example. In this case, the microarray chip C10 is instructed to be photographed. The CCD camera 112 that has received such an instruction from the CCD controller 135 shoots the microarray chip C10 every time the exposure time 1 [ms], 2 [ms], 4 [ms],... 1024 [ms] elapses. To generate a background image.

  Then, when receiving a background image shot with an exposure time of 1 [ms] from the CCD camera 112, the shooting control unit 136 receives the background image file name, the exposure time of 1 [ms], and the pattern type “ “PT1” is associated with and stored in the background image storage unit 133b. Similarly, every time a background image is received, the imaging control unit 136 causes the background image storage unit 133b to store the background image and the like.

  Here, the reason for acquiring a plurality of background images having different exposure times will be described. As described above, when acquiring the sample image, the imaging control unit 136 changes the exposure time until the luminance of the sample image is not saturated. Therefore, the exposure time may vary depending on the sample image. When removing background noise from the sample image, the screening apparatus 100 desirably uses a background image whose exposure time matches the exposure time of the sample image. This is because the background noise changes depending on the exposure time.

  This will be specifically described with reference to FIG. FIG. 8 is a diagram showing the relationship between the brightness of the sample image and the exposure time. In FIG. 8, a graph L10 indicates the luminance of the sample image. A graph N11 shows the luminance that appears due to noise of the image sensor. A graph N12 shows the fluorescence brightness of the microarray chip C10 itself. As shown in FIG. 8, the brightness of the sample image increases as the exposure time increases. Further, the longer the exposure time, the higher the luminance that appears due to the noise of the image sensor and the fluorescence luminance of the microarray chip C10 itself.

  For this reason, the imaging control unit 136 acquires a plurality of background images having different exposure times so that a background image captured at the same or approximate exposure time as the exposure time of the sample image can be used.

  The removal unit 137 removes background noise from the sample image generated by the imaging control unit 136. Specifically, the removal unit 137 first acquires the pattern type of the sample image from the pattern correspondence storage unit 133a. Subsequently, the removal unit 137 acquires a background image stored in association with the pattern type of the sample image from the background image storage unit 133b. Further, the removal unit 137 selects a background image whose exposure time is equal to or shorter than the exposure time of the sample image and a background image whose time is equal to or longer than the exposure time of the sample image from the acquired background images.

  Subsequently, the removing unit 137 calculates a background image corresponding to the exposure time of the sample image by interpolating the two selected background images. Specifically, the removal unit 137 calculates a background image corresponding to the exposure time of the sample image by the following equation (1). Hereinafter, the background image corresponding to the exposure time of the sample image is referred to as “background image Bs”, and the two background images selected by the removal unit 137 are referred to as “background image B (j)” and “background image”. B (j + 1) ".

  Is = Ia + {Ts−Tb (j)} / {Tb (j + 1) −Tb (j)} × (Ib−Ia) (1)

  In the above formula (1), Is indicates the luminance of the predetermined pixel Ps of the background image Bs. Ia indicates the luminance of the pixel Pa of the background image B (j) corresponding to the pixel Ps. Ib indicates the luminance of the pixel Pb of the background image B (j + 1) corresponding to the pixel Ps. Ts indicates the exposure time of the sample image. Tb (j) represents the exposure time of the background image B (j). Tb (j + 1) indicates the exposure time of the background image B (j + 1).

  The removing unit 137 calculates the luminance of all the pixels of the background image Bs using the above equation (1). Then, the removal unit 137 subtracts the calculated luminance of the background image for each pixel from the luminance of the sample image.

  The background removal processing by the removal unit 137 will be described using the example shown in FIG. FIG. 9 is a diagram for explaining an example of background removal processing by the removal unit 137. Here, a case where background noise of the sample image S12 shown in FIG. 3 is removed will be described as an example. It is assumed that the exposure time Ts of the sample image S12 is 820 [ms]. The background image storage unit 133b is assumed to be in the state shown in FIG.

  In such a case, the removal unit 137 first acquires the pattern type “PT1” of the sample image S12 (imaging position H12) from the pattern correspondence storage unit 133a. Subsequently, the removal unit 137 acquires background images B1 (1) to B1 (11) whose pattern type matches the pattern type “PT1” of the sample image S12 from the background image storage unit 133b. Furthermore, the removal unit 137, for example, from among the background images B1 (1) to B1 (11), for example, the background image B1 (10) whose exposure time is equal to or shorter than the exposure time Ts and the background image whose exposure time is equal to or longer than Ts. B1 (11) is selected. Then, the removing unit 137 linearly interpolates the background image B1 (10) and the background image B1 (11) to calculate a background image B11s corresponding to the exposure time Ts (820 [ms]).

  Specifically, as illustrated in FIG. 9, the removing unit 137 substitutes the luminance I11a of the pixel P11a and the luminance I11b of the pixel P11b corresponding to the pixel P11a into the above formula (1), thereby obtaining the background image B11s. The luminance I11s at the pixel P11s is calculated. Similarly, the removal unit 137 calculates the luminance of all the pixels of the background image B11s.

  Then, the removal unit 137 subtracts the luminance of the background image B11s for each pixel from the luminance of the sample image S12. Accordingly, the removing unit 137 can remove background noise from the sample image S12 using the background image B11s corresponding to the exposure time Ts (820 [ms]) of the sample image S12.

  If the background image stored in the storage unit 133 has a background image whose exposure time matches the exposure time of the sample image, the removal unit 137 uses the background image. Remove background noise from the sample image. In such a case, the removal unit 137 does not perform a process of calculating a background image corresponding to the exposure time of the sample image.

  The shading correction unit 138 performs shading correction on the sample image from which the background noise has been removed by the removal unit 137. Specifically, the shading correction unit 138 divides the shading coefficient calculated in advance by the luminance of each pixel of the sample image from which the background noise has been removed by the removal unit 137.

  The shading will be briefly described with reference to FIG. As shown in FIG. 10, shading is caused by factors such as (A) unevenness of the light source (fluorescent lamp 107), (B) error in the position of the lens and the light source, and (C) (D) cos 4th power law. A phenomenon in which a mismatch occurs between the original luminance of an image and a video signal. For example, when shading occurs, the peripheral part of the captured image becomes darker than the central part. The shading correction unit 138 corrects the luminance distortion due to such shading using a shading coefficient calculated in advance.

  Here, a method for calculating a shading coefficient will be briefly described with reference to FIGS. FIG. 11A to FIG. 11D are diagrams for explaining a method for calculating a shading coefficient.

  First, the screening apparatus 100 generates a background image of the microarray chip C10. Subsequently, the screening apparatus 100 irradiates the microarray chip C10 on which a homogeneous substance is arranged with excitation light, images the microarray chip C10, and generates a fluorescent image. FIG. 11A illustrates an example of the luminance distribution of the fluorescent image.

  Subsequently, the screening apparatus 100 removes background noise from the generated fluorescent image. FIG. 11B illustrates an example of the luminance distribution of the fluorescent image from which background noise has been removed. Subsequently, the screening apparatus 100 extracts only the influence of the light source and the optical system by performing function approximation or averaging processing on each pixel of the fluorescence image. FIG. 11C illustrates an example of the luminance distribution of the fluorescent image in which only the influence of the light source and the optical system is extracted.

  Then, the screening apparatus 100 calculates a shading coefficient by normalizing the maximum luminance value as “1” for the fluorescent image from which only the influence of the light source and the optical system is extracted. FIG. 11-4 illustrates an example of a fluorescent image that has been subjected to shading correction.

  Returning to the description of FIG. 5, the classification unit 139 calculates the luminance of the sample from the sample image subjected to the shading correction by the shading correction unit 138, and classifies the sample based on the calculated luminance. Specifically, the classification unit 139 extracts an image including a well and a slightly wider range than the well from the sample image, and calculates the sum of the luminances of the extracted images. At this time, it is preferable that the classification unit 139 extracts an image of a slightly larger range than the well from the sample image so as not to include an adjacent well. For example, the classification unit 139 extracts an image included in a circle whose middle point is the center of the well and whose diameter is 1.5 times the diameter of the well, and calculates the total luminance of the extracted images.

  Subsequently, the classification unit 139 normalizes the luminance sum Is by the following equation (2).

  Is = I × T0 / Tb (2)

  In the above formula (2), I represents the sum of the luminances calculated by the classification unit 139, T0 represents the reference exposure time, and Tb represents the exposure time for the sample.

  For example, it is assumed that the exposure time Tb for the sample C1 is 1000 [ms], and the total luminance of the image including the sample C1 is 200. Further, for example, it is assumed that the exposure time Tb for the sample C2 is 500 [ms], and the total luminance of the image including the sample C2 is 200. When the reference exposure time T0 is “100”, the total luminance of the sample C1 is normalized to 200 × 100/1000 = 20 by the above equation (2). Further, the total luminance of the sample C2 is normalized to 200 × 100/500 = 40.

  Then, the sorting unit 139 sorts the sample based on the normalized luminance sum. For example, the sorting unit 139 sorts the samples in the order of high luminance, or sorts the samples for each predetermined range of luminance.

  Here, the reason why the classification unit 139 extracts an image of a slightly wider range than the well will be described. The screening apparatus 100 changes the imaging position by moving the stage 101. That is, if there is an error in the positioning accuracy of the stage 101, an error may occur between the well position in the background image and the well position in the sample image. When such an error occurs, even if an image corresponding to the size of the well is extracted from the sample image, there is a possibility that background noise is not correctly removed from the extracted image. In such a case, the classification unit 139 cannot correctly calculate the luminance of the sample. Therefore, the classification unit 139 absorbs the variation in the position of the well by extracting an image of a slightly wider range than the well. Thereby, the classification | category part 139 can calculate the brightness | luminance of a sample correctly.

  The case where the luminance of the sample C11 shown in FIG. 3 is calculated will be described as an example with reference to FIGS. 12-1 and 12-2. 12A and 12B are diagrams for explaining an example of the sorting process by the sorting unit 139. FIG. FIG. 12A shows a case where there is no error in the positioning accuracy of the stage 101. FIG. 12-2 shows a case where there is an error in the positioning accuracy of the stage 101.

  In the example shown in FIGS. 12A and 12B, the sorting unit 139 is included in a circle whose midpoint is the center of the well W11-6 and whose diameter is larger than the diameter of the well W11-6 by a predetermined value. Images to be extracted. In the example illustrated in FIGS. 12A and 12B, the image S11-6 is a part of the sample image. The image B11-6 is a part of the background image. The image S′11-6 is a part of the sample image from which the background noise is removed by the removing unit 137 and the shading correction is performed by the shading correcting unit 138.

  Here, the sample image S11-6 shown in FIG. 12A and the sample image S11-6 shown in FIG. This is because the fluorescence of the sample C11 and the fluorescence of the well W11-6 are included in both sample images S11-6 without being lost. The background image B11-6 shown in FIG. 12A and the background image B11-6 shown in FIG. This is because the fluorescence of the well W11-6 is included in both the background images B11-6 without loss. Therefore, the image S′11-6 illustrated in FIG. 12A and the image S′11-6 illustrated in FIG. As described above, the sorting unit 139 extracts an image in a range slightly wider than the well, so that the sample can be correctly sorted even when there is an error in the positioning accuracy of the stage 101.

[Processing Procedure by Screening Apparatus According to Embodiment 1]
Next, the procedure of the sample separation process performed by the screening apparatus 100 according to the first embodiment will be described with reference to FIG. FIG. 13 is a flowchart illustrating the procedure of the sample separation process performed by the screening apparatus 100 according to the first embodiment.

  As illustrated in FIG. 13, the screening apparatus 100 starts the process when an instruction to start the process is received after the culture solution is dropped onto the microarray chip C10 (Yes in step S101). Specifically, the stage controller 115 of the screening apparatus 100 moves the stage 101 according to an instruction from the imaging control unit 136 so that the well arrangement pattern in the imaging range becomes a basic pattern (step S102).

  Subsequently, the shutter controller 116 opens the shutter 108 and irradiates the microarray chip C10 with excitation light (step S103). Subsequently, the shooting control unit 136 performs background shooting processing for acquiring a background image (step S104). The background photographing process will be described later in detail with reference to FIG. Subsequently, the shutter controller 116 closes the shutter 108 and blocks the excitation light (step S105).

  If all the basic patterns have not been photographed (No at Step S106), the stage controller 115 follows the instruction from the photographing control unit 136 so that the arrangement pattern of the wells in the photographing range becomes an unphotographed basic pattern. The stage 101 is moved (step S102). The subsequent processing is the same as the processing procedure in steps S103 to S105. On the other hand, when all the basic patterns have been photographed (Yes at step S106), the screening apparatus 100 performs the processing at the next processing procedure step S107.

  Specifically, after the sample is dropped onto the microarray chip C10 (step S107), the stage controller 115 moves the stage 101 to a predetermined position in accordance with an instruction from the imaging control unit 136 (step S108). At this time, the stage controller 115 moves the stage 101 so that the arrangement pattern of the wells in the imaging range becomes one of the basic patterns.

  Subsequently, the screening apparatus 100 sets the exposure time Ts to the initial value 1024 [ms] (step S109). FIG. 13 shows an example in which the initial value of the exposure time Ts is set to 1024 [ms], but the initial value of the exposure time Ts is not limited to this, for example, 2048 [ms], 512 [ms], 1000 [Ms] may be used.

  Subsequently, the shutter controller 116 opens the shutter 108 and irradiates the microarray chip C10 with excitation light. Subsequently, the photographing control unit 136 instructs the CCD controller 135 to photograph the microarray chip C10 when the exposure time Ts (1024 [ms]) has elapsed. The CCD camera 112 receives an instruction from the CCD controller 135, and when the exposure time Ts (1024 [ms]) has elapsed, the CCD camera 112 captures the microarray chip C10 and generates a sample image S. Then, the imaging control unit 136 acquires the sample image S from the CCD camera 112 (step S110).

  Subsequently, when the acquired sample image S is saturated (Yes at Step S111), the imaging control unit 136 sets the exposure time Ts to be shorter than the exposure time at the previous imaging (Step S112). Here, the photographing control unit 136 sets the exposure time Ts to a value 820 [ms] obtained by multiplying the exposure time 1024 [ms] at the previous photographing by 0.8. Subsequently, the imaging control unit 136 instructs the CCD controller 135 to image the microarray chip C10 when the exposure time Ts (820 [ms]) has elapsed, and acquires the sample image S (Step S1). S110).

  The imaging control unit 136 repeats the processes in steps S110 to S112 until the sample image S is no longer saturated. Note that FIG. 13 shows an example in which when the exposure time Ts is shortened, the exposure time at the previous photographing is multiplied by 0.8. However, the degree of shortening the exposure time Ts is not limited to this. For example, the shooting control unit 136 may multiply the exposure time at the previous shooting by 0.9, or may subtract 100 [ms] from the exposure time at the previous shooting.

  If the sample image S is not saturated (No at Step S111), the removal unit 137 performs background removal processing for removing background noise from the sample image S (Step S113). The background removal process will be described in detail later with reference to FIG.

  Subsequently, the shading correction unit 138 performs shading correction on the sample image S from which the background noise has been removed by the removal unit 137 (step S114).

  When the microarray chip C10 is not photographed at all photographing positions (No at Step S115), the stage controller 115 moves the stage 101 so that the photographing position becomes an unphotographed photographing position (Step S108). The imaging control unit 136 repeats the processes in steps S108 to S115 until the microarray chip C10 is imaged at all imaging positions.

  When the microarray chip C10 is photographed at all photographing positions (Yes at step S115), the classification unit 139 determines that the midpoint is the center of the well and the diameter is the diameter of the well from the sample image corrected by the shading correction unit 138. An image included in a circle that is 1.5 times as large is extracted, and the sum of the luminances of the extracted images is calculated (step S116). FIG. 13 shows an example in which the classification unit 139 extracts an image included in a circle whose diameter is 1.5 times the diameter of the well, but the range of the image extracted by the classification unit 139 is not limited to this. . For example, the classification unit 139 may extract an image included in a circle whose midpoint is the center of the well and whose diameter is 1.2 times the diameter of the well, or when the diameter is twice the diameter of the well. Images included in a certain circle may be extracted.

  Then, the sorting unit 139 sorts the sample based on the normalized sum of luminances after normalizing the calculated sum of luminances with a predetermined reference exposure time (step S117).

[Background processing]
Next, the background photographing process in step S104 of FIG. 13 will be described in detail with reference to FIG. FIG. 14 is a flowchart illustrating a procedure of background photographing processing by the photographing control unit 136. Note that the processing procedure shown in FIG. 14 is performed for each basic pattern.

  As shown in FIG. 14, the imaging control unit 136 first sets the exposure time Tb (i) to 1 [ms] (step S201). Here, it is assumed that the initial value of the counter i is “1”. That is, the imaging control unit 136 sets the exposure time Tb (1) to 1 [ms]. FIG. 14 shows an example in which the exposure time Tb (1) is 1 [ms]. However, the value of the exposure time Tb (1) is not limited to this, and for example, 2 [ms], 10 [ms], etc. But you can.

  Subsequently, the photographing control unit 136 instructs the CCD controller 135 to photograph the microarray chip C10 when the exposure time 1 [ms] (Tb (1)) has elapsed. The CCD camera 112 receives an instruction from the CCD controller 135, and when the exposure time of 1 [ms] (Ts) has elapsed, captures the microarray chip C10 and generates a background image B (i).

  Then, the imaging control unit 136 acquires the background image B (i) from the CCD camera 112 (step S202), and sets the acquired background image B (i), exposure time, and pattern type of the background image B (i) as the background. The image is stored in the image storage unit 133b.

  Subsequently, when the exposure time Tb (i) is not 1024 [ms] or more (No at Step S203), the imaging control unit 136 is a value obtained by multiplying the exposure time Tb (i + 1) by 2 by the exposure time Tb (i). A certain 2 [ms] is set (step S204).

  Subsequently, the photographing control unit 136 instructs the CCD controller 135 to photograph the microarray chip C10 when the exposure time 2 [ms] (Tb (i + 1)) has elapsed. Then, the imaging control unit 136 acquires the background image B (i + 1) from the CCD camera 112 (step S202).

  The shooting control unit 136 sets the exposure time Tb (i + 1) to a value obtained by multiplying the exposure time Tb (i) at the previous shooting by 2 until the exposure time Tb (i) becomes 1024 [ms] or more ( Step S204), the background image B (i + 1) is acquired (Step S202).

  When the exposure time Tb is 1024 [ms] or longer (Yes at Step S203), the imaging control unit 136 ends the process. In the example illustrated in FIG. 14, the imaging control unit 136 acquires background images B (1), B (2),..., B (11).

  Although FIG. 14 shows an example in which the background image is acquired while doubling the exposure time, the imaging control unit 136 may acquire the background image while increasing the exposure time by 1.5 times or 3 times. Good. FIG. 14 shows an example in which the imaging process is repeated until the exposure time reaches 1024 [ms] or more. However, the imaging control unit 136 sets the exposure time to 500 [ms] or more, or 2000 [ms] or more. The imaging process may be repeated until

[Background removal]
Next, the background removal process in step S113 of FIG. 13 will be described in detail with reference to FIG. FIG. 15 is a flowchart showing the procedure of background removal processing by the removal unit 137. Here, it is assumed that the background image storage unit 133b stores the background images B (1), B (2),..., B (11) described with reference to FIG. .

  As shown in FIG. 15, the removal unit 137 first selects a background image in which the well arrangement pattern matches the well arrangement pattern in the sample image S from the background image storage unit 133b (step S301). Further, the removing unit 137 includes a background image B (j) that satisfies the condition “Tb (j) ≦ Ts ≦ Tb (j + 1)” between the exposure time Ts of the sample image S and the exposure time Tb of the background image B. B (j + 1) is selected (step S302).

  Subsequently, the removing unit 137 calculates a background image Bs corresponding to the exposure time Ts of the sample image S using the background images B (j) and B (j + 1). Specifically, the removal unit 137 calculates the luminance Ia at a predetermined pixel Pa of the background image B (j) and the luminance Ib at the pixel Pb of the background image B (j + 1) corresponding to the pixel Pa by the above formula (1). Assign to. Thereby, the removal unit 137 calculates the luminance Is at the pixel Ps of the background image Bs corresponding to the pixels Pa and Pb (step S303).

  Subsequently, the removing unit 137 subtracts the luminance Is calculated in step S303 from the luminance in the pixel of the sample image S corresponding to the pixels Pa and Pb (step S304). When the subtracting process is not performed on all the pixels of the sample image S (No at Step S305), the removing unit 137 moves the processing target pixel to the next pixel (Step S306), and the above Steps S303 to S306. The process in is repeated.

  And the removal part 137 complete | finishes a process, when the said subtraction process is performed with respect to all the pixels of the sample image S (step S305 affirmation).

[Effect of Example 1]
As described above, the screening apparatus 100 according to the first embodiment stores one background image for each pattern type in the background image storage unit 133b in association with the pattern type. Then, the screening apparatus 100 removes background noise from the sample image using a background image whose pattern type is the same as the pattern type of the sample image. Thereby, the screening apparatus 100 according to the first embodiment can reduce the number of background images. As a result, the screening apparatus 100 can shorten the photographing time for generating the background image without squeezing the storage capacity.

  In particular, when shooting a plurality of background images having different exposure times as in the above example, if the microarray chip is shot at all shooting positions as in a conventional screening apparatus, the number of background images becomes enormous. On the other hand, in the screening apparatus 100 according to the first embodiment, the background images having the same pattern type are stored without being overlapped. Therefore, even when shooting a plurality of background images having different exposure times, the number of background images Can be reduced to several tens.

  In addition, the screening apparatus 100 according to the first embodiment generates a background image by changing the exposure time. Then, the screening apparatus 100 removes background noise from the sample image using a background image whose exposure time matches the exposure time of the sample image. Thereby, the screening apparatus 100 according to the first embodiment can accurately remove background noise from the sample image.

  In addition, the screening apparatus 100 according to the first embodiment interpolates a plurality of background images according to the exposure time when there is no background image whose exposure time matches the exposure time of the sample image, thereby obtaining the exposure time of the sample image. The corresponding background image is calculated. Then, the background noise is removed from the sample image using the calculated background image. Thereby, the screening apparatus 100 according to the first embodiment can accurately remove background noise from the sample image even when there is no background image whose exposure time matches the exposure time of the sample image.

  In addition, the screening apparatus 100 according to the first embodiment extracts the image of the sample image from which the background noise has been removed, which includes a well and is slightly wider than the well, and sums the luminance of the extracted image. The sample is sorted based on Thereby, the screening apparatus 100 according to the first embodiment can correctly sort the sample even when there is an error in the positioning accuracy of the stage 101.

  In the first embodiment, the case where the well arrangement pattern is a lattice has been described as an example (see FIG. 1). However, in the imaging apparatus disclosed in the present application, the well arrangement pattern is other than the lattice. Can also be applied. For example, the imaging device disclosed in the present application can be applied even if the well arrangement pattern is a staggered pattern. FIG. 16 shows an example of a microarray chip whose well arrangement pattern is a staggered pattern. In the example shown in FIG. 16, for example, the well arrangement pattern at the photographing positions H111, H112, H114, H121, H122, H124, H131, H134, H141, H142, and H144 corresponds to the basic pattern. In other words, the screening apparatus 100 captures the microarray chip C20 at the photographing positions H111, H112, H114, H121, H122, H124, H131, H134, H141, H142, and H144 to generate a background image. Thereby, the screening apparatus 100 can remove background noise from the sample image. Since the basic pattern varies depending on the shooting range, the basic pattern described above is merely an example.

  In the first embodiment, an example in which a plurality of background images with different exposure times is generated has been shown. However, in the case of a system that acquires a sample image with a constant exposure time, the screening apparatus 100 performs each exposure time. The background image may not be generated.

  In the first embodiment, when the sample photographing process is performed, an example in which the microarray chip C10 is photographed at all photographing positions has been described. However, the screening apparatus 100 does not photograph the microarray chip C10 at all photographing positions. May be. For example, when the screening apparatus 100 recognizes in advance the well in which the sample is disposed, the screening apparatus 100 may photograph the microarray chip C10 only at the photographing position including the well in which the sample is disposed.

  In the first embodiment, the background image is generated on the premise that the shooting position at which the microarray chip C10 is shot is determined in advance. However, when the background image is generated, the screening apparatus 100 uses the background image to remove noise from the sample image even if the shooting position at which the microarray chip C10 is shot is not predetermined. The number of can be reduced. Hereinafter, two examples of the processing performed by the screening apparatus 100 when the photographing position for photographing the background image is not predetermined will be described.

  First, a first processing example will be described using the example shown in FIG. For example, the screening apparatus 100 images the microarray chip C10 at all the imaging positions H11 to H13, H21 to H23, and H31 to H33, and generates a background image for each imaging position. Then, the screening apparatus 100 causes the background image storage unit 133b to store one background image for each pattern type of the well arrangement pattern among the generated background images. That is, after generating background images at all shooting positions, the screening apparatus 100 discards overlapping background images and stores the minimum necessary background images in the background image storage unit 133b. By processing in this way, the screening apparatus 100 can reduce the number of background images.

  Next, a second processing example will be described using the example shown in FIG. When the background image is generated, the screening apparatus 100 determines whether the well arrangement pattern at the photographing position is the same as the well arrangement pattern of the already generated background image. When the well arrangement patterns are the same, the screening apparatus 100 does not perform the photographing process and does not generate a background image. On the other hand, when the well arrangement patterns are not the same, the screening apparatus 100 performs a photographing process to generate a background image. By processing in this way, the screening apparatus 100 can reduce the number of background images.

  In the first embodiment, an example in which background images are generated as many as the number of basic patterns is shown. However, the imaging apparatus disclosed in the present application can also perform sample separation processing using one background image. Therefore, in the second embodiment, an example in which sample separation processing is performed using one background image will be described.

[Sample separation process by screening apparatus according to Example 2]
First, the sample separation process by the screening apparatus 200 according to the second embodiment will be described. The screening apparatus 200 according to the second embodiment stores an arbitrary well, and stores a background image (hereinafter referred to as “well background image”) in a slightly wider range than the well. Then, the screening apparatus 200 generates a background image corresponding to the sample image using the well background image, and removes background noise of the sample image using the generated background image.

  The sample separation process described above will be specifically described with reference to FIGS. FIG. 17 is a diagram for explaining the sample separation process by the screening apparatus 200 according to the second embodiment. The screening apparatus 200 first shoots the microarray chip C10 at an arbitrary shooting position without irradiating the microarray chip C10 with excitation light, and generates a shot image.

  Here, as shown in FIG. 17, the screening apparatus 200 captures the microarray chip C10 at the capturing position H11 and generates a captured image. Hereinafter, an image of the microarray chip C10 taken in a state where the excitation light is blocked is referred to as a “dark noise image”. FIG. 18A shows an example of a dark noise image. The dark noise image U11 illustrated in FIG. 18A includes noise of the image sensor as in the image illustrated in FIG.

  Subsequently, the screening apparatus 200 moves the stage 101 so that an arbitrary well is positioned at the center of the imaging range, and then images the microarray chip C10 to generate a background image. Here, as shown in FIG. 17, the screening apparatus 200 shoots the microarray chip C10 at the shooting position H11 where the well W11-5 is located at the center of the shooting position H11 to generate a background image.

  Subsequently, the screening apparatus 200 extracts a well background image from the generated background image, and stores the extracted well background image in the storage unit 133. FIG. 18-2 shows an example of a well background image. In the example illustrated in FIG. 18B, the screening apparatus 200 divides the background image B11 into nine equal parts, and among the images divided into nine equal parts, the well background image WB11-5 including the well W11-5 is stored in the storage unit 133. Remember me.

  The screening apparatus 200 generates a background image corresponding to an arbitrary shooting position based on the dark noise image U11 and the well background image WB11-5 acquired in this way. Here, background image generation processing by the screening apparatus 200 will be described.

  First, the screening apparatus 200 generates an image obtained by subtracting the luminance of the dark noise image U11 for each pixel from the luminance of the well background image WB11-5. Hereinafter, an image obtained by subtracting the luminance of the dark noise image from the luminance of the well background image will be referred to as a “chip fluorescence image”.

  Such a chip fluorescence image is an image including only the fluorescence of the microarray chip C10 itself. More specifically, the dark noise image U11 includes noise of the image sensor. On the other hand, the well background image WB11-5 includes noise of the image sensor and fluorescence of the microarray chip C10 itself. Therefore, the screening apparatus 200 can generate a chip fluorescence image including only the fluorescence of the microarray chip C10 itself by subtracting the luminance of the dark noise image U11 for each pixel from the luminance of the well background image WB11-5. .

  Here, since the fluorescence of the microarray chip C10 itself is uniform within the imaging range, it can be said that the luminance of the chip fluorescence image indicates the luminance of the fluorescence of the microarray chip C10 itself within one imaging range. That is, it can be said that the screening apparatus 200 can obtain the fluorescence of the microarray chip C10 itself within one imaging range using the chip fluorescence image.

  However, the fluorescence of the microarray chip C10 itself inherently includes luminance distortion due to shading. Therefore, even if the luminance of the chip fluorescent image is used as the fluorescent luminance of the microarray chip C10 itself within one photographing range, the luminance distortion due to shading is not considered.

  Therefore, the screening apparatus 200 obtains the fluorescence of the microarray chip C10 itself within one imaging range by multiplying and dividing the luminance of the chip fluorescence image by a shading coefficient. Thereby, the screening apparatus 200 can obtain fluorescence of the microarray chip C10 itself in consideration of luminance distortion due to shading.

  Then, the screening apparatus 200 generates a background image within one photographing range by adding the luminance of the dark noise image U11 for each pixel to the luminance of fluorescence in consideration of luminance distortion due to shading.

  Next, the background image generation process described above will be described in detail with reference to FIGS. 19 and 20. 19 and 20 are diagrams for explaining background image generation processing by the screening apparatus 200 according to the second embodiment. Hereinafter, a case where the background image B11 is generated using the dark noise image U11 and the well background image WB11-5 will be described as an example.

  First, the screening apparatus 200 extracts a dark noise image corresponding to the well background image WB11-5. Specifically, the screening apparatus 200 extracts the dark noise image U11-5 illustrated in FIG. 18A as the dark noise image corresponding to the well background image WB11-5. Then, the screening apparatus 200 subtracts the luminance of the dark noise image U11-5 for each pixel from the luminance of the well background image WB11-5 to generate a chip fluorescence image BU11-5.

  Subsequently, as shown on the left side of FIG. 19, the screening apparatus 200 calculates chip fluorescence images BU11-1 to BU11-4 and BU11-6 to BU11-9 using the chip fluorescence image BU11-5. Processing for calculating the chip fluorescence image BU11-1 using the chip fluorescence image BU11-5 will be described with reference to FIG.

  As shown in FIG. 20, the screening apparatus 200 divides the shading coefficient corresponding to the pixel P11-5a with respect to the luminance I11-5a of the predetermined pixel P11-5a of the chip fluorescence image BU11-5. Subsequently, the screening apparatus 200 multiplies the divided value by a shading coefficient corresponding to the pixel P11-1a of the chip fluorescence image BU11-1. Thereby, the screening apparatus 200 can calculate the luminance of the pixel P11-1a of the chip fluorescent image BU11-1. The screening apparatus 200 calculates the chip fluorescence image BU11-1 by performing the above process on all the pixels of the chip fluorescence image BU11-5. The screening apparatus 200 calculates chip fluorescence images BU11-2 to BU11-4 and BU11-6 to BU11-9 by performing the same processing.

  Returning to the explanation of FIG. 19, the screening apparatus 200 adds the luminance of the dark noise image U11 to the luminance of the chip fluorescent images BU11-1 to BU11-9 for each pixel. Thereby, the screening apparatus 200 can generate the background image B11 at the photographing position H11.

  The screening apparatus 200 may apply the background image generation processing using the dark noise image U11 and the well background image WB11-5 to other shooting positions (for example, the shooting positions H31 and H33 shown in FIG. 17). it can.

  As described above, since the screening apparatus 200 according to the second embodiment generates a background image using only one dark noise image and one well background image, the number of background images to be stored in advance is set. Can be less.

  In the above description, when generating a dark noise image, an example of shooting at the shooting position H11 shown in FIG. 17 has been shown. However, the screening apparatus 200 can be used at other shooting positions (for example, shooting positions H31 and H33). The microarray chip C10 may be photographed to generate a dark noise image.

  In the above description, the background image including the well W11-5 is used as the well background image. However, the screening apparatus 200 uses the background image including other wells (for example, wells W31-5 and W33-4). It may be a well background image.

  In the above description, the background image is divided into nine equal parts, and the middle image among the nine divided images is used as the well background image. However, the screening apparatus 200 may use any background image as a well background image as long as the background image includes an arbitrary well. For example, the screening apparatus 200 may equally divide the background image into an arbitrary number and may use an image including a predetermined well among the equally divided images as the well background image. Moreover, the screening apparatus 200 may use a background image of a predetermined region including an arbitrary well as a well background image without equally dividing the background image.

[Configuration of Screening Device 200 According to Example 2]
Next, the configuration of the screening apparatus 200 according to the second embodiment will be described. The configuration of the screening apparatus 200 according to the second embodiment includes an information processing apparatus 230 instead of the information processing apparatus 130 as compared with the configuration of the screening apparatus 100 illustrated in FIG. FIG. 21 shows the configuration of the information processing apparatus 230 in the second embodiment.

  As illustrated in FIG. 21, the information processing device 230 is different from the information processing device 130 illustrated in FIG. 5 in that a storage unit 233, a photographing control unit is used instead of the storage unit 133, the photographing control unit 136, and the removal unit 137. 236 and a removal unit 237.

  The storage unit 233 includes a well background image storage unit 233a. The well background image storage unit 233a stores a dark noise image and a well background image. The well background image storage unit 233a stores a well background image for each exposure time, which will be described in detail below using a flowchart.

  The imaging control unit 236 causes the CCD controller 135 to image the microarray chip C10 that is not irradiated with excitation light. Thereby, the imaging control unit 336 acquires the dark noise image U from the CCD camera 112, and stores the acquired dark noise image U in the well background image storage unit 233a. In addition, the imaging control unit 236 performs well background imaging processing for acquiring a well background image. The well background photographing process will be described later with reference to FIG.

  The removal unit 237 performs background image generation processing and background removal processing. Such background image generation processing and background removal processing will be described later with reference to FIG.

[Procedure for Sample Sorting by Screening Apparatus According to Example 2]
Next, a procedure of sample separation processing by the screening apparatus 200 according to the second embodiment will be described. FIG. 22 is a flowchart illustrating the procedure of the sample separation process performed by the screening apparatus 200 according to the second embodiment.

  As shown in FIG. 22, when an instruction to start processing is received after the culture solution is dropped on the microarray chip C10 (Yes at step S401), the stage controller 115 sets an arbitrary well at the center of the imaging range. The stage 101 is moved so that is positioned (step S402).

  Subsequently, the shutter controller 116 closes the shutter 108 and blocks the excitation light. Subsequently, the photographing control unit 236 instructs the CCD controller 135 to photograph the microarray chip C10. The CCD camera 112 receives an instruction from the CCD controller 135 and shoots the microarray chip C10 to generate a dark noise image U. Then, the photographing control unit 236 acquires the dark noise image U from the CCD camera 112 (step S403), and stores the acquired dark noise image U in the well background image storage unit 233a.

  Subsequently, the shutter controller 116 opens the shutter 108 and irradiates the microarray chip C10 with excitation light (step S404). Subsequently, the imaging control unit 236 performs well background imaging processing for acquiring a well background image (step S405). The well background photographing process will be described in detail later with reference to FIG. Subsequently, the shutter controller 116 closes the shutter 108 and blocks the excitation light (step S406).

  Subsequently, after the sample is dropped onto the microarray chip C10 (step S407), the stage controller 115 moves the stage 101 so that an arbitrary well is positioned at the center of the imaging range (step S408).

  Subsequently, the screening apparatus 200 sets the exposure time Ts to the initial value 1024 [ms] (step S409). Subsequently, the shutter controller 116 opens the shutter 108 and irradiates the microarray chip C10 with excitation light. Subsequently, the photographing control unit 236 instructs the CCD camera 112 to photograph the microarray chip C10 when the exposure time Ts (1024 [ms]) has elapsed. The CCD camera 112 receives an instruction from the CCD controller 135, and when the exposure time Ts (1024 [ms]) has elapsed, the CCD camera 112 captures the microarray chip C10 and generates a sample image S. Then, the imaging control unit 236 acquires the sample image S from the CCD camera 112 (step S410).

  Subsequently, when the acquired sample image S is saturated (Yes at Step S411), the imaging control unit 236 multiplies the exposure time Ts by 0.8 to the exposure time 1024 [ms] at the previous imaging. The value is set to 820 [ms] (step S412). Subsequently, the imaging control unit 236 instructs the CCD camera 112 to image the microarray chip C10 when the exposure time 820 [ms] has elapsed, and acquires the sample image S (step S410). . The imaging control unit 236 repeats the processes in steps S410 to S412 until the sample image S is no longer saturated.

  If the sample image S is not saturated (No at Step S411), the removal unit 237 performs background image generation processing and background removal processing (Step S413). The background image generation process and the background removal process will be described in detail later with reference to FIG.

  Subsequently, the shading correction unit 138 performs shading correction on the sample image S from which the background noise has been removed by the removal unit 237 (step S414).

  When all the imaging target wells have not been captured (No at step S415), the stage controller 115 moves the stage 101 so that the imaging target well is located in the imaging range (step S408). The screening apparatus 200 repeats the processes in steps S408 to S415 until all wells to be imaged are imaged.

  When all the wells to be imaged are photographed (Yes at step S415), the classification unit 139 determines that the center point is the center of the well and the diameter is 1. of the well diameter from the sample image corrected by the shading correction unit 138. An image included in a circle that is 5 times larger is extracted, and the sum of the luminances of the extracted images is calculated (step S416). Then, the sorting unit 139 sorts the sample based on the normalized sum of luminances after normalizing the calculated sum of luminances with a predetermined reference exposure time (step S417).

[Well background photography processing]
Next, the well background photographing process in step S405 of FIG. 22 will be described in detail with reference to FIG. FIG. 23 is a flowchart showing a procedure of well background photographing processing by the photographing control unit 236.

  As shown in FIG. 23, the imaging control unit 236 first sets the exposure time Tb (i) to 1 [ms] (step S501). Here, it is assumed that the initial value of the counter i is “1”. That is, the imaging control unit 236 sets the exposure time Tb (1) to 1 [ms].

  Subsequently, the imaging control unit 236 instructs the CCD controller 135 to image the microarray chip C10 when the exposure time 1 [ms] (Tb (1)) has elapsed. Then, the photographing control unit 236 acquires the background image B (i) from the CCD camera 112 (step S502). Subsequently, the imaging control unit 236 extracts a well background image WB (i) within a predetermined range from the acquired background image B (i) (step S503), and the extracted well background image WB (i) and exposure time. Are stored in the well background image storage unit 233a.

  Subsequently, when the exposure time Tb (i) is not 1024 [ms] or more (No in step S504), the imaging control unit 236 multiplies the exposure time Tb (i + 1) by 2 to the exposure time Tb (i). A certain 2 [ms] is set (step S505).

  Subsequently, the photographing control unit 236 instructs the CCD camera 112 to photograph the microarray chip C10 when the exposure time 2 [ms] (Tb (i + 1)) has elapsed. Then, the imaging control unit 236 acquires the background image B (i + 1) from the CCD camera 112 (step S502), and extracts the well background image WB (i + 1) from the background image B (i + 1) (step S503). Then, the imaging control unit 236 associates the well background image WB (i + 1) with the exposure time, and stores them in the well background image storage unit 233a.

  The shooting control unit 236 sets the exposure time Tb (i + 1) to a value obtained by multiplying the exposure time Tb (i) at the previous shooting by 2 until the exposure time Tb (i) becomes 1024 [ms] or more ( In step S505, a well background image WB (i + 1) is acquired (step S503).

  Then, when the exposure time Tb is 1024 [ms] or longer (Yes at Step S504), the imaging control unit 236 ends the process. In the example illustrated in FIG. 23, the imaging control unit 236 generates well background images WB (1), WB (2),..., WB (11).

[Background image generation processing and background removal processing]
Next, the background image generation processing and background removal processing in step S413 in FIG. 22 will be described in detail with reference to FIG. FIG. 24 is a flowchart illustrating a procedure of background image generation processing and background removal processing by the removal unit 237. Here, it is assumed that the imaging control unit 236 stores the well background images WB (1), WB (2),..., WB (11) described in FIG.

  As shown in FIG. 24, the removing unit 237 first selects the condition “Tb (j) between the exposure time Ts of the sample image S and the exposure time Tb of the well background image WB from the well background image storage unit 233a. Well background images WB (j) and WB (j + 1) satisfying “) ≦ Ts ≦ Tb (j + 1)” are selected (step S601).

  Subsequently, the removing unit 237 calculates the well background image WBs corresponding to the exposure time Ts of the sample image S using the well background images WB (j) and WB (j + 1) (step S602). Specifically, the removal unit 237 calculates the well background image WBs by linearly interpolating the luminance for each pixel, similarly to the processing procedure illustrated in FIG.

  Subsequently, the removing unit 237 extracts a dark noise image corresponding to the well background image WBs. For example, it is assumed that the well background image WB is the middle image obtained by dividing the background image into nine equal parts as in the example illustrated in FIG. In such a case, the removing unit 237 extracts the dark noise image U11-5 illustrated in FIG. 18A as the dark noise image corresponding to the well background image WBs.

  Subsequently, the removal unit 237 subtracts the luminance of the dark noise image (in the above example, the dark noise image U11-5) for each pixel from the luminance of the well background image WBs to generate a chip fluorescent image BUs (step S603). ).

  Subsequently, the removing unit 237 calculates the chip fluorescence image BU corresponding to the size of the imaging range using the chip fluorescence image BUs (step S604). Specifically, as shown in FIG. 20, the removal unit 237 divides the shading coefficient corresponding to the pixel with respect to the luminance of a predetermined pixel of the chip fluorescent image BUs. Subsequently, the removing unit 237 multiplies the divided value by a shading coefficient corresponding to the pixel of the chip fluorescence image to be calculated (in the example illustrated in FIG. 20, the chip fluorescence image BU11-1). The removal unit 237 calculates the chip fluorescence image BU by performing the above process on all the pixels of the chip fluorescence image BU.

  Subsequently, the imaging control unit 236 generates the background image B by adding the luminance of the dark noise image U for each pixel to the luminance of the chip fluorescent image BU (step S605). Then, the imaging control unit 236 subtracts the luminance of the background image B for each pixel from the luminance of the sample image S (step S606).

[Effect of Example 2]
As described above, the screening apparatus 200 according to the second embodiment generates a background image using only one dark noise image and one well background image. Then, the screening apparatus 200 removes background noise from the sample image using the generated background image. Thereby, the screening apparatus 200 according to the second embodiment can reduce the number of background images to be held in advance.

  In the first embodiment, the shading coefficient calculation method (FIGS. 11-1 to 11-4) has been described. The shading coefficient is calculated by a method other than the method shown in FIGS. 11-1 to 11-4. It may be calculated. Therefore, in the third embodiment, an example in which the shading coefficient is calculated by a method other than the method illustrated in FIGS. 11A to 11D will be described.

[Shading coefficient calculation processing in Embodiment 3]
First, a shading coefficient calculation process performed by the screening apparatus 300 according to the third embodiment will be described with reference to FIGS. 25-1 to 25-3. FIG. 25A is a diagram illustrating a distribution example of luminance that appears due to noise of the image sensor. As illustrated in FIG. 25A, the noise of the image sensor does not include luminance distortion due to shading. In the example illustrated in FIG. 25A, the noise of the image sensor is uniform in the image, but is actually non-uniform.

  FIG. 25B is a diagram of an example of luminance distribution of background noise. As illustrated in FIG. 25B, the background noise includes luminance distortion due to shading. Therefore, it is conceivable to calculate the shading coefficient from the luminance of the background noise as shown in FIG. However, the background noise includes noise of the image sensor. And the noise of this image pick-up element is non-uniform in an image. Therefore, an accurate shading coefficient cannot be calculated from the luminance of background noise as shown in FIG.

  Therefore, the screening apparatus 300 according to the third embodiment subtracts the luminance that appears due to the noise of the image sensor shown in FIG. 25-1 from the luminance of the background noise shown in FIG. The luminance showing only the fluorescence of C10 itself is obtained. FIG. 25-3 shows an example of the fluorescence luminance distribution of the microarray chip C10 itself. As shown in FIG. 25-3, the fluorescence of the microarray chip C10 itself includes luminance distortion due to shading and does not include noise of the image sensor.

  Then, the screening apparatus 300 calculates a shading coefficient based on the luminance representing the fluorescence of the microarray chip C10 itself shown in FIG. Specifically, the screening apparatus 300 calculates the shading coefficient of each pixel by setting the maximum value of the luminance representing the fluorescence of the microarray chip C10 itself as “1”.

  For example, in the example illustrated in FIG. 25C, the maximum luminance value is “1000”. In the example illustrated in FIG. 25C, it is assumed that the luminance of the pixel A is “1000”, the luminance of the pixel B is “500”, and the luminance of the pixel C is “100”. In such a case, the screening apparatus 300 sets the shading coefficient of the pixel A to “1”. Further, the screening apparatus 300 sets the shading coefficient of the pixel B to a value “0.5” obtained by dividing the luminance “500” of the pixel B by the luminance “1000” of the pixel A. Further, the screening apparatus 300 sets the shading coefficient of the pixel C to a value “0.1” obtained by dividing the luminance “100” of the pixel C by the luminance “1000” of the pixel A.

[Configuration of Screening Apparatus 300 According to Embodiment 3]
Next, the configuration of the screening apparatus 300 according to the third embodiment will be described. The configuration of the screening apparatus 300 according to the third embodiment is the same as that of the screening apparatus 100 shown in FIG. However, although illustration is omitted, the information processing apparatus 130 according to the third embodiment includes a shooting control unit 336 instead of the shooting control unit 136 illustrated in FIG. 5.

  The shooting control unit 336 performs the same processing as the shooting control unit 136 described in the first embodiment. Further, the shooting control unit 336 according to the third embodiment performs a shading coefficient calculation process. Specifically, the imaging control unit 336 causes the CCD controller 135 to image the microarray chip C10 that is not irradiated with excitation light. Thereby, the imaging control unit 336 acquires the dark noise image U from the CCD camera 112. Subsequently, the imaging control unit 336 moves the stage 101 so that the well is not located within the imaging range, and then causes the CCD controller 135 to image the microarray chip C10 irradiated with the excitation light. Thereby, the imaging control unit 336 acquires the background image B from the CCD camera 112. Then, the photographing control unit 336 subtracts the luminance of the dark noise image U for each pixel from the luminance of the background image B, and calculates a shading coefficient for each pixel based on the subtracted luminance.

[Shading coefficient calculation processing by screening apparatus according to embodiment 3]
Next, the procedure of the shading coefficient calculation process performed by the screening apparatus 300 according to the third embodiment will be described with reference to FIG. FIG. 26 is a flowchart illustrating a shading coefficient calculation processing procedure performed by the screening apparatus 300 according to the third embodiment.

  As shown in FIG. 26, first, the shutter controller 116 of the screening apparatus 300 closes the shutter 108 and blocks the excitation light (step S701). Subsequently, the imaging control unit 336 instructs the CCD controller 135 to image the microarray chip C10, and acquires the dark noise image U from the CCD camera 112 (step S702).

  Subsequently, the stage controller 115 moves the stage 101 so that the well is not located within the imaging range (step S703). Subsequently, the shutter controller 116 opens the shutter 108 and irradiates the microarray chip C10 with excitation light (step S704).

  Subsequently, the photographing control unit 336 instructs the CCD controller 135 to photograph the microarray chip C10, and acquires the background image B from the CCD camera 112 (step S705). Subsequently, the shutter controller 116 closes the shutter 108 and blocks the excitation light (step S706).

  Subsequently, the imaging control unit 336 subtracts the luminance of the dark noise image U for each pixel from the luminance of the background image B (step S707). The imaging control unit 336 calculates a shading coefficient for each pixel based on the subtracted luminance (step S708).

[Effect of Example 3]
As described above, the screening apparatus 300 according to the third embodiment subtracts the luminance of the dark noise image for each pixel from the luminance of the background image, and calculates a shading coefficient for each pixel based on the subtracted luminance. Thereby, the screening apparatus 300 can calculate an accurate shading coefficient.

  By the way, the imaging device disclosed in the present application may be implemented in various different forms other than the above-described embodiments. Therefore, in the fourth embodiment, another embodiment of the photographing apparatus disclosed in the present application will be described.

[System configuration, etc.]
Among the processes described in the first to third embodiments, all or a part of the processes described as being automatically performed can be manually performed, or the processes described as being manually performed. All or a part of the above can be automatically performed by a known method. In addition, the processing procedure, control procedure, specific name, and information including various data and parameters shown in the above-mentioned document and drawings can be arbitrarily changed unless otherwise specified.

  Each component of each illustrated device is functionally conceptual and does not necessarily need to be physically configured as illustrated. In other words, the specific form of distribution / integration of each device is not limited to that shown in the figure, and all or a part thereof may be functionally or physically distributed or arbitrarily distributed in arbitrary units according to various loads or usage conditions. Can be integrated and configured. Further, all or a part of each processing function performed in each device may be realized by a CPU and a program analyzed and executed by the CPU, or may be realized as hardware by wired logic.

[program]
The various processes described in the first to third embodiments can be realized by executing a program prepared in advance on a computer such as a personal computer or a workstation. Therefore, in the following, an example of a computer that executes an imaging program having the same function as that of the first embodiment will be described with reference to FIG. FIG. 27 is a diagram illustrating a computer that executes an imaging program.

  As shown in FIG. 27, in a computer 1000, a RAM (Random Access Memory) 1010, a cache 1020, an HDD 1030, a ROM (Read Only Memory) 1040, and a CPU (Central Processing Unit) 1050 are connected by a bus 1060. Here, the ROM 1040 has a shooting program that exhibits the same function as that of the first embodiment, that is, as shown in FIG. 27, the shooting control program 1041, the removal program 1042, the shading correction program 1043, and the classification program. 1044 is stored in advance.

  The CPU 1050 reads out and executes each of these programs 1041 to 1044. Accordingly, each of the programs 1041 to 1044 becomes an imaging control process 1051, a removal process 1052, a shading correction process 1053, and a classification process 1054, as shown in FIG. Each of the processes 1051 to 1054 corresponds to the imaging control unit 136, the removal unit 137, the shading correction unit 138, and the sorting unit 139 illustrated in FIG.

  The HDD 1030 is provided with image data 1031 as shown in FIG. The image data 1031 corresponds to the storage unit 133 illustrated in FIG.

  By the way, the above-described programs 1041 to 1044 are not necessarily stored in the ROM 1040. For example, the programs 1041 to 1044 may be stored in a “portable physical medium” such as a flexible disk (FD), a CD-ROM, an MO disk, a DVD disk, a magneto-optical disk, and an IC card inserted into the computer 1000. Good. Alternatively, the programs 1041 to 1044 may be stored in a “fixed physical medium” such as a hard disk drive (HDD) provided inside or outside the computer 1000. Furthermore, the programs 1041 to 1044 may be stored in “another computer (or server)” connected to the computer 1000 via a public line, the Internet, a LAN, a WAN, or the like. The computer 1000 may read and execute each of the programs 1041 to 1044 from the above-mentioned “portable physical medium”, “fixed physical medium”, or “other computer (or server)”. .

C10 Microarray chip C20 Microarray chip 100, 200, 300 Screening apparatus 101 Stage 102 Culture dish 103 LED
104 Pipette 105 Manipulator 106 Objective Lens 107 Fluorescent Lamp 108 Shutter 109 Fluorescent Filter 110 Reflective Mirror 111 Reflective Mirror 112 CCD Camera 113 Objective Lens Drive Motor 114 LED Controller 115 Stage Controller 116 Shutter Controller 117 Focus Controller 118, 120 RS232C Conversion Unit 119 DIO
121 AIO
122 USB
123 Amplifier 130 Information Processing Device 131 Display Unit 132 Input Unit 133 Storage Unit 133a Pattern Corresponding Storage Unit 133b Background Image Storage Unit 134 Servo Controller 135 CCD Controller 136 Imaging Control Unit 137 Removal Unit 138 Shading Correction Unit 139 Sorting Unit 230 Information Processing Device 233 Storage unit 233a Well background image storage unit 236 Shooting control unit 237 Removal unit 336 Shooting control unit 1000 Computer 1010 RAM
1020 Cache 1030 HDD
1031 Image data 1040 ROM
1041 Shooting control program 1042 Removal program 1043 Shading correction program 1044 Sorting program 1050 CPU
1051 Imaging control process 1052 Removal process 1053 Shading correction process 1054 Sorting process 1060 Bus

Claims (8)

Background image storage for storing a background image in association with the pattern type for each pattern type, which is the type of well arrangement pattern in the background image, of the background image that is a photographed image of the microarray chip on which no sample is arranged And
A background image stored in association with a pattern type of a sample image that is a photographed image of a microarray chip on which a sample is arranged is acquired from the background image storage unit, and the sample image is acquired using the acquired background image And a removal unit that removes noise contained in the image pickup apparatus. When generating the background image, if there are a plurality of shooting positions where the well arrangement pattern is the same, the microarray chip is shot at one of the plurality of shooting positions and the well arrangement is performed. When there is a shooting position where the pattern is not the same as the arrangement pattern of the wells at other shooting positions, the camera further includes a shooting unit for shooting the microarray chip at the shooting position,
The imaging apparatus according to claim 1, wherein the background image storage unit stores a background image captured by the imaging unit and a pattern type of the background image in association with each other. The background image storage unit stores the background image, the pattern type of the background image, and an exposure time that is a time for irradiating the microarray chip with excitation light,
The removal unit acquires a background image that matches the pattern type of the sample image and matches the exposure time of the sample image from the background image storage unit, and uses the acquired background image to acquire the sample image The photographing apparatus according to claim 1, wherein noise included in the image is removed.   The removing unit acquires a plurality of background images that match the pattern type of the sample image from the background image storage unit, and interpolates the acquired plurality of background images according to the exposure time, whereby the exposure time of the sample image The imaging apparatus according to claim 3, wherein a background image corresponding to is calculated, and noise included in the sample image is removed using the calculated background image. Of the background image that is a photographed image of the microarray chip on which the sample is not arranged, the well background image that includes an arbitrary well and is slightly wider than the arbitrary well, and excitation light is irradiated A well background image storage unit for storing a dark noise image which is a photographed image of a non-microarray chip;
Using a well background image and a dark noise image stored in the well background image storage unit, a corresponding background image that is a background image corresponding to a sample image that is a photographed image of a microarray chip on which the sample is arranged is generated. And a removing unit that removes noise contained in the sample image using the generated corresponding background image.   Sorting the sample image from which noise has been removed by the removing unit by extracting an image including a well and a slightly wider range than the well, and sorting the sample based on the sum of the luminances of the extracted images The imaging device according to claim 1, further comprising a unit. When there are a plurality of imaging positions where the well arrangement pattern is the same, a microarray chip on which no sample is arranged at one of the plurality of imaging positions is imaged, and the well arrangement pattern is changed to another When there is an imaging position that is not the same as the well arrangement pattern at the imaging position, an imaging step of imaging a microarray chip on which no sample is arranged at the imaging position;
A background image storage step of associating a background image that is a captured image of the microarray chip imaged in the imaging step with a pattern type that is a type of a well arrangement pattern in the background image in a background image storage unit; ,
A background image stored in association with a pattern type of a sample image that is a photographed image of a microarray chip on which a sample is arranged is acquired from the background image storage unit, and the sample image is acquired using the acquired background image And a removal step for removing noise contained in the image. When there are a plurality of imaging positions where the well arrangement pattern is the same, a microarray chip on which no sample is arranged at one of the plurality of imaging positions is imaged, and the well arrangement pattern is changed to another When there is an imaging position that is not the same as the well arrangement pattern at the imaging position, an imaging procedure for imaging the microarray chip on which the sample is not arranged at the imaging position;
A background image storage procedure in which a background image that is a captured image of the microarray chip imaged by the imaging procedure and a pattern type that is a type of a well arrangement pattern in the background image are associated and stored in the background image storage unit; ,
A background image stored in association with a pattern type of a sample image that is a photographed image of a microarray chip on which a sample is arranged is acquired from the background image storage unit, and the sample image is acquired using the acquired background image An imaging program that causes a computer to execute a removal procedure for removing noise contained in the computer.

Images