JP2016045289A - Imaging apparatus and method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an imaging apparatus and method for sequentially imaging a subject many times, with which exposure time taking a temporal change of light to be imaged into consideration is calculated.SOLUTION: An imaging apparatus comprises an imaging unit 20 for sequentially imaging a subject many times, an exposure time calculation unit 112 for calculating exposure time for each imaging and an image processing unit 108 for adding each image sequentially imaged. The exposure time calculation unit 112 calculates exposure time of imaging for the (n)th time (n is an integer of 2 or higher) on the basis of an image imaged for the (n-1)th time or before and the imaging unit 20 performs imaging on the basis of exposure time for each imaging calculated by the exposure time calculation unit 112.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an imaging apparatus and method for sequentially imaging a subject arranged in a casing a plurality of times.

  2. Description of the Related Art Conventionally, photographing systems that shoot a subject by placing the subject in a housing and irradiating the subject with light using a light source provided in the housing are used in various fields. In such a photographing system, photographing methods are mainly used depending on the type of the subject. For example, in Patent Documents 1 to 3, chemiluminescent light, fluorescence, reflected light from the subject, or the subject is transmitted. An imaging system that generates an image by imaging transmitted light with an imaging device is disclosed.

  Further, in Patent Document 1, chemiluminescent light and fluorescence emitted from a subject are weak, so when photographing these lights, a plurality of times are taken sequentially, and the plurality of times It has been proposed to generate an addition image obtained by cumulatively adding the obtained images.

  Further, Patent Document 2 proposes that pre-photographing is performed a plurality of times, a light emission characteristic of a sample is calculated based on the result, and an appropriate exposure time for each photographing is calculated based on the light emission characteristic. .

JP 2004-128546 A JP2013-68725A JP 2008-042746 A

  Here, as described above, when performing multiple shootings sequentially, if each exposure time for each shooting is set according to the user's experience, the exposure time may not be appropriate and the exposure time is short. In some cases, a sufficiently large image signal cannot be obtained or the exposure time is too long, resulting in a reduction in photographing efficiency.

  In addition, when chemiluminescent light is photographed, the light emission intensity has a temporal characteristic that decreases with time due to the influence of the fading of the reagent. On the other hand, when fluorescence is photographed, there is almost no influence of reagent fading, and the light emission intensity has a time-dependent characteristic that maintains a substantially constant magnitude.

  In this way, when chemiluminescent light is photographed and when fluorescence is photographed, the temporal change of the light to be photographed is different, so when performing multiple photographing sequentially, each of these lights is photographed. If the exposure time for each shooting is set in the same way, an appropriate image may not be acquired.

  In Patent Document 2, a method for calculating the exposure time in consideration of the light emission characteristics of the sample has been proposed. What is the method for calculating the exposure time for each shooting in the above-described sequential multiple shootings? Has also not been proposed.

  Further, in Patent Document 3, it is proposed to synthesize images acquired by a plurality of shootings, and it is proposed to perform shooting while changing the exposure time. No method has been proposed for calculating the exposure time for each image taking into account the time-dependent characteristics.

  In view of the above problems, an object of the present invention is to provide an imaging apparatus and method capable of setting an appropriate exposure time in consideration of a temporal change of light due to a reagent fading or the like.

  An imaging apparatus of the present invention includes an imaging unit that sequentially images a subject a plurality of times, an exposure time calculation unit that calculates each exposure time of each imaging, and an image processing unit that adds each image that is sequentially captured And when the exposure time calculation unit sets n to an integer of 2 or more, the exposure time for the n-th shooting is calculated based on the images obtained before the (n-1) th shooting, and the shooting unit calculates the exposure time calculation unit. Each shooting is performed based on each exposure time calculated for each shooting.

  In the above-described photographing apparatus of the present invention, the exposure time calculation unit can calculate the exposure time of the n-th shooting based on the images obtained by shooting before the n-1th time.

  In addition, the photographing unit performs pre-photographing before the first photographing, and the exposure time calculating unit includes an image of one or plural pre-photographs and an image of one or plural photographings before the n−1th time. The exposure time for the nth shooting can be calculated based on the above.

  Further, the exposure time calculation unit can calculate the exposure time of the first shooting based on a plurality of pre-shot images.

  Further, a shooting target light information acquisition unit that acquires information of light of the shooting target is further provided, and the exposure time calculation unit is configured to determine the light based on the information of the light of the shooting target acquired by the shooting target light information acquisition unit. It is possible to select an exposure time calculation method for each shooting according to the temporal characteristics, and to calculate each exposure time for each shooting using the selected exposure time calculation method.

  In addition, a reagent information acquisition unit for acquiring information on a reagent used when photographing the subject is further provided, and the exposure time calculation unit is configured to determine the exposure time of each photographing based on the information on the light to be photographed and the information on the reagent. A calculation method can be selected, and each exposure time of each image can be calculated using the selected calculation method of exposure time.

  The exposure time calculation unit can set a part of the region of interest or the pixel of interest in the image, and can calculate the exposure time based on the signal value of the region of interest or the pixel of interest.

  In addition, an attention area designation receiving unit that receives designation of the attention area or the attention pixel can be provided.

  Further, the image processing unit can add an image obtained by multiplying an image before saturation by a time proportional coefficient when the signal value of the attention area or the attention pixel is saturated.

  In addition, when the signal value of the attention area or the target pixel is saturated, the exposure time calculation unit sets the auxiliary attention area or the auxiliary attention pixel at a position different from the attention area or the attention pixel, and sets the auxiliary attention area or the auxiliary attention pixel. The exposure time can be calculated based on the signal value.

  Further, when the auxiliary attention area or the auxiliary attention pixel is saturated, the image processing unit can add an image obtained by multiplying the image before saturation by the time proportional coefficient.

  In addition, a display control unit that displays the added image added in the image processing unit can be provided.

  Further, the display control unit can display the total exposure time obtained by adding the exposure times of all photographing.

  In the imaging method of the present invention, when n is an integer equal to or larger than 2, the exposure time of the n-th shooting is determined based on the images obtained before the (n-1) -th shooting. Each image is calculated based on the calculated exposure time of each image, and each image obtained by each image is added.

  According to the photographing apparatus and method of the present invention, when the subject is photographed sequentially a plurality of times, the exposure time of the n-th photographing is calculated based on the image obtained by photographing before the (n-1) -th photographing. Since the exposure time is calculated based on the images acquired by the previous shooting, the appropriate exposure time considering the temporal change of the light at the previous shooting time is automatically set regardless of the user's experience. Can be calculated.

1 is a schematic perspective view of a photographing system using an embodiment of a photographing apparatus of the present invention. 1 is a schematic cross-sectional view showing an internal configuration of an embodiment of a photographing apparatus of the present invention. 1 is a schematic block diagram of an embodiment of a photographing apparatus of the present invention. Graph showing the time-dependent characteristics of chemiluminescence and fluorescence The flowchart for demonstrating the effect | action of the imaging | photography system using one Embodiment of the imaging device of this invention. Table showing an example of signal increase amount, actual signal increase amount, and exposure time set and input by the user in each shooting The figure for demonstrating the method of calculating the exposure time of the 1st imaging | photography based on the image of pre imaging | photography. The figure for demonstrating the method of calculating the exposure time of the 2nd imaging | photography based on the image of the 1st imaging | photography. The figure for demonstrating the method of calculating the exposure time of the n-th imaging | photography based on the n-1st image. 1 is a schematic block diagram showing a modification of an imaging system using an embodiment of an imaging apparatus of the present invention. The figure which shows an example of the attention area The figure which shows an example of an attention area and an auxiliary attention area

  Hereinafter, an imaging system 1 using an embodiment of an imaging apparatus and method of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic perspective view showing the photographing system of the present embodiment, FIG. 2 is a schematic sectional view showing the internal configuration of the photographing apparatus of the present embodiment, and FIG. 3 shows the photographing system of the present embodiment. It is a schematic block diagram shown.

  The imaging system 1 of this embodiment includes a dark box 10 and an imaging control device 100 as shown in FIGS. 1 and 2.

  The dark box 10 includes a housing 12 having a door 14, a stage 16 on which a subject S is installed, a photographing unit 20, a lens unit 22, an incident light source unit 24, a transmitted light source unit 26, and a subject observation monitor 50.

  The housing 12 has a hollow portion 18 formed in a substantially rectangular parallelepiped, and is provided with a stage 16 in which the subject S is disposed. Moreover, the door 14 shown in FIG. 1 is attached to the housing 12 so as to be openable and closable. The user opens the door 14, arranges the subject S on the stage 16, and then closes the door 14. The subject S can be accommodated in the twelve. The housing 12 constitutes a dark box in which outside light does not enter the hollow portion 18. The stage 16 is formed of a material that transmits light from the transmissive light source unit 26.

  The imaging unit 20 is fixed to the upper surface of the housing 12, and includes an imaging element such as a cooled CCD (Charge Coupled Device) image sensor or a CMOS (Complementary Metal-Oxide Semiconductor) image sensor, and reflects the subject S. The light emitted from the subject S or the light transmitted through the subject S is detected to generate an image signal. The image signal generated in the imaging unit 20 is output to the imaging control apparatus 100 after being subjected to amplification processing, for example.

  A lens unit 22 is attached to the photographing unit 20. The lens unit 22 includes, for example, a plurality of lenses, and the lens is provided so as to be movable in the arrow Z direction in order to focus on the subject S. The lens unit 22 also includes optical elements such as a diaphragm and an excitation light cut filter, for example, and adjusts the light amount and wavelength of light to be detected.

  Each of the epi-illumination light source unit 24 and the transmission light source unit 26 includes, for example, an excitation light source and a white light source for fluorescence photography, and is configured to be able to switch the light source as needed under the control of the photography control device 100. For example, when photographing to detect fluorescence emitted from the fluorescently labeled subject S, excitation light is applied to the subject S from the incident light source unit 24 or the transmitted light source unit 26, and reflected light from the subject S is detected. When shooting, white light is irradiated from the incident light source unit 24 to the subject S, and when shooting is performed to detect transmitted light that has passed through the subject S, white light is irradiated from the transmitted light source unit 26 to the subject S. Is done.

  The subject observation monitor 50 displays a state on the stage 16 taken by a small camera (not shown) provided on the top of the housing 12. Thereby, the position of the subject S arranged on the stage 16 and the height of the stage 16 can be confirmed, and the position of the subject and the height of the stage can be adjusted so that the subject S has an arrangement suitable for photographing. It is.

  The imaging control device 100 is made up of a personal computer, for example, and includes a control device main body 102, an input unit 104, and a display unit 106. The imaging control device 100 controls the operations of the imaging unit 20, the incident light source unit 24, and the transmission light source unit 26 of the dark box 10, and the dark box 10 is controlled by the imaging control device 100 to image the subject S. is there. In the present embodiment, the imaging device of the present invention is configured by the imaging unit 20 in the dark box 10, the exposure time calculation unit 112, and the image processing unit 108 in the imaging control device 100.

  Here, the imaging system 1 of the present embodiment captures chemiluminescent light and fluorescence emitted from the subject S, but these lights are weak. Therefore, when photographing the chemiluminescent light or fluorescence, the photographing system 1 according to the present embodiment sequentially performs a plurality of times of imaging, and an addition obtained by cumulatively adding the images obtained by the plurality of times of imaging. Generate an image. Therefore, the imaging control apparatus 100 according to the present embodiment controls the imaging unit 20 of the dark box 10 so that imaging is performed a plurality of times sequentially as described above when imaging chemiluminescent light and fluorescence. It is.

  As shown in FIG. 3, the control device main body 102 includes an image processing unit 108, a photographing target light information acquisition unit 110, an exposure time calculation unit 112, and a control unit 114.

  The image processing unit 108 receives the image signal output from the photographing unit 20, and performs necessary signal processing (for example, noise removal processing and sharpness processing) on the image signal. In addition, the image processing unit 108 of the present embodiment cumulatively adds the image signals of the images sequentially captured by the imaging unit 20 when imaging the chemiluminescent light and fluorescence emitted from the subject. Thus, the addition image data is generated. Note that the cumulative addition of the image signals of the respective images means that, for example, if the image signal of the first shooting is G1, the image signal of the second shooting is G2, and the image signal of the third shooting is G3, G1 + G2. Is calculated as an added image, or G1 + G2 + G3 is calculated as an added image.

  The imaging target light information acquisition unit 110 acquires information about the imaging target light. The imaging target light information acquisition unit 110 of the present embodiment acquires information indicating whether the imaging target is chemiluminescent light or fluorescence. Specifically, this information is used to capture the subject S. It is acquired as information. Information on the photographing method of the subject S is input by the user using the input unit 104. The photographing technique will be described in detail later.

  The exposure time calculation unit 112 calculates each exposure time for each shooting when the above-described sequential shooting is performed a plurality of times. Specifically, the exposure time calculation unit 112 of the present embodiment calculates the exposure time of the n-th shooting based on an image obtained before the (n-1) th shooting (n is an integer of 2 or more). Further, the exposure time calculation unit 112 of the present embodiment further selects a calculation method of each exposure time for each shooting based on the information on the shooting method acquired by the shooting target light information acquisition unit 10, and the selected exposure. Each exposure time for each photographing is calculated using a time calculation method. A specific method for calculating the exposure time in the exposure time calculation unit 112 will be described in detail later.

  The control unit 114 includes, for example, a CPU (Central Processing Unit) and a ROM (Read Only Memory). The control unit 114 controls the operation of each unit in the dark box 10 and the imaging control device 100 in an integrated manner. In addition, the control unit 114 includes a display control unit 115, and the display control unit 115 displays the above-described addition image or the like on the display unit 106.

  The display unit 106 includes a display device such as a CRT (Cathode Ray Tube) display or a liquid crystal display, and displays the added image generated by the image processing unit 108 as described above. The display unit 106 also displays a setting screen for performing various settings and giving instructions to each unit of the dark box 10.

  The input unit 104 includes a mouse, a keyboard, and the like. Using the input unit 104, the user performs various settings and gives instructions to each unit in the dark box 10 using the input unit 104. The user uses this input unit 104 to set and input information such as information on the imaging technique and the name of the reagent to be used. The input information is stored in a storage unit (not shown) in the control unit 114, for example.

  Since the imaging system 1 of the present embodiment has the above-described configuration, it is possible to perform imaging using four imaging methods according to the type of subject and the purpose of imaging. The four imaging methods include an imaging method for detecting chemiluminescent light emitted from a subject (hereinafter referred to as a first imaging method) and an imaging method for detecting fluorescence emitted from an object (hereinafter referred to as a second imaging method). There are an imaging method for detecting reflected light reflected from the subject (hereinafter referred to as a third imaging method) and an imaging method for detecting transmitted light transmitted through the subject (hereinafter referred to as a fourth imaging method).

  The first imaging technique uses a phenomenon (chemiluminescence or chemiluminescence) that releases energy as light when a subject molecule excited by a chemical reaction returns to a ground state. Thereby, for example, it is possible to perform genetic analysis, examination and research of biological tissues related to diseases and aging, and deterioration evaluation of organic compounds and polymer compounds. For example, chemiluminescent light can be generated by labeling a subject to be imaged in a subject with a labeling substance that emits chemiluminescence upon contact with the chemiluminescent substrate, and then contacting the chemiluminescent substrate with the labeling substance. In the first imaging method, light irradiation from the incident light source unit 24 and the transmitted light source unit 26 is not performed.

  In the second imaging method, excitation light is irradiated from the epi-illumination light source unit 24 or the transmission light source unit 26, and fluorescence from a fluorescent substance that labels the imaging target substance in the subject is detected. Examples of the subject of the second imaging method include a gel support containing a DNA (deoxyribonucleic acid) fragment that is fluorescently labeled and separated by electrophoresis. If this photographing system 1 is used, the distribution of DNA fragments in the gel support can be imaged and evaluated.

  In the third imaging method, white light, for example, is irradiated as illumination light from the incident light source unit 24, and reflected light from the subject of the illumination light is detected. Accordingly, a digital image can be obtained by photoelectrically reading a reflection original such as a photograph. In the fourth imaging method, for example, white light is irradiated as illumination light from the transmission light source unit 26, and transmitted light transmitted through the subject of the illumination light is detected. Thus, a digital image can be obtained by photoelectrically reading a transparent original such as a film.

  Here, in the imaging system 1 of the present embodiment, when the chemiluminescent light is imaged as in the first imaging method or the fluorescence is imaged as in the second imaging method, the subject S as described above is used. Images are taken several times in succession. At this time, if each exposure time for each shooting is set according to the user's experience, it may not be an appropriate exposure time, and the exposure time is too short and large enough. Image signal cannot be obtained, or the exposure time is too long, resulting in a decrease in photographing efficiency.

  Further, when chemiluminescent light is imaged as in the first imaging method described above, the light emission intensity has a temporal characteristic that decreases with time due to the influence of the fading of the reagent. On the other hand, when fluorescence is imaged as in the second imaging method described above, there is almost no influence of reagent fading.

FIG. 4I is a graph showing the temporal characteristics of the emission intensity of chemiluminescent light, and FIG. 4II is a graph showing the temporal characteristics of the fluorescence emission intensity. As shown in FIG. 4I, the emission intensity of chemiluminescent light often attenuates exponentially, that is, according to y = y _α · exp (−k · t) (y _α and k are positive constants). This is because the intensity of the chemiluminescent light decreases as the concentration of the reactant in the excited state decreases with the progress of the chemical reaction. Note that y _α and k are determined by a substance that generates chemiluminescence.

On the other hand, as shown in FIG. 4II, the fluorescence emission intensity hardly attenuates and ideally maintains a constant value of y = y _β (y _β is a positive constant) as long as excitation light is supplied. Be drunk. This is because fluorescence is generated without destroying the fluorescent material. Note that _yβ is determined by the fluorescent material. Fluorescence may also be attenuated depending on the type of substance, but even in this case, the decay rate of the emission intensity with time is smaller than that of chemiluminescent light. Therefore, in this case, the temporal characteristics of fluorescence can be approximated by a linear function y = −a · t + y _γ (a and y _γ are positive constants).

  As described above, the first imaging method and the second imaging method have different temporal changes in the light to be imaged. Therefore, when performing multiple times of imaging sequentially, for each of these imaging methods, If the exposure time is set in the same manner, an appropriate image may not be acquired.

  In addition, when the temporal characteristics of chemiluminescent light and fluorescence as described above are known in advance, the temporal characteristics are set in advance, and the exposure time is calculated based on the set temporal characteristics. However, there is a case where the set time-dependent characteristic and the time-dependent characteristic of the light of the subject S to be actually photographed may be different, and in this case, an appropriate exposure time cannot be calculated.

  Further, as in the imaging system 1 of the present embodiment, when the images acquired by a plurality of shootings are cumulatively added to generate an added image, the more images to be added are included in each image. Since the noise increases, the image quality deteriorates. Therefore, it is desirable that the number of images to be added is as small as possible and that the image signal of the added image is sufficiently large.

  Therefore, the exposure time calculation unit 112 according to the present embodiment calculates the appropriate exposure time according to the temporal characteristics of light during actual shooting regardless of the user's experience. (N is an integer equal to or greater than 2) The exposure time of the n-th shooting is calculated based on the image of the previous shooting. In addition, when calculating each exposure time for each shooting in this way, the calculation method is switched according to the shooting method, so that the exposure time takes into account the temporal change of light and ends at the desired number of shooting times. Such an exposure time is calculated.

  In the case of the third and fourth imaging methods, the appropriate exposure time value depends on the intensity of illumination light and the reflectance or transmittance of the stage, and hardly changes depending on the subject. Therefore, a preset value is used for the exposure time, and the number of times of shooting is not one of the plurality of times as in the first and second shooting methods, but one time of shooting.

  Hereinafter, the operation of the imaging system 1 of the present embodiment will be described focusing on the calculation method of each exposure time for each shooting in the exposure time calculation unit 112 described above. FIG. 5 is a flowchart for explaining the operation of the imaging system 1 of the present embodiment.

  First, shooting method information is set and input by the user using the input unit 104, and the shooting method information input by the setting is acquired by the shooting target light information acquisition unit 110 (S10).

  Next, the user uses the input unit 104 to set and input a desired number of shootings and a signal increase amount desired to be acquired in each shooting, and the exposure time calculation unit 112 sets the input number of shootings and the signal increase amount in each shooting. Obtained (S12). As the desired number of times of shooting, the number of times of shooting that seems to suppress the amount of noise in the added image within a desired range is set and input, and the user wants to add to the image in each shooting as the amount of signal increase. The signal increase amount to be set is input.

  Next, after the setting input as described above, pre-photographing is performed before the main photographing (S14). Note that the above-mentioned actual photographing means photographing performed for analyzing the subject and obtaining an image for analysis, and the pre-photographing refers to photographing performed in advance in order to obtain information for determining the exposure time of the main photographing. means. In pre-photographing, for example, referring to a table in which photographing methods and exposure times for pre-photographing are associated with each other, the pre-photographing exposure time corresponding to the designated photographing method is acquired, and photographing is performed with this exposure time. Is implemented.

  Specifically, the photographing unit 20 is controlled based on a control signal output from the control unit 114 of the photographing control apparatus 100, and pre-photographing is performed (S14). The image signal acquired by the pre-photographing is output to the exposure time calculation unit 112.

  The exposure time calculation unit 112 calculates the exposure time of the first main shooting based on the image signal acquired by the pre-shooting and the information of the shooting method acquired by the shooting target light information acquisition unit 110 (S16).

  Specifically, the exposure time calculation unit 112 reads a function corresponding to the shooting method, determines an initial value of the function based on an image signal acquired by pre-shooting, and sets the determined function and a user. Each exposure time for each image is calculated based on the input signal increase amount for each image.

For example, when the photographing method is the first photographing method, that is, when the light to be photographed is chemiluminescent light, the exposure time calculation unit 112 sets the time of the previously set chemiluminescent light as described above. The attenuation function y = y _α · exp (−k · t) approximating the characteristic is read out. Then, an image signal obtained by the pre-shooting acquires the signal value per unit time by dividing the exposure time of the pre-imaging, to determine the decay function the signal value as a y _alpha. Here, the coefficient k in the attenuation function is set in advance. Further, the attenuation function is not limited to a decreasing exponential function, and may be a linear function having a negative slope.

Specifically, for example, the signal value per unit calculated time by the pre-photographing as shown in FIG. 6 is the case of the S _p, as shown in FIG. 7, to determine the attenuation function of the S _p as y _alpha .

Then, using the attenuation function determined as described above, the exposure time calculation unit 112 calculates an exposure time in which the signal increase amount of the first shooting is the signal increase amount set and input by the user. Specifically, as shown in FIG. 7, a time T _{1 at} which the integral value of the attenuation function becomes the signal increase amount Q _{1 of the first} shooting set and input by the user is calculated, and this time T ₁ is calculated for the first time. The exposure time for shooting. The integral value here is a value obtained by integrating the attenuation function by the length of the exposure time, with the length of a predetermined photographing section in the function shown in FIG. 4I as the exposure time. In addition, the following description will be made with reference to FIGS.

Then, the exposure time T ₁ calculated by the exposure time calculation unit 112 is output to the control unit 114, and the control unit 114 outputs a control signal based on the input exposure time T ₁ to the imaging unit 20, 20 performs first photographing in the exposure time T ₁ based on the input control signal (S18).

Then, the image signal obtained by the first imaging is output to the exposure time calculation unit 112, the exposure time calculation section 112 divides the image signal obtained by the first imaging by the first exposure time T ₁ obtaining a signal values S ₁ per unit time by (see FIG. 6).

Then, the exposure time calculation unit 112, as shown in FIG. 8, the signal values S ₁ obtained by the first imaging and the value of y of the attenuation function, the integral value from the photographing time t in this case, the user The time T ₂ when the signal increase amount Q _{2 for the second} shooting input as set is input is calculated, and this time T ₂ is set as the exposure time for the second shooting.

As described above, after the second shooting, the exposure time of the n-th shooting is calculated based on the image signal of the (n−1) -th shooting (n ≧ 2). That is, the image signal acquired by the (n-1) th shooting is output to the exposure time calculation unit 112, and the exposure time calculation unit 112 converts the image signal acquired by the (n-1) th shooting to (n -1) A signal value S _n-1 per unit time is obtained by dividing by the exposure time T _n-1 of the _first time (see FIG. 6).

Next, as shown in FIG. 9, the exposure time calculation unit 112 sets the signal value _Sn−1 acquired by the (n−1) -th shooting as the value of y of the attenuation function, and from the shooting time t at this time The time T _n when the integral value becomes the signal increase amount Q _n of the n-th shooting set and input by the user is calculated, and this time T _n is set as the exposure time of the n-th shooting.

  Then, the calculation of the exposure time for the second and subsequent shootings as described above and the shooting based on the calculated exposure time for each shooting are performed for the number of times set and input by the user (S20, S22).

  The image signals photographed by the photographing unit 20 are sequentially output to the image processing unit 108, and the image processing unit 108 cumulatively adds the sequentially input image signals to generate an added image signal. The signal is output to the display control unit 115 (S24).

  The display control unit 115 generates a display control signal based on the input addition image signal, and outputs the display control signal to the display unit 106 to display the addition image on the display unit 106 (S26). In addition, as an addition image displayed on the display unit 106, only an addition image obtained by adding all the captured images may be displayed, and an image of the first shooting and an addition image generated for each shooting are also included. You may make it display. That is, for example, when shooting three times, the first shot image, the added image obtained by adding the first shot image and the second shot image, the first shot image, and the second shot image, The added image obtained by adding the third captured image may be displayed side by side.

  The above is the calculation method of the exposure time for each shooting when the shooting method is the first shooting method.

On the other hand, when the shooting method is the second shooting method, that is, when the shooting target light is fluorescent, the exposure time calculation unit 112 acquires the exposure time of the first shooting by pre-shooting. acquires the signal value S _p per unit time, dividing the signal-increment value Q of the first shooting set and input by the user by the signal value S _p by dividing the image signal with an exposure time of the pre-shooting Thus, the exposure time T1 for the _first shooting is calculated.

The exposure time for the second and subsequent shootings is obtained by dividing the image signal of the (n−1) th shooting (n ≧ 2) by the (n−1) th exposure time T _n−1. acquires the signal value S _n-1 of calculating the exposure time T _n of the n-th shot by dividing the signal increase value Qn signal value S _n-1 of n-th shot set and inputted by the user .

  Then, as in the case of the first imaging method described above, an added image is generated by the image processing unit 108, and the added image is displayed on the display unit 106 by the display control unit 115.

  According to the photographing system 1 of the above embodiment, when the subject is photographed sequentially a plurality of times, the exposure time of the n-th photographing is calculated based on the image obtained by photographing before the (n-1) -th photographing. Since the exposure time is calculated based on the images acquired by the previous shooting, the appropriate exposure time considering the temporal change of the light at the previous shooting time is automatically set regardless of the user's experience. Can be calculated.

  Further, since the effect of image superimposition (signal increase amount) can be predicted, deterioration in image quality can be prevented by optimizing the number of times of image superposition.

  In addition, pre-photographing is unnecessary in the second and subsequent photographing, and the total time can be reduced.

  Further, since the exposure time is calculated using the image of the actual photographing, the exposure conditions such as binning are unified, and the exposure time can be calculated with higher accuracy.

  In the imaging system of the second embodiment, each exposure time of each imaging is calculated so that the signal increase amount of each image in each imaging becomes a value set and input by the user. However, the present invention is not limited to this, and each exposure time of each shooting may be calculated so that the added value of the signal increase amount of each image in each shooting becomes a value set and input by the user.

  Further, in the imaging system 1 of the above embodiment, as shown in FIG. 10, the reagent information acquisition unit 116 is further provided, and the exposure time calculation unit 112 is based on the reagent information acquired by the reagent information acquisition unit 116. An exposure time calculation method for each shooting may be selected, and each exposure time for each shooting may be calculated using the selected exposure time calculation method. The reagent information is set and input by the user using the input unit 104. For example, when photographing chemiluminescent light, it is information on a substance (for example, chemiluminescent substrate) involved in chemiluminescence. In the case of photographing, it is information on the fluorescent substance.

  Specifically, for example, as shown in Table 1 below, a table associating imaging method and reagent information with a function used when calculating the exposure time for each imaging is set in the exposure time calculation unit 112 in advance. In addition, the exposure time calculation unit 112 refers to the table based on the information on the imaging technique acquired by the imaging target light information acquisition unit 110 and the information on the reagent acquired by the reagent information acquisition unit 116, and corresponds to the function. And using the function, the exposure time for each photographing may be calculated in the same manner as described above. As a function set in the table, a mathematical expression representing the function may be set, or a function type such as an exponential function, a constant function, or a linear function and a coefficient of the function are set in the table. You may make it leave.

For example, item No. 1 is a case where there is no set of reagent name by the first imaging method, in this case, the exposure time calculator 112 obtains an attenuation function F _0, the exposure of each shot by using the attenuation function F ₀ Calculate time. For example, item No. 5 shows a case where a fluorescent substance name B ₁ is set and inputted as the second imaging techniques and reagents name, in this case, the exposure time calculator 112 obtains an attenuation function G _1, the damping function G ₁ Use to calculate each exposure time for each shooting. In the above embodiment has described a method of calculating the exposure time in the case of approximating the temporal characteristics of the fluorescence at constant function, when approximated by a linear function such as attenuation function G ₁ is a first imaging techniques Similarly to the above case, the exposure time may be calculated so that the integral value becomes the signal increase amount that is set and inputted.

Regarding the table in Table 1, it is preferable that the user can add and change items. For example, it is conceivable to change exponential approximation to linear approximation, change the slope of linear approximation, or add a new item. If the contents of the table in Table 1 can be changed using the input unit 104, for example, a wide range of reagents can be handled, and when the amount of illumination light changes due to deterioration of the light source, an attenuation function that takes into account deterioration of the light source Alternatively, it is possible to approximate the temporal characteristics of the illumination light with a constant function.

  In the imaging system 1 of the above-described embodiment, the maximum value, the representative value, the average value, or the mode value in the image is used as the pre-shooting and main shooting image signals when calculating the signal value per unit time. be able to. Alternatively, the maximum value, the representative value, the average value, or the mode value in a predetermined region of interest in the image acquired by the pre-photographing and the main photographing may be used. For example, as shown in FIG. 11, the attention area may be set at the center of the photographing area (in the image), but is not limited thereto, and may be another part. The attention area may be designated by the user using the input unit 104 (corresponding to the attention area designation receiving unit) while viewing the pre-photographed image displayed on the display unit 106, for example. Of these, an important area may be automatically detected, and the detected area may be set as the attention area. Further, instead of setting as a region, a predetermined pixel of interest may be set, and the exposure time may be calculated using a signal value per unit time of the pixel of interest.

  In the imaging system 1 of the above embodiment, as described above, each imaging is performed on the basis of the image signal acquired by the previous imaging, the function approximating the temporal characteristics of light, and the signal increment set and input by the user. For example, if the light emission intensity is larger than the approximate function value, or the signal increase amount set and input by the user is too large, the image signal of the previous shooting is calculated. May be saturated, and in that case, an appropriate exposure time may not be calculated. In addition, saturation here is saturation of the image pick-up element in the imaging | photography part 20. As shown in FIG.

  Therefore, when the exposure time is calculated based on the image signal of the attention area or the attention pixel (hereinafter referred to as the attention area) as described above, when the image signal of the attention area is saturated, FIG. As shown in FIG. 3, an auxiliary attention area or an auxiliary attention pixel (hereinafter referred to as an auxiliary attention area) is set at a position different from the attention area, and the exposure time is calculated based on an image signal of the auxiliary attention area. It may be. For example, as shown in FIG. 11, the auxiliary attention area or the like may be set in a peripheral portion in the imaging area (image), but is not limited thereto, and may be set in other positions. Similarly to the attention area, the user may specify the area, the area where the image signal is smaller than a preset threshold value, or the like may be automatically extracted, or the image signal may be relatively extracted in the shooting area. It is also possible to automatically extract a small area or the like as an auxiliary attention area.

  However, when calculating the exposure time based on the image signal of the auxiliary attention area as described above, the ratio of the image signal of the attention area and the auxiliary attention area before the image signal is saturated is calculated, and The exposure time may be calculated based on the ratio, the image signal such as the auxiliary attention area, and the signal increase amount set and input by the user. Specifically, for example, when the actual signal increase amount of the attention area before saturation is 20000 and the actual signal increase amount of the auxiliary attention area is 2000, the ratio is 10: 1. Therefore, for example, when the signal increase amount set and input by the user is 60000, and the image signal of the attention area or the like is saturated by the photographing, the signal increase amount of the auxiliary attention area or the like becomes 6000. The exposure time may be calculated.

  In addition, when the image signal of the above-described attention area or the like is saturated, the image processing unit 108 adds an image obtained by multiplying the image signal before saturation by a time proportional coefficient to obtain an image signal of a desired exposure time. It may be. Specifically, for example, when an image signal photographed with an exposure time of 10 seconds is saturated, an image of the photograph with an exposure time of 10 seconds is obtained by multiplying, for example, the image signal before saturation photographed with an exposure time of 1 second. You may make it acquire a signal. As a result, an image with a high dynamic range can be acquired.

  In the imaging system of the above embodiment, the exposure time of the first shooting is calculated based on the image signal of one pre-shooting. However, the present invention is not limited to this. Based on the above, the exposure time of the first shooting may be calculated. Specifically, for example, a signal value per unit time is obtained by adding image signals of a plurality of pre-shoots and dividing the added image signal by a time obtained by adding an exposure time of a plurality of pre-shoots. The signal value may be used as an initial value of a function approximating the light temporal characteristics.

In the imaging system of the above embodiment, a preset value is used as the coefficient k of the attenuation function. However, pre-imaging is performed twice, and an image signal acquired by the two pre-imaging is used. Thus, the coefficient k may be calculated based on the following expression 2. Note that S _p1 in the following formula 2 is a signal value per unit time of the first pre-shooting, S _p2 is a signal value per unit time of the second pre-shooting, and T _g is the first pre-shooting. This is the time from the point of time until the point of the second pre-shooting. By performing the pre-photographing twice in this way, the coefficient k can be appropriately set even when photographing a time-dependent characteristic such as when a new reagent is used.

Further, in the case of calculating the exposure time of the main photographing, in the above embodiment, the exposure time is calculated based on the image signal of the last one photographing. The exposure time of the n-th shooting may be calculated based on the image signals of a plurality of shootings before the first time. Specifically, for example, a unit time is obtained by adding the image signals of a plurality of times of actual photographing before the (n-1) th time and dividing the added image signal by the time obtained by adding the exposure times of the times of actual photographing. The winning signal value may be acquired, and the exposure time of the n-th shooting may be calculated using the signal value as described above. Further, when calculating the exposure time of the n-th shooting, not only the image signal of the main shooting before the (n-1) -th shooting but also the image signal of one or a plurality of pre-shooting is used to perform the n-th shooting in the same manner as described above. You may make it calculate the exposure time of imaging | photography.

  In the imaging system of the above embodiment, the total imaging time obtained by adding the exposure times for all imaging may be calculated, and the display control unit 115 may display the total imaging time on the display unit 106.

In the imaging system of the above-described embodiment, it is desirable to increase sensitivity by performing binning when performing pre-imaging. Making this way a binning signal value Sp per unit time of the pre-photographing is converted to the signal value S _m based on the following equation 1. Note that B _p in the formula 2 is a binning number in the pre shooting, B _m is the binning number in the photographing.

DESCRIPTION OF SYMBOLS 1 Shooting system 10 Dark box 12 Case 14 Door 16 Stage 18 Hollow part 20 Shooting part 22 Lens part 24 Incident light source part 26 Transmission light source part 50 Subject observation monitor 100 Imaging control apparatus 102 Control apparatus main body 104 Input part 106 Display part 108 Image Processing unit 110 Imaging target light information acquisition unit 110 Imaging technique acquisition unit 112 Exposure time calculation unit 114 Control unit 115 Display control unit 116 Reagent information acquisition unit

Claims (14)

A shooting unit for shooting a subject multiple times sequentially;
An exposure time calculation unit for calculating each exposure time of each photographing,
An image processing unit for adding the sequentially captured images,
When the exposure time calculation unit sets n to an integer of 2 or more, the exposure time for the n-th shooting is calculated based on the images obtained before the (n-1) th shooting,
The photographing apparatus, wherein the photographing unit performs each photographing based on each exposure time of each photographing calculated by the exposure time calculating unit.   The imaging apparatus according to claim 1, wherein the exposure time calculation unit calculates an exposure time of the n-th shooting based on a plurality of images obtained before the n−1th shooting. The photographing unit performs pre-photographing before the first photographing,
The exposure time calculation unit calculates an exposure time of the n-th shooting based on one or a plurality of pre-shooting images and an image of one or a plurality of shootings before the n-1th shot. Item 3. An imaging apparatus according to item 1 or 2.   The photographing apparatus according to claim 3, wherein the exposure time calculation unit calculates an exposure time of the first photographing based on the plurality of pre-photographed images. A shooting target light information acquisition unit for acquiring information of light of the shooting target is provided.
The exposure time calculation unit selects a calculation method of the exposure time of each shooting according to the temporal characteristics of the light based on the information of the light of the shooting target acquired by the shooting target light information acquisition unit, 5. The photographing apparatus according to claim 1, wherein each exposure time of each photographing is calculated using a selected exposure time calculation method. 6. A reagent information acquisition unit for acquiring information of a reagent used in photographing the subject;
The exposure time calculation unit selects a calculation method of the exposure time for each imaging based on the information on the light to be imaged and the information on the reagent, and uses the selected exposure time calculation method to select each of the imagings. The imaging device according to claim 5, wherein each exposure time is calculated.   The exposure time calculation unit sets a part of a region of interest or a pixel of interest in the image, and calculates the exposure time based on a signal value of the region of interest or the pixel of interest. Shooting device.   The imaging device according to claim 7, further comprising an attention area designation receiving unit that receives designation of the attention area or the attention pixel.   The imaging device according to claim 8, wherein when the signal value of the region of interest or the pixel of interest is saturated, the image processing unit adds an image obtained by multiplying an image before saturation by a time proportional coefficient.   When the signal value of the region of interest or the pixel of interest is saturated, the exposure time calculation unit sets an auxiliary region of interest or an auxiliary pixel of interest at a position different from the region of interest or the pixel of interest, and the auxiliary region of interest The imaging apparatus according to claim 8, wherein the exposure time is calculated based on a signal value of the auxiliary target pixel.   The imaging device according to claim 10, wherein when the auxiliary attention area or the auxiliary attention pixel is saturated, the image processing unit adds an image obtained by multiplying an image before saturation by a time proportional coefficient.   The imaging device according to claim 1, further comprising a display control unit that displays the added image added in the image processing unit.   The photographing apparatus according to claim 12, wherein the display control unit displays a total exposure time obtained by adding all the exposure times of the photographing. In the shooting method of shooting a subject multiple times sequentially,
When n is an integer greater than or equal to 2, the exposure time of the n-th shooting is calculated based on the image of the shooting before the (n-1) -th shooting,
Based on the calculated exposure time of each shooting, each shooting is performed,
A method of photographing, characterized in that each image obtained by each photographing is added.