Imaging device

Abstract

To provide an imaging apparatus that can prevent a reduction in the intensity of incident light and adjust the balance between acquired signals in respective wavelengths.SOLUTION: An imaging apparatus has an imaging unit including a first image pick-up device that receives light of a first image formed by an optical system, and a second image pick-up device that receives light of a second image formed by the optical system. The first image and the second image are formed by the rays of light different in wavelength from each other, and the first image pick-up device and the second image pick-up device perform imaging in exposure conditions different from each other.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an imaging device.

Background Art

[0002] In recent years, in addition to the three-band (wavelength band) information of RGB that matches the visual characteristics of humans, a method has been proposed that uses a camera capable of acquiring band information in the visible and non-visible regions to analyze the composition of a subject or to accurately discriminate an object that is difficult for humans to visually recognize. In the following description, a spectroscopic image including four or more band information is referred to as a "multi-band image" in order to distinguish it from a conventional RGB image.

[0003] A silicon sensor generally used as an imaging element has a characteristic that the sensitivity to light of a wavelength decreases as the wavelength deviates from the designed center wavelength. Therefore, when a plurality of images formed from lights of different wavelengths are simultaneously imaged by one imaging element, a distribution occurs in the intensity of the acquired signal, and the dynamic range of the acquired signal corresponding to the light of the wavelength on the low-sensitivity side becomes narrow.

[0004] Patent Document 1 discloses a camera that equalizes the intensity of the acquired signal by adjusting the transmittance of a band-pass filter.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, in the camera of Patent Document 1, since the transmittance of the band-pass filter corresponding to the light in the visible region where the sensitivity of the imaging element is high is lowered to reduce the intensity of the incident light, the light utilization efficiency with respect to the incident light is reduced.

[0007] An object of the present invention is to provide an imaging device capable of suppressing a decrease in the intensity of incident light and adjusting the balance of acquisition signals for each wavelength. **Means for Solving the Problems**

[0008] An imaging device according to one aspect of the present invention includes An optical system that forms a first image with light of a first wavelength and forms a second image with light of a second wavelength different from the first wavelength, a plurality of first imaging elements arranged adjacent to each other in a first direction, a plurality of second imaging elements arranged adjacent to each other in the first direction, and a control unit that controls the plurality of first imaging elements and the plurality of second imaging elements, The optical system includes a diffraction element whose spectroscopic direction is non-parallel to the first direction, each of the plurality of first imaging elements The receives a first image, and each of the plurality of second imaging elements The receives a second image, and the control unit controls the plurality of first imaging elements under a common first exposure condition and controls the plurality of second of imaging elements under a common second exposure condition different from the first exposure condition. **Advantages of the Invention**

[0009] According to the present invention, it is possible to provide an imaging device capable of suppressing a decrease in the intensity of incident light and adjusting the balance of acquisition signals for each wavelength. **Brief Description of the Drawings**

[0010]

Figure 1

Figure 2

Figure 3

Figure 4

[0011] Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. In each drawing, the same members are denoted by the same reference numerals, and redundant descriptions are omitted.

Example

[0012] FIG. 1 is an explanatory diagram of the imaging device C1 of this embodiment. As shown in FIG. 1(a), the imaging device C1 includes an imaging unit C11 and a control system B1.

[0013] The imaging unit C11 includes a spectroscopic optical system and an imaging sensor (imaging unit) SS1. The spectroscopic optical system includes a lens L11, a slit SL, a lens L12, a diffraction element DO, and a lens L13. The imaging sensor SS1 includes a first imaging element group including a first imaging element that receives a first spectroscopic image having a first optical characteristic formed by the spectroscopic optical system. Further, the imaging sensor SS1 includes a second imaging element group including a second imaging element that receives a second spectroscopic image having a second optical characteristic formed by the spectroscopic optical system. As will be described later, the first and second imaging element groups perform imaging under different exposure conditions. Specifically, the first imaging element group performs imaging under the first exposure condition, and the second imaging element group performs imaging under the second exposure condition. Note that the exposure in the present invention refers to control parameters such as exposure time and ISO sensitivity that increase or decrease the acquired luminance value of the imaging element. Further, the spectroscopic optical system may be configured to be detachable from the imaging device C1.

[0014] The imaging unit C11 of this embodiment is a push-bloom type imaging system. The imaging sensor SS1 can control a plurality of two-dimensionally arranged imaging elements under common exposure conditions for at least each row.

[0015] Lens L11 forms an image of the light beam from a subject (not shown) on slit SL. Slit SL cuts out the spatial information of the subject as a substantially one-dimensional image. In this embodiment, assuming that the slit shape will be re-imaged by the subsequent optical system, the length of the short side is adjusted to the length of 1 pixel of the imaging device, and the length of the long side is adjusted to the length in the width direction (x-axis direction in FIG. 1) of imaging sensor SS1. Lens L12 returns the one-dimensional image cut out by slit SL to a parallel light beam and makes it incident on diffraction element DO. Since the diffraction angle of the light beam that has passed through diffraction element DO is different for each wavelength, diffraction element DO functions as a spectroscopic optical element that performs spectroscopy in the angular direction. The diffracted parallel light beam is condensed onto imaging sensor SS1 by lens L13 and re-imaged. In the spectroscopic image formed on imaging sensor SS1, the spatial information of the subject is developed orthogonally in the x-axis direction, and the wavelength information of the subject is developed orthogonally in the y-axis direction (see FIG. 1(b)). In FIG. 1(b), the section where the one-dimensional spectroscopic image (spatial information) for each wavelength on imaging sensor SS1 is formed is shown as spectroscopic region SR. The number of spectroscopic regions SR may be less or more than that shown in FIG. 1(b). As described above, by using imaging unit C11, a spectroscopic image in a one-dimensional subject image at a certain moment can be obtained. Also, by relatively scanning the subject and imaging device C1 in the y-axis direction, a two-dimensional spectroscopic image of the subject can also be acquired.

[0016] Hereinafter, the problems of the present invention will be described. FIG. 2 is a diagram showing the wavelength sensitivity of a general imaging device (for example, a silicon sensor) used in a camera. As shown in FIG. 2, a general imaging device has the characteristic that the sensitivity to light with a central wavelength (around 500 nm) in the visible region is the maximum, and the sensitivity to light of that wavelength decreases as the wavelength moves away from the peak wavelength. For example, for light with a wavelength of 500 nm and light with a wavelength of 900 nm, the sensitivity differs by more than 6 times. That is, in an imaging device incorporating an imaging device having the characteristics of FIG. 2, when a spectroscopic image is taken under certain exposure conditions, the spectroscopic image corresponding to light with a wavelength of 900 nm is 6 times darker than the spectroscopic image corresponding to light with a wavelength of 500 nm.

[0017] Here, consider a case where an imaging element having the characteristics of FIG. 2 is incorporated into the imaging device C1 of this embodiment to photograph a subject with little reflected light in the near-infrared wavelength (around 900 nm). When the exposure is set so that the spectral image corresponding to the light with a wavelength of 900 nm becomes as bright as possible, the luminance value may saturate in the spectral image corresponding to the light with a wavelength of 500 nm. In spectroscopic analysis, since the intensity distribution (i.e., intensity ratio) of the acquired signals for each wavelength is important, saturation of the luminance value in the spectral image becomes an error in analysis and the data cannot be handled normally. Therefore, in a spectroscopic imaging device such as this embodiment, since the exposure can only be controlled within a range where luminance saturation does not occur, a limit occurs in the signal-to-noise ratio in dark regions of the spectral image, particularly in the near-ultraviolet region and the near-infrared region. Although it is possible to shift the peak wavelength in the design of the imaging element, since the wavelength sensitivity also has a peak-like curve, the same problem occurs when trying to simultaneously obtain a plurality of spectral images corresponding to light of a wide wavelength range.

[0018] In this embodiment, the control system B1 is devised. The control system B1 includes a storage unit B11, an acquisition unit B12, a shooting control unit B13, an A / D converter B14, and an image output unit B15.

[0019] The storage unit B11 holds information on the wavelength sensitivity characteristics of the imaging sensor SS1 and position information on the spectral region SR on the imaging sensor SS1, and outputs each piece of information to the acquisition unit B12. Note that the information held by the storage unit B11 may be held by a device different from the imaging device C1.

[0020] The acquisition unit B12 acquires exposure conditions that can balance the acquired luminance values for each spectral region SR using the information from the storage unit B11. In this embodiment, the acquisition unit B12 simply acquires, as the exposure conditions, the coefficient obtained by inverting the graph of FIG. 2 vertically in order to cancel the sensitivity characteristics of the imaging sensor SS1 with respect to the wavelength. Thereby, when the light from the subject is white light with a constant intensity in the acquired wavelength region, the luminance value of the spectral image becomes a constant value. In this embodiment, since the spectral region SR is configured horizontally on the imaging sensor SS1 as shown in FIG. 1(b), in the spectral region SR, information of the same wavelength is arranged along the spatial axis direction (x-axis direction). Therefore, it is not necessary to change the exposure conditions along the spatial axis direction, and the circuit scale can be made relatively small. Note that in this embodiment, the acquisition unit B12 acquires the exposure conditions, but a device different from the imaging device C1 may acquire them. Further, the acquisition unit B12 may acquire, as the exposure conditions, the exposure time, ISO sensitivity, etc. according to the wavelength sensitivity characteristics of the imaging sensor SS1.

[0021] The shooting control unit B13 controls the imaging sensor SS1 using the exposure conditions for each spectral region SR in the imaging sensor SS1 acquired from the acquisition unit B12. The imaging sensor SS1 is controlled by the shooting control unit B13 and outputs the image on the imaging surface as an electrical signal.

[0022] The A / D converter B14 converts the output signal from the imaging sensor SS1, which is an analog signal, into a digital signal.

[0023] The image output unit B15 outputs a spectral image spectrally divided in the wavelength axis direction (Y-axis direction) of the imaging sensor SS1 using the signal output from the A / D converter B14.

[0024] Since the imaging unit C11 of this embodiment is a push-bloom type imaging system, two-dimensional information of space can also be acquired by scanning the subject in the Y-axis direction. It is possible to form a multi-band image by bundling the line spectroscopic images output from the image output unit B15 with an external computer (not shown). Further, in this embodiment, although the image information is digitized in the imaging device C1, the image may be output as analog information.

[0025] As described above, by combining the function of partially controlling the exposure in the imaging sensor SS1 with respect to the spectroscopic optical system, it is not necessary to reduce the light intensity with an optical filter, so that the incident light can be used efficiently. Further, when the exposure is controlled by the exposure time, in the spectroscopic region SR where the wavelength sensitivity is high (the exposure time is short), a predetermined luminance value can be obtained immediately, and data transfer can be started. As a result, since it is possible to immediately shift (scan) to the data acquisition of the next spectroscopic region SR at the stage when the exposure in a certain spectroscopic region SR is completed, the acquisition time of the spectroscopic image of one surface can be shortened. It is also possible to realize high-speed shooting when acquiring continuous spectroscopic images, particularly when acquiring a multi-band image with a push-bloom type imaging system. Note that the spectroscopic regions SR in the imaging sensor SS1 do not necessarily have to be adjacent regions, but it is preferable that they are arranged so as to be easily wired on the circuit. Scanning adjacent pixels or rows of pixels sequentially can simplify the configuration.

[0026] Hereinafter, the advantages of combining the push-bloom type imaging system with the present invention will be supplemented. First, the case of combining the present invention with a sensor having a configuration in which spectroscopic filters are discretely arranged in a mosaic pattern on the imaging sensor (hereinafter referred to as a "mosaic type sensor") will be described. In a mosaic type sensor, since the spectroscopic regions for which spectroscopic images should be obtained under the same exposure conditions are discretely distributed over the entire imaging sensor surface, it is necessary to provide an exposure control mechanism for each pixel on the imaging sensor. Therefore, the wiring becomes complicated and high-density integration of the circuit is required, so the manufacturing difficulty increases, or the aperture ratio of the photoelectric conversion element decreases.

[0027] On the one hand, by combining a spectroscopic optical system with a certain degree of concentration in the spectroscopic region and an imaging sensor as in this embodiment, the effects of the present invention can be realized at a lower cost. For example, in a push-bloom type imaging system, it is effective to use a rolling shutter type CMOS sensor as the imaging sensor SS1. By aligning the line direction corresponding to one-line scan of the CMOS sensor with the longitudinal direction (spatial axis direction) of the spectroscopic region SR, the spectroscopic region SR coincides with the line to be scanned, so exposure control may be performed for each line to be scanned. That is, the exposure control mechanism on the CMOS sensor side only needs to be connected to the circuit blocks in units of lines, and the circuit scale can be kept smaller compared with the case of using a mosaic type sensor.

[0028] As described above, according to the configuration of this embodiment, it is possible to suppress a decrease in the intensity of incident light and to adjust the balance of the acquired signals for each wavelength.

[0029] In this embodiment, an example in which the exposure conditions are made constant in the spatial axis direction on the imaging sensor SS1 has been shown. However, depending on the configurations of the spectroscopic optical system and the imaging device, there may be cases where the luminance decreases outside the angle of view (vignetting, shading, defects of the imaging device, etc.). Therefore, controls for correcting these may be combined to adjust the in-plane luminance uniformity. For example, information regarding the luminance distribution and luminance unevenness in the imaging sensor SS1 derived from the imaging device C1 is also stored in the storage unit B11. By considering this information as well, the acquisition unit B12 outputs the exposure conditions under which the acquired image becomes uniform over the entire surface to the imaging control unit B13, so that the user can always obtain a homogeneous image without worrying about the luminance distribution and luminance unevenness derived from the imaging device C1.

[0030] In addition, in this embodiment, when controlling the exposure conditions by the exposure time, an example is shown in which the scan is shifted to the next spectral region at the timing when the exposure time reaches a specified amount in a certain spectral region. As another example, when the exposure time reaches the specified amount in a certain spectral region, the scan of the same spectral region may be restarted. That is, image updates may be performed asynchronously for each spectral region. In this case, at the timing when the exposure time ends, the signal regarding the spectral image corresponding to that spectral region is output without waiting for the exposure of another spectral region. Thereby, it is possible to generate continuous multi-band videos with different frame rates for each spectral region. In the spectral image of a wavelength with low sensitivity of the imaging device, sufficient luminance cannot be obtained unless the exposure time is lengthened, and a low-speed video is generated. However, by using the spectral image of a wavelength with high sensitivity, intermediate frames can be generated by image synthesis, enabling time-direction upsampling.

[0031] Also, in this embodiment, the spectroscopic optical system and the imaging sensor SS1 are arranged such that the y-axis (diffraction direction axis) in the spectroscopic direction of the imaging unit C11 is orthogonal to one line (one row of the imaging sensor SS1) corresponding to one scan of the imaging sensor SS1. However, the present invention is not limited to this. It is only necessary that the y-axis in the spectroscopic direction of the imaging unit C11 is non-parallel to one line corresponding to one scan of the imaging sensor SS1, and the x-axis having spatial information does not have to be completely parallel to one line. Since the axes of the spectroscopic information (y) and the spatial information (x) are slightly inclined (not orthogonal) from the orthogonal matrix of the imaging sensor SS1, information corresponding to sub-pixels can be obtained from adjacent pixels, and in some cases, information acquisition with a resolution higher than that of the imaging sensor SS1 can be achieved by interpolation. Utilizing this principle, the positional relationship between the spectroscopic direction and the line direction of the imaging sensor SS1 may be shifted. However, since the spectroscopic information located at the four corners of the imaging sensor SS1 is missing as the deviation from the orthogonal relationship shown in this embodiment increases, it is preferable that the amount of protrusion in the y-axis direction due to the inclination of the spectral region SR is within a range of about ±1 to 3 pixels.

Embodiment

[0032] FIG. 3 is an explanatory diagram of the imaging device C1 of this embodiment. In this embodiment, only the differences from Embodiment 1 will be described, and the description of the same configuration will be omitted.

[0033] As shown in FIG. 3(a), the imaging device C1 includes an imaging unit C11 and a control system B2. The control system B2 includes a storage unit B21, an acquisition unit B22, a shooting control unit B23, an A / D converter B24, and an image output unit B25.

[0034] The acquisition unit B22 acquires exposure conditions using, in addition to the information on the wavelength sensitivity characteristics of the imaging sensor SS1 from the storage unit B21, the information on the currently acquired image from the imaging sensor SS1 from the A / D converter B24. The luminance value for each wavelength varies for each region of the subject depending on the ambient light and the spectral reflectance of the subject. In this embodiment, the exposure conditions are acquired so that the luminance value does not saturate within the imaging sensor SS1 and is an appropriate value that is not too dark, and the exposure conditions for the next imaging are updated. With such a configuration, it becomes possible to perform shooting while following the brightness of the dynamically changing subject. In particular, when shooting with the imaging device C1 of this embodiment, depending on the lighting used, narrow peaks and valleys (spectral lines and absorption lines of constituent atoms, etc.) may occur at specific wavelengths. In this case, since the brightness of the spectral image may vary extremely, by using the configuration of this embodiment, it is possible to avoid luminance saturation while maintaining the signal-to-noise ratio.

[0035] If it is possible to obtain the wavelength intensity distribution (spectral characteristics) of the ambient light during shooting, the reflection characteristics of the subject for each wavelength can be restored from the multi-band image. Therefore, it is preferable that the control system B1 has an estimation unit that can estimate the wavelength intensity distribution of the ambient light from the information of the currently acquired image (the intensity ratio of the first and second spectral images). For example, using the principle of auto white balance, the wavelength intensity distribution of the ambient light may be estimated from the intensity balance of the wavelengths of the entire acquired image. Also, the wavelength intensity distribution on the surface of the reflection characteristics where the characteristics with respect to the wavelength are substantially uniform within the subject may be substituted as the wavelength intensity distribution of the ambient light. If it is an experimental system that projects a known light source as the ambient light, the wavelength intensity distribution of the light source may be directly input. When the types of ambient light are known and limited in number, the respective wavelength intensity distributions may be stored in the storage unit B21. Note that instead of providing an estimation unit, the acquisition unit B22 may be configured to estimate the wavelength intensity distribution of the ambient light.

[0036] Also, an exposure evaluation region (not shown) provided with an element specialized for exposure evaluation may be provided within the spectral region SR. By providing such a region, appropriate exposure conditions can be obtained with high accuracy.

[0037] As described above, according to the configuration of the present embodiment, in addition to the effects of the first embodiment, imaging can be performed following even if the luminance of the subject for each wavelength varies dynamically.

Embodiment

[0038] In the first and second embodiments, a push-bloom type imaging system was used, but in this embodiment, the case of using other imaging systems will be described. FIG. 4 is an explanatory diagram of the imaging device C3 of this embodiment. In this embodiment, only the differences from the first embodiment will be described, and the description of the same configuration will be omitted.

[0039] As shown in FIG. 4(a), the imaging device C3 includes an imaging unit C31 and a control system B3. The imaging unit C31 includes a spectroscopic optical system and an imaging sensor SS3. The imaging sensor SS3 includes a first imaging element that receives a first spectroscopic image having a first optical characteristic formed by the spectroscopic optical system, and a second imaging element that receives a second spectroscopic image having a second optical characteristic formed by the spectroscopic optical system. The first and second imaging elements perform imaging under different exposure conditions, as will be described later.

[0040] The imaging unit C31 includes an objective lens L31, a field stop ST, a collimating lens L32, a filter array (spectroscopic filter array) FA, a lens array LA, and an imaging sensor SS3, which are arranged in order from the subject side (the left side in FIG. 4(a)) to the image side. The filter array FA is composed of a group of spectroscopic filters having different spectroscopic transmittance characteristics. The lens array LA is composed of a group of small-diameter lenses (imaging elements). With such a configuration, an intermediate image of a subject on the field stop ST formed by the objective lens L31 can be replicated onto the imaging sensor SS3 by the individual small-diameter lenses of the lens array LA, and an image can be formed in an array form. At this time, since spectroscopic filters having different spectroscopic transmittance characteristics are arranged (a filter array is formed) on the optical paths of the small-diameter lenses, spectroscopic images can be obtained simultaneously on the imaging sensor SS3.

[0041] FIG. 4(b) shows a schematic view of the filter array FA as viewed from the subject side. In FIG. 4(b), a 3×3 filter array of a total of 9 bands is formed. In FIG. 4(b), A11 to A33 indicate spectroscopic regions corresponding to each spectroscopic filter in the filter array FA. Also, the central value of the transmission wavelength for each spectroscopic filter is indicated as "xxx nm". In this embodiment, a narrow-band band-pass filter centered on the transmission wavelength is used as the spectroscopic filter, but the combination of the spectroscopic transmittance distributions of the spectroscopic filters is arbitrary. For example, even an image formed through a spectroscopic filter having a broadband and discrete spectroscopic transmittance distribution can be regarded as a "spectroscopic image (array)" in a broad sense if the spectroscopic transmittance distributions are different between the filter arrays.

[0042] Between the filter array FA and the imaging sensor SS3, small-diameter lenses corresponding to the respective spectroscopic filters of the filter array FA are arranged. Therefore, spectroscopic images are formed on the surface of the imaging sensor SS3 for each of the spectroscopic regions A11 to A33. That is, the imaging device C3 of the present embodiment is a 9-band multi-band camera. Note that the division of the array in the present embodiment is an example, and the number of divisions may be increased to 5×5, or the aspect ratio may be different, such as 4×3. Further, the spectroscopic optical system of the present embodiment is configured such that the filter array is replaceable. Therefore, the imaging device C3 can easily acquire various multi-band images.

[0043] The field stop ST is arranged at a position where the focal position of the objective lens L31 and the focal position of the collimating lens L32 overlap. By arranging the field stop ST in this way, parallel light fluxes enter the filter array FA and the lens array LA for each angle of view. When the spectroscopic filter is an interference-type optical filter, there is an angular dependence of the transmission wavelength, and generally, it is known that the variation in the central value of the transmission wavelength is larger for longer wavelengths. However, in the configuration of the present embodiment, since parallel light enters the filter array FA at substantially the same angle for each angle of view, the problem of angular dependence of the transmission wavelength can be minimized.

[0044] The objective lens L31, the collimating lens L32, and the central lens of the lens array LA share the optical axis AX0, but the small-diameter lenses outside the lens array LA are displaced from the optical axis AX0. The optical axis AX12 is described as a representative of the optical axes of the small-diameter lenses outside the lens array LA. The spectroscopic image of the subject is developed around the intersection of the optical axis of each small-diameter lens and the imaging sensor SS3.

[0045] The control system B3 includes a storage unit B31, an acquisition unit B32, a shooting control unit B33, an A / D converter B34, and an image output unit B35. The control system B3 has the same functions as either the control system B1 of the first embodiment or the control system B2 of the second embodiment.

[0046] The spectral region is rectangular and long in the X-axis direction in Examples 1 and 2, but has the same size in both the X-axis and Y-axis directions in this example (the aspect ratio varies depending on the arrangement of the lens array LA). By setting exposure conditions for each grouped section, the present invention can be realized with a relatively small circuit scale even when a mosaic sensor is applied to the imaging sensor SS3. When a general rolling shutter type CMOS sensor is applied to the imaging sensor SS3, for example, by setting a plurality of lines to the same exposure conditions, the present invention can be realized with the same simplicity as in Examples 1 and 2. For example, in FIG. 4(b), the arrangement of the filter array FA is determined so that a spectral image of a wavelength close to a set of spectral regions arranged along the X-axis direction (for example, the set of A11, A12, and A13) is formed. In FIG. 4(b), the spectral regions A21, A22, and A23 corresponding to wavelengths around 500 nm where the sensitivity of the imaging device is the highest are arranged along the row direction. In the upper and lower rows, spectral regions corresponding to wavelengths with similar sensitivity of the imaging device are grouped and arranged. Although the step of wavelengths for which exposure can be controlled becomes coarser than in a push-bloom type imaging system, since the exposure of the spectral region where the sensitivity of the imaging device is the highest can be reduced, luminance saturation can be suppressed. By using the spectroscopic optical system of this example, a general CMOS sensor can be used, so the present invention can be realized at low cost.

[0047] As described above, according to the configuration of this example, it is possible to suppress a decrease in the intensity of incident light and adjust the balance of the acquired signals for each wavelength.

[0048] As described above, the preferred embodiments of the present invention have been described, but the present invention is not limited to these embodiments, and various modifications and changes are possible within the scope of the gist thereof.

Explanation of Reference Numerals

[0049] C1, C3 Imaging device SS1, SS3 Imaging sensor

Claims

1. An optical system that forms a first image with light of a first wavelength and forms a second image with light of a second wavelength different from the first wavelength, A plurality of first image sensors arranged adjacent to each other in a first direction, A plurality of second image sensors arranged adjacent to each other in the first direction, And a control unit that controls the plurality of first image sensors and the plurality of second image sensors, The optical system includes a diffraction element whose spectroscopic direction is non-parallel to the first direction, Each of the plurality of first image sensors receives the first image, and each of the plurality of second image sensors receives the second image, The control unit controls the plurality of first image sensors under a common first exposure condition and controls the plurality of second image sensors under a common second exposure condition different from the first exposure condition. An imaging device characterized by that.

2. The imaging device according to claim 1, wherein the first and second exposure conditions include an exposure time.

3. The imaging device according to claim 1, wherein the first and second exposure conditions include an ISO sensitivity.

4. The imaging device according to any one of claims 1 to 3, further comprising an acquisition unit that acquires the first and second exposure conditions using wavelength sensitivity characteristics of the plurality of first image sensors and the plurality of second image sensors.

5. The imaging device according to claim 4, further comprising a storage unit that stores wavelength sensitivity characteristics of the plurality of first image sensors and the plurality of second image sensors.

6. The imaging device according to any one of claims 1 to 3, further comprising an acquisition unit that acquires the first and second exposure conditions using signals from the plurality of first image sensors and the plurality of second image sensors.

7. The imaging device according to any one of claims 1 to 6, further comprising an estimation unit that estimates the spectral characteristics of ambient light during imaging using the ratio of the signal intensity corresponding to the first image and the signal intensity corresponding to the second image.

8. The imaging device according to any one of claims 1 to 7, wherein the control unit starts the exposure of the plurality of second imaging elements at a timing when the plurality of first imaging elements are exposed for a specific time.

9. The imaging device according to any one of claims 1 to 7, wherein the control unit causes the plurality of first imaging elements to output a signal corresponding to the first image at a timing when the plurality of first imaging elements are exposed for a specific time, and starts the exposure of the plurality of first imaging elements again.

10. A plurality of first imaging elements each receiving a first image formed by light of a first wavelength and arranged adjacent to each other in a first direction, A plurality of second imaging elements each receiving a second image formed by light of a second wavelength and arranged adjacent to each other in the first direction, An optical system that forms the first and second images, A control unit that controls the plurality of first imaging elements and the plurality of second imaging elements, A storage unit that stores the wavelength sensitivity characteristics of the plurality of first imaging elements and the plurality of second imaging elements, An acquisition unit that acquires a first exposure condition using the wavelength sensitivity characteristics of the plurality of first imaging elements and acquires a second exposure condition different from the first exposure condition using the wavelength sensitivity characteristics of the plurality of second imaging elements, The optical system includes a diffraction element whose spectral direction is non-parallel to the first direction, The first and second exposure conditions include ISO sensitivity, The imaging device, wherein the control unit controls the plurality of first imaging elements under the common first exposure condition and controls the plurality of second imaging elements under the common second exposure condition.

11. A plurality of first imaging elements that receive first images respectively formed by light of a first wavelength and are arranged adjacent to each other in a first direction, A plurality of second imaging elements that receive second images respectively formed by light of a second wavelength and are arranged adjacent to each other in the first direction, An optical system that forms the first and second images, A control unit that controls the plurality of first imaging elements and the plurality of second imaging elements, An acquisition unit that acquires a first exposure condition using signals from the plurality of first imaging elements and acquires a second exposure condition different from the first exposure condition using signals from the plurality of second imaging elements, and The optical system includes a diffraction element whose spectroscopic direction is non-parallel to the first direction, The first and second exposure conditions include ISO sensitivity, The control unit controls the plurality of first imaging elements under the common first exposure condition and controls the plurality of second imaging elements under the common second exposure condition. An imaging device characterized by this.

12. The imaging device according to any one of claims 1 to 11, characterized in that the optical system is detachable.

Images