JP7150515B2 - Imaging element and imaging device - Google Patents

Description

The present invention relates to an imaging device and an imaging device.

Imaging devices such as digital still cameras and digital video cameras use imaging devices such as CMOS image sensors and CCD image sensors. In recent years, as the number of pixels in imaging devices has increased, the number of colors at the time of imaging, that is, the types of wavelength bands that are dispersed, has increased to more accurately detect the color components of the subject and improve color reproducibility. An imaging device using a multispectral sensor has been proposed for the purpose of. For example, a technique using 16 types of color filters with narrow band characteristics (Patent Document 1) and a technique of dividing each region in the Bayer array to divide the spectral wavelength band have been proposed (Patent Document 1). 2).

JP-A-2003-87806 JP 2012-44519 A

In the technique described in Patent Document 1, the pixel arrangement in the imaging element is not a so-called Bayer arrangement, so a color image cannot be output as an image to be actually output. Patent Document 2 describes an imaging device using a plurality of color filters having narrower band widths than the band widths of RGB colors in the Bayer array. By adding a plurality of narrow-bandwidth pixel signals corresponding to RGB colors, processing in the conventional Bayer array is made possible.

However, since the imaging device described in Patent Document 2 has a so-called RGGB arrangement, it is possible to obtain information of only 12 wavelength bands even though 16 pixels are used. The present invention has been made in view of such circumstances, and an object of the present invention is to increase the types of wavelength bands for acquiring information in an image sensor.

The imaging device according to the present invention is arranged in a first region of two regions corresponding to the second color in a Bayer array consisting of first, second, and third colors, and a plurality of first pixels having spectral characteristics in wavelength bands different from each other according to the second color; and a plurality of second pixels having spectral characteristics of a wavelength band, wherein the wavelength band of the spectral characteristics of the plurality of first pixels arranged in the first region and arranged in the second region The wavelength band of the spectral characteristics of the plurality of second pixels, which are arranged in the first region and the wavelength bands of the spectral characteristics of the plurality of second pixels, are partly or entirely different, and are arranged in the first region and the second region. The number of the second pixels is 4 or more .

According to the present invention, the two regions corresponding to the second color in the Bayer array consisting of the first, second, and third colors have different spectral characteristics, thereby increasing the types of wavelength bands from which information is obtained. This allows for finer spectral spectroscopy.

1 is a diagram showing a configuration example of an imaging device having an imaging device according to an embodiment of the present invention; FIG. It is a figure which shows the example of the color filter arrangement|sequence of a Bayer arrangement. 3 is a diagram showing spectral transmittance characteristics of the color filter shown in FIG. 2; FIG. FIG. 10 is a diagram showing another example of a Bayer array color filter array; 5 is a diagram showing spectral transmittance characteristics of the color filter shown in FIG. 4; FIG. FIG. 4 is a diagram showing an example of spectral transmittance characteristics of color filters according to the present embodiment; FIG. 4 is a diagram showing an example of spectral transmittance characteristics of color filters according to the present embodiment; It is a figure explaining the 1st example of the color filter arrangement|sequence in this embodiment. It is a figure explaining the 2nd example of the color filter arrangement|sequence in this embodiment. It is a figure explaining the 3rd example of the color filter arrangement|sequence in this embodiment. It is a figure explaining the 4th example of the color filter arrangement|sequence in this embodiment. It is a figure explaining the 5th example of the color filter arrangement|sequence in this embodiment. It is a figure explaining the 6th example of the color filter arrangement|sequence in this embodiment.

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the drawings. Imaging devices having an imaging device according to the present embodiment described below are not limited to digital still cameras, digital video cameras, etc.; It is also applicable to cameras and the like.

FIG. 1 is a block diagram showing a configuration example of an imaging device having an imaging device according to one embodiment of the present invention. The imaging apparatus in this embodiment has an imaging device 101, an image acquisition unit 102, a pixel data addition unit 103, a line memory 104, an image processing unit 105, a spectral data analysis unit 106, a data output unit 107, and an image output unit 108. .

The imaging device 101 is, for example, a CMOS image sensor, a CCD image sensor, or the like. It is an imaging device having various spectral transmittance characteristics. The image acquisition unit 102 acquires each pixel signal (pixel data) output from the image pickup device 101 and outputs it to the pixel data addition unit 103 and the spectrum data analysis unit 106 .

The pixel data addition unit 103 adds pixel signals (pixel data) of narrow wavelength bands (narrow bands) to generate signals corresponding to the respective colors of R, G, and B, and broadens the pixel signals of narrow bands. It is added to the pixel signal (pixel data) of the (wide) wavelength band. Addition of pixel signals (pixel data) is performed using a memory such as the line memory 104, for example, but the memory such as the line memory 104 is not essential in this embodiment.

The image processing unit 105 performs image processing on the R, G, and B signals obtained by the pixel data addition unit 103 . For example, the image processing unit 105 performs white balance processing, gamma processing, and the like on the R, G, and B color signals according to a form for outputting video. Further, the image processing unit 105 appropriately performs center-of-gravity shift correction processing, false color suppression processing, and the like according to the signal addition method in the pixel data addition unit 103 .

The spectrum data analysis unit 106 analyzes the signal of each wavelength band and performs arbitrary image processing. For example, the spectral data analysis unit 106 obtains a signal with a narrower wavelength band than a broad band, estimates the light source of the light impinging on the subject, and controls the video data to perform appropriate white balance processing. Also, the spectrum data analysis unit 106 performs specific processing or determination based on the output of only a certain wavelength band. The spectrum data analysis unit 106 outputs the processing result as data to the data output unit 107 or feeds it back to the image output unit 108 . It should be noted that the method for analyzing the spectrum data and the like are not particularly limited in this embodiment, and any method can be applied.

The data output unit 107 outputs the processing results and the like supplied from the spectrum data analysis unit 106 to the outside. The image output unit 108 outputs video data obtained by image processing by the image processing unit 105 . The image output unit 108 appropriately processes the video data output from the image processing unit 105 according to the processing result or the like supplied from the spectrum data analysis unit 106, and outputs the processed video data.

Next, the color filter arrangement in the image sensor will be described.
FIG. 2 is a diagram showing an example of an arrangement of color filters for each pixel in a general Bayer arrangement. A group of four pixels, two pixels each in the vertical direction and the horizontal direction, is defined as two pixels among the four pixels (G pixels) that capture light of a wavelength corresponding to G (green). For the remaining two pixels, one pixel is a pixel (R pixel) that captures light with a wavelength corresponding to R (red), and another pixel is a pixel (B pixel) that captures light with a wavelength corresponding to B (blue). ).

For example, as shown in FIG. 2, in four pixels 201 to 204, a color filter (B) having spectral characteristics for transmitting light in a wavelength band corresponding to B is arranged with respect to the pixel 201. FIG. Further, a color filter (G) having spectral characteristics for transmitting light in a wavelength band corresponding to G is arranged for the pixels 202 and 203, and a color filter having spectral characteristics for transmitting light in a wavelength band corresponding to R. (R) is positioned relative to pixel 204 . In FIG. 2, Gb indicates a G pixel next to a B pixel, and Gr indicates a G pixel next to an R pixel.

Thus, in the Bayer array, two G pixels and one R pixel and one B pixel are arranged, and the G pixels are arranged diagonally. The pixels of the image sensor are a series of such combinations as a unit. In addition, in the example shown in FIG. 2, the B pixel is arranged at the upper left, but it is not specified.

FIG. 3 is a diagram showing an example of spectral transmittance characteristics of a single photodiode of a CMOS sensor to which the Bayer arrangement shown in FIG. 2 is applied. In FIG. 3, the horizontal axis is the wavelength of light, and the vertical axis is the spectral transmittance. In FIG. 3, 301 indicates the spectral transmittance characteristic of the B pixel, 302 indicates the spectral transmittance characteristic of the G pixel, and 303 indicates the spectral transmittance characteristic of the R pixel.

A photodiode of a CMOS sensor is generally fabricated on a silicon wafer, and has the highest spectral transmittance characteristics in the vicinity of a wavelength band of 480 to 600 nm corresponding to G. The wavelength band corresponding to R is around 590 to 720 nm, and the wavelength band corresponding to B is around 400 to 540 nm. In this embodiment, the characteristics shown in FIG. 3 are referred to as spectral transmittance characteristics in a broad wavelength band in the Bayer array. As described above, the Bayer array generally uses color filters of three wavelength bands of R, G, and B. FIG.

FIG. 4 is a diagram showing another example of the arrangement of color filters for each pixel in the Bayer arrangement. In the imaging device shown in FIG. 4, regions corresponding to respective colors in the Bayer array are composed of four pixels having spectral characteristics in different wavelength bands. For example, an area 401 corresponding to the color B (blue) is composed of λ1 pixels, λ2 pixels, λ3 pixels, and λ4 pixels that capture light in the wavelength band of λ1 to λ4, which is part of the wavelength band corresponding to B. be done.

Regions 402 and 403 corresponding to the color G (green) are λ5 pixels, λ6 pixels, λ7 pixels, and λ8 pixels that capture light in the wavelength band of λ5 to λ8, which is part of the wavelength band corresponding to G. consists of Furthermore, an area 404 corresponding to the color R (red) is composed of λ9 pixels, λ10 pixels, λ11 pixels, and λ12 pixels that capture light in the wavelength band of λ9 to λ12, which is part of the wavelength band corresponding to R. be done.

Each of the λ1 to λ12 pixels shown in FIG. 4 is provided with a color filter that transmits light in a narrower wavelength band than the broad wavelength band in the Bayer array. , for example, as shown in FIG. FIG. 5 is a diagram showing an example of spectral transmittance characteristics in each pixel shown in FIG.

Here, in the configuration with the wavelength band of λ1 to λ12 as shown in FIG. 4 and FIG. It consists of wavelength bands. Therefore, although the area for 16 pixels is used, only 12 types of wavelength band information can be obtained.

In this case, for example, it is not possible to meet the need for more detailed analysis of the G wavelength region for checking the growth condition in agricultural applications. On the other hand, simply increasing the types of wavelength bands to be spectrally dispersed increases the color difference between the two regions corresponding to the color of G, making false colors more likely to occur.

Therefore, in the imaging device of this embodiment, two regions corresponding to the G color in the Bayer array are provided with narrow band color filters having different wavelength bands, and the arrangement is devised to generate false colors. suppress. In the following description, a color filter having spectral characteristics for transmitting light in a wavelength band of λi (where i is a subscript and i=1 to 16) is referred to as “color filter (λi)”.

Also, a pixel in which a color filter (λi) is arranged and which captures light in the wavelength band of λi, that is, a pixel that acquires information in the wavelength band of λi is referred to as a “λi pixel”. Also, although only a unit array is shown for the pixel array (color filter array) in the image sensor, in the image sensor, the unit arrays are arranged continuously so as to be adjacent to each other.

FIG. 6 is a diagram showing an example of the spectral transmittance characteristics of the color filters (λ1) to (λ16) in this embodiment, in other words, the spectral transmittance characteristics of the λ1 to λ16 pixels. As shown in FIG. 6, the wavelength band λ1 to λ4 is part of the wavelength band corresponding to B, the wavelength bands λ5 to λ8 and λ13 to λ16 are part of the wavelength band corresponding to G, and λ9 The wavelength band of ~λ12 is part of the wavelength band corresponding to R.

In this embodiment, the wavelength band corresponding to G has spectral characteristics of eight different narrow wavelength bands (narrow bands) of λ5 to λ8 and λ13 to λ16. The wavelength bands of λ5 to λ8 and λ13 to λ16 have the shortest center wavelength in the wavelength band of λ5, and the center wavelengths are at similar wavelength intervals in the order of λ5, λ13, λ6, λ14, λ7, λ15, λ8, and λ16. become longer. That is, each of the wavelength bands λ5 to λ8 and λ13 to λ16 corresponds to each wavelength band when the wavelength band corresponding to G is divided into eight.

FIG. 7(a) shows the spectral transmittance characteristics shown in FIG. 6 by narrow-band color filters (λ5) to (λ8) and color filters (λ13) to (λ16) in the wavelength band corresponding to G. It is a figure which shows the transmittance|permeability characteristic. When each of the color filters (λ1) to (λ16) is configured to have substantially the same wavelength bandwidth (half width), the spectral transmittance value overlaps with the color filter of the adjacent band in the G wavelength band. T1 is higher than other B and R wavelength bands.

In this case, since it is the same as other color filters in terms of securing the amount of light, it is advantageous in terms of adding image data and securing gain. put away. Therefore, for example, as shown in FIG. 7B, the wavelength bandwidth (half width) of the color filters (λ5) to (λ8) and the color filters (λ13) to (λ16) included in the wavelength band of G is narrowed ( for example, about 1/2). By doing so, it is possible to reduce the value T2 of the spectral transmittance that overlaps with the color filter of the adjacent band, make the amount of overlap equivalent to that of the other B and R wavelength bands, and improve the accuracy of spectral separation. be.

First Arrangement Example FIGS. 8A to 8C are diagrams for explaining a first example of the color filter arrangement of the imaging device according to the present embodiment. In the first example, as illustrated in FIG. 8(a), the image pickup device has four pixels having spectral characteristics in different wavelength bands in regions corresponding to respective colors in the Bayer array. In addition, the pixels are arranged so that the wavelength bands of the spectral characteristics are all different between the two regions corresponding to the color of G.

For example, an area 801 corresponding to the B color in the Bayer array is composed of λ1 to λ4 pixels in which color filters (λ1) to (λ4) for the B color are arranged. Of the two regions corresponding to the G color in the Bayer array, the first region (Gb region) 802 is λ5 to λ8 pixels in which the color filters (λ5) to (λ8) related to the G color are arranged. Configured.

A second area (Gr area) 803 corresponding to the G color is composed of λ13 to λ16 pixels in which the color filters (λ13) to (λ16) for the G color are arranged. A region 804 corresponding to the R color in the Bayer array is composed of λ9 pixels to λ12 pixels in which color filters (λ9) to (λ12) related to the R color are arranged.

As a result, when the signals of the B, Gr, Gb, and R regions are added and calculated, the calculation can be performed using the following formulas.
B=λ1+λ2+λ3+λ4
Gb=λ5+λ6+λ7+λ8
Gr=λ13+λ14+λ15+λ16
R=λ9+λ10+λ11+λ12
In these equations, λi indicates the signal obtained from the λi pixel (the same applies to the following equations).

The spectral characteristics of the Gb region and the Gr region calculated by the above formula are shown in FIGS. 8B and 8C, respectively. As shown in FIGS. 8(b) and 8(c), in the Gb and Gr regions, the center values λ _Gb and λ _Gr of the wavelengths of the spectral characteristics are close values, and the obtained gain is also a general value. Almost the same gain can be obtained for the object. Therefore, the Gr and Gb regions can be treated as regions corresponding to substantially the same G color, and since there is little color shift between the Gr and Gb regions, false colors are less likely to occur. In addition, since the wavelength bands of the spectral characteristics of the four pixels in each region of Gr and Gb are separated at approximately equal intervals, it is also advantageous in terms of spectrum data analysis.

In this way, the area corresponding to each color of the Bayer array is composed of a plurality of pixels in which narrow-band color filters are arranged, and by devising the arrangement of the color filters, an efficient spectral characteristic array is configured, Finer spectral spectroscopy becomes possible. Further, in two regions corresponding to the color of G, the central wavelengths of the spectral characteristics in the first region (Gb region) and the spectral characteristics in the second region (Gr region) are made substantially the same to generate false colors. can be suppressed.

Second Arrangement Example FIGS. 9A to 9C are diagrams for explaining a second example of the color filter arrangement of the image sensor in this embodiment. Also in the second example, as illustrated in FIG. 9(a), the image pickup element is composed of four pixels having spectral characteristics in mutually different wavelength bands in regions corresponding to respective colors in the Bayer array. . Also, as in the first example, the pixels are arranged such that the wavelength bands of the spectral characteristics are all different between the two regions corresponding to the color G. FIG.

For example, an area 901 corresponding to the B color in the Bayer array is composed of λ1 to λ4 pixels in which color filters (λ1) to (λ4) for the B color are arranged. Of the two regions corresponding to the G color in the Bayer array, the first region (Gb region) 902 contains color filters (λ5), (λ6), (λ15), and (λ16) related to the G color. λ5 pixels, λ6 pixels, λ15 pixels, and λ16 pixels are arranged.

In addition, a second region (Gr region) 903 corresponding to the G color has λ13 pixels and λ14 pixels in which color filters (λ13), (λ14), (λ7), and (λ8) related to the G color are arranged. λ7 pixels and λ8 pixels. A region 904 corresponding to the R color in the Bayer array is composed of λ9 to λ12 pixels in which color filters (λ9) to (λ12) related to the R color are arranged.

As a result, when the signals of the B, Gr, Gb, and R regions are added and calculated, the calculation can be performed using the following formulas.
B=λ1+λ2+λ3+λ4
Gb=λ5+λ6+λ15+λ16
Gr=λ13+λ14+λ7+λ8
R=λ9+λ10+λ11+λ12

The spectral characteristics of the Gb region and the Gr region calculated by the above formula are shown in FIGS. 9B and 9C, respectively. As shown in FIGS. 9(b) and 9(c), in the Gb and Gr regions, the center values λ _Gb and λ _Gr of the wavelengths of the spectral characteristics are the same, and the obtained gain is Approximately the same gain can be obtained. Therefore, the Gr and Gb regions can be treated as regions corresponding to substantially the same G color, and since there is little color shift between the Gr and Gb regions, false colors are less likely to occur.

In this way, by devising the arrangement of narrow-band color filters, an efficient arrangement of spectral characteristics can be formed, and finer spectrum spectroscopy becomes possible. In addition, it is possible to make the center wavelengths of the spectral characteristics the same in the two regions corresponding to the color of G, thereby suppressing the occurrence of false colors.

Third Arrangement Example FIGS. 10(a) to 10(c) are diagrams for explaining a third example of the color filter arrangement of the imaging element in this embodiment. Also in the third example, as illustrated in FIG. 10(a), the imaging element is composed of four pixels having spectral characteristics in mutually different wavelength bands in regions corresponding to respective colors in the Bayer array. . Also, in the same manner as in the above example, the pixels are arranged so that the wavelength bands of the spectral characteristics are all different between the two regions corresponding to the G color.

For example, an area 1001 corresponding to the B color in the Bayer array is composed of λ1 to λ4 pixels in which color filters (λ1) to (λ4) for the B color are arranged. Of the two regions corresponding to the G color in the Bayer array, the first region (Gb region) 1002 is the color filters (λ5), (λ13), (λ8), and (λ16) associated with the G color. λ5 pixels, λ13 pixels, λ8 pixels, and λ16 pixels are arranged.

In addition, the second region (Gr region) 1003 corresponding to the G color is λ6 pixels, λ14 pixels, in which the color filters (λ6), (λ14), (λ7), and (λ15) related to the G color are arranged. λ7 pixels and λ15 pixels. A region 1004 corresponding to the R color in the Bayer array is composed of λ9 pixels to λ12 pixels in which color filters (λ9) to (λ12) related to the R color are arranged.

As a result, when the signals of the B, Gr, Gb, and R regions are added and calculated, the calculation can be performed using the following formulas.
B=λ1+λ2+λ3+λ4
Gb=λ5+λ13+λ8+λ16
Gr=λ6+λ14+λ7+λ15
R=λ9+λ10+λ11+λ12

The spectral characteristics of the Gb region and the Gr region calculated by the above formulas are shown in FIGS. 10(b) and 10(c), respectively. As shown in FIGS. 10(b) and 10(c), in the Gb and Gr regions, the center values λ _Gb and λ _Gr of the wavelengths of the spectral characteristics are the same. can be treated as a region corresponding to the G color of .

Fourth Arrangement Example FIGS. 11A to 11C are diagrams for explaining a fourth example of the color filter arrangement of the imaging device according to this embodiment. Also in the fourth example, as illustrated in FIG. 11( a ), the image pickup element is composed of a plurality of pixels having spectral characteristics in different wavelength bands in regions corresponding to respective colors in the Bayer array. . Also, in the same manner as in the above example, the pixels are arranged so that the wavelength bands of the spectral characteristics are all different between the two regions corresponding to the G color.

For example, an area 1101 corresponding to the B color in the Bayer array is composed of λ1 to λ4 pixels in which color filters (λ1) to (λ4) for the B color are arranged. Of the two regions corresponding to the G color in the Bayer array, the first region (Gb region) 1102 contains color filters (λ5), (λ14), (λ7), and (λ16) related to the G color. λ5 pixels, λ14 pixels, λ7 pixels, and λ16 pixels are arranged.

A second region (Gr region) 1103 corresponding to the G color is λ13 pixels, λ6 pixels, in which color filters (λ13), (λ6), (λ15), and (λ8) related to the G color are arranged. λ15 pixels and λ8 pixels. A region 1104 corresponding to the R color in the Bayer array is composed of λ9 to λ12 pixels in which color filters (λ9) to (λ12) related to the R color are arranged.

As a result, when the signals of the B, Gr, Gb, and R regions are added and calculated, the calculation can be performed using the following formulas.
B=λ1+λ2+λ3+λ4
Gb=λ5+λ14+λ7+λ16
Gr=λ13+λ6+λ15+λ8
R=λ9+λ10+λ11+λ12

The spectral characteristics of the Gb region and the Gr region calculated by the above formula are shown in FIGS. 11(b) and 11(c), respectively. As shown in FIGS. 11(b) and 11(c), in the Gb and Gr regions, the center values λ _Gb and λ _Gr of the wavelengths of the spectral characteristics are the same, and the obtained gain is Approximately the same gain can be obtained. Therefore, the Gr and Gb regions can be treated as regions corresponding to substantially the same G color, and since there is little color shift between the Gr and Gb regions, false colors are less likely to occur.

In this way, by devising the arrangement of narrow-band color filters, an efficient arrangement of spectral characteristics can be formed, and finer spectrum spectroscopy becomes possible. In addition, it is possible to make the center wavelengths of the spectral characteristics the same in the two regions corresponding to the color of G, thereby suppressing the occurrence of false colors.

Note that the color filter arrays shown in the above-described first to fourth examples are merely examples, and the present invention is not limited to these. The area corresponding to each color in the Bayer array is composed of four pixels having spectral characteristics in different wavelength bands, and the two areas corresponding to the color G are completely different in the wavelength band of the spectral characteristics. Any color filter arrangement as arranged is applicable.

Fifth Arrangement Example FIGS. 12(a) to 12(c) are diagrams for explaining a fifth example of the color filter arrangement of the imaging element in this embodiment. In the fifth example, as illustrated in FIG. 12(a), the image pickup device has four pixels having spectral characteristics in different wavelength bands in regions corresponding to respective colors in the Bayer array. Also, in the fifth example, at least one spectral characteristic of the same wavelength band is present between two regions corresponding to the G color in the Bayer array. That is, in the fifth example, the pixels are arranged such that the wavelength bands of the spectral characteristics are partially different between the two regions corresponding to the color of G.

For example, an area 1201 corresponding to the B color in the Bayer array is composed of λ1 to λ4 pixels in which color filters (λ1) to (λ4) for the B color are arranged. Of the two regions corresponding to the G color in the Bayer array, the first region (Gb region) 1202 is λ5 to λ8 pixels in which the color filters (λ5) to (λ8) related to the G color are arranged. Configured.

In addition, the second region (Gr region) 1203 corresponding to the G color is λ13 pixel, λ14 pixel, in which the color filters (λ13), (λ14), (λ7), and (λ16) related to the G color are arranged. λ7 pixels and λ16 pixels. A region 1204 corresponding to the R color in the Bayer array is composed of λ9 to λ12 pixels in which color filters (λ9) to (λ12) related to the R color are arranged.

In this way, by arranging the λ7 pixels having the spectral characteristics of the same λ7 wavelength band in the Gb and Gr regions, the signals obtained by the λ7 pixels are used as the reference for center-of-gravity adjustment, and the values in the Gb and Gr regions can be easily matched. In addition, when the signal of each area|region of B, Gr, Gb, and R is added and calculated, it can calculate by the numerical formula illustrated below.
B=λ1+λ2+λ3+λ4
Gb=λ5+λ6+λ7+λ8
Gr=λ13+λ14+λ7+λ16
R=λ9+λ10+λ11+λ12

The spectral characteristics of the Gb region and the Gr region calculated by the above formula are shown in FIGS. 12(b) and 12(c), respectively. As shown in FIGS. 12(b) and 12(c), in the Gb and Gr regions, the center values λ _Gb and λ _Gr of the wavelengths of the spectral characteristics are close values, and the obtained gain is also a general value. Almost the same gain can be obtained for the object.

Therefore, the Gr and Gb regions can be treated as regions corresponding to substantially the same G color, and since there is little color shift between the Gr and Gb regions, false colors are less likely to occur. By arranging pixels having spectral characteristics in the λ7 wavelength band in each of the Gb and Gr regions, it is possible to obtain spectral data for 15 different wavelength bands, although the resolution for one wavelength band is reduced. Become.

In this example, the spectral characteristics of the wavelength band of λ7 are configured so that two regions corresponding to the color of G have the spectral characteristics, but the present invention is not limited to this wavelength band. It may be configured to have two areas corresponding to colors. Also, two regions corresponding to the color G may be configured to have not only one pixel having the same spectral characteristic but also a plurality of pixels each having the same spectral characteristic.

In this manner, even in the configuration shown in the fifth example, by devising the arrangement of narrow-band color filters, an efficient arrangement of spectral characteristics can be formed, and finer spectrum spectroscopy becomes possible. In addition, it is possible to make the center wavelengths of the spectral characteristics the same in the two regions corresponding to the color of G, thereby suppressing the occurrence of false colors.

Sixth Arrangement Example FIGS. 13A to 13C are diagrams for explaining a sixth example of the color filter arrangement of the imaging device according to the present embodiment. In the sixth example, as illustrated in FIG. 13(a), the imaging element has color filters (λ1) to (λ4) for the B color in a region 1301 corresponding to the B color in the Bayer array. λ1 pixel to λ4 pixel. Of the two regions corresponding to the G color in the Bayer array, the first region (Gb region) 1302 is the color filters (λ5), (λ13), (λ6), and (λ14) associated with the G color. λ5 pixels, λ13 pixels, λ6 pixels, and λ14 pixels are arranged.

A second region (Gr region) 1303 corresponding to the G color is λ7 pixels, λ15 pixels, and λ15 pixels in which the color filters (λ7), (λ15), (λ8), and (λ16) related to the G color are arranged. λ8 pixels and λ16 pixels. A region 1304 corresponding to the R color in the Bayer array is composed of λ9 pixels to λ12 pixels in which color filters (λ9) to (λ12) related to the R color are arranged.

As a result, when the signals of the B, Gr, Gb, and R regions are added and calculated, the calculation can be performed using the following formulas.
B=λ1+λ2+λ3+λ4
Gb=λ5+λ13+λ6+λ14
Gr=λ7+λ15+λ8+λ16
R=λ9+λ10+λ11+λ12

The spectral characteristics of the Gb region and the Gr region calculated by the above formula are shown in FIGS. 13(b) and 13(c), respectively. The Gb region has the spectral characteristics of the wavelength band on the blue side within the wavelength band associated with the color G, and the region Gr has the spectral characteristics of the wavelength band on the red side of the wavelength band associated with the color G. have As a result, although a color shift occurs between the Gb and Gr regions, the wavelength components can be arranged in order and added, and the spectrum data can be analyzed more smoothly.

In the above description, an example in which the regions corresponding to the respective colors in the Bayer array are composed of four pixels having spectral characteristics of different wavelength bands has been described, but the present invention is not limited to this. A region corresponding to each color in the Bayer array may be composed of a plurality of pixels having spectral characteristics of different wavelength bands. For example, each region may be composed of four or more pixels having spectral characteristics of different wavelength bands. good too.
In this embodiment, the spectral transmittance characteristics of the color filter and the photodiode alone are used as factors for determining the spectral transmittance characteristics. is not limited to

It should be noted that the above-described embodiments are merely examples of specific implementations of the present invention, and the technical scope of the present invention should not be construed to be limited by these. That is, the present invention can be embodied in various forms without departing from its technical concept or main features.

101: image sensor 102: image acquisition unit 103: pixel data addition unit 104: line memory 105: image processing unit 106: spectral data analysis unit 107: data output unit 108: image output unit

Claims (8)

spectrum of different wavelength bands associated with the second color, arranged in the first region of two regions corresponding to the second color in a Bayer array consisting of first, second, and third colors; a plurality of first pixels having characteristics;
a plurality of second pixels arranged in a second region of the two regions corresponding to the second color and having spectral characteristics in different wavelength bands related to the second color;
The wavelength band of the spectral characteristics of the plurality of first pixels arranged in the first region and the wavelength band of the spectral characteristics of the plurality of second pixels arranged in the second region , partly or wholly different,
The imaging device , wherein the number of the first pixels arranged in the first region and the number of the second pixels arranged in the second region are four or more . 2. The imaging device according to claim 1, wherein the center value of the wavelength of the spectral characteristics in said first region and the center value of the wavelengths of the spectral characteristics in said second region are the same . A central wavelength when the spectral characteristics of the plurality of first pixels arranged in the first region are combined, and the spectral characteristics of the plurality of second pixels arranged in the second region. 2. The imaging device according to claim 1, wherein the central wavelengths are the same when they are combined. The half width of the spectral characteristics of each of the first pixel and the second pixel is narrower than the half width of the spectral characteristics of the pixels of a color other than the second color in the Bayer array. 4. The imaging device according to any one of claims 1 to 3. The half width of the spectral characteristics of each of the first pixel and the second pixel is (1/2) the half width of the spectral characteristics of the pixels of the other color different from the second color in the Bayer array. ), the imaging device according to any one of claims 1 to 3. One of the plurality of first pixels arranged in the first region and one of the plurality of second pixels arranged in the second region 6. The imaging device according to claim 1, wherein the wavelength band of spectral characteristics of the second pixel is the same as that of the second pixel. The wavelength band of the spectral characteristics of the plurality of first pixels arranged in the first region is a wavelength band on the side of the first color in the wavelength band associated with the second color, and The wavelength band of the spectral characteristics of the plurality of second pixels arranged in the second region is a wavelength band on the side of the third color in the wavelength band associated with the second color. The imaging device according to any one of claims 1, 4 and 5. An imaging device according to any one of claims 1 to 7 ,
Acquisition means for acquiring pixel data from the imaging device;
addition means for adding the acquired pixel data;
and analysis means for analyzing the acquired pixel data.

Images