Patent Publication Number: US-2023164452-A1

Title: Photoelectric conversion element and photoelectric conversion device

Description:
BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The present invention relates to a photoelectric conversion element and a photoelectric conversion device capable of acquiring a visible light image and an infrared light image concurrently. 
     Description of the Related Art 
     In general, in the field of monitoring or inspection, a camera capable of photographing visible light and infrared light concurrently is in demand. To cope with this, there is proposed a photoelectric conversion element having a pixel array of red (R), green (G), blue (B), and infrared (IR). In this photoelectric conversion element, in addition to color filters of R, G, and B each having sensitivity in a wavelength band of visible light, a color filter of IR having sensitivity to infrared light is stacked on a photodiode (PD). 
     In addition, in the pixel array of R, G, B, and IR, a G pixel is replaced with an IR pixel, and hence information on visible light is lost. To cope with this, Japanese Patent Application Publication No. 2008-289000 proposes a configuration in which color filters of R+IR, G+IR, B+IR, and white (W)+IR each having sensitivity in wavelength bands of visible light and infrared light are provided on PDs. In the technique in Japanese Patent Application Publication No. 2008-289000, information on IR is extracted on the assumption that the sum of sensitivities of R, G, and B corresponds to the sensitivity of W. 
     In the technique in Japanese Patent Application Publication No. 2008-289000, that the sum of the sensitivities of R, G, and B corresponds to the sensitivity of W is the assumption of IR component extraction. 
     However, both ends of a transmittance characteristic of each wavelength of G overlap with a transmittance characteristic of each of R and B, and hence it becomes difficult to satisfy the above assumption. As a result, accuracy of the extraction of the IR component deteriorates, and color reproducibility of a visible light image may deteriorate. 
     SUMMARY OF THE INVENTION 
     In view of the foregoing, the technique of the present disclosure provides a photoelectric conversion element and a photoelectric conversion device capable of photographing high-sensitivity and high-resolution visible light and infrared light concurrently. 
     According to an aspect of the present disclosure, it is provided a photoelectric conversion element including a pixel area which includes a plurality of rows and a plurality of columns, a first filter which is provided in a first pixel constituting the pixel area and allows passage of visible light in a first wavelength band and infrared light in a second wavelength band, a second filter which is provided in a second pixel constituting the pixel area and allows the passage of the visible light in the first wavelength band and the infrared light in the second wavelength band, and a first light reduction unit which reduces the infrared light having passed through the second filter, wherein a third filter which allows the passage of the visible light in the first wavelength band and the infrared light in the second wavelength band is provided in, among pixels constituting the pixel area, each pixel other than the first pixel and the second pixel. 
     Further features of the present invention will become apparent from the following description of exemplary embodiments with reference to the attached drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a block diagram showing an example of the configuration of a photoelectric conversion device according to an embodiment; 
         FIG.  2    is a circuit diagram showing an example of the configuration of an image sensor unit according to the embodiment; 
         FIG.  3    is a view showing a transmittance characteristic of each wavelength of a DBPF according to the embodiment; 
         FIG.  4    is a view showing a color filter array of the image sensor unit according to the embodiment; 
         FIG.  5    is a view showing the transmittance characteristic of each wavelength of a color filter according to the embodiment; 
         FIGS.  6 A and  6 B  are views simply showing cross sections of pixels of the image sensor unit according to the embodiment; 
         FIG.  7    is a view showing the transmittance characteristic of each wavelength of an infrared neutral density filter according to the embodiment; 
         FIG.  8    is a view schematically showing separation between a visible light image and an infrared light image in the embodiment; 
         FIG.  9    is a view showing the color filter array of the image sensor unit according to an embodiment; 
         FIGS.  10 A and  10 B  are views showing the cross sections of the pixels of the image sensor unit according to the embodiment; 
         FIG.  11    is a view schematically showing the separation between the visible light image and the infrared light image in the embodiment; 
         FIG.  12    is a view showing the color filter array of the image sensor unit according to an embodiment; 
         FIG.  13    is a view showing the transmittance characteristic of each wavelength of the color filter according to the embodiment; 
         FIGS.  14 A and  14 B  are views showing the cross sections of the pixels of the image sensor unit according to the embodiment; 
         FIG.  15    is a view showing the transmittance characteristic of each wavelength of the infrared neutral density filter according to the embodiment; 
         FIG.  16    is a view schematically showing the separation between the visible light image and the infrared light image in the embodiment; 
         FIG.  17    is a view showing the color filter array of the image sensor unit according to an embodiment; 
         FIG.  18    is a view showing the transmittance characteristic of each wavelength of the color filter according to the embodiment; 
         FIGS.  19 A and  19 B  are views showing the cross sections of the pixels of the image sensor unit according to the embodiment; 
         FIG.  20    is a view schematically showing the separation between the visible light image and the infrared light image in the embodiment; 
         FIG.  21    is a view showing an example of application of the photoelectric conversion device according to an embodiment; 
         FIG.  22    is a flowchart showing an example of acquisition processing of aberration information in the embodiment; 
         FIG.  23    is a view showing an example of application of the photoelectric conversion device according to an embodiment; 
         FIG.  24    is a flowchart showing an example of the acquisition processing of the aberration information in the embodiment; 
         FIG.  25    is a view showing the color filter array of the image sensor unit according to a modification; and 
         FIG.  26    is a view showing the transmittance characteristic of each wavelength of the color filter according to the modification. 
     
    
    
     DESCRIPTION OF THE EMBODIMENTS 
     Hereinbelow, preferred embodiments of the technique of the present disclosure will be described with reference to the drawings. Note that the individual drawings are merely drawn for the purpose of explaining structures and configurations, and the dimensions of individual members shown in the drawings do not necessarily reflect actual dimensions. In addition, in the individual drawings, the same reference numerals denote the same members or components and, hereinbelow, the description of duplicate contents will be omitted. 
     First Embodiment 
     (Configuration) A photoelectric conversion device  1  of a first embodiment will be described with reference to  FIGS.  1  to  8   .  FIG.  1    is a block diagram showing an example of the configuration of the photoelectric conversion device  1 . The photoelectric conversion device  1  includes a lens unit  11 , a dual band pass filter (DBPF) unit  12 , an image sensor unit  13 , a processor unit  14 , an external computer unit  15 , an image display unit  16 , and an image recording unit  17 . 
     The lens unit  11  has a transmittance which allows the passage of light from a wavelength band of visible light to a wavelength band of infrared light. Note that the lens unit  11  is preferably subjected to chromatic aberration correction in ranges of the wavelength bands of the passage. The DBPF unit  12  is an optical filter which allows the passage of light in part of the wavelength band of visible light and light in part of the wavelength band of infrared light. Though described later, the DBPF unit  12  blocks light in a wavelength band positioned between visible light and near-infrared light in order to separate light having passed through the lens unit  11  into a visible light component and an IR component with high accuracy. With this, the DBPF unit  12  separates light having passed through the lens unit  11  into visible light and infrared light, and causes the visible light and the infrared light to be incident on a pixel area of the image sensor unit  13 . As shown in  FIG.  2   , the image sensor unit  13 , which serves as a photoelectric conversion element, has a pixel array  131  and a controller  132 . The processor unit  14  can communicate with the controller  132 , and controls the pixel array  131  with the controller  132  and acquires image data of a subject (not shown). The processor unit  14 , which serves as an image generation unit, generates a visible light image and an infrared light image by using a signal output from the photoelectric conversion element. The detail of processing executed by the processor unit  14  will be described later. 
     The processor unit  14  processes the image data of the subject acquired from the image sensor unit  13 , and transmits the processed image data to each of the external computer unit  15 , the image display unit  16 , and the image recording unit  17 . In addition, the processor unit  14  has an image data separation unit  141  which separates the image data of the subject into a visible light image and an infrared light image. The detail of processing executed by the processor unit  14  will be described later. The processor unit  14  may be, e.g., an integrated circuit or a device capable of programming individual functions (e.g., a programmable logic device (PLD) such as a field programmable gate array (FPGA)). Alternatively, the processor unit  14  may also be an arithmetic unit such as a micro processing unit (MPU) or a digital signal processor (DSP) for implementing the individual functions. Alternatively, the processor unit  14  may be a dedicated integrated circuit (an application specific integrated circuit (ASIC) or the like). Alternatively, the processor unit  14  may include a CPU and a memory, and the individual functions may be implemented on software. That is, the functions of the processor unit  14  are implemented by hardware and/or software. 
     The external computer unit  15  can communicate with the processor unit  14  and the image recording unit  17 , and acquires the image data of the subject or the image data which is separated into the visible light image and the infrared light image of the subject and performs image processing. The image display unit  16  can communicate with the processor unit  14  and the external computer unit  15 , and displays RAW data of the image data of the subject, the image data which is separated into the visible light image and the infrared light image of the subject, and image data after adjustment in which the image quality of each image data mentioned above is adjusted. The image recording unit  17  records the image data received from the processor unit  14  or the external computer unit  15 . 
       FIG.  2    shows an example of the configuration of the image sensor unit  13  in the first embodiment. The image sensor unit  13  has a control unit  133  and a signal reading unit  134  in addition to the pixel array  131  and the controller  132 . The pixel array  131  includes a plurality of pixels PX arranged in a matrix (so as to form a pixel area including a plurality of rows and a plurality of columns). In the present embodiment, a color filter array shown as an example in  FIG.  4    is provided on the pixels PX. In the present embodiment, the control unit  133  is a vertical scanning circuit constituted by a decoder and a shift register, and drives the plurality of pixels PX for each row. The signal reading unit  134  includes a signal amplification circuit  1341  and a sampling circuit  1342  disposed in each column, a multiplexer  1343 , and a horizontal scanning circuit  1344  constituted by a decoder and a shift register. 
     With this configuration, the signal reading unit  134  performs signal reading for each column from the plurality of pixels PX driven by the control unit  133 . In sampling by the sampling circuit  1382 , correlated double sampling (CDS) processing is used. The controller  132  includes a timing generator, and performs synchronization control of the pixels PX, the control unit  133 , and the signal reading unit  134 . 
       FIG.  3    shows a transmittance characteristic of each wavelength of the DBPF unit  12 . In an example shown in  FIG.  3   , the transmittance characteristic is a characteristic which allows the passage of part of visible light (light having a wavelength of 400 nm to 700 nm) and the passage of part of infrared light (light having a wavelength of 850 nm to 1000 nm). The transmittance characteristic shown in the drawing for separating visible light and infrared light condensed by the lens unit  11  into lights in wavelength bands which are different from each other with the DBPF unit  12  is only an example, and the transmittance characteristic may be any transmittance characteristic which can satisfy an arithmetic expression which allows separation between a visible light component and an infrared light component. The detail of the arithmetic expression will be described later. 
       FIG.  4    schematically shows the color filter array of the image sensor unit  13  in the first embodiment. As shown in  FIG.  4   , when a pixel array of two columns×two rows is assumed to be one unit of a pixel area including a plurality of rows and a plurality of columns, an R+IR pixel  41  and a B+IR pixel  44  are included in the unit, and the R+IR pixel  41  and the B+IR pixel  44  are disposed so as to be positioned diagonally. In addition, a W+IR pixel  42  and a W+2IR pixel  43  are included in the unit, and the W+IR pixel  42  and the W+2IR pixel  43  are disposed so as to be positioned diagonally. Note that the W+2IR pixel  43  is provided as an example of a first pixel, and the W+IR pixel  42  is provided as an example of a second pixel. 
       FIG.  5    shows the transmittance characteristic of each wavelength of each color filter of the image sensor unit  13  in the first embodiment. As shown in  FIG.  5   , the B+IR pixel  44  has the transmittance characteristic which allows the passage of light having a wavelength of 400 nm to 550 nm and light having a wavelength of 700 nm to 1000 nm. In addition, the R+IR pixel  41  has the transmittance characteristic which allows the passage of light having a wavelength of 550 nm to 1000 nm. Further, each of the W+IR pixel  42  and the W+2IR pixel  43  has the transmittance characteristic which allows the passage of light of 400 nm to 1000 nm which includes the wavelength band of visible light serving as a first wavelength band and the wavelength band of infrared light serving as a second wavelength band. An example of visible light in the first wavelength band is white light. 
       FIGS.  6 A and  6 B  show schematic views of cross-sectional structures of four pixels which are the W+IR pixel  42  and the W+2IR pixel  43  ( FIG.  6 A ), and the R+IR pixel  41  and the B+IR pixel  44  ( FIG.  6 B ) which are included in the image sensor unit  13 . Note that a microlens (ML) unit  139   a  is an optical system for efficiently performing light condensing to the W+IR pixel  42 . A W+2IR filter unit  1310   a  is a filter which allows the passage of, out of light condensed in the ML unit  139   a , light in a wavelength band from visible light to infrared light shown in  FIG.  5   . Note that the W+2IR filter unit  1310   a  is a second filter which allows the passage of visible light in the first wavelength band and infrared light in the second wavelength band. An infrared neutral density filter unit  1311   a  is a filter having a transmittance which reduces infrared light having passed through the W+2IR filter unit  1310   a , and reduces sensitivity to infrared light by half. Note that the infrared neutral density filter unit  1311   a  is an example of a first light reduction unit which reduces infrared light having passed through the second filter. A photodiode (PD) unit  1312   a  converts light having passed through the infrared neutral density filter unit  1311   a  into electrical charge. 
     In addition, an ML unit  139   b  is an optical system for efficiently performing light condensing to the W+2IR pixel  43 . A W+2IR filter unit  1310   b  is a filter which allows the passage of, out of light condensed in the ML unit  139   b , light in the wavelength band from visible light to infrared light shown in  FIG.  5   . Note that the W+2IR filter unit  1310   b  is a first filter which allows the passage of visible light in the first wavelength band and infrared light in the second wavelength band. A PD unit  1312   b  converts light having passed through the W+2IR filter unit  1310   b  into electrical charge. With the structure described above, in one unit of the pixel area, the W+2IR pixel  43  has IR sensitivity which is twice as high as that of the W+IR pixel  42 . 
     In addition, ML units  139   c  and  139   d  are optical systems for efficiently performing light condensing to the R+IR pixel  41  and the B+IR pixel  44 , respectively. An R+2IR filter unit  1310   c  and a B+2IR filter unit  1310   d  are filters which allow the passage of, out of light condensed in the ML units  139   c  and  139   d , light in the wavelength band from visible light to infrared light shown in  FIG.  5   . Note that each of the R+2IR filter unit  1310   c  and the B+2IR filter unit  1310   d  is a third filter which allows the passage of visible light in the first wavelength band and infrared light in the second wavelength band. Infrared neutral density filter units  1311   c  and  1311   d  are filters having the transmittances which reduce infrared lights having passed through the R+2IR filter unit  1310   c  and the B+2IR filter unit  1310   d , and reduce sensitivity to infrared light by half. Note that each of the infrared neutral density filter units  1311   c  and  1311   d  is an example of a second light reduction unit which reduces infrared light having passed through the third filter. Thus, the infrared neutral density filter units  1311   c  and  1311   d  are provided also in the R+IR pixel  41  and the B+IR pixel  44  other than the W+IR pixel  42  and the W+2IR pixel  43 . In addition, the light reduction rate of each of the infrared neutral density filter units  1311   c  and  1311   d  serving as the light reduction units provided in the R+IR pixel  41  and the B+IR pixel  44  is equal to the light reduction rate of the infrared neutral density filter unit  1311   a . PD units  1312   c  and  1312   d  convert lights having passed through the infrared neutral density filter units  1311   c  and  1311   d  into electrical charge. 
     Note that, in the present embodiment, as shown in  FIGS.  6 A and  6 B , a structure in which the infrared neutral density filter is stacked on the PD as means for providing a difference in infrared sensitivity is adopted, but other structures may also be adopted. That is, for example, a structure in which, by providing a difference in the depth of impurity implantation for photoelectric conversion of the PD, a desired difference is provided in the sensitivity to infrared light may also be adopted. For example, the W+2IR pixel  43  is provided as an example of a third pixel, and the W+IR pixel  42  is provided as an example of a fourth pixel. In addition, the W+2IR filter unit  1310   a  is used as a fourth filter which allows the passage of visible light in a third wavelength band and infrared light in a fourth wavelength band. Further, the W+2IR filter unit  1310   b  is used as a fifth filter which allows the passage of visible light in the third wavelength band and infrared light in the fourth wavelength band. In addition, the PD unit  1312   b  is used as a first photoelectric conversion unit, and the PD unit  1312   a  is used as a second photoelectric conversion unit. At this point, it is possible to provide a difference in infrared sensitivity between the PD units by providing a difference between the depth of impurity implantation in the PD unit  1312   b  and the depth of impurity implantation in the PD unit  1312   a . Further, each of the R+2IR filter unit  1310   c  and the B+2IR filter unit  1310   d  serves as a sixth filter which allows the passage of visible light in the third wavelength band and infrared light in the fourth wavelength band. 
       FIG.  7    shows the transmittance characteristic of each wavelength of each of the infrared neutral density filters stacked on the R+IR pixel  41 , the W+IR pixel  42 , and the B+IR pixel  44  of the image sensor unit  13 . In addition, though the depiction thereof is omitted, the transmittance of light reaching each of the individual PD units  1312   a ,  1312   c , and  1312   d  is a product of the transmittance shown in  FIG.  3   , the transmittance shown in  FIG.  5   , and the transmittance shown in  FIG.  7   . 
     (Arithmetic Calculation) Image data generated by the image sensor unit  13  including the R+IR pixel  41 , the W+IR pixel  42 , the W+2IR pixel  43 , and the B+IR pixel  44  described above is transmitted to the processor unit  14 . The processor unit  14  includes at least the image data separation unit  141  which performs separation between the visible light image and the infrared light image. In addition, in the present embodiment, the image data separation unit  141  is included in the processor unit  14 , but may also be included in the image sensor unit  13 . 
     Hereinbelow, a description will be given of an example of processing executed by the image data separation unit  141  in the first embodiment. As shown in  FIG.  8   , pixel values of pixels after the separation between the visible light image and the infrared light image are denoted by R′, G21′, G12′, B′, and IR′. By performing addition and subtraction by using the following expressions (1-1) to (1-6), it is possible to separate the pixel values of the individual pixels into the pixel values R′, G21′, G12′, B′, and IR′. 
         G=W −( R+B )  (1-1)
 
         IR ′=( W+ 2 IR )−( W+IR )  (1-2)
 
         R ′=( R+IR )− IR′   (1-3)
 
         B ′=( B+IR )− IR′   (1-4)
 
         G 12′=( W+IR )− IR′   (1-5)
 
         G 21′=( W+ 2 IR )−{( R+IR )+( B+IR )}  (1-6)
 
     Herein, it is assumed that the transmittance characteristics shown in  FIGS.  3 ,  5   , and  7  are set such that the above expression (1-1) is satisfied. 
     (Effect) The photoelectric conversion element according to the present embodiment is different from a conventional photoelectric conversion element which is configured to acquire the visible light image and the infrared light image concurrently in that the IR pixel and the G pixel are replaced with the W pixels. With this configuration, in the photoelectric conversion element according to the present embodiment, information which can be used for the generation of the visible light image is increased as compared with the conventional photoelectric conversion element, i.e., it is possible to achieve increases in the resolution and the sensitivity of a captured image. 
     In addition, according to the photoelectric conversion element of the present embodiment, as compared with a conventional color filter array, it is possible to implement the separation between the visible light image and the infrared light image more easily, and higher color reproducibility is obtained when a color image is generated from the visible light image. In addition, in the photoelectric conversion element of the present embodiment, the IR components are included in the pixel values obtained from all pixels, and hence, even in the case where the color image is generated without separating visible light and infrared light from each other, an increase in sensitivity can be expected to be achieved. For example, in the photoelectric conversion element of the present embodiment, edge detection performance can be expected to be improved in a low-illuminance photographing environment in night-time photographing or the like. 
     Second Embodiment 
     (Configuration) Next, the photoelectric conversion device  1  according to a second embodiment will be described with reference to  FIGS.  1 ,  3 ,  5 ,  7 ,  9 ,  10 A and  10 B . An example of the configuration of the photoelectric conversion device  1  according to the second embodiment is the same as that of the photoelectric conversion device  1  according to the first embodiment shown in  FIG.  1   . In addition, the transmittance characteristic of each wavelength of the DBPF unit  12  of the photoelectric conversion device  1  according to the second embodiment is the transmittance characteristic shown in  FIG.  3   . Further, the circuit diagram showing an example of the configuration of the image sensor unit  13  of the photoelectric conversion device  1  according to the second embodiment and the transmittance characteristic of each color filter stacked on the pixel are the same as those shown in  FIGS.  2  and  5   . In addition, in the photoelectric conversion device  1  according to the second embodiment, the transmittance characteristic of the infrared neutral density filter stacked on the pixel of the image sensor unit  13  serving as the photoelectric conversion element is the transmittance characteristic shown in  FIG.  7   . 
     In the photoelectric conversion device  1  according to the second embodiment, the configurations of the color filter and the infrared neutral density filter which are stacked on the pixels of the image sensor unit  13  are different from those in the first embodiment. In addition, the arithmetic expressions used by the image data separation unit  141  of the photoelectric conversion device  1  according to the second embodiment are different from the arithmetic expressions in the first embodiment. 
       FIG.  9    shows the color filter array of the image sensor unit  13  in the second embodiment. When the pixel array of two columns×two rows is assumed to be one unit of the pixel area, an R+2IR pixel  91  and a B+2IR pixel  94  are included in the unit, and the R+2IR pixel  91  and the B+2IR pixel  94  are disposed so as to be positioned diagonally. In addition, a W+2IR pixel  92  and a W+IR pixel  93  are included in the unit, and the W+2IR pixel  92  and the W+IR pixel  93  are disposed so as to be positioned diagonally. 
       FIGS.  10 A and  10 B  show schematic views of cross-sectional structures of the W+2IR pixel  92  and the W+IR pixel  93  ( FIG.  10 A ), and the R+2IR pixel  91  and the B+2IR pixel  94  ( FIG.  10 B ) which are included in the image sensor unit  13 . An ML unit  139   e  is an optical system for efficiently performing light condensing to the W+IR pixel  93 . A W+2IR filter unit  1310   e  is a filter which allows the passage of, out of light condensed in the ML unit  139   e , light in the wavelength band from visible light to infrared light shown in  FIG.  5   . An infrared neutral density filter unit  1311   e  is a filter having the transmittance which reduces infrared light having passed through the W+2IR filter unit  1310   e , and reduces sensitivity to infrared light by half. A PD unit  1312   e  converts light having passed through the infrared neutral density filter unit  1311   e  into electrical charge. 
     In addition, an ML unit  139   f  is an optical system for efficiently performing light condensing to the W+2IR pixel  92 . A W+2IR filter unit  1310   f  is a filter which allows the passage of, out of light condensed in the ML unit  139   f , light in the wavelength band from visible light to infrared light shown in  FIG.  5   . A PD unit  1312   f  converts light having passed through the W+2IR filter unit  1310   f  into electrical charge. With the structure described above, in one unit of the pixel area, the W+2IR pixel  92  has the IR sensitivity which is twice as high as that of the W+IR pixel  93 . 
     In addition, an ML unit  139   g  is an optical system for efficiently performing light condensing to the R+2IR pixel  91 . An R+2IR filter unit  1310   g  is a filter which allows the passage of, out of light condensed in the ML unit  139   g , light in the wavelength band from visible light to infrared light shown in  FIG.  5   . A PD unit  1312   g  converts light having passed through the R+2IR filter unit  1310   g  into electrical charge. In addition, an ML unit  139   h  is an optical system for efficiently performing light condensing to the B+2IR pixel  94 . A B+2IR filter unit  1310   h  is a filter which allows the passage of, out of light condensed in the ML unit  139   h , light in the wavelength band from visible light to infrared light shown in  FIG.  5   . A PD unit  1312   h  converts light having passed through the B+2IR filter unit  1310   h  into electrical charge. Consequently, similarly to the W+2IR pixel  92 , each of the R+2IR pixel  91  and the B+2IR pixel  94  has a structure in which the infrared neutral density filter is “not” stacked. 
     The transmittance characteristic of each wavelength of the infrared neutral density filter stacked on the W+IR pixel  93  of the image sensor unit  13  in the present embodiment is the same as that in the first embodiment, as shown in  FIG.  7   . Note that the transmittance of light reaching the PD unit  1312   e  is a product of the transmittance shown in  FIG.  3   , the transmittance shown in  FIG.  5   , and the transmittance shown in  FIG.  7   . 
     (Arithmetic Calculation) Image data generated by the image sensor unit  13  including the R+2IR pixel  91 , the W+2IR pixel  92 , the W+IR pixel  93 , and the B+2IR pixel  94  described above is transmitted to the processor unit  14 . The processor unit  14  includes at least the image data separation unit  141  which performs separation between the visible light image and the infrared light image. In addition, in the present embodiment, the image data separation unit  141  is included in the processor unit  14 , but may also be included in the image sensor unit  13 . 
     Hereinbelow, a description will be given of an example of processing executed by the image data separation unit  141  in the second embodiment. As shown in  FIG.  11   , the pixel values of the pixels after the separation between the visible light image and the infrared light image are denoted by R′, G21′, G12′, B′, and IR′. By performing addition and subtraction by using the expression (1-1) and the following expressions (2-1) to (2-5), it is possible to separate the pixel values of the individual pixels into the pixel values R′, G21′, G12′, B′, and IR′. 
         IR ′=( W+ 2 IR )−( W+IR )  (2-1)
 
         R ′=( R+ 2 IR )−2 IR′   (2-2)
 
         B ′=( B+ 2 IR )−2 IR′   (2-3)
 
         G 12′=( W+ 2 IR )−2 IR′   (2-4)
 
         G 21′=( W+ 2 IR )−2 IR′   (2-5)
 
     Herein, it is assumed that the transmittance characteristics shown in  FIGS.  3 ,  5   , and  7  are set such that the above expression (1-1) is satisfied. 
     (Effect) The photoelectric conversion element according to the present embodiment is different from the conventional photoelectric conversion element which is configured to acquire the visible light image and the infrared light image concurrently in that the IR pixel and the G pixel are replaced with the W pixels. With this configuration, in the photoelectric conversion element according to the present embodiment, information which can be used for the generation of the visible light image is increased as compared with the conventional photoelectric conversion element, i.e., it is possible to achieve increases in the resolution and the sensitivity of the captured image. Further, in the photoelectric conversion element according to the present embodiment, the IR sensitivity in one unit is improved as compared with the first embodiment, and hence the infrared light image having higher sensitivity can be expected to be generated. 
     Third Embodiment 
     (Configuration) Next, the photoelectric conversion device  1  according to a third embodiment will be described with reference to  FIGS.  1 ,  3 ,  5 ,  12 ,  13 ,  14 A,  14 B,  15 , and  16   . An example of the configuration of the photoelectric conversion device  1  according to the third embodiment is the same as that of the photoelectric conversion device  1  according to the first embodiment shown in  FIG.  1   . In addition, the transmittance characteristic of each wavelength of the DBPF unit  12  of the photoelectric conversion device  1  according to the third embodiment is the transmittance characteristic shown in  FIG.  3   . Further, in the photoelectric conversion device  1  according to the third embodiment, the circuit diagram showing an example of the configuration of the image sensor unit  13  serving as the photoelectric conversion element and the transmittance characteristic of each color filter stacked on the pixel are the same as those shown in  FIGS.  2  and  5   . 
     In the photoelectric conversion device  1  according to the third embodiment, the configuration of the infrared neutral density filter stacked on the pixel of the image sensor unit  13  is different from that in the first embodiment. In addition, the configurations of the color filter and the infrared neutral density filter which are stacked on the pixels of the image sensor unit  13  of the photoelectric conversion device  1  according to the third embodiment are different from those in the first embodiment. Further, the arithmetic expressions used by the image data separation unit  141  of the photoelectric conversion device  1  according to the third embodiment are different from the arithmetic expressions in the first embodiment. 
       FIG.  12    shows the color filter array of the image sensor unit  13  in the third embodiment. When the pixel array of two columns×two rows is assumed to be one unit of the pixel area, an R+2IR pixel  1201  and a B+2IR pixel  1204  are included in the unit, and the R+2IR pixel  1201  and the B+2IR pixel  1204  are disposed so as to be positioned diagonally. In addition, a W+IR pixel  1202  and a W+4IR pixel  1203  are included in the unit, and the W+IR pixel  1202  and the W+4IR pixel  1203  are disposed so as to be positioned diagonally. 
       FIG.  13    shows the transmittance characteristic of each wavelength of each color filter of the image sensor unit  13  in the third embodiment. As shown in  FIG.  13   , the R+2IR pixel  1201  has the transmittance characteristic which allows the passage of light having a wavelength of 550 nm to 1000 nm. In addition, the B+2IR pixel  1204  has the transmittance characteristic which allows the passage of light having a wavelength of 400 nm to 550 nm and light having a wavelength of 750 nm to 1000 nm. Further, each of the W+IR pixel  1202  and the W+4IR pixel  1203  has the transmittance characteristic which allows the passage of light having a wavelength of 400 nm to 1000 nm. The IR sensitivity in the third embodiment is twice as high as that in the first embodiment. 
       FIGS.  14 A and  14 B  show schematic views of cross-sectional structures of the W+IR pixel  1202  and the W+4IR pixel  1203  ( FIG.  14 A ), and the R+2IR pixel  1201  and the B+2IR pixel  1204  ( FIG.  14 B ) which are included in the image sensor unit  13 . An ML unit  139   i  is an optical system for efficiently performing light condensing to the W+IR pixel  1202 . A W+4IR filter unit  1310   i  is a filter which allows the passage of, out of light condensed in the ML unit  139   i , light in a wavelength band from visible light to infrared light shown in  FIG.  13   . An infrared neutral density filter unit  1311   i  is a filter having the transmittance which reduces infrared light having passed through the W+4IR filter unit  1310   i , and reduces sensitivity to infrared light to ¼. A PD unit  1312   i  converts light having passed through the infrared neutral density filter unit  1311   i  into electrical charge. 
     In addition, an ML unit  139   j  is an optical system for efficiently performing light condensing to the W+4IR pixel  1203 . A W+4IR filter unit  1310   j  is a filter which allows the passage of, out of light condensed in the ML unit  139   j , light in the wavelength band from visible light to infrared light shown in  FIG.  13   . A PD unit  1312   j  converts light having passed through the W+4IR filter unit  1310   j  into electrical charge. With the structure described above, in one unit of the pixel area, the W+4IR pixel  1203  has the IR sensitivity which is four times as high as that of the W+IR pixel  1202 . 
     In addition, an ML unit  139   k  is an optical system for efficiently performing light condensing to the R+2IR pixel  1201 . An R+4IR filter unit  1310   k  is a filter which allows the passage of, out of light condensed in the ML unit  139   k , light in the wavelength band from visible light to infrared light shown in  FIG.  13   . An infrared neutral density filter unit  1311   k  is a filter having the transmittance which reduces infrared light having passed through the R+4IR filter unit  1310   k , and reduces sensitivity to infrared light by half. A PD unit  1312   k  converts light having passed through the infrared neutral density filter unit  1311   k  into electrical charge. 
     In addition, an ML unit  139   m  is an optical system for efficiently performing light condensing to the B+2IR pixel  1204 . A B+4IR filter unit  1310   m  is a filter which allows the passage of, out of light condensed in the ML unit  139   m , light in the wavelength band from visible light to infrared light shown in  FIG.  13   . An infrared neutral density filter unit  1311   m  is a filter having the transmittance which reduces infrared light having passed through the B+4IR filter unit  1310   m , and reduces sensitivity to infrared light by half. Consequently, the light reduction rate of each of the infrared neutral density filter units  1311   k  and  1311   m  serving as the light reduction units provided in the R+2IR pixel  1201  and the B+2IR pixel  1204  is lower than the light reduction rate of the infrared neutral density filter unit  1311   i . A PD unit  1312   m  converts light having passed through the infrared neutral density filter unit  1311   m  into electrical charge. 
       FIG.  15    shows the transmittance characteristic of each wavelength of each of the infrared neutral density filters stacked on the R+2IR pixel  1201 , the W+IR pixel  1202 , and the B+2IR pixel  1204  of the image sensor unit  13  in the present embodiment. In addition, the transmittance of light reaching each of the PD units  1312   i ,  1312   k , and  1312   m  is a product of the transmittance shown in  FIG.  3   , the transmittance shown in  FIG.  13   , and the transmittance shown in  FIG.  15   . 
     (Arithmetic Calculation) Image data generated by the image sensor unit  13  including the R+2IR pixel  1201 , the W+IR pixel  1202 , the W+4IR pixel  1203 , and the B+2IR pixel  1204  described above is transmitted to the processor unit  14 . The processor unit  14  includes at least the image data separation unit  141  which performs separation between the visible light image and the infrared light image. In addition, in the present embodiment, the image data separation unit  141  is included in the processor unit  14 , but may also be included in the image sensor unit  13 . 
     Hereinbelow, a description will be given of an example of processing executed by the image data separation unit  141  in the third embodiment. As shown in  FIG.  16   , the pixel values of the pixels after the separation between the visible light image and the infrared light image are denoted by R′, G21′, G12′, B′, and IR′. By performing addition and subtraction by using the expression (1-1) and the following expressions (3-1) to (3-5), it is possible to separate the pixel values of the individual pixels into the pixel values R′, G21′, G12′, B′, and IR′. 
         IR ′={( W+ 4 IR )−( W+IR )}/3  (3-1)
 
         R ′=( R+ 2 IR )−2 IR′   (3-2)
 
         B ′=( B+ 2 IR )−2 IR′   (3-3)
 
         G 12′=( W+IR )− IR′   (3-4)
 
         G 21′=( W+ 4 IR )−{( R+ 2 IR )+( B+ 2 IR )}  (3-5)
 
     Herein, it is assumed that the transmittance characteristics shown in  FIGS.  3 ,  13 , and  15    are set such that the above expression (1-1) is satisfied. 
     (Effect) Similarly to the first embodiment, the photoelectric conversion element according to the present embodiment is different from the conventional photoelectric conversion element which is configured to acquire the visible light image and the infrared light image concurrently in that the IR pixel and the G pixel are replaced with the W pixels. With this configuration, in the photoelectric conversion element according to the present embodiment, information which can be used for the generation of the visible light image is increased as compared with the conventional photoelectric conversion element, i.e., it is possible to achieve increases in the resolution and the sensitivity of the captured image. Further, in the photoelectric conversion element according to the present embodiment, the IR sensitivity in one unit is improved as compared with the first and second embodiments, and hence the infrared light image having higher sensitivity can be expected to be generated. Further, in the photoelectric conversion element according to the present embodiment, the dynamic range of the IR sensitivity can also be expected to be extended by using a difference in the IR sensitivity. 
     Fourth Embodiment 
     (Configuration) Next, the photoelectric conversion device  1  according to a fourth embodiment will be described with reference to  FIGS.  1 ,  3 ,  5 ,  7 , and  17  to  20   . An example of the configuration of the photoelectric conversion device  1  according to the fourth embodiment is the same as that of the photoelectric conversion device  1  according to the first embodiment shown in  FIG.  1   . The transmittance characteristic of each wavelength of the DBPF unit  12  of the photoelectric conversion device  1  according to the fourth embodiment is the transmittance characteristic shown in  FIG.  3   . In addition, in the photoelectric conversion device  1  according to the fourth embodiment, the circuit diagram showing an example of the configuration of the image sensor unit  13  serving as the photoelectric conversion element and the transmittance characteristic of each color filter stacked on the pixel are the same as those shown in  FIGS.  2  and  5   . 
     In the photoelectric conversion device  1  according to the fourth embodiment, the configuration of each color filter stacked on the pixel of the image sensor unit  13  is different from that in the first embodiment. In addition, the configurations of the color filter and the infrared neutral density filter which are stacked on the pixels of the image sensor unit  13  of the photoelectric conversion device  1  according to the fourth embodiment are different from those in the first embodiment. Further, the arithmetic expressions used by the image data separation unit  141  of the photoelectric conversion device  1  according to the fourth embodiment are different from the arithmetic expressions in the first embodiment. 
       FIG.  17    shows the color filter array of the image sensor unit  13  in the fourth embodiment. When the pixel array of two columns×two rows is assumed to be one unit of the pixel area, three W+IR pixels  1701 ,  1702 , and  1704  and one W+2IR pixel  1703  are included in the unit. 
       FIG.  18    shows the transmittance characteristic of each wavelength of each color filter of the image sensor unit  13  in the fourth embodiment. As shown in  FIG.  18   , each of the W+IR pixels  1701 ,  1702 , and  1704 , and the W+2IR pixel  1703  has the transmittance characteristic which allows the passage of light having a wavelength of 400 nm to 1000 nm. 
       FIGS.  19 A and  19 B  show schematic views of cross-sectional structures of the W+IR pixels  1701 ,  1702 , and  1704 , and the W+2IR pixel  1703  which are included in the image sensor unit  13  in the fourth embodiment. ML units  139   n ,  139   q , and  139   r  are optical systems for efficiently performing light condensing to the W+IR pixels  1701 ,  1702 , and  1704 . W+2IR filter units  1310   n ,  1310   q , and  1310   r  are filters which allow the passage of, out of light condensed in the ML units  139   n ,  139   q , and  139   r , light in a wavelength band from visible light to infrared light shown in  FIG.  18   . Infrared neutral density filter units  1311   n ,  1311   q , and  1311   r  are filters having the transmittances which reduce infrared light having passed through the W+2IR filter units  1310   n ,  1310   q , and  1310   r , and reduce sensitivity to infrared light by half. PD units  1312   n ,  1312   q , and  1312   r  convert light having passed through the infrared neutral density filter units  1311   n ,  1311   q , and  1311   r  into electrical charge. 
     In addition, an ML unit  139   p  is an optical system for efficiently performing light condensing to the W+2IR pixel  1703 . A W+2IR filter unit  1310   p  is a filter which allows the passage of, out of light condensed in the ML unit  139   p , light in the wavelength band from visible light to infrared light shown in  FIG.  18   . A PD unit  1312   p  is a unit which converts light having passed through the W+2IR filter unit  1310   p  into electrical charge. With the structure described above, in one unit of the pixel area, the W+2IR pixel  1703  has the IR sensitivity which is twice as high as that of each of the W+IR pixels  1701 ,  1702 , and  1704 . 
     The transmittance characteristic of each wavelength of each of the infrared neutral density filters stacked on the W+IR pixels  1701 ,  1702 , and  1704  of the image sensor unit  13  in the present embodiment is the transmittance characteristic shown in  FIG.  7   . In addition, the transmittance of light reaching each of the PD units  1312   n ,  1312   q , and  1312   r  is a product of the transmittance shown in  FIG.  3   , the transmittance shown in  FIG.  7   , and the transmittance shown in  FIG.  18   . 
     (Arithmetic Calculation) Image data generated by the image sensor unit  13  including the W+IR pixels  1701 ,  1702 , and  1704 , and the W+2IR pixel  1703  described above is transmitted to the processor unit  14 . The processor unit  14  includes at least the image data separation unit  141  which performs separation between the visible light image and the infrared light image. In addition, in the present embodiment, the image data separation unit  141  is included in the processor unit  14 , but may also be included in the image sensor unit  13 . 
     Hereinbelow, a description will be given of an example of processing executed by the image data separation unit  141  in the fourth embodiment. As shown in  FIG.  20   , the pixel values of the pixels after the separation between the visible light image and the infrared light image are denoted by W11′, W21′, W12′, W22′, and IR′. By performing addition and subtraction by using the following expressions (4-1) to (4-5), it is possible to separate the pixel values of the individual pixels into the pixel values W11′, W21′, W12′, W22′, and IR′. 
         IR ′=( W 21+ IR )−{( W 11+ IR )+( W 12+ IR )+( W 22+ IR )}/3  (4-1)
 
         W 11′=( W 11+ IR )− IR′   (4-2)
 
         W 12′=( W 12+ IR )− IR′   (4-3)
 
         W 22′=( W 22+ IR )− IR′   (4-4)
 
         W 21′=( W 21+2 IR )−2 IR′   (4-5)
 
     (Effect) The photoelectric conversion element according to the present embodiment is different from the conventional photoelectric conversion element which is constituted by the pixel array of two columns×two rows of, e.g., W, W, W, and IR in that the IR pixel is replaced with the W pixel. With this configuration, in the photoelectric conversion element according to the present embodiment, information which can be used for the generation of the visible light image is increased as compared with the conventional photoelectric conversion element, i.e., it is possible to achieve increases in the resolution and the sensitivity of the captured image. 
     Fifth Embodiment 
     (Configuration) Next, the photoelectric conversion device  1  according to a fifth embodiment will be described with reference to  FIGS.  1 ,  21 , and  22   . An example of the configuration of the photoelectric conversion device  1  according to the fifth embodiment is the same as that of the photoelectric conversion device  1  according to the first embodiment shown in  FIG.  1   . In addition, in the photoelectric conversion device  1  according to the fifth embodiment, as the array and the transmittance characteristic of the color filter stacked on the pixel of the image sensor unit  13 , the cross-sectional view of the pixel, and the transmittance characteristic of the infrared neutral density filter, the arrays and the transmittance characteristics in the first to fourth embodiments may be appropriately combined and adopted. 
       FIG.  21    shows an example of application of the photoelectric conversion device  1  according to the fifth embodiment. As shown in  FIG.  21   , an infrared irradiation device  52  applies infrared rays to an area in the angle of view which is imaged by the photoelectric conversion device  1 . A subject  53  is a suspicious person imaged by the photoelectric conversion device  1  during, e.g., night-time monitoring. With regard to the material of sunglasses  54  worn by the subject  53 , a common material which reflects visible light but allows the passage of infrared light is assumed to be used. In addition, with regard to clothes  55  worn by the subject  53 , a complicated design (“ABC” in the drawing) which requires image generation with high resolution in the photoelectric conversion device  1  is assumed to be provided in the clothes  55 . 
     (Processing Flow)  FIG.  22    is a flowchart showing an example of a control method at the time of imaging of the subject  53  which is executed by the processor unit  14  of the photoelectric conversion device  1 . First, in Step S 100  (hereinafter simply described as “S 100 ”. The same applies to other steps), the image sensor unit  13  serving as the photoelectric conversion element receives an instruction to start imaging by an operation from, e.g., a user of the photoelectric conversion device  1 , and starts imaging. Next, in S 110 , the image data separation unit  141  separates image data acquired by the imaging of the image sensor unit  13  into a visible light image and an infrared light image. Next, in S 120 , the processor unit  14  executes color development processing of the visible light image. Note that this processing may be executed by the external computer unit  15 . Next, in S 130 , the processor unit  14  executes image recognition processing on the subject  53  by using the visible light image and the infrared light image. Note that this processing may be executed by the external computer unit  15 . 
     Next, in S 140 , the processor unit  14  determines whether or not the subject  53  satisfies a predetermined condition related to the suspicious person with the image recognition processing in S 130 . Herein, examples of the predetermined condition include abnormal behavior of the subject  53  and abnormal clothes (a design of clothes) of the subject. For example, the predetermined condition includes that the subject  53  wears the sunglasses  54  as shown in  FIG.  21    or that the subject  53  repeats back-and-forth movement in the angle of view. In the case where the subject  53  satisfies the predetermined condition (S 140 : YES), the processor unit  14  advances the processing to S 150 . On the other hand, in the case where the subject  53  does not satisfy the predetermined condition (S 140 : NO), the processor unit  14  ends the processing of the present flowchart. Note that the processor unit  14  may perform the determination processing by using a plurality of the predetermined conditions in S 140 , and may also be configured to advance to S 150  in the case where at least one predetermined condition is satisfied. Alternatively, the processor unit  14  may also be configured to advance to S 150  in the case where two or more or all predetermined conditions are satisfied. In S 150 , the processor unit  14  records the image of the subject  53  having served as a determination target in S 140  in the image recording unit  17 , and ends the processing of the present flowchart. 
     (Effect) According to the photoelectric conversion device according to the present embodiment, in the case where a suspicious person is found during, e.g., night-time photographing, it is possible to perform image generation having high sensitivity and high resolution, and hence it is possible to detect the subject determined to be the suspicious person with high accuracy and record the image thereof. For example, in the case where the subject  53  is determined to be the suspicious person in  FIG.  21   , it is possible to resolve the detail of the design of the clothes  55  in the visible light image of the subject  53 , and reproduce the color of the clothes  55  with high accuracy. Further, in the infrared light image of the subject  53 , it is possible to image eyes of the subject  53  through the sunglasses  54 , and hence it becomes possible to discern expressions of the subject  53  from the infrared light image. With this, the image generated by the photoelectric conversion device  1  can be expected to be useful for preventing crime. 
     Sixth Embodiment 
     (Configuration) Next, the photoelectric conversion device  1  according to a sixth embodiment will be described with reference to  FIGS.  1 ,  23 , and  24   . An example of the configuration of the photoelectric conversion device  1  according to the sixth embodiment is the same as that of the photoelectric conversion device  1  according to the first embodiment shown in  FIG.  1   . In addition, in the photoelectric conversion device  1  according to the sixth embodiment, as the array and the transmittance characteristic of the color filter stacked on the pixel of the image sensor unit  13 , the cross-sectional view of the pixel, and the transmittance characteristic of the infrared neutral density filter, the arrays and the transmittance characteristics in the first to fourth embodiments may be appropriately combined and adopted. 
       FIG.  23    shows an example of application of the photoelectric conversion device  1  according to the sixth embodiment. As shown in  FIG.  23   , an infrared irradiation device  62  applies infrared rays to an area in the angle of view which is imaged by the photoelectric conversion device  1  with low illuminance. An inspection object  63  is an object to be inspected which is imaged by the photoelectric conversion device  1  in this low-illuminance environment. A belt conveyer  64  conveys the inspection object  63  and moves the inspection object  63  in one direction. 
     (Flow)  FIG.  24    is a flowchart showing an example of a control method at the time of imaging of the inspection object  63  which is executed by the processor unit  14  of the photoelectric conversion device  1 . First, in S 200 , the image sensor unit  13  serving as the photoelectric conversion element receives an instruction to start imaging by an operation from, e.g., a user of the photoelectric conversion device  1 , and starts imaging. Next, the image data separation unit  141  separates image data acquired by the imaging of the image sensor unit  13  into a visible light image and an infrared light image. Next, in S 220 , the processor unit  14  executes color development processing of the visible light image. Note that this processing may also be executed by the external computer unit  15 . Next, in S 230 , the processor unit  14  executes color inspection of the inspection object  63  by using the visible light image with image recognition processing, and executes contamination inspection by using the infrared light image. Note that the color inspection and the contamination inspection can be implemented by using known techniques, and hence, herein, the detailed description thereof will be omitted. 
     Next, in S 240 , the processor unit  14  determines whether or not the inspection object  63  satisfies predetermined conditions related to appearance abnormality and contamination based on results of various inspections in S 230 . Herein, with regard to examples of the predetermined condition, examples of the predetermined condition in S 240  include the occurrence of color unevenness in an image of the inspection object  63  in the visible light image, and the presence of a foreign matter which reflects infrared light from the inspection object  63  in the infrared light image. In the case where the inspection object  63  satisfies the predetermined condition (S 240 : YES), the processor unit  14  advances the processing to S 250 . On the other hand, in the case where the inspection object  63  does not satisfy the predetermined condition (S 240 : NO), the processor unit  14  ends the processing of the present flowchart. Note that the processor unit  14  may perform the determination processing by using a plurality of the predetermined conditions in S 240 , and may also be configured to advance to S 250  in the case where at least one predetermined condition is satisfied. Alternatively, the processor unit  14  may also be configured to advance to S 250  in the case where two or more or all predetermined conditions are satisfied. In S 250 , the processor unit  14  records the image of the inspection object  63  having served as the determination target in S 240  in the image recording unit  17 , and ends the processing of the present flowchart. 
     (Effect) According to the photoelectric conversion device according to the present embodiment, in the inspection of the inspection object in an environment in which an illumination condition is limited such as, e.g., a low-illuminance environment, it is possible to perform image generation having high sensitivity and high resolution, and hence it is possible to detect the inspection object having abnormality with high accuracy and record the image thereof. In addition, it is possible to execute inspection processing on both of the visible light image and the infrared light image, and hence it is possible to perform both of the appearance inspection and the contamination inspection of the inspection object. With this, for example, the appearance inspection and the contamination inspection can be expected to be performed on each of a plurality of inspection objects which are conveyed successively at high speed by the belt conveyer with high accuracy even when turnaround time (TAT) is reduced. 
     While the foregoing is the description related to the present embodiments, the configurations and the processing of the photoelectric conversion element and the photoelectric conversion device described above are not limited to the above-described embodiments, and various modifications may be made within the range which does not lose identity with the technical idea of the present invention. For example, the placement of the individual pixels of two columns×two rows described above is not limited to those shown in the drawings, and the pixels may be appropriately interchanged. In addition, the transmittance characteristic of each filter described above is not limited to those shown in the drawings, and the wavelength band of light which passes through the filter may be appropriately adjusted. Further, the same effects as those of the embodiments described above can be expected to be achieved also by arranging the pixels in the same manner as in each of the above embodiments in a pixel area in which at least one of the number of columns and the number of rows is larger than two. 
     In addition, in the embodiments described above, a pixel provided with a filter which allows the passage of light in a wavelength band of green (G) may also be adopted instead of the pixel provided with the filter which allows the passage of white light. For example, as shown in  FIG.  25   , as a modification of the first embodiment, it is possible to constitute one unit of the pixel area with the G+IR pixel  45  and G+2IR pixel  46  instead of the W+IR pixel  42  and the W+2IR pixel  43 . In this case, the transmittance characteristic of each color filter corresponds to the transmittance characteristic shown in  FIG.  26    instead of the transmittance characteristic shown in  FIG.  5   . Note that the transmittance characteristic shown in  FIG.  26    is only an example, and the transmittance may be appropriately adjusted. In addition, by causing the configuration of the G+IR pixel  45  and the G+2IR pixel  46  to correspond to the configuration of the W+IR pixel  42  and the W+2IR pixel  43  described above, it is possible to achieve increases in the resolution and the sensitivity of each of the visible light image and the infrared light image. 
     According to the technique of the present disclosure, there are provided a photoelectric conversion element and a photoelectric conversion device which adequately perform separation between a visible component and an infrared component for the purpose of acquiring both of a visible light image and an infrared light image, and allow the visible light image to have high sensitivity and high resolution while maintaining high color separation. 
     (Other Embodiments) While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions. 
     This application claims the benefit of Japanese Patent Application No. 2021-188610, filed on Nov. 19, 2021, which is hereby incorporated by reference herein in its entirety.