JP7016557B1 - Imaging device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image pickup device capable of generating high-definition images of a subject taken with two kinds of light having different wavelength ranges. SOLUTION: This image pickup apparatus splits light from a lens and a subject incident through the lens into light having a first wavelength component including visible light and light having a second wavelength component including invisible light. An absorber provided between the spectroscope, the lens and the spectroscope, and absorbing at least a part of the light of the overlapping component of the light of the first wavelength component and the light of the second wavelength component, and the first It is characterized by including a first image pickup element that receives the light of the wavelength component of the above and a second image pickup element that receives the light of the second wavelength component. [Selection diagram] Fig. 1

Description

The present invention relates to an image pickup apparatus.

An imaging device that shoots using visible light is used. The Charge Coupled Device (CCD) image sensor and the Complex Mary Metal-Oxide-Semicondutor (CMOS) image sensor that generate image pickup data based on incident light have sensitivity to a wider range of wavelengths than visible light. Therefore, in an imaging device that shoots with visible light, a filter that suppresses the incident of light other than visible light on the CCD image sensor or CMOS image sensor is used.

For example, in Patent Document 1, a beam splitter that splits light incident through a lens into a first light wavelength component mainly containing visible light and a second light wavelength component mainly containing invisible light, and a first beam splitter. A low-pass filter arranged on the optical path of the first optical wavelength component and restricting the passage of overlapping components of the first optical wavelength component and the second optical wavelength component, and a first arranged on the optical path of the second optical wavelength component. An imaging device including a high-pass filter that limits the passage of overlapping components of a wavelength component and a second wavelength component has been proposed.

JP-A-2015-108692

The visible light image acquired by shooting with visible light includes information on the color of the subject. Therefore, according to the visible light image, it is possible to easily identify a subject whose color is different only. In a dark environment, the visible light image tends to be unclear, so infrared light is used for shooting. By shooting with infrared light, it is possible to obtain an infrared light image that is clearer than the visible light image in a dark environment. However, since the infrared light image is a black-and-white image, it is difficult to determine what color the subject was from the infrared light image. As described above, the images generated based on the light having different wavelength components have different characteristics.

One aspect of the disclosed technique is to provide an image pickup apparatus capable of producing high-definition images of a subject taken with light of two kinds of different wavelength components.

One aspect of the disclosed technique is exemplified by the following imaging devices. The image pickup apparatus includes a lens and a spectroscope that splits light from a subject incident through the lens into light having a first wavelength component including visible light and light having a second wavelength component including invisible light. An absorber provided between the lens and the spectroscope, which absorbs at least a part of the light of the overlapping component of the light of the first wavelength component and the light of the second wavelength component, and the first wavelength. It is characterized by including a first image pickup element that receives light of a component and a second image pickup element that receives light of a second wavelength component.

This image pickup apparatus can generate high-definition images of a subject taken with light of two kinds of different wavelength components.

FIG. 1 is a diagram schematically showing an image pickup apparatus according to an embodiment. FIG. 2 is a diagram schematically illustrating the characteristics of the beam splitter used in the embodiment. FIG. 3 is a diagram schematically illustrating the transmission characteristics of the near-infrared light absorption substrate. FIG. 4 is a diagram schematically showing the characteristics when the near-infrared light absorption substrate and the beam splitter are combined in the embodiment. FIG. 5 is a diagram illustrating the composition of a visible light image and an infrared light image by an image processing circuit. FIG. 6 is a diagram showing an example of an image pickup apparatus according to the first modification. FIG. 7 is a diagram showing an example of an image pickup apparatus according to a second modification. FIG. 8 is a diagram schematically illustrating an application example.

<Embodiment>
The configurations of the embodiments shown below are exemplary, and the disclosed techniques are not limited to the configurations of the embodiments. The image pickup apparatus according to the embodiment includes, for example, the following configurations. The image pickup device according to the present embodiment includes a lens, a first image pickup element, a second image pickup element, and an absorber.

The first image pickup device is an image pickup device having a peak sensitivity to the light of the first wavelength component dispersed by the spectroscope. The second image pickup device is an image pickup device having a peak sensitivity to the light of the second wavelength component dispersed by the spectroscope. Here, as the sensitivity distribution of the first image sensor and the second image sensor, various sensitivity distributions such as a mountain type and a trapezoidal type can be mentioned. Further, the sensitivities of the first image sensor and the second image sensor may have peaks for a plurality of wavelengths. When having a plurality of peaks, any one of the plurality of peaks may be included in a desired wavelength component (for example, in the case of the first image sensor, the first wavelength component). For example, one of the light having the first wavelength component and the light having the second wavelength component is light containing visible light, and the other is light containing near infrared light.

The spectroscope is, for example, a prism beam splitter. The spectroscope splits the light from the subject incident through the lens into the light of the first wavelength component including visible light and the light of the second wavelength component including invisible light. The spectroscope may, for example, transmit the light of the first wavelength component among the incident light incident through the lens and incident it on the first image pickup device. Further, the spectroscope may reflect the light of the second wavelength component and make it incident on the second image pickup device. The light of the first wavelength component and the light of the second wavelength component spectroscopically separated by the spectroscope have an overlap of a wavelength range of about 100 nm in the vicinity of the near infrared light.

The absorber is provided between the lens and the spectroscope. The absorber absorbs at least a part of the light of the overlapping component of the light of the first wavelength component and the light of the second wavelength component.

The first image pickup element and the second image pickup element are sensitive to light having a wavelength other than the desired wavelength component. Therefore, when the light of the overlapping components is incident on the first image sensor and the second image sensor, the image quality of the images generated by the first image sensor and the second image sensor may deteriorate. The present image pickup apparatus can suppress such deterioration of image quality by allowing the absorber to absorb at least a part of the light among the overlapping components.

The spectroscope is provided so that the angle between the normal line of the spectral surface of the spectroscope and the optical axis of the lens is 45 degrees, and the light of the first wavelength component and the light of the second wavelength component are One of the light may be transmitted and the other of the light having the first wavelength component and the light having the second wavelength component may be reflected in the direction perpendicular to the optical axis.

Here, the light having the first wavelength component may be light having a wavelength of 750 nm or less. Further, the light having the second wavelength component may be light having a wavelength of 650 nm or more. Further, the absorber may have an absorption rate of light of 95% or more in the wavelength range of 100 nm or more in the wavelength range of 650 nm or more and 800 nm or less. In other words, the first image pickup element generates a visible light image based on the light in the wavelength range of 650 nm or less (that is, visible light), and the second image pickup element generates the visible light image in the wavelength range of 750 nm or more (that is, near). It may generate an infrared light image based on (infrared light).

The spectroscope is selected from the group of magnesium fluoride (MgF ₂ ), titanium dioxide (TIO ₃ ), silicon dioxide (SiO ₂ ), niobium pentoxide (Nb ₂ O ₅ ), and tantalum pentoxide (Ta ₂ O ₅ ). It may be formed by laminating dielectrics having different refractive indexes from each other. Further, the spectroscope may contain a squarylium compound.

The present image pickup apparatus may further include a generation means for generating a composite image obtained by synthesizing a first image generated by the first image pickup element and a second image generated by the second image pickup element. The first image pickup element and the second image pickup element have different wavelength components used for image generation. Therefore, the image generated by the first image sensor and the image generated by the second image sensor have different characteristics. By synthesizing such images with different characteristics, it is possible to generate a new image that can be used for various purposes. For example, while a visible light image contains information indicating the color of a subject, it tends to be unclear in a dark environment. Infrared light images are clearly imaged even in a dark environment, but the color information of the subject is converted to black and white. By synthesizing the visible light image and the infrared light image, the generation means can generate a composite image that is clear even in a dark environment and includes information on the color of the subject.

Hereinafter, embodiments of the image pickup apparatus will be further described with reference to the drawings. FIG. 1 is a diagram schematically showing an image pickup apparatus according to an embodiment. The image pickup apparatus 100 exemplified in FIG. 1 includes a lens unit 1, a beam splitter 2, a visible light sensor 3, an infrared light sensor 4, an image processing circuit 5, and a near-infrared light absorption substrate 6.

The lens unit 1 is a unit that accommodates one or a plurality of lenses 11 in the lens barrel 12. In the image pickup apparatus 100, the beam splitter 2 and the visible light sensor 3 are provided on the optical axis L of the lens 11. The lens unit 1 and the lens 11 are examples of "lenses".

The visible light sensor 3 is, for example, an image pickup device that generates a visible light image based on incident visible light. The visible light sensor 3 has, for example, a peak of sensitivity to light having a wavelength of 650 nm or less. The visible light sensor 3 is, for example, a CCD image sensor or a CMOS image sensor. The CCD image sensor and the CMOS image sensor are also sensitive to light other than visible light (for example, infrared light). Therefore, a filter is provided between the visible light sensor 3 and the lens unit 1 to prevent light other than visible light from being incident on the visible light sensor 3 from the light incident on the lens 11. The visible light sensor 3 is an example of the "first image sensor". Visible light is an example of "light having a first wavelength component".

The beam splitter 2 is a cube-shaped prism that separates subject light incident through the lens 11 into visible light and infrared light. The beam splitter 2 is arranged behind the lens 11 (in the image pickup apparatus 100, the visible light sensor 3 and the infrared light sensor 4 are closer to the lens 11). The beam splitter 2 transmits the light including visible light among the subject lights and causes the light to be incident on the visible light sensor 3, and reflects the light including the infrared light among the subject lights to be incident on the infrared light sensor 4. That is, the beam splitter 2 can be said to be a filter that suppresses light other than visible light from entering the visible light sensor 3.

The beam splitter 2 includes triangular prisms 24a and 24b whose side surfaces are formed into a quadrangle and whose bottom surface is formed into a right triangle. The beam splitter 2 is made, for example, as follows. A near-infrared reflector 21 is provided on one of the side surfaces of the triangular prism 24b. The beam splitter 2 is produced by sticking one of the side surfaces of the triangular prism 24a to the side surface of the triangular prism 24b provided with the near-infrared reflector 21. In the image pickup apparatus 100, the beam splitter 2 produced in this way has a normal line N on the side surface where the near-infrared reflector 21 is provided so that the near-infrared reflector 21 is oblique to the optical axis L (for example, the near-infrared reflector 21 is provided. (So that the angle D between the light axis L and the optical axis L is 45 degrees). The angle D may be an angle other than 45 degrees as long as the reflected infrared light can be incident on the infrared light sensor 4 and the transmitted visible light can be incident on the visible light sensor 3.

The beam splitter 2 reflects light in a predetermined wavelength band (for example, near-infrared light) and transmits light in another wavelength band (for example, visible light). The beam splitter 2 is made by stacking dielectrics having different refractive indexes from each other, for example. Examples of the dielectric used for producing the beam splitter 2 include magnesium fluoride (MgF ₂ ), titanium dioxide (TiO ₃ ), silicon dioxide (SiO ₂ ), niobium pentoxide (Nb ₂ O ₅ ), and tantalum pentoxide (Tantalum pentoxide). Ta ₂ O ₅ ) and the like can be mentioned. The wavelength of light reflected by the beam splitter 2 can be appropriately set depending on the thickness and material of each of the dielectrics to be laminated. The beam splitter 2 is an example of a "spectrometer". The side surface on which the near-infrared reflector 21 is provided is an example of a “spectral surface”.

The infrared light sensor 4 is, for example, an image pickup device that generates an infrared light image based on infrared light. The infrared light sensor 4 has, for example, a peak of sensitivity to light having a wavelength of 750 nm or more. The infrared light sensor 4 is, for example, a CCD image sensor or a CMOS image sensor having sensitivity to infrared light. The infrared light sensor 4 is an example of a "second image sensor". Infrared light is an example of "light having a second wavelength component".

The image processing circuit 5 is a circuit that generates a composite image obtained by synthesizing a visible light image acquired from the visible light sensor 3 and an infrared light image acquired from the infrared light sensor 4. The image processing circuit 5 may be realized by a dedicated circuit formed by a Field-Programmable Gate Array (FPGA) or the like, or may be realized by a combination of a processor and a memory. The image processing circuit 5 is an example of a “generation means”.

The near-infrared light absorption substrate 6 is arranged between the lens 11 and the beam splitter 2 on the optical axis L. The near-infrared light absorption substrate 6 transmits visible light and absorbs near-infrared light. The near-infrared light absorbing substrate 6 contains a near-infrared absorbing dye. Examples of the near-infrared absorbing dye include an organic dye and an organic-inorganic composite dye. Examples of the near-infrared absorbing dye include a squarylium compound. The near-infrared light absorbing substrate 6 may further contain an ultraviolet absorbing dye. The wavelength of the light absorbed by the near-infrared light absorbing substrate 6 can be appropriately adjusted by selecting the material of the near-infrared absorbing dye or the ultraviolet absorbing dye. As the near-infrared light absorption substrate 6, for example, the light selection filter described in JP-A-2019-49586 can be adopted.

<Characteristics of beam splitter 2>
FIG. 2 is a diagram schematically illustrating the characteristics of the beam splitter used in the embodiment. In FIG. 2, the solid line exemplifies the transmittance (%) transmitted through the beam splitter 2. Further, the dotted line exemplifies the reflectance (%) reflected by the beam splitter 2. The horizontal axis of FIG. 2 illustrates the wavelength (nm) of light incident on the beam splitter 2. In FIG. 2, the solid line graph illustrates the transmittance of the beam splitter 2. Further, in FIG. 2, the dotted line graph exemplifies the reflectance of the beam splitter 2. As can be understood with reference to FIG. 2, the beam splitter 2 causes light having a wavelength of 700 nm or less to have a transmittance of 5% or more, and reflects light having a wavelength of 650 nm or more with a reflectance of 5% or more. Light having a wavelength range of 750 nm or less is an example of "light having a first wavelength component". Light having a wavelength range of 650 nm or more is an example of "light having a second wavelength component".

Here, the beam splitter 2 has a reflectance and a transmittance of 50% for light having a wavelength of 650 nm to 750 nm. Hereinafter, in the present specification, the range of wavelengths from 650 nm to 750 nm is also referred to as “overlapping wavelength region”. When the image pickup apparatus 100 does not include the near-infrared light absorption substrate 6, the light in the overlapping wavelength region is a mixture of the light transmitted through the beam splitter 2 and the light reflected by the beam splitter 2. That is, the light in the overlapping wavelength region passes through the beam splitter 2 and is incident on the visible light sensor 3, and is reflected by the beam splitter 2 and incident on the infrared light sensor 4. Light having a wavelength of 650 nm to 750 nm is an example of "light of at least a part of the light having overlapping components".

When light in an overlapping wavelength region is incident on the visible light sensor 3, the image quality of the visible light image generated by the visible light sensor 3 may deteriorate. Further, when light in an overlapping wavelength region is incident on the infrared light sensor 4, the image quality of the infrared light image generated by the infrared light sensor 4 may deteriorate. The image pickup apparatus 100 according to the present embodiment employs a near-infrared light absorption substrate 6 in order to suppress such deterioration of image quality.

<Characteristics of near-infrared light absorption substrate 6>
FIG. 3 is a diagram schematically illustrating the transmission characteristics of the near-infrared light absorption substrate. The vertical axis of FIG. 3 exemplifies the transmittance (%) of the light transmitted through the near-infrared light absorption substrate 6. The horizontal axis of FIG. 3 exemplifies the wavelength (nm) of light incident on the near-infrared light absorption substrate 6.

Referring to FIG. 3, the near-infrared light absorption substrate 6 has a low transmittance (for example, 5% or less) for light having a wavelength in the range of 680 nm to 750 nm, and has a low transmittance for light having a wavelength in the range of 450 nm to 600 nm. It can be understood that has a high transmittance (for example, an average transmittance of 80% or more). It can also be understood that the near-infrared light absorption substrate 6 has a high transmittance for light having a wavelength of 780 nm or more. The transmission characteristics of the near-infrared light absorption substrate 6 do not depend on the incident angle of the subject light. Therefore, the near-infrared light absorption substrate 6 may be arranged so as to be orthogonal to the optical axis L, or may be arranged diagonally to the optical axis L. Although FIG. 3 describes the characteristics of the near-infrared light absorbing substrate 6 having a transmittance of 5% or less (absorption rate of 95% or more) for light having a wavelength in the range of 680 nm to 750 nm. The characteristics of the light absorption substrate 6 are not limited to this, and for example, the transmittance for light having a wavelength in the range of 650 nm to 800 nm may be 5% or less. As the characteristics of the near-infrared light absorption substrate 6, those having a low transmittance for light within the overlapping wavelength region (for example, 5% or less, in other words, an absorption rate of 95% or more) are preferable. For example, the near-infrared light absorption substrate 6 preferably has a light absorption rate of 95% or more in a wavelength range of 100 nm or more in the overlapping wavelength region. The near-infrared light absorption substrate 6 is an example of an “absorbent”.

<Characteristics of combining the near-infrared light absorption substrate 6 and the beam splitter 2>
FIG. 4 is a diagram schematically showing the characteristics when the near-infrared light absorption substrate and the beam splitter are combined in the embodiment. FIG. 4 illustrates a case where the near-infrared light absorption substrate 6 is arranged between the beam splitter 2 and the lens 11 on the optical axis L of the lens 11 (see FIG. 1). In FIG. 4, the solid line exemplifies the transmittance (%) transmitted through the near-infrared light absorption substrate 6 and the beam splitter 2. Further, the dotted line exemplifies the reflectance (%) transmitted through the near-infrared light absorbing substrate 6 and reflected by the beam splitter 2. The horizontal axis of FIG. 4 illustrates the wavelength (nm) of light.

With reference to FIG. 4, it can be understood that by arranging the near-infrared light absorption substrate 6 between the lens 11 and the beam splitter 2, both reflection and transmission of light in the overlapping wavelength region are suppressed. That is, by arranging the near-infrared light absorption substrate 6 between the lens 11 and the beam splitter 2, the incident of light in the overlapping wavelength region is applied to both the visible light sensor 3 and the infrared light sensor 4. It can be understood that it is suppressed. By suppressing the incident of light in the overlapping wavelength region on the visible light sensor 3, deterioration of the image quality of the visible light image generated by the visible light sensor 3 is suppressed. Further, by suppressing the incident of light in the overlapping wavelength region on the infrared light sensor 4, deterioration of the image quality of the infrared light image generated by the infrared light sensor 4 is suppressed.

(Combining visible light image and infrared light image by image processing circuit 5)
It is difficult to obtain a clear visible light image by shooting with visible light at night or in a dark environment such as a room without lighting. Therefore, in an environment where the surroundings are dark, infrared light is often used for photography. However, since the color information of the subject cannot be acquired by shooting with infrared light, the subject is expressed in black and white in black and white imaging. In the image pickup apparatus 100, the visible light sensor 3 generates a visible light image by visible light, and the infrared light sensor 4 generates an infrared light image by infrared light. Then, in the image processing circuit 5, by synthesizing the visible light image and the infrared light image, it is possible to generate a clearer composite image even in an environment where the surroundings are dark.

FIG. 5 is a diagram illustrating the composition of a visible light image and an infrared light image by an image processing circuit. In FIG. 5, a visible light image P1 generated by the visible light sensor 3 and an infrared light image P2 generated by the infrared light sensor 4 are exemplified. The subjects P11 and P12 are reflected in the visible light image P1 and the infrared light image P2. In FIG. 5, the presence / absence of color information of the subjects P11 and P12 in the imaging is illustrated by the presence / absence of a pattern in the subjects P11 and P12. Further, in FIG. 5, whether or not the subjects P11 and P12 are clearly reflected is illustrated by the color density of the boundary line between the subjects P11 and P12.

It can be understood that in the visible light image P1, while the color information of the subjects P11 and P12 is acquired, the subject is not clearly reflected. It can be understood that the infrared light image P2 clearly shows the subject, but the color information of the subjects P11 and P12 cannot be acquired. In the image processing circuit 5, by synthesizing such a visible light image P1 and an infrared light image P2, a composite image P3 that includes color information and clearly reflects the subjects P11 and P12 is generated.

<Action and effect of the embodiment>
In the image pickup apparatus 100 according to the embodiment, the subject light incident through the lens unit 1 is split into visible light and infrared light by the beam splitter 2. The visible light separated from the subject light by the beam splitter 2 is incident on the visible light sensor 3. Further, the infrared light separated from the subject light by the beam splitter 2 is incident on the infrared light sensor 4. By adopting such a configuration, the image pickup apparatus 100 according to the embodiment can acquire a visible light image and an infrared light image of a subject in one shooting without using a plurality of lens units 1. ..

While the visible light sensor 3 can generate a visible light image including color information, it is difficult to generate a clear image in a dark environment. Further, the infrared light sensor 4 can generate a clear image even in a dark environment, while the generated image is black and white. The image pickup apparatus 100 according to the embodiment synthesizes the visible light image generated by the visible light sensor 3 and the infrared light image generated by the infrared light sensor 4, so that the color becomes clearer and more vivid even in a dark surrounding environment. It is possible to generate a composite image containing the information of.

In the image pickup apparatus 100 according to the embodiment, the beam splitter 2 is provided so as to be oblique to the optical axis L of the lens 11. Therefore, the light reflected by the beam splitter 2 does not back-inject into the lens 11. Therefore, the image pickup apparatus 100 according to the embodiment has no stray light that is back-incident to the lens 11, and can suppress the deterioration of the image quality of the image pickup generated by the visible light sensor 3 and the infrared light sensor 4.

In the image pickup apparatus 100 according to the embodiment, the near-infrared light absorption substrate 6 is arranged between the lens 11 and the beam splitter 2. Therefore, the incident of light in the overlapping wavelength region is suppressed for both the visible light sensor 3 and the infrared light sensor 4. Therefore, the image pickup apparatus 100 according to the embodiment can suppress the deterioration of the image quality of the visible light image generated by the visible light sensor 3, and also suppresses the deterioration of the image quality of the infrared light image generated by the infrared light sensor 4. It can be suppressed.

In the present embodiment, as described above, the incident of light in the overlapping wavelength region on the visible light sensor 3 and the infrared light sensor 4 is suppressed by the near-infrared light absorption substrate 6. Therefore, the technique described in Patent Document 1 that employs a low-pass filter for suppressing the incident of light in the overlapping wavelength region on the visible light sensor 3 and adopts a high-pass filter for suppressing the incident on the infrared light sensor 4 in the overlapping wavelength region. In comparison, the image pickup apparatus according to the present embodiment has merits such as easy optical system design, easy assembly, high production efficiency, and low manufacturing cost.

(First modification)
FIG. 6 is a diagram showing an example of an image pickup apparatus according to the first modification. The imaging device 100a exemplified in FIG. 6 is different from the imaging device 100 according to the embodiment in that the beam splitter 2a is provided in place of the beam splitter 2.

The beam splitter 2a is provided with an optical path length correction filter 23 on the surface of each surface of the prism forming the beam splitter 2a that faces the infrared light sensor 4. The optical path length correction filter 23 is a filter that corrects the optical path length by refracting the incident light. The optical path length correction filter 23 can correct the optical path length of the infrared light incident on the infrared light sensor 4 to a length suitable for imaging by the infrared light sensor 4.

(Second modification)
FIG. 7 is a diagram showing an example of an image pickup apparatus according to a second modification. The image pickup apparatus 100b exemplified in FIG. 7 is different from the image pickup apparatus 100 according to the embodiment in that it includes an infrared light sensor 4a instead of the infrared light sensor 4.

The infrared light sensor 4a is a small sensor having a smaller detection surface for detecting infrared light than the infrared light sensor 4. Since infrared rays have a longer wavelength than visible light, it is considered to be more suitable than visible light for shooting distant subjects. The angle of view may be narrow for shooting distant subjects. Therefore, when a near subject is photographed with visible light and a distant subject is photographed with infrared rays, a small infrared light sensor 4a can be adopted. Further, by adopting the infrared light sensor 4a, it becomes easy to miniaturize the image pickup apparatus 100b.

(Other variants)
In the embodiment and the first and second modifications, the beam splitter and the visible light sensor 3 are arranged on the optical axis L. Then, the visible light transmitted through the beam splitter was incident on the visible light sensor 3, and the near-infrared light reflected by the beam splitter was incident on the infrared light sensor 4. However, the disclosed technique is not limited to such a configuration. In the disclosed technique, for example, a beam splitter that reflects visible light may be arranged in place of the beam splitter that reflects near infrared rays, and the positions of the visible light sensor 3 and the infrared light sensor 4 may be exchanged. That is, a beam splitter that reflects visible light and an infrared light sensor 4 may be arranged on the optical axis L. Then, the near-infrared light transmitted through the beam splitter that reflects visible light may be incident on the infrared light sensor 4, and the visible light reflected by the beam splitter that reflects visible light may be incident on the visible light sensor 3. ..

<Application example>
The image pickup apparatus according to the embodiment and each modification described above can be applied to various systems. FIG. 8 is a diagram schematically illustrating an application example. In the application example described below, the image pickup apparatus 100b according to the second modification is adopted as the surveillance camera of the vehicle 800. In the example of FIG. 8, two image pickup devices 100b are provided so as to photograph the traveling direction of the vehicle 800.

In the application example, the visible light sensor 3 uses visible light to photograph the monitoring area W1, and the infrared light sensor 4a uses infrared light to photograph the monitoring area W2 farther than the monitoring area W1. As described above, since infrared light is suitable for photographing farther than visible light, according to the application example, the monitoring area W1 and the monitoring area W2 farther than the monitoring area W1 can be suitably monitored. ..

In FIG. 8, the image pickup device 100b is adopted as the surveillance camera outside the vehicle 800, but the image pickup device 100b may be adopted for monitoring the inside of the vehicle 800. For example, in the vehicle 800, an area where it is preferable to take a picture with a wide angle of view such as a rear seat is taken by the visible light sensor 3 of the image pickup device 100b, and an area which can be taken with a narrow angle of view such as a driver's seat is taken with the image pickup device 100b. It is conceivable to take a picture with the infrared light sensor 4a of.

In the application example described with reference to FIG. 8, the image pickup device 100b according to the second modification is adopted as the surveillance camera, but both the image pickup device 100 according to the embodiment and the image pickup device 100a according to the first modification are monitored. It can be used as a camera.

Further, in the image pickup apparatus according to the embodiment and each modification, a composition having clear and color information even in a dark environment is based on an infrared light image that is clear even in a dark environment and a visible light image that includes color information. The image processing circuit 5 generates an image. Therefore, by adopting the image pickup device according to the embodiment and each modification as the surveillance camera of the vehicle 800, it is possible to discriminate between the white line and the yellow line on the road with high accuracy, which was difficult with the conventional infrared camera. become.

(Other application examples)
The image pickup apparatus according to the embodiment and each modification can generate a composite image having clear color information even in a dark environment. Therefore, it is also suitable for monitoring the wandering of old people, monitoring the invasion of railway tracks, photographing wild animals, searching for people in distress in mountains, and the like. Further, by adopting the image pickup device according to the embodiment and each modification to the robot vacuum cleaner, the accuracy of cleaning in a dark room can be improved. Further, by adopting the image pickup device according to the embodiment and each modification as the camera for face recognition, face recognition can be performed with high accuracy even in a dark environment.

The embodiments, modifications and applications disclosed above can be combined.

100, 100a, 100b ... Imaging device 1 ... Lens unit 11 ... Lens 2, 2a ... Beam splitter 21 ... Near infrared reflector 23 ... Optical path length correction filter 3 ... Visible Optical sensor 4, 4a ... Infrared light sensor 5 ... Image processing circuit 6 ... Near infrared light absorption substrate

Claims (4)

With the lens
A spectroscope that splits light from a subject incident through the lens into light having a first wavelength component including visible light and light having a second wavelength component including invisible light.
An absorber provided between the lens and the spectroscope and absorbing at least a part of the light of the overlapping component of the light of the first wavelength component and the light of the second wavelength component.
The first image sensor that receives the light of the first wavelength component, and
A second image pickup device that receives light of the second wavelength component is provided.
The absorber has an absorption rate of 95% or more for at least a part of the light of the overlapping components .
The spectroscope is provided so that the angle between the normal line of the spectroscopic surface of the spectroscope and the optical axis of the lens is 45 degrees, and the light of the first wavelength component and the light of the second wavelength component are One of the light is transmitted and the other of the light of the first wavelength component and the light of the second wavelength component is reflected in the direction perpendicular to the optical axis.
The light having the first wavelength component is light having a wavelength of 750 nm or less.
The light having the second wavelength component is light having a wavelength of 650 nm or more.
At least a part of the light having the overlapping components includes light having a wavelength range of 100 nm or more in a wavelength range of 650 nm or more and 800 nm or less .
Imaging device. The spectroscopic body is selected from the group of magnesium fluoride (MgF), titanium dioxide (TIO), silicon dioxide (SiO), niobium pentoxide (NbO), and tantalum pentoxide (TaO), which have different refractive indexes from each other. Formed by stacking bodies,
The imaging device according to claim 1 . The spectroscope contains a squarylium compound.
The imaging device according to claim 1 or 2 . Further comprising a generation means for generating a composite image in which the first image generated by the first image pickup element and the second image generated by the second image pickup element are combined.
The imaging device according to any one of claims 1 to 3 .

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