JP2013003482A - Imaging device for visible light and far-infrared light, vehicle imaging device including imaging device, and image forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an imaging device capable of photographing an object irrespective of brightness of the object with a simple configuration, a vehicle including an imaging device, and an image forming method.SOLUTION: Visible light and far-infrared light both reflected from an object can be transmitted with the use of a lens 11. Accordingly, an imaging element 12A and an imaging element 12B can be provided at the same position; image processing can be executed in a simplified manner in superposing the imaging elements without the need for considering a difference in the angle of view; and the entire device can be reduced in size.

Description

  The present invention relates to an imaging device that acquires subject information to form a subject image, a vehicle with an imaging device to which the imaging device is attached, and an image forming method, and more particularly to an imaging device and an imaging device that can form an appropriate subject image even at night. The present invention relates to an attached vehicle and an image forming method.

  In recent years, both the number of car accidents and the number of casualties have been decreasing, but they are still at a high level. In addition, since it is expected that the number of elderly drivers will increase in the future, there is a further demand for a technology for compensating for a decrease in physical function due to aging and supporting safe driving. Recently, in order to ensure safe driving of automobiles, pre-crash prevents accidents due to reduced driver concentration and human error by detecting and recognizing obstacles such as people and cars ahead in the direction of travel. Safety technology has been developed and is partly on the market.

  By the way, as a means for recognizing obstacles ahead, radar devices using radio waves and lasers, camera devices using visible light and infrared light, etc. are generally used, but each method has advantages and disadvantages. In order to increase reliability, it can be said that it is desirable to use a combination of different methods. For example, when considering a combination of a visible light camera and a far-infrared light camera, the amount of light in the subject is sufficient during the daytime. In this case, it is difficult to photograph a distant subject where the headlight does not reach with a visible light camera. Therefore, in such a case, by using a combination of a far-infrared light camera, a person outside the headlight irradiation range can be recognized at an early stage even if it cannot be seen with the naked eye.

  Therefore, as shown in Patent Document 1, in order to inform the driver of images taken with a visible light camera and a far-infrared light camera, or information on obstacles obtained from the images, these images are improved. Information is displayed in one piece.

JP 2000-19259 A

  However, for example, a visible light camera and a far-infrared light camera have different wavelength ranges of light to be detected, and thus the visible light camera and the far-infrared light camera cannot be used in common. That is, the camera of Patent Document 1 is not actually established. On the other hand, although it is possible to install a visible light camera and a far-infrared light camera separately and synthesize the obtained images, it takes time and effort to perform image processing.

  The present invention has been made in view of the above-described problems, and an object thereof is to provide an imaging apparatus and an image acquisition method that can capture a subject regardless of the brightness of the subject, while having a simple configuration. .

The imaging apparatus of the present invention
An optical element on which electromagnetic waves are incident;
Among the electromagnetic waves transmitted through the optical element, an electric signal of a visible light image component based on a first electromagnetic wave that is a wavelength region corresponding to a visible light region and a far electromagnetic wave based on a second electromagnetic wave that is a wavelength region corresponding to a far infrared region. An image sensor for converting into an infrared image component electrical signal;
An image pickup apparatus comprising: an image processing unit that generates a visible image and a far-infrared image based on the electric signal of the visible light image component and the electric signal of the far-infrared image component;
The optical element is formed using a material containing 80% by weight or more of methylpentene.

  According to the present invention, the optical element on which the electromagnetic wave is incident is configured to be formed using a material that transmits both visible light suitable for daytime shooting and far-infrared light suitable for nighttime shooting. By processing in the latter stage image sensor or the latter stage image processing unit including the image sensor, it is possible to easily form images of different wavelength components for the same subject. In addition, a good color image can be obtained.

  In addition, the wavelength range of visible light means the range of wavelength 400nm -700nm, for example. Further, the far-infrared light wavelength region is at least a longer wavelength range than the visible light wavelength region, for example, far-infrared light having a wavelength of about 8 μm or more, terahertz wave, millimeter wave, microwave, etc. Near-infrared light refers to the range of wavelengths between this “visible light” and “far-infrared light”.

  Here, the 4-methylpentene polymer refers to a polymer resin represented by the following chemical formula (Formula 1).

  According to an aspect of the present invention, the optical element is a photographic lens that transmits the first electromagnetic wave and the second electromagnetic wave so as to enter the imaging element. Thereby, it can serve as a cover member of an image sensor.

  According to an aspect of the present invention, the imaging device converts the incident first electromagnetic wave and the second electromagnetic wave into an electric signal of the visible light image component and an electric signal of the far infrared image component, respectively. It is characterized by being a single imaging device. As a result, the imaging apparatus is reduced in size and simplified.

  According to one aspect of the present invention, the imaging device includes a first imaging device that converts the incident first electromagnetic wave into an electrical signal of the visible light image component, and the incident second electromagnetic wave as the far-infrared image. And a second image sensor for converting the component into an electrical signal. By using an image sensor specialized for visible light images and far-infrared light images, high-quality images can be formed while reducing costs.

  According to an aspect of the present invention, the first electromagnetic wave that has been transmitted through the optical element is reflected, the separation optical element that transmits the second electromagnetic wave is provided, and the first electromagnetic wave that has been reflected by the separation optical element is While making it inject into a 1st image pick-up element, it is the structure which injects into the said 2nd image pick-up element 2nd electromagnetic waves which permeate | transmitted the said separation optical element, Comprising: The said separation optical element uses the raw material which mix | blended methylpentene 80weight% or more. It is characterized by being formed. Thereby, it becomes difficult to generate stray light or the like by separating visible light and far-infrared light.

  According to an aspect of the present invention, the optical element is formed using a material containing 80% by weight or more of methylpentene and having a saturated water absorption of 0.3% or less. Thereby, when mounted on a vehicle, it is possible to cope with rainwater and the like scattered from the outside.

  According to an aspect of the present invention, the imaging device includes an image sensor unit in which a plurality of pixels are arranged in a matrix, and a plurality of types of colors corresponding to a visible light wavelength region from an incident electromagnetic wave in the pixel unit. The light of the wavelength region corresponding to one kind of color element and the light of the wavelength region corresponding to the far infrared region are separated, and the light corresponding to each color element and the light of the far infrared wavelength region It is characterized by including at least a color filter part that makes the light incident on each pixel. Thereby, a color image can be formed.

  According to an aspect of the present invention, the imaging element includes a first image sensor unit that receives the first electromagnetic wave in which a plurality of pixels are arranged in a matrix, and a visible light wavelength from the incident electromagnetic wave in the pixel unit. A first image sensor having a first color filter section that separates light in a wavelength region corresponding to one type of color element among a plurality of types of color elements corresponding to the region and transmits light corresponding to each color element A second image sensor unit that receives the second electromagnetic wave, which is arranged at a position where the second electromagnetic wave transmitted from the first imaging element is incident, and in which a plurality of pixels are arranged in a matrix, and for each pixel. And a second image pickup device having a second filter unit for allowing light in a wavelength region corresponding to a far-infrared region from the second electromagnetic wave transmitted through the first image pickup device to be incident on each pixel. To do.

  According to an aspect of the present invention, the color filter unit of the image pickup device further includes a portion for allowing light in a wavelength region corresponding to a near infrared region from incident electromagnetic waves to be incident on each pixel in the pixel unit. Features.

  According to an aspect of the present invention, the image processing unit calculates a color difference signal and a first luminance signal corresponding to a visible image as an electrical signal of the visible light image component obtained by the imaging device, while the far red A second luminance signal is calculated as an electric signal of the outer image component, and the color difference signal, the first luminance signal, and the second luminance signal are combined in correspondence with each pixel position.

The imaging apparatus of the present invention
A first photographing lens that transmits a first electromagnetic wave in a visible light region; a second photographing lens that is disposed on an optical axis different from the first photographing lens and transmits a second electromagnetic wave in a far infrared region;
A cover member disposed on the object side with respect to the first and second photographing lenses;
A first imaging element that converts an electric signal of a visible light image component based on the first electromagnetic wave transmitted through the first photographing lens;
A second imaging element different from the first imaging element that converts an electric signal of a far-infrared image component based on the second electromagnetic wave transmitted through the second photographing lens;
An image pickup apparatus comprising: an image processing unit that generates a visible image and a far-infrared image based on the electric signal of the visible light image component and the electric signal of the far-infrared image component;
The cover member includes at least a material containing 80% by weight or more of methylpentene.

  According to the present invention, the cover member into which electromagnetic waves are incident is a structure formed using a material that transmits both visible light suitable for daytime shooting and far-infrared light suitable for nighttime shooting. Images of different wavelength components can be easily formed with respect to the same subject by processing in the subsequent image processing unit including the first and second imaging elements in the latter stage and the imaging element, thereby reducing the size of the entire apparatus, A good color image can be obtained even at night photography.

  According to an aspect of the present invention, the cover member is formed using a material containing 80% by weight or more of methylpentene and having a saturated water absorption of 0.3% or less.

  According to an aspect of the present invention, the image processing unit calculates a color difference signal and a first luminance signal corresponding to a visible image as an electrical signal of the visible light image component obtained by the imaging device, while the far red A second luminance signal is calculated as an electric signal of the outer image component, and the color difference signal, the first luminance signal, and the second luminance signal are combined in correspondence with each pixel position.

  A vehicle with an imaging device is configured by attaching the above imaging device to the vehicle.

The image acquisition method of the present invention includes:
An electromagnetic wave is incident on an optical element formed using a material in which 80% by weight or more of methylpentene is blended, and the electromagnetic wave transmitted through the optical element is visible on the imaging element based on the first electromagnetic wave that is a wavelength range corresponding to the visible light range. Converting the electrical signal of the optical image component and the electrical signal of the far-infrared image component based on the second electromagnetic wave in the wavelength range corresponding to the far-infrared region,
A visible image and a far-infrared image are generated based on the converted electric signal of the visible light image component and the electric signal of the far-infrared image component.

  According to the present invention, the optical element on which the electromagnetic wave is incident is formed by using a material that transmits both visible light suitable for daytime photographing and far infrared light suitable for nighttime photographing. Therefore, it is possible to easily form images of different wavelength components with respect to the same subject by subsequent image processing based on the signal from the signal, thereby obtaining a good color image even at night shooting while downsizing the entire imaging device. Is possible.

  According to the present invention, the optical member on which the electromagnetic wave is incident is formed by using a material that transmits both visible light suitable for daytime shooting and far-infrared light suitable for nighttime shooting. By processing in the latter stage image sensor or the latter stage image processing unit including the image sensor, it is possible to easily form images of different wavelength components for the same subject. In addition, it is possible to provide an imaging device, a vehicle with an imaging device, and an image forming method capable of obtaining a good color image.

It is the schematic of the vehicle carrying the imaging device concerning this Embodiment. 1 is a block diagram illustrating an imaging apparatus 10 according to a first embodiment. It is a figure which shows an example of a filter. It is a figure which shows a far-infrared light image and a visible light image, respectively. It is a figure which shows the example of the synthesized image which superimposed the far-infrared light image on the visible light image. It is a figure which shows the filter of the image pick-up element by the modification of this Embodiment. It is the schematic of the image pick-up element 12 'concerning another modification. It is a block diagram showing imaging device 10 'concerning a 2nd embodiment. It is a flowchart figure which shows the image formation method using the imaging device of this Embodiment. It is the schematic concerning the modification of this Embodiment. The graph which shows the spectral transmittance of the optical material which concerns on this embodiment. The graph which shows the spectral transmittance of the raw material which is a comparative example.

  Hereinafter, an imaging device according to an embodiment of the present invention will be described. FIG. 1 is a schematic diagram of a vehicle equipped with an imaging apparatus according to the present embodiment. In FIG. 1, an imaging device 10 is mounted near the front grill of a vehicle VH, and an image signal is output to the control unit CONT and displayed on a monitor MT.

  FIG. 2 is a block diagram illustrating the imaging apparatus 10 according to the first embodiment. The imaging device 10 includes a photographing lens 11 as an optical element that transmits visible light and far-infrared light, an imaging element 12 that receives subject light that has passed through the photographing lens 11, and converts the subject light into an electrical signal. The image processing unit 13 that receives the above signal and the control unit 14 that inputs a control signal from the outside of the imaging apparatus and controls the imaging element 12 and the image processing unit 13.

  The taking lens 11 is formed using a material in which 4-methylpentene polymer is blended in an amount of 80% by weight or more, specifically, 85% by weight and a material having a saturated water absorption rate of 0.3% or less. Such a material can be produced by maintaining the water repellency by increasing the number average molecular weight (n in Formula 1) of the 4-methylpentene polymer to 50,000 or more and making it difficult for moisture to enter. In addition, this material is disposed on the subject side with respect to the imaging lens 11 and used in the same manner for a cover element as an optical element, so that both visible light and far-infrared light reflected from the subject are directed to the photographing lens. Can be transmitted well.

  The visible light camera and the far-infrared light camera have different photographing lenses arranged on different optical axes, and the cover elements as described above are arranged on the subject side with respect to each photographing lens. Needless to say, when the image pickup apparatus is configured by being incorporated in a housing, only the cover element may be formed of the above material.

  By using such a material, both the visible light and the far-infrared light can be received by the image sensor 12, and when the visible light image and the far-infrared light image are overlapped by image processing, the angle of view. The processing can be performed in a short time without having to consider the difference. Further, since the saturated water absorption rate of the photographing lens 11 is 0.3% or less, a stable transmittance can be maintained over a long period of time even when installed in front of a vehicle where rainwater scatters.

  The imaging device 12 for photographing visible light includes an image sensor unit (not shown) composed of a photodiode in which a plurality of pixels are arranged in a matrix and a CMOS device, and a photographing lens for each pixel of the image sensor unit. The image sensor unit has a filter unit that separates the incident light that has passed through the wavelength light corresponding to one predetermined color element, the near-infrared light, and the far-infrared wavelength, and enters the separated light. The image data is generated and output based on the image signal data output in. In addition, as shown in FIG. 3, the filter section here has three primary colors (red, green, blue) of R, G, and B complementary colors and far-infrared light using a Ye filter, R filter, and W filter. The filter unit is composed of a single unit filter group having FIr filters arranged in the same layer and having sensitivity in any of a plurality of bands of FIr corresponding to.

  More specifically, in the example of FIG. 3, in the unit filter group, an R filter is arranged in the first row and the first column, a W filter is arranged in the second row and the first column, and the first row and the second column are arranged. Ye filters are arranged, and FIr filters are arranged in the second row and the second column. Pixels corresponding to these filters are respectively called R pixel, W pixel, Ye pixel, and FIr pixel. In other words, the imaging device includes an image sensor unit in which a plurality of pixels are arranged in a matrix, and changes from incident electromagnetic waves to one type of color elements corresponding to the visible light wavelength region in units of pixels. A color filter unit that separates light in the corresponding wavelength region and light in the wavelength region corresponding to the far infrared region, and causes light corresponding to each color element and light in the far infrared wavelength region to enter each pixel. Is included at least. However, the above is an example, and the R pixel, the FIr pixel, the W pixel, and the Ye pixel may be arranged in a zigzag pattern in other patterns.

  The Ye filter has a characteristic of transmitting light in the sensitive wavelength band excluding the blue region of the visible wavelength region. Therefore, the Ye filter mainly transmits yellow light and infrared light. The R filter has a characteristic of transmitting light in a sensitive wavelength band excluding a blue region and a green region in the visible wavelength region. Therefore, the R filter mainly transmits red light and infrared light. The FIr filter has a characteristic of transmitting light in a far-infrared wavelength band exceeding the visible wavelength region. W indicates a case where no filter is provided, and all light in the sensitive wavelength band of the pixel is transmitted.

  Since the Ye pixel includes a Ye filter, it captures an image component Ye (original image component) and an infrared image component, which are visible color image components of Ye. Since the R pixel includes an R filter, an image component R (original image component) and an infrared image component, which are visible color image components of R, are imaged. Since the FIr pixel includes an FIr filter, an image component FIr (original image component) that is a far-infrared image component is captured. Since the W pixel does not include a filter, an image component W (original image component) that is a luminance image component including a visible luminance image component and an image component FIr is captured. Thus, the four filters have different spectral transmission characteristics.

  According to the present embodiment, the signals of the visible light image components Ye, R, and W are transmitted by the Ye pixel, the R pixel, the W pixel, and the FIr pixel through each color element of the filter unit of the single image sensor 12; An electric signal of the far infrared light component FIr is obtained. Next, the image processing unit 13 performs color interpolation processing on the image components Ye, R, FIr, and W. Further, since the color signals dR, dG, dB can be calculated by calculating dR = R−FIr, dG = Ye−R, and dB = W−Ye, the color spaces Y, Cr, Cb (or R, G, B) can be obtained and output to form a color image. On the other hand, a monochrome far-infrared image can be formed by the image component FIr.

  FIG. 4A is an image taken at dusk with the imaging device 2b for far-infrared light photography, and the subjects HM1 and HM2 as people appear white because they generate heat. LED traffic lights with low heat generation are not clearly visible. On the other hand, FIG. 4B is an image obtained by photographing the same subject at the same timing with the imaging element 2b for visible light photography. Since it is dusk, the overall brightness of the subject is low, and the lamp of the self-light-emitting traffic light SG is clearly visible, but the people HM1, HM2, etc. are not clearly visible.

  FIG. 5 is a diagram illustrating an example of a composite image when a far-infrared light image is superimposed on a visible light image. In FIG. 6, since the whitish persons HM1 and HM2 are displayed so as to float in the dim sunset scene, the driver can quickly and clearly identify the subject to be noted.

  FIG. 6 is a diagram illustrating a filter of an image sensor according to a modification of the present embodiment. In the example of FIG. 6, in the unit filter group, an R filter is arranged in the first row and the first column, a W filter is arranged in the second row and the first column, and a Ye filter is arranged in the first row and the second column, Ir filters or FIr filters are arranged in the second row and the second column. The Ir filter uses the near-infrared band as a sensitive band, and is arranged alternately with the FIr filter. The corresponding pixels of these filter units are called R pixels, W pixels, Ye pixels, Ir pixels, or FIr pixels, respectively.

  In this modification, it is possible to calculate color signals dR, dG, and dB by calculating dR = R−Ir, dG = Ye−R, and dB = W−Ye. Other than that, it is the same as the embodiment described above.

  FIG. 7A is a schematic diagram of an image sensor 12 ′ according to another modification. In the present modification, the image pickup device 12 ′ is arranged such that the first image pickup device 12 a ′ and the second image pickup device 12 b ′ are overlapped in the optical axis direction. More specifically, the sensor surface 12a ′ of the first image sensor unit is a sensor surface that receives visible light, and on the front surface (object side surface), as shown in FIG. A filter having sensitivity in a plurality of bands of G, B, and Ir is employed. On the other hand, the sensor surface 12b ′ of the second image sensor unit is a sensor surface that receives far-infrared light transmitted through the first image sensor 12a ′, and as shown in FIG. Employs a FIr filter having sensitivity in the far-infrared band. As described above, a color image signal can be acquired from the sensor surface 12a ', and a far infrared light image signal can be acquired from the sensor surface 12b'.

  The configuration in which a plurality of image pickup devices are arranged in this manner is an image sensor unit in which the light of each color element of visible light and the far infrared light, which are separated from each other by the filter unit as shown in FIGS. Because it is configured to receive light with a light receiving unit corresponding to each pixel, it is somewhat difficult to manufacture so that light is received with high accuracy. Therefore, there is an advantage that the manufacturing load as described above can be reduced and an accurate image sensor can be configured.

  FIG. 8 is a block diagram illustrating an imaging apparatus 10 ′ according to the second embodiment. The imaging device 10 ′ includes a lens 11 that transmits visible light, a first image sensor 12A that includes a first color filter unit and a sensor surface (first image sensor unit) that receive visible light that has transmitted through the lens 11, and imaging. A second filter having a second filter and a sensor surface (second image sensor unit) that receive the far-infrared light that passes through the lens 12 and is provided with the element 12A (both sensor surfaces are at the imaging position of the lens 11). The image sensor 12B, an image processor 12 that receives signals from the image sensors 12A and 12B, and a controller 14 that receives a control signal from the outside and controls the image sensor 12 and the image processor 13 are provided. . As shown by the one-dot chain line, a cover member CV formed by using a material having 85% by weight of 4-methylpentene polymer on the object side of the lens 11 and a saturated water absorption of 0.3% or less. It can also be provided. In this case, a first photographing lens that transmits visible light is provided between the cover member CV and the first image sensor 12A, and far-infrared light is transmitted between the cover member CV and the second image sensor 12B. It is desirable to provide a second photographic lens that transmits light.

  The first color filter section of the first image sensor 12A is similar to that shown in FIG. 7B, in the unit filter group, R filters are arranged in the first row and first column, and the second row and first column. W filters are arranged, Ye filters are arranged in the first row and second column, and Ir filters are arranged in the second row and second column. The second filter section of the second image sensor 12B is only the FIr filter, similar to that shown in FIG.

  The lens 11 is formed using a material containing 85% by weight of 4-methylpentene polymer and a saturated water absorption of 0.3% or less.

  Next, an image acquisition method using the imaging apparatus of the present embodiment will be described with reference to FIG. First, the subject light that has passed through the lens 11 is imaged on the sensor surface of the image sensor 12A using a complementary color filter to capture one frame of original image data. Thereby, image components Ye, R, Ir, and W are obtained (step S1).

  Here, the imaging element 12A images the image component Ye by the Ye pixel, images the image component R by the R pixel, images the image component Ir by the Ir pixel, images the image component W by the W pixel, and performs color interpolation. Process.

  Next, color interpolation processing is performed on the image components Ye, R, Ir, and W. Further, calculation of dR = R−Ir, dG = Ye−R, and dB = W−Ye is performed to calculate color signals dR, dG, and dB (color separation processing: step S2).

  Next, interpolation gain processing is performed in order to compensate for the decrease due to the visible light absorption rate of the lens 11 (step S3). Further, Y = 0.3 dR + 0.59 dG + 0.11 dB, Cb = dB−Y, Cr = dR−Y are calculated to calculate a luminance signal (first luminance signal) Y and color difference signals Cr and Cb, and a visible light image A component electrical signal is obtained (step S4). At this time, the color difference signals Cr and Cb may be smoothed. Here, as the smoothing process, for example, a cascade filter process, which is a filter process that multi-resolutions the color difference signals Cb and Cr by repeatedly using a relatively small size low-pass filter such as 5 × 5, is adopted. Also good. Further, a filter process using a low-pass filter of a predetermined size having a relatively large size may be employed.

  Also, an edge-preserving filter that smoothes areas other than edges without blurring the subject that emits light (smoothing when the signal level difference between pixels is smaller than a certain reference value, and smoothing the part larger than the reference value Filter) processing that does not enable conversion may be employed. Note that it can be estimated that light emission is detected by comparing an infrared component and a visible light component.

  As described above, by performing the smoothing process on the color difference signals Cb and Cr, the noise components included in the color difference signals Cb and Cr are blurred, and the S / N ratio of the color difference signals Cb and Cr can be improved.

  On the other hand, in synchronization with the image pickup device 12A, the subject light that has passed through the lens 11 is imaged on the sensor surface of the image pickup device 12B, and one frame of original image data is picked up (step S5). Thereby, an electric signal of the image component FIr including only the far infrared component is obtained.

Thereafter, a gain setting value is obtained based on the following formula, and the gain setting value is multiplied by the image component FIr to calculate a far infrared light luminance signal (second luminance signal) Y ′ (step S6). According to the examination results of the present inventors, since the attenuation of far-infrared light of 2 to 10% was confirmed in the wavelength band of 8 to 14 μm, the gain setting value is set to, for example, 1. Set to 1. It should be noted that the gain setting value is preferably 0 during the daytime.
Gain setting value = 1 / (Transmittance T in the wavelength region where the image sensor has a predetermined sensitivity x Spectral sensitivity of the image sensor) S

  Next, the luminance signal Y of visible light obtained from the image information of the image pickup device 12A and the luminance signal Y ′ of far infrared light obtained from the image information of the image pickup device 12B are added together to obtain a combined luminance signal Yc (= Y + Y ′) is obtained (step S7).

  Next, the color difference signals Crm and Cbm are calculated as Crm = Crs × Yc and Cbm = Cbs × Yc, and further the inverse conversion of step S2 is executed, whereby the color signal dR is obtained from the luminance signal Yc and the color difference signals Crm and Cbm. Since ', dG' and dB 'can be calculated, these are output as a visible image to the external control device CONT. In parallel with this, the far-infrared light luminance signal Y 'is output as a far-infrared image to the external control device CONT (step S8). The control device CONT superimposes two images to form one image information. At this time, the signal values of the same pixel coordinates may be simply averaged. The obtained image information is output to the monitor MT and an image is displayed. This is the end of the flow. The image processing described above can also be applied to the above-described embodiment.

  According to the present embodiment, by arranging the image sensor 12A for visible light and the image sensor 12B for far-infrared light at substantially the same position, the positions of the subjects photographed by each overlap on the screen. The obtained image information can be simply superimposed. Thereby, it is also possible to obtain an image in which color information is included in far-infrared information while shooting at night.

  FIG. 10 is a schematic diagram according to a modification of the present embodiment. In this modification, a dichroic mirror 16 that is a separation optical element is disposed between the lens 11 similar to that described above, and the imaging element 12A and the imaging element 12B. The dichroic mirror 16 is formed by using a material having 85% by weight of 4-methylpentene polymer and a saturated water absorption of 0.3% or less, reflecting visible light, and far infrared light. A selective reflection film 16a that transmits the light is provided. Therefore, of the light transmitted through the lens 11, visible light is reflected by the selective reflection film 16a of the dichroic mirror 16 and travels toward the image sensor 12A, and far-infrared light is selectively reflected by the dichroic mirror 16. The light passes through the film 16a and travels toward the image sensor 12B. Other configurations are the same as those of the above-described embodiment. The dichroic mirror 16 may use a material that transmits far-infrared light instead of using the above-described material.

  In the above embodiment, the filter configuration is illustrative and arbitrary, and for example, RGB filters can be used for visible light imaging.

  FIG. 11 is a graph showing the spectral transmittance according to an example of a material containing 85% by weight of 4-methylpentene polymer and a saturated water absorption of 0.3% or less. FIG. 12 is a graph showing the spectral transmittance according to an example of a conventional material as a comparative example. The comparative example was polycarbonate, and infrared transmission was measured using an FTIR Fourier transform infrared spectrophotometer FT / IR-6200 manufactured by JASCO Corporation.

As shown in FIG. 11, it can be seen that this example achieves a transmittance of approximately 90% or more in the infrared region (700 nm to 800 nm) in the range of 800 to 2500 nm, preferably 900 to 1400 nm. Since it is already known that this material has a high transmittance of 90% or more in the visible light region, it has a high transmittance over a wide wavelength region from the visible light region to the far infrared region as in the present invention. By using this material for an imaging device that is desired, an imaging device having a small and good image as described above can be provided.
On the other hand, as shown in FIG. 12, which is cited as a comparative example, it is understood that the transmittance of polycarbonate is reduced at 800 nm or more.

  The present invention is particularly effective for an in-vehicle camera or a robot-mounted camera, for example, but the application is not limited thereto.

DESCRIPTION OF SYMBOLS 10, 10 'Image pick-up device 11 Lens 12, 12' Image pick-up element 12A Image pick-up element 12B Image pick-up element 12a 'Sensor surface 12b' Sensor surface 13 Image processing part 14 Control part 16 Dichroic mirror 16a Selective reflection film MT Monitor CONT Control part VH Vehicle

Claims (15)

An optical element on which electromagnetic waves are incident;
Among the electromagnetic waves transmitted through the optical element, an electric signal of a visible light image component based on a first electromagnetic wave that is a wavelength region corresponding to a visible light region and a far electromagnetic wave based on a second electromagnetic wave that is a wavelength region corresponding to a far infrared region. An image sensor for converting into an infrared image component electrical signal;
An image pickup apparatus comprising: an image processing unit that generates a visible image and a far-infrared image based on the electric signal of the visible light image component and the electric signal of the far-infrared image component;
The optical device is formed using a material in which 80% by weight or more of methylpentene is blended.   The imaging device according to claim 1, wherein the optical element is a photographic lens that transmits the first electromagnetic wave and the second electromagnetic wave so as to enter the imaging element.   The imaging device is a single imaging device that converts the incident first electromagnetic wave and second electromagnetic wave into an electric signal of the visible light image component and an electric signal of the far-infrared image component, respectively. The imaging apparatus according to claim 1, wherein:   The image pickup device converts the incident first electromagnetic wave into an electric signal of the visible light image component and a second image pickup device that converts the incident second electromagnetic wave into an electric signal of the far-infrared image component. The imaging apparatus according to claim 1, further comprising an imaging element. While including the separation optical element that transmits the second electromagnetic wave while reflecting the first electromagnetic wave transmitted through the optical element, the first electromagnetic wave reflected by the separation optical element is incident on the first imaging element, A structure in which the second electromagnetic wave transmitted through the separation optical element is incident on the second imaging element, wherein the separation optical element is formed using a material containing 80% by weight or more of methylpentene. The imaging device according to claim 4.   The said optical element is formed using the raw material which mix | blends 80 weight% or more of methyl pentene, and is 0.3% or less of saturated water absorption, It is characterized by the above-mentioned. Imaging device.   The image pickup device includes an image sensor unit in which a plurality of pixels are arranged in a matrix, and is converted into one type of color elements from a plurality of types of color elements corresponding to a visible light wavelength region from an incident electromagnetic wave in units of pixels. A color filter unit that separates light in the corresponding wavelength region and light in the wavelength region corresponding to the far infrared region, and causes light corresponding to each color element and light in the far infrared wavelength region to enter each pixel. The imaging apparatus according to claim 3, comprising at least The imaging element includes a first image sensor unit that receives the first electromagnetic wave in which a plurality of pixels are arranged in a matrix, and a plurality of types of color elements corresponding to a visible light wavelength region from the incident electromagnetic wave in the pixel unit. A first image sensor having a first color filter section that separates light in a wavelength region corresponding to one type of color element and transmits light corresponding to each color element;
A second image sensor unit configured to receive the second electromagnetic wave, wherein the second electromagnetic wave is disposed at a position where the second electromagnetic wave transmitted from the first imaging element is incident, and a plurality of pixels are arranged in a matrix; A second imaging element having a second filter unit that causes light in a wavelength region corresponding to a far-infrared region from the second electromagnetic wave transmitted through the first imaging device to enter each pixel;
The imaging apparatus according to claim 3, further comprising:   8. The imaging according to claim 7, wherein the color filter unit of the imaging device further includes a part for allowing light in a wavelength region corresponding to a near infrared region from incident electromagnetic waves to be incident on each pixel in the pixel unit. apparatus.   The image processing means calculates a color difference signal and a first luminance signal corresponding to a visible image as an electric signal of the visible light image component obtained by the imaging device, and a second as an electric signal of the far infrared image component. The luminance signal is calculated, and the color difference signal, the first luminance signal, and the second luminance signal are synthesized in correspondence with each pixel position. Imaging device. A first photographing lens that transmits a first electromagnetic wave in a visible light region; a second photographing lens that is disposed on an optical axis different from the first photographing lens and transmits a second electromagnetic wave in a far infrared region;
A cover member disposed on the object side with respect to the first and second photographing lenses;
A first imaging element that converts an electric signal of a visible light image component based on the first electromagnetic wave transmitted through the first photographing lens;
A second imaging element different from the first imaging element that converts an electric signal of a far-infrared image component based on the second electromagnetic wave transmitted through the second photographing lens;
An image pickup apparatus comprising: an image processing unit that generates a visible image and a far-infrared image based on the electric signal of the visible light image component and the electric signal of the far-infrared image component;
The image pickup apparatus, wherein the cover member includes at least a material containing 80% by weight or more of methylpentene.   12. The imaging apparatus according to claim 11, wherein the cover member is formed using a material containing 80% by weight or more of methylpentene and a saturated water absorption of 0.3% or less.   The image processing means calculates a color difference signal and a first luminance signal corresponding to a visible image as an electric signal of the visible light image component obtained by the imaging device, and a second as an electric signal of the far infrared image component. The imaging apparatus according to claim 11 or 12, wherein a luminance signal is calculated, and the color difference signal, the first luminance signal, and the second luminance signal are combined in correspondence with each pixel position.   A vehicle with an imaging device, wherein the imaging device according to any one of claims 1 to 13 is attached to the vehicle. An electromagnetic wave is incident on an optical element formed using a material in which 80% by weight or more of methylpentene is blended, and the electromagnetic wave transmitted through the optical element is visible on the imaging element based on the first electromagnetic wave that is a wavelength range corresponding to the visible light range. Converting the electrical signal of the optical image component and the electrical signal of the far-infrared image component based on the second electromagnetic wave in the wavelength range corresponding to the far-infrared region,
An image forming method, wherein a visible image and a far infrared image are generated based on the converted electrical signal of the visible light image component and the electrical signal of the far infrared image component.