JP6055167B2 - Imaging device - Google Patents

Description

  The present invention relates to an imaging apparatus.

  An imaging apparatus including a plurality of light receiving elements arranged in a planar shape is used for imaging a vein image for biometric authentication, for example (Patent Document 1). Specifically, an imaging device mounted on a mobile device such as a mobile phone can be used for biometric authentication during electronic payment. For imaging a vein image, near infrared light having a high transmittance with respect to a living tissue is used.

  However, when the imaging device is used outdoors (for example, when a portable device equipped with the imaging device is located outdoors), sunlight passes through the living tissue together with near-infrared light emitted from the light source of the imaging device. Then, the light reaches each light receiving element, and the charge amount of each light receiving element is saturated (so-called whiteout), and a vein image may not be appropriately captured. In order to solve the above problems, Patent Documents 2 and 3 disclose an authentication device in which an optical filter that suppresses a visible light component is installed between a subject and each light receiving element. Patent Document 4 discloses an imaging apparatus in which an optical filter having a pass band in the entire wavelength range (for example, 650 nm to 900 nm) of infrared light irradiated by a light source is disposed between a subject and each light receiving element. ing.

JP 2004-265269 A JP 2008-168118 A JP 2009-238205 A JP 2009-172263 A

  However, in the techniques of Patent Document 2 and Patent Document 3, since the visible light component of sunlight is only suppressed, the near-infrared light contained in sunlight transmits through the living tissue together with the irradiation light from the light source. To each light receiving element. Similarly, in the technique of Patent Document 4, the near-infrared light of sunlight passes through the optical filter and reaches each light receiving element. Therefore, in the techniques of Patent Document 2 to Patent Document 4, it is actually difficult to effectively prevent saturation of the charge amount of each light receiving element. In view of the above circumstances, an object of the present invention is to effectively suppress the influence of sunlight on a light receiving element.

In order to solve the above-described problems, an imaging apparatus according to the present invention includes a light receiving unit in which a plurality of light receiving elements that receive light from a subject are formed on a first substrate (for example, the substrate 32), a light receiving unit, and a subject. A band-pass filter (for example, a band-pass filter 64A or a band-pass filter 64B) that is installed in between and has a wavelength at which the transmittance reaches a peak (for example, a transmission peak wavelength λ F) matches the wavelength of the Fraunhofer line of sunlight. . In the above configuration, since the wavelength at which the transmittance of the bandpass filter reaches a peak (transmission peak wavelength) matches the wavelength of the Fraunhofer line of sunlight, the intensity of sunlight reaching each light receiving element can be reduced. Is possible. The transmission peak wavelength and the Fraunhofer line wavelength are “matched” when both values are completely matched or when both values are substantially matched (when both values are equal) ) Also implies. For example, even if the transmission peak wavelength and the wavelength of the Fraunhofer line are formally different, if the difference between the two is within the range of manufacturing error, for example, they are substantially the same (ie, the present invention It belongs to the scope).

  In a preferred embodiment of the present invention, the bandpass filter includes a thin film formed of amorphous silicon. Since amorphous silicon has the property of absorbing visible light components of sunlight, it is necessary to install an independent optical filter that blocks visible light components according to the configuration including a bandpass filter including a thin film of amorphous silicon. Absent. Therefore, there is an advantage that the imaging apparatus can be thinned.

  An imaging apparatus according to a preferred aspect of the present invention includes a light source that irradiates light to a subject, and a pass band of the band-pass filter includes a wavelength at which the intensity of light irradiated by the light source reaches a peak (emission peak wavelength λL). . In the above aspect, since the wavelength at which the intensity of light emitted from the light source reaches a peak is included in the passband of the bandpass filter, the light emitted from the light source is suppressed from being attenuated by the bandpass filter. According to an aspect in which the wavelength at which the intensity of light emitted from the light source reaches a peak (emission peak wavelength) matches the wavelength at which the transmittance of the bandpass filter reaches a peak (transmission peak wavelength), attenuation of the irradiation light by the light source is reduced. The effect of suppressing becomes particularly remarkable. Note that the peak emission wavelength and the transmission peak wavelength are “matched” when both values are completely the same and when both values are substantially the same (when both values are equal) ) Also implies. For example, even if the emission peak wavelength and the transmission peak wavelength are formally different from each other, for example, if the difference between the two is within the range of manufacturing errors, they are substantially coincident (that is, within the scope of the present invention). ).

In a preferred embodiment of the present invention, the light source emits near infrared light (for example, light having a wavelength of 700 nm to 900 nm), and the bandpass filter has a wavelength of the Fraunhofer line of sunlight in the wavelength range of near infrared light. Is included in the passband. In the above aspect, since the light source irradiates near-infrared light that passes through the biological tissue, it is particularly suitable for a biometric authentication apparatus that uses a subject as a living body (vein).

  An image pickup apparatus according to a preferred aspect of the present invention includes a condensing unit in which a plurality of lenses for condensing incident light from a subject on each light receiving element is formed on a surface of a second substrate (for example, the substrate 42), and a band. The pass filter is formed on the surface of the second substrate. For example, the band pass filter is formed on the surface of the second substrate on the light receiving unit side, and the plurality of lenses are formed on the surface of the band pass filter. In the above aspect, since the band pass filter is formed on the surface of the second substrate on which the plurality of lenses are formed, the substrate on which the band pass filter is formed is compared with the configuration in which the substrate is provided separately from the second substrate. Thus, the image pickup apparatus can be thinned.

  The imaging device according to a preferred aspect of the present invention includes a light-shielding unit that is installed between the light-receiving unit and the light-collecting unit and has a plurality of openings corresponding to the respective light-receiving elements. In the above aspect, since the light shielding portion in which the opening corresponding to each light receiving element is formed is installed, it is possible to limit the angle of light incident on the light receiving element (and thus to prevent light crosstalk). . The light shielding portion includes, for example, a light transmissive third substrate (for example, the substrate 52) and a light shielding layer formed on the third substrate and having a plurality of openings.

  The imaging apparatus of the present invention can be mounted on various electronic devices. Applications and types of electronic devices are arbitrary, but considering the effect of the present invention that the intensity of sunlight reaching each light receiving element is reduced, the imaging device of the present invention may be irradiated with sunlight. This is particularly suitable for electronic devices with high (for example, portable personal computers, mobile phones, and portable information terminals).

1 is a perspective view of an imaging apparatus according to a first embodiment of the present invention. It is the spectrum of sunlight. It is sectional drawing of the imaging part in 1st Embodiment. It is a characteristic view of the band pass filter in a 1st embodiment. It is sectional drawing of the imaging part in 2nd Embodiment. It is sectional drawing of the band pass filter in 2nd Embodiment. It is a characteristic view of the band pass filter in 2nd Embodiment. It is sectional drawing of the imaging part in 3rd Embodiment. 1 is a perspective view of a portable personal computer according to an embodiment of an electronic apparatus of the present invention. 1 is a perspective view of a mobile phone according to an embodiment of an electronic apparatus of the present invention.

<A: First Embodiment>
FIG. 1 is a perspective view of an imaging apparatus 100 according to the first embodiment of the present invention. The imaging apparatus 100 is a biometric authentication apparatus (vein sensor) that captures a vein image of a user's finger as a subject, and includes a housing 10, an imaging unit 12, and a plurality of light sources 14 as shown in FIG.

  The housing 10 accommodates and supports the imaging unit 12 and the plurality of light sources 14. A rectangular opening 11 having a size corresponding to a finger is formed on the upper surface of the housing 10. The imaging unit 12 is fixed to the housing 10 such that the surface (hereinafter referred to as “light receiving surface”) 16 of the imaging unit 12 is exposed in the opening 11. The light source 14 is disposed at each position overlapping the finger in a state where the finger is disposed in the opening 11 so as to cover the light receiving surface 16. Each light source 14 emits light (hereinafter referred to as “inspection light”) to the finger. For example, a light emitting diode or a laser diode is suitable as the light source 14. The position and number of the light sources 14 are arbitrary. For example, in a configuration in which a finger guide (not shown) for inserting a finger by a user is installed, it is possible to install a plurality of light sources 14 at positions where the finger is sandwiched from both sides on the inner wall surface of the finger guide.

The inspection light emitted by each light source 14 is near infrared light having a peak intensity at a wavelength λL (hereinafter referred to as “emission peak wavelength”) within a predetermined wavelength range BL. The wavelength band BL is a band that passes through the living tissue and is absorbed by the reduced hemoglobin of blood in the vein, and is in the range of 700 nm to 900 nm (so-called “biological window”), for example.

  FIG. 2 is a spectrum of sunlight in the wavelength band BL. As understood from FIG. 2, the component of the wavelength corresponding to each absorption line (Fraunhofer line) in sunlight has a lower intensity than other components. Specifically, in the wavelength band BL, 759 nm and 823 nm correspond to sunlight absorption lines. The emission peak wavelength λL of the inspection light emitted by each light source 14 substantially matches the wavelength of the absorption line of sunlight in the wavelength band BL. In the first embodiment, the emission peak wavelength λL of each light source 14 is set to 759 nm.

  FIG. 3 is a cross-sectional view of the imaging unit 12. As shown in FIG. 3, the imaging unit 12 includes a light receiving unit 30, a light collecting unit 40, a light shielding unit 50, and an optical filter unit 60. The condensing unit 40 is interposed between the finger 200 serving as a subject and the light receiving unit 30. Further, the optical filter unit 60 is interposed between the finger 200 and the light collecting unit 40, and the light shielding unit 50 is interposed between the light collecting unit 40 and the light receiving unit 30. The light receiving unit 30 and the light shielding unit 50 are fixed to each other with a light-transmitting adhesive 38.

  The light receiving unit 30 (for example, a CMOS sensor or a CCD sensor) includes a flat substrate 32 and a plurality of light receiving elements 34. The plurality of light receiving elements 34 are formed on the surface of the substrate 32 on the finger 200 side (the light collecting unit 40 side and the light shielding unit 50 side) and arranged in a matrix. Electric charges corresponding to the amount of incident light are generated in each light receiving element 34.

  The condensing unit 40 includes a substrate 42 and a plurality of lenses (microlenses) 44. The substrate 42 is a plate-like member (for example, a glass substrate) that transmits inspection light. Each of the plurality of lenses 44 is formed on the surface of the substrate 42 on the light receiving unit 30 side, and is arranged in a matrix so as to correspond to each light receiving element 34 of the light receiving unit 30 on a one-to-one basis. The optical axis of each lens 44 passes through the center of the light receiving element 34 corresponding to the lens 44. Each lens 44 is a convex lens that condenses incident light from the finger 200 side on the light receiving element 34. For the formation of the plurality of lenses 44, for example, a reflow method in which the surface of the resin film formed on the surface of the substrate 42 is curved by heating and melting is suitable. It is also possible to integrally form the substrate 42 and the plurality of lenses 44 by, for example, injection molding. A configuration in which a plurality of lenses 44 are formed on the surface of the substrate 42 on the finger 200 side is also employed.

  The light shielding unit 50 includes a substrate 52 and a light shielding layer 54. The substrate 52 is a plate-like member (for example, a glass substrate) that transmits inspection light. A light shielding layer 54 is formed on the surface of the substrate 52 on the light receiving unit 30 side. The light shielding layer 54 is a thin film formed of a light shielding material that absorbs or reflects inspection light (for example, a resin material mixed with a light absorbing material or a metal material such as chromium). Openings 56 corresponding to the lenses 44 of the light collecting unit 40 are formed in the light shielding layer 54 in a one-to-one correspondence. The optical axis of the lens 44 passes through the center of the opening 56 corresponding to the lens 44. The light shielding layer 54 prevents light collected by each lens 44 from reaching the light receiving elements 34 other than the light receiving elements 34 corresponding to the lenses 44 (light beam crosstalk). It is also possible to use a light-shielding flat plate material in which a through hole corresponding to each lens 44 is formed as the light-shielding portion 50.

  The optical filter unit 60 in FIG. 3 includes a substrate 62 and a band pass filter 64A. The substrate 62 is a plate-like member (for example, a glass substrate) that transmits inspection light. The surface on the finger 200 side of the substrate 62 corresponds to the light receiving surface 16. The band pass filter 64A is formed on the surface of the substrate 62 on the light condensing unit 40 side (opposite to the light receiving surface 16), and selectively selects a component in a predetermined pass band (wavelength region) BF of incident light. This is an optical filter that blocks (absorbs or reflects) other components by passing them through.

  The solid line in FIG. 4 is a graph showing the relationship between the wavelength of incident light with respect to the bandpass filter 64A and the transmittance of the bandpass filter 64A with respect to the light. As understood from FIG. 4, the pass band BF of the bandpass filter 64A is set so as to include the emission peak wavelength λL of the light source 14 (and thus the wavelength of the absorption line of sunlight in the wavelength band BL). Specifically, the wavelength λF (hereinafter referred to as “transmission peak wavelength”) at which the transmittance of the bandpass filter 64A reaches a peak is set to 759 nm corresponding to the emission peak wavelength λL and the wavelength of the absorption line of sunlight.

As shown in FIG. 3, the band pass filter 64A of the first embodiment has a structure in which a first optical filter 642 and a second optical filter 644 are laminated. The first optical filter 642 is a band pass filter in which a plurality of dielectric layers made of, for example, silicon oxide (SiO ₂ ) and a plurality of dielectric layers made of, for example, titanium oxide (TiO ₂ ) are alternately stacked. is there. As indicated by a broken line in FIG. 4, the first optical filter 642 having the above structure alone has a pass band β on the short wavelength side (visible light region) in addition to the pass band BF. Therefore, the second optical filter 644 that blocks (absorbs or reflects) a component in the passband β of the incident light is used in combination with the first optical filter 642. For example, a multilayer cut filter or colored glass is used as the second optical filter 644.

  In the above configuration, as indicated by an arrow in FIG. 3, the inspection light emitted from the light source 14 enters the finger 200, propagates through the finger 200, and is absorbed by the reduced hemoglobin of blood in the vein. Then, light emitted from the finger 200 enters the optical filter unit 60 (substrate 62) from the light receiving surface 16, and a component in the pass band BF of the incident light passes through the band pass filter 64A. The light that has passed through the band pass filter 64A enters the light collecting unit 40, is collected by each lens 44, passes through the opening 56 of the light shielding layer 54, and reaches the light receiving element 34. Therefore, a vein image of the finger 200 is captured.

  In the first embodiment, since the pass band BF of the bandpass filter 64A includes the wavelength of the absorption line of sunlight, all the components in the near-infrared wavelength region of sunlight can reach the light receiving element 34. Compared with (for example, the configuration of Patent Document 4 in which an optical filter having a pass band in the entire wavelength range of near infrared light) is installed, the intensity of sunlight reaching each light receiving element 34 can be reduced. is there. Therefore, there is an advantage that a vein image having a high contrast can be taken by suppressing saturation (so-called whiteout) of the charge amount of each light receiving element 34. Particularly in the first embodiment, since the transmission peak wavelength λF of the bandpass filter 64A matches the wavelength of the solar absorption line (759 nm), compared to the configuration in which the transmission peak wavelength λF is different from the absorption line wavelength, The above effect that the intensity of sunlight reaching each light receiving element 34 can be reduced is particularly remarkable. The imaging apparatus according to the first embodiment in which the influence of sunlight is reduced since the possibility of sunlight is high for portable devices used outdoors (for example, the portable devices shown in FIGS. 9 and 10 described later). 100 is particularly effective when mounted on a portable device.

  Further, in the first embodiment, since the pass band BF of the bandpass filter 64A includes the emission peak wavelength λL of the inspection light of the light source 14, the attenuation of the inspection light at the bandpass filter 64A is prevented. Therefore, it is possible to capture a high-quality vein image with high contrast. Particularly in the first embodiment, since the transmission peak wavelength λF of the bandpass filter 64A coincides with the emission peak wavelength λL of the light source 14, the above effect of preventing the attenuation of the inspection light in the bandpass filter 64A is particularly remarkable. It is.

  By the way, when the incident angle of the sunlight with respect to the finger 200 is large (for example, when the sun is irradiated to the finger 200), all the components in the wavelength region of the near infrared light transmitted through the finger 200 reach the light receiving element. In the technique of No. 2 to Patent Document 4, gradation spots (unevenness of brightness) of vein images occur. In the first embodiment, since the intensity of sunlight is relatively reduced with respect to the inspection light, even in a situation where sunlight is incident on the finger 200 in an oblique direction, high-quality with less gradation spots is obtained. There is an advantage that a vein image can be taken. As described above, in the first embodiment, a good vein image can be taken regardless of whether it is indoors or outdoors, so that the accuracy of biometric authentication using the vein image can be improved.

<B: Second Embodiment>
A second embodiment of the present invention will be described below. In addition, about the element in which an effect | action and a function are equivalent to 1st Embodiment in each structure illustrated below, the detailed description of each is abbreviate | omitted suitably using the code | symbol referred by the above description.

  FIG. 5 is a cross-sectional view of the imaging unit 12 in the second embodiment. As shown in FIG. 5, the optical filter unit 60 of the imaging unit 12 of the second embodiment uses the bandpass filter 64A (the first optical filter 642 and the second optical filter 644) of the first embodiment as a bandpass filter 64B. This is a replacement configuration. The band pass filter 64B selectively passes the components in the pass band BF of the incident light, similarly to the band pass filter 64A of the first embodiment.

FIG. 6 is a cross-sectional view of the optical filter unit 60 (bandpass filter 64B). As shown in FIG. 6, the band-pass filter 64B is a wavelength selection filter in which high refractive index layers 681 and low refractive index layers 682 are alternately stacked over odd layers ((2n + 1) layers) (n is a natural number). Each high refractive index layer 681 is made of, for example, amorphous silicon (a-Si), and each low refractive index layer 682 is made of, for example, silicon oxide (SiO ₂ ). The (n + 1) th layer of the bandpass filter 64B has a film thickness such that the optical distance (optical path length) is smaller than 1/4 of 600 nm, which is shorter than the transmission peak wavelength λF (emission peak wavelength λL). The thicknesses of the selected layers other than the (n + 1) th layer are selected so that the optical distance is 1/4 of 600 nm, which is shorter than the transmission peak wavelength λF (emission peak wavelength λL).

  FIG. 7 is a graph showing the relationship between the wavelength of incident light with respect to the bandpass filter 64B and the transmittance of the bandpass filter 64B with respect to the light. As shown in FIG. 7, the pass band BF of the band pass filter 64B of the second embodiment is similar to the band pass filter 64A of the first embodiment. Absorption wavelength). Specifically, the transmission peak wavelength λF of the bandpass filter 64B is set to the emission peak wavelength λL (759 nm).

  Amorphous silicon, which is the material of each high refractive index layer 681, has a property of absorbing visible light components of sunlight. Therefore, as can be understood from FIG. 7, an independent multilayer cut filter or color glass (the second optical filter 642 of the first embodiment) dedicated to the shading (absorption) of visible light components is unnecessary.

  In the second embodiment, the same effect as in the first embodiment is realized. In the second embodiment, since the band pass filter 64B includes the high refractive index layer 681 of amorphous silicon, an optical filter for shielding visible light components (the second optical filter 642 of the first embodiment) is independently provided. There is no need to install it. Therefore, there is an advantage that the imaging device 100 is thinned as compared with the first embodiment.

<C: Third Embodiment>
FIG. 8 is a cross-sectional view of the imaging unit 12 according to the third embodiment of the present invention. As shown in FIG. 8, in the third embodiment, the independent optical filter unit 60 is omitted, and the same bandpass filter 64B as in the second embodiment is installed in the light collecting unit 40. Specifically, the band-pass filter 64B is formed on the surface of the substrate 42 of the light collecting unit 40 on the light receiving unit 30 side. As described with reference to FIG. 6, the bandpass filter 64B includes the high refractive index layer 681 of amorphous silicon (a-Si), and the transmission peak wavelength λF is the emission peak wavelength λL (wavelength range) of the light source 14. It corresponds to the wavelength of the absorption line of sunlight in BL (759 nm). The plurality of lenses 44 of the condenser 40 are formed on the surface of the bandpass filter 64B and arranged in a matrix. As understood from FIG. 8, the surface on the finger 200 side of the substrate 42 corresponds to the light receiving surface 16.

  In the third embodiment, the same effect as in the first embodiment is realized. In the third embodiment, the band pass filter 64 </ b> B is formed on the substrate 42 of the light collecting unit 40 together with the plurality of lenses 44. Therefore, it is possible to further reduce the thickness of the imaging device 100 as compared with the second embodiment in which the bandpass filter 64B is formed on the substrate 62 separate from the substrate 42. 8 illustrates the band-pass filter 64B of the second embodiment, but the band-pass filter 64A of the first embodiment may be formed on the substrate 42 of the light collecting unit 40.

<D: Modification>
Each of the above forms can be variously modified. Specific modifications are exemplified below. Two or more modes arbitrarily selected from the following examples can be appropriately combined.

(1) Modification 1
The emission peak wavelength λL and the transmission peak wavelength λF are not limited to 759 nm. For example, as described with reference to FIG. 2, the emission peak wavelength λL and the transmission peak wavelength λF can be matched with the wavelength of other absorption lines (for example, 823 nm) in the near-infrared wavelength region BL. is there. Further, it is not necessary that the emission peak wavelength λL and the transmission peak wavelength λF completely coincide with the wavelength of the absorption line of sunlight. That is, even if the emission peak wavelength λL and the transmission peak wavelength λF are different from the wavelength of the solar absorption line within the range of manufacturing error, for example, the emission peak wavelength λL and the transmission peak wavelength λF are substantially the same as those of sunlight. It is assumed that it matches the wavelength of the absorption line. However, the configuration in which the emission peak wavelength λL and the transmission peak wavelength λF coincide with the wavelength of the absorption line of sunlight is a particularly effective configuration from the viewpoint of the effect of the invention, but effectively suppresses the influence of sunlight. It cannot be said that the structure is indispensable for the desired effect.

(2) Modification 2
The position where the bandpass filter 64 (64A, 64B) is installed is arbitrary. For example, the structure which formed the band pass filter 64 in the surface on the opposite side (finger 200 side) of the condensing part 40 among the board | substrates 62, or the other side (the several lens 44 among the board | substrates 42 of the condensing part 40 ( A configuration in which a band pass filter 64 is formed on the surface of the finger 200 side) is also employed. Further, it is also possible to form the band pass filter 64 on the surface of the substrate 52 of the light shielding unit 50 on the light collecting unit 40 side or the surface of the light receiving unit 30 (on the surface of the substrate 52 or on the surface of the light shielding layer 54). is there. Furthermore, the structure which formed the band pass filter 64 which covers each light receiving element 34 on the surface of the light-receiving part 30 is also employ | adopted. As understood from the above examples, the band pass filter 64 can be formed at an arbitrary position on the path from the subject (finger 200) to each light receiving element 34.

<E: Application example>
The imaging device 100 of each embodiment described above is used in various electronic devices. FIG. 9 is a perspective view of a portable personal computer using the imaging device 100 of each embodiment described above. The personal computer 92 in FIG. 9 includes a display unit 922 that displays an image, a plurality of operators 924 operated by a user, and the imaging device 100 of each of the above-described forms. Authentication processing using a vein image captured by the imaging apparatus 100 is executed, and whether to start using the personal computer 92 or whether electronic payment is permitted is determined according to the authentication result.

  FIG. 10 is a perspective view of a mobile phone using the imaging device 100 of each embodiment described above. The mobile phone 94 in FIG. 10 includes a display unit 942 that displays an image, a plurality of operators 944 operated by a user, and the imaging device 100 of each of the above-described forms. An authentication process using a vein image captured by the imaging apparatus 100 is executed, and whether or not the operation lock state is released and whether or not electronic payment is permitted are determined according to the authentication result.

  The electronic apparatus to which the imaging device 100 of each form is applied is not limited to the above examples. For example, the imaging device 100 is applied to a personal digital assistant (PDA), a digital camera, a video camera, a car navigation device, and the like as in the examples of FIGS.

DESCRIPTION OF SYMBOLS 100 ... Imaging device, 10 ... Housing, 12 ... Imaging part, 14 ... Light source, 16 ... Light-receiving surface, 30 ... Light-receiving part, 32, 42, 52, 62 ... Board | substrate, 34 ... Light reception Element: 40 ... Condensing part, 44 ... Lens, 50 ... Light shielding part, 54 ... Light shielding layer, 56 ... Opening part, 60 ... Optical filter part, 64A, 64B ... Band pass filter.

Claims (8)

A light receiving section in which a plurality of light receiving elements for receiving light coming from a subject are formed on a first substrate;
A light-transmissive second substrate installed between the light receiving unit and the subject ;
A bandpass filter formed on the surface of the second substrate of the second substrate, the wavelength at which the transmittance reaches a peak matches the wavelength of the Fraunhofer line of sunlight ;
An imaging apparatus comprising: a plurality of lenses formed on a surface of the bandpass filter and condensing incident light from the subject on the light receiving elements . 2. The imaging apparatus according to claim 1, wherein in the band-pass filter , a wavelength at which the transmittance reaches a peak that matches a wavelength of the Fraunhofer line is in a wavelength range from 700 nm to 900 nm . Comprising a light source for irradiating the subject with near-infrared light in a wavelength range from 700 nm to 900 nm;
The imaging device according to claim 1, wherein a wavelength at which the intensity of light emitted from the light source reaches a peak coincides with a wavelength at which the transmittance of the bandpass filter reaches a peak. The bandpass filter is a filter in which a high refractive index layer and a low refractive index layer are alternately stacked over (2n + 1) layers (n is a natural number), and the (n + 1) th layer is a layer other than the (n + 1) th layer. The imaging device according to any one of claims 1 to 3, wherein an optical distance is small compared to each layer. The bandpass filter is
A first optical filter that includes a region including the wavelength of the Fraunhofer line of sunlight in the wavelength region of near infrared light, and a visible light region on the short wavelength side of the region in the passband;
The imaging apparatus according to claim 1, further comprising: a second optical filter that blocks light components in the visible light region. 6. The imaging device according to claim 1 , further comprising: a light shielding unit that is installed between the light receiving unit and the second substrate and has a plurality of openings corresponding to the light receiving elements. The shading part is
A light transmissive third substrate;
A light shielding layer formed on the third substrate and having the plurality of openings.
The imaging device according to claim 6 . An electronic apparatus comprising the imaging device according to claim 1 .

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