TW201245836A - Optical filter module and optical filter system - Google Patents

Abstract

A plurality of filters is disposed in an optical filter module which is disposed in an image capture device. The plurality of filters comprises a first filter which transmits visible light and blocks at least infrared, and a second filter which allows only infrared to pass. The first filter and the second filter are positioned to be selectively switchable.

Description

201245836 VI. Description of the Invention: [Technical Field of the Invention] The present invention relates to an optical filter module and an optical filter system. [Prior Art] In the optical system of an electronic camera represented by a general video camera and a digital still camera, a combined optical system, an infrared ray interrupt filter, and optical are sequentially arranged from the object side along the optical axis. An imaging element such as a low-pass filter, a CCD (Charge Coupled Device), or a MOS (Metal Oxide Semiconductor) (see, for example, Patent Document 1). Further, the image pickup element herein has a sensitivity characteristic of light in a wavelength band which is wider than light (visible light) which is visible in the wavelength band visible to the human eye. To this end, in addition to visible light, it also responds to light in the infrared or ultraviolet range. The human eye responds to light at a wavelength in the range of 400 to 620 nm in the dark, and responds to light having a wavelength in the range of 420 nm to 7 〇 Onm. On the other hand, for example, in the CCD, light having a wavelength in the range of 400 to 700 nm is responded to with a sensitivity of 髙, and light having a wavelength of less than 400 nm and light having a wavelength exceeding 700 nm are also responded. For this reason, in the imaging device described in Patent Document 1 to be described later, an infrared ray blocking filter is provided in addition to the CCD of the imaging element, so that the light in the infrared light region does not reach the imaging element, and an image of the image close to the human eye is obtained. In addition, in the previous optical filter 'in order to maximize the transmittance of the visible field visible to the human eye, the main surface of the optical filter' is applied to reduce the reflection of light in the field of view. The anti-reflection film (AR coating) is a general filter structure. [Prior Art] [Patent Document 1] [Patent Document 1] JP-A-2000-2095 No. 1 (Invention) [Problems to be Solved by the Invention] However, in addition to general video cameras and digital stills, In addition to the camera, there is also an imaging device used for other purposes such as a surveillance camera that is different from normal photography. For example, in a surveillance camera, it is necessary to perform surveillance photography under dark vision such as nighttime, not only during the daytime. In the sneak peek, since the photograph is in a state in which the human eye cannot see it, the camera having the normal visible field as the photographing region cannot perform photography under scotopic vision. For this reason, the photographic recording system in the illuminating state is performed by using the light in the infrared light field. However, the imaging device described in Patent Document 1 is provided with an infrared ray blocking filter that blocks the light in the infrared light field. Used for squint photography. Here, in order to solve the above problems, an object of the present invention is to provide an optical filter module and an optical filter system that can perform photographing not only during daylight hours when natural light enters, but also under dark vision such as nighttime. [Means to solve the problem] -6 -

S 201245836 In order to achieve the foregoing object, an optical filter mold according to the present invention is disposed on an image pickup device, and an optical filter capable of switching a plurality of filters is characterized in that: the plurality of filters transmit visible light, at least interrupt the infrared filter, And the second filter that passes only infrared rays; the first filter of the first filter is arranged to be selectively switchable. According to the present invention, since the first filter and the second filter can be selectively switched, photographing can be performed not only during daylight when natural light enters, but also during dark vision. Specifically, the first filter is disposed in the white state, and the second filter is disposed in a dark state. In the daytime, photographing can be performed under dark vision such as at night. In particular, when the visible light is transmitted and at least the infrared rays are blocked, the first filter can be photographed during the day, so that an image of the human eye can be obtained during the day. Further, since night photography can be performed only in the state in which the above-described first medium of the infrared rays exists, there is no possibility that a part of the natural light in the visible region of the image is incident and the exposure is made to obtain a more stable and vivid infrared image. In the above structure, the "second oven mirror" may be used to block other regions of the infrared rays only by the specific band region set in the infrared first. At this time, in addition to the above-described action effect, the "specific band of the second filter system in which the infrared rays are set in advance" blocks the infrared rays, so that the photography under scotopic effect is better. In the above structure, the 'first filter' is provided with an absorbing red infrared absorbing body' and a reflecting red ray external line @#彳泉@ Μ ^, but in addition to the above-mentioned effects, 'because of the aforementioned group, The module, the line mirror and the front mirror configuration make it suitable for nighttime, not only because of the presence of the 2 filters due to the nighttime, but also the line only through the band, the outer line 〇1 filter 201245836 Infrared absorbers that absorb infrared rays and infrared reflectors that reflect infrared rays can suppress ghosts and spots while improving color realism, so that daytime photography can be better. In the above configuration, the infrared absorber is a light transmission characteristic having a transmittance of 50% in a wavelength band of 620 nm to 660 nm: the infrared reflector is a wavelength in a wavelength band of 670 nm to 690 nm. a light transmission characteristic having a medium transmittance of 50%; a combination of the infrared absorber and the infrared reflector described above indicates a transmittance of 50% in a wavelength band of 620 nm to 66 〇 nm, and a wavelength of 70 nm The light transmission property of the transmittance of less than 5% is also acceptable. In this case, the first filter includes the infrared absorber and the infrared reflector, and the infrared absorber indicates a light transmission characteristic in which a transmittance in a wavelength band of 620 nm to 660 nm is 50%, and the infrared reflector indicates a light transmission characteristic in which a transmittance in a wavelength band of 670 nm to 690 nm is 50%, and a combination of the infrared absorber and the infrared reflector indicates a transmittance in a wavelength band of 620 nm to 660 nm. 50%, the transmittance of the wavelength of 700 nm is less than 5%. Therefore, by the combination of the above-mentioned infrared absorber and the above-mentioned infrared reflector, it is possible to obtain a slow decrease in transmittance from the visible pre-covered infrared light field, 700 nm. The transmittance in the wavelength is about 0% which is close to the light transmission characteristic of the sensitivity characteristic of the human eye. Further, in the infrared absorber, the infrared absorber having a light transmittance of 50% in a wavelength in a wavelength band of 620 nm to 660 nm is used, for example, 'the one shown by L 1 1 of FIG. Optical characteristics

In the infrared absorbing glass of -8-S 201245836, the transmittance is about 〇% (less than 5%), and the infrared ray absorbing effect of the infrared ray absorber is combined with the infrared ray reflection of the infrared ray reflector. 70〇nm. For this reason, the first filter of the present invention is compared with the conventional infrared ray interrupting filter formed of the infrared absorbing glass having the light transmitting property shown by L12 of Fig. 1 in the visible region, especially at 600 nm. The 700 nm wavelength band maintains high transmittance. In other words, it is possible to transmit a sufficient amount of red light (light having a wavelength of 600 nm to 700 nm) which can be sensed by the image pickup element of the image pickup device while blocking infrared rays having a wavelength exceeding 700 ηη. Therefore, the first filter of the present invention is applied to the infrared ray blocking filter of the imaging device, and the sensitivity of the red color of the imaging element can be eliminated, and the image captured by the imaging device can easily become a dark image. The shortcomings. Further, in the first filter, the infrared ray reflector is combined with the infrared ray absorbing body to suppress the amount of light reflected by the infrared ray reflector. For this reason, it is possible to suppress the occurrence of ghosting due to reflection of the light of the infrared reflector. Further, the thickness of the infrared absorbing glass having a light transmission characteristic indicated by L 1 1 in Fig. 10 having a transmittance of 50% at a wavelength of 640 nm is used as a conventional infrared ray interrupting filter. The thickness of the infrared absorbing glass of the light transmitting property indicated by L 1 2 is less than or equal to half, and accordingly, the transmittance in the wavelength band of 620 to 660 nm constituting the aforementioned first filter of the present invention is 50. The infrared ray absorbing body having a light transmission characteristic of % can be thinner than the infrared ray blocking filter composed of the previous infrared absorbing glass having the light transmitting property shown by L12 in Fig. 1A, which is -9-201245836. Therefore, according to the first filter of the present invention, the previous infrared ray constituted by the infrared absorbing body blocks a thin thickness 'on the side, sufficiently transmits red visible light' and in the visible field, has a light transmittance close to the human eye. Special filter. Further, in order to achieve the above object, the present invention relates to a combined optical system in which light is incident on at least a part of an object from the outside along the optical axis, and a switchable configuration of a multi-mirror system, an optical filter, and an imaging element. The device is characterized in that: the plurality of filters transmit visible light to the first filter and the second filter that passes only infrared rays; and any one of the second filters is selectively switchable according to the present invention, because the foregoing 1 The filter and the front-side can be selectively switched and arranged on the optical axis, and during the daytime, even in the dark vision at night, the first filter can be used in the daytime to switch between In the view state, the second filter is arranged to be placed in the daylight only, and in the dark vision such as at night, the visible light can be captured, and at least the infrared rays can be blocked in the first state, so that daytime photography can be performed. Get a natural camera portrait. In addition, since it is possible to perform nighttime photography in a state in which only the infrared mirror is interposed, it is possible to obtain a more stable and vivid infrared photographic image by partially injecting a natural light in the visible field in the photography of the future. An optical filter system that cuts off infrared rays and blocks infrared rays, and an optical filter system that optically filters from an external filter is provided with the first filter that blocks infrared rays and the optical axis. on. The second filter is not only photographed in natural light. Specifically, it is placed on the aforementioned optical axis on the optical axis, and is not shadowed. In particular, because the 1 filter has a second filter that is close to the line of the human eye, there is no overexposure due to night.

-10- S 201245836 In the above configuration, the second filter is only a specific band set in advance by infrared rays, and the other bands of the infrared rays may be blocked. In this case, in addition to the above-described effects, the second The filter only blocks the other areas of the infrared rays by the specific band set in advance by the infrared rays, so that the photography under scotopic has a better effect. In the above configuration, the first filter may include an infrared absorber that absorbs infrared rays and an infrared reflector that reflects infrared rays. In this case, in addition to the above-described effects, the first filter includes an infrared absorber that absorbs infrared rays and an infrared reflector that reflects infrared rays, so that it is possible to suppress ghosting and light spots while improving color realism. Make daytime photography a better result. In the above configuration, the infrared absorber is a light transmitting property having a transmittance of 50% in a wavelength band of 62 〇 nm to 660 nm; and the infrared ray reflector is in a wavelength band of 670 nm to 690 nm. a light transmission characteristic having a transmittance of 50% in the wavelength; a combination of the infrared absorber and the infrared reflector, indicating a wavelength in a wavelength band of 620 nm to 660 nm of 50%, a wavelength of 7 〇 Onm A light transmission characteristic in which the medium transmittance is less than 5% is also acceptable. In this case, the first filter includes the infrared absorber and the infrared reflector, and the infrared absorber indicates a light transmission characteristic of a wavelength in a wavelength band of 620 nm to 660 nm of 50%. A light transmission characteristic indicating a transmittance in a wavelength band of 670 nm to 690 nm in a wavelength range of 50%, and a combination of the infrared absorber and the infrared reflector means a -11 in a wavelength band of 620 nm to 660 nm. 201245836 The transmittance in the wavelength is 50%, and the transmittance in the wavelength of 700 nm is less than 5%. Therefore, by combining the above-mentioned infrared absorber and the above-mentioned infrared reflector, it is possible to obtain the infrared light field from the visible region, and the transmittance Slowly decreasing, the transmission at a wavelength of 700 nm is about 0% close to the light transmission characteristic of the sensitivity characteristic of the human eye. In the infrared absorber, the infrared absorber having a light transmission characteristic of a wavelength of 50% in a wavelength band of 620 nm to 660 nm is used, for example, as shown by L 1 1 in FIG. In the infrared absorbing glass of the optical property, the transmittance is about 〇% (less than 5%), and the infrared ray absorbing effect of the infrared ray absorbing body is combined with the infrared ray reflecting action of the infrared ray reflector to be 700 nm. For this reason, the first filter of the present invention is compared with the conventional infrared ray interrupting filter formed of the infrared absorbing glass having the light transmitting property shown by L 1 2 of FIG. 1 in the visible region, especially in the visible region. A wavelength band of 600 nm to 700 nm maintains high transmittance. In other words, it is possible to transmit a sufficient amount of red light (light having a wavelength of 600 nm to 700 nm) which can be sensed by the image pickup element of the image pickup device while blocking infrared rays having a wavelength exceeding 700 nm. Therefore, the first filter of the present invention is applied to the infrared ray blocking filter of the imaging device, and the sensitivity of the red color of the imaging element can be eliminated, and the image captured by the imaging device can easily become a dark image. The shortcomings. Further, in the first filter, the infrared ray reflector is combined with the infrared ray absorbing body to suppress the amount of light reflected by the infrared ray reflector. For this reason, it is possible to suppress the occurrence of ghosting due to reflection of the light of the infrared reflector. 8 201245836 Further, the thickness of the infrared absorbing glass having a light transmission characteristic indicated by L 1 1 in Fig. 10 having a transmittance of 50% at a wavelength of 640 nm is used as a conventional infrared ray interrupting filter. The thickness of the infrared absorbing glass of the light transmitting property indicated by L12 is less than or equal to half, and accordingly, the transmittance in the wavelength range of 620 to 660 nm constituting the first filter of the present invention is 50%. The infrared absorber of the light transmission property can be made thinner than the infrared ray shielding filter which consists of the previous infrared absorbing glass which has the light transmission characteristic shown by L12 of FIG. Therefore, according to the first filter of the present invention, it is possible to provide a visible light having a thickness equal to or thinner than that of the conventional infrared ray interrupting filter formed of only the infrared absorbing body, and to sufficiently transmit the visible light of the red light to block the infrared ray. And in the visible field, an infrared ray blocking filter having a light transmission property close to the human eye. Further, in the above configuration of the present invention, the infrared ray absorbing system indicates a light transmission characteristic of a transmittance of 10% to 40% at a wavelength of 700 nm, and the infrared reflection system indicates a transmittance of less than 15% at a wavelength of 700 nm. The light transmission characteristics are also available. In this case, the infrared absorber having a light transmission characteristic of a transmittance of 10% to 40% in a wavelength of 7〇Onm and the infrared ray having a light transmission characteristic of a wavelength of less than 15% in a wavelength of 7 00 nm are used. The combination of the reflectors can surely achieve high transmittance in the wavelength band of the visible light of red (600 nm to 700 nm). Further, in the above-described configuration of the present invention, the infrared reflecting system may have a light transmittance of 90% or more in the wavelength band of 43 0 nm to 600 nm. At this time, since the light transmission property of the light transmitting property of the infrared absorbing body in the wavelength band of 430 nm to 650 nm is obtained, the infrared light domain is covered from the visible region, and the transmittance is slowly decreased, and a wavelength of 70 〇 Tim can be obtained. The medium transmittance is a light transmission characteristic close to the sensitivity characteristic of the human eye, and in addition, the transmittance can be surely obtained in the visible region, particularly in the wavelength band of the visible light of red (600 nm to 700 nm). [Effects of the Invention] According to the present invention, photographing can be performed not only during daylight when natural light enters, but also under dark vision such as nighttime. [Embodiment] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. <Embodiment> The imaging device 1 of the present embodiment is photographed from the outside along the optical axis 11 as shown in Fig. 1 . On the body side, at least a lens 2 that combines optical light from the outside is provided, an optical filter module 3 that can switch between a plurality of filters (see below), an optical filter 8 that is a 〇LPF, and Imaging Device 9 » The optical filter module 3 is provided with a first filter 4 that transmits visible light, at least blocks infrared rays, and a second filter 7 that passes only infrared rays. The

-14-S 201245836 Any one of the first filter 4 and the second filter 7 is selectively switched to the optical axis 11 by a known switching means (not shown). Specifically, the first filter 4 is placed on the optical axis 11 when natural light such as daylight enters. 5 The second filter 7 is placed on the optical axis 1 1 in a dark vision such as at night. Further, when the second filter 7 is disposed on the optical axis U, light from an LED (not shown) having a peak wavelength of 850 to 900 nm (in the present embodiment, 8 70 nm) Irradiate to the subject. Further, in the present embodiment, the definition of the daytime illuminance is more than 4001x, and the definition of nighttime is the condition of 400x1 or less. Furthermore, the 400x1 system is an example here, and the daytime and nighttime illumination can be freely set by the practitioner. Alternatively, only the nighttime definition is made, and the illuminance of the definition that deviates from the nighttime is judged to be daytime, or only the daytime definition is made, and the illuminance of the definition that deviates from the daytime is judged to be nighttime. In other words, the first filter 4 and the second filter 7 may be switched in accordance with the set illuminance based on the illuminance reference. Moreover, since the optical filter module 3 includes the first filter 4, the optical filter 8 which is an OLPF does not form an infrared ray interrupting filter, and only two wavelength bands (visible field and infrared light field) are prevented. The reflection preventing film of the single layer of the light is formed on both main faces. In the present embodiment, only the single-layer anti-reflection film 81 is formed on the both main surfaces of the optical filter 8. However, the present invention is not limited thereto, and an anti-reflection film capable of preventing reflection of light of a specific wavelength is formed. can. According to the imaging device 1 shown in Fig. 1, the lens 2, the first filter 4, the optical filter 8, and the imaging element 9 are sequentially disposed from the external subject side along the optical axis 1 1 during the daytime. The imaging device 1 (optical filter module 3) has the light transmission characteristics shown in Fig. 2 by the structure in which the first filter is disposed on the optical axis -15-201245836 1 1 . On the other hand, at night, the lens 2, the second filter 7, the optical filter 8, and the imaging element 9 are sequentially disposed from the external subject side along the optical axis 11. By arranging the second filter 7 on the optical axis 11, the imaging device 1 (optical filter module 3) has the light transmission characteristics shown in Fig. 5. As described above, according to the imaging apparatus shown in FIG. 1, since either the first filter 4 and the second filter 7 are selectively switched and arranged on the optical axis 11, in the visible region, sensitivity characteristics close to the human eye can be obtained. The spectral characteristic, and can transmit the light of the desired band of the infrared light domain. As a result, according to the image pickup apparatus 1 shown in Fig. 1, it is possible to appropriately perform photographing during the day when the infrared rays are blocked, and photographing under the dark vision such as nighttime only by infrared rays. That is, photographing can be performed not only during the day when natural light enters, but also under squint at night. Specifically, the first filter 4 is switched to be disposed on the optical axis 11 during the daytime, and the second filter 7 is switched to be disposed on the optical axis 11 in the dark state, not only during the day, but also at night or the like. Photography can also be taken. In particular, since the daytime photography can be performed while the visible light is transmitted through at least the first filter 4 that blocks the infrared rays, a more natural image of the image close to the human eye can be obtained during the day. Further, since nighttime photography can be performed in a state in which only the second filter 7 of the infrared rays is present, there is no possibility that overexposure occurs due to partial injection of natural light in the visible region in nighttime photography, and it is possible to obtain more stable. A vivid portrait of infrared photography. Next, the optical filter module 3 will be described with reference to Figs. 1 to 7 . In the optical filter module 3, a first filter 4 and a second filter are provided

S-16-201245836 7 and well-known switching means (not shown). As shown in Figs. 2 and 3, the first filter 4 is composed of an infrared ray absorber 5 that transmits visible light and absorbs infrared rays, and an infrared ray reflector 6 that transmits visible light and reflects infrared rays. The infrared absorbing body 5 is formed by forming an anti-reflection film 54 (AR coating) on one main surface 52 of the infrared absorbing glass 51. As the infrared absorbing glass 51, a blue glass in which a dye such as copper ions is dispersed is used, for example, a square thin plate glass having a thickness of 0.2 mm to 1.2 mm. Further, the anti-reflection film 54 is formed on a main surface 52 of the infrared absorbing glass 51 by a vacuum deposition apparatus (not shown) to form a single layer made of MgF2 by vacuum deposition. 'Multilayer film made of A1202 and Zr02 and MgF2, or a film of a multilayer film made of TiO 2 and Si 〇 2 . In addition, the anti-reflection film 54 performs a vapor deposition operation while monitoring the film thickness, and when the predetermined film thickness is reached, the gate (not shown) provided in the vicinity of the vapor source (not shown) is closed, and the steaming is stopped. In the case of vapor deposition of a plating material, the infrared absorber 5 shows a transmittance of 50% in a wavelength band of 620 nm to 660 nm, and a transmittance of 1% to 40% in a wavelength of 700 nm. Further, in the light transmission characteristics of the infrared absorber 5, the transmittance is 90% or more of the maximum wavelength in the wavelength range of 4 〇〇 nm to 550 nm. The infrared reflecting body 6 is formed by forming an infrared reflecting film 64 on one main surface 62 of the transparent substrate 61. -17- 201245836 As the transparent substrate 6-1, a colorless transparent glass that transmits visible light and infrared rays is used, for example, a square thin plate glass having a thickness of 0.2 mm to 1.0 mm. As shown in Fig. 4, the infrared reflecting film 64 is a multilayer film in which a first film 65 made of a high refractive index material and a second film 66 made of a low refractive index material are alternately laminated. Further, in this embodiment, TiO 2 is used for the first film 65, SiO 2 is used for the second film 66, Ti 〇 2 for the odd layer, and SiO 2 for the even layer, but the odd layer is SiO 2 and the even layer is T i Ο 2 can also. As a method of manufacturing the infrared ray reflection film 64, TiO2 and SiO2 are alternately vacuum-deposited on a main surface 62 of the transparent substrate 61 by a known vacuum vapor deposition apparatus (not shown) to form an infrared ray reflection film as shown in FIG. 64 methods. In addition, the film thickness adjustment of the first film 65 and the second film 66 is performed while monitoring the film thickness, and when the film thickness is reached, the gate provided in the vicinity of the vapor deposition source (not shown) is closed. (The illustration is omitted), the vapor deposition of the vapor deposition material (Ti_02, SiO2) is stopped, and the infrared reflection film 64 is sequentially numbered from the main surface 62 side of the transparent substrate 61 as shown in FIG. The plural layer defined is composed of one layer, two layers, and three layers in the present embodiment. The one layer 'two layers, three layers, ... each layer is formed by laminating the first film 65 and the second film 66. The thickness of each of the enamel layer, the two layers, and the third layer is different depending on the optical film thickness of the first film 65 and the second film 66 which are laminated. Here, the optical film thickness is determined by the following calculation formula 1.

-18- S 201245836 [Calculation 1]

Nd = dxNx4 / Λ (Nd: optical film thickness, d: physical film thickness, ν: refractive index, λ: center wavelength) In the present embodiment, the infrared ray reflector 6 has a wavelength band of 43 Onm 〜 6 50 nm The transmittance in the wavelength is 90% or more, the transmittance is 50% in the wavelength range of 660 nm to 6 9 Onm, and the transmission characteristic is less than 15% in the wavelength of 7OO nm, and the infrared ray is appropriately adjusted. The number of layers of the reflector 64 and the optical film thickness of each layer. The first filter 4 composed of the infrared absorber 5 and the infrared reflector 6 has a thickness of, for example, 0.4 mm to 1.6 mm. In other words, the thickness of the infrared absorbing glass 51 constituting the infrared absorbing glass 5 and the thickness of the transparent substrate 61 constituting the infrared ray reflector 6 are appropriately adjusted so that the total thickness of the infrared absorbing body 5 and the infrared ray reflector 6 is, for example, 0.4 mm. 1.6 mm 〇 Then, the first filter 4 is a combination of the light transmitting characteristics of the infrared ray absorbing body 5 and the infrared ray reflector 6, and the transmittance in the wavelength band of 40 Onm to 550 nm is the maximum 値, The transmittance in the wavelength range of 62 Onm to 66 Onm is 50%, and the transmittance at the wavelength of 700 nm is less than 5%. Since the first filter 4 formed by the above-described structure has the infrared absorbing body 5 ′ that absorbs infrared rays and the infrared ray reflecting body 6 that reflects infrared rays as described above, it is possible to suppress the ghost image and the spot spot while improving the color reality. 19-201245836 degrees, so that daytime photography can have a better effect. Further, as shown in Figs. 5 and 6, the second filter 7 blocks only the visible band (in the present embodiment, the half-turn I), and blocks the visible region. Further, the second filter 7 is provided with a 値 wavelength of 850 to 900 nm (in the present embodiment, an LED (not shown), and the second filter 7 is disposed to illuminate the light from the LED to be In this way, the filter for photography under the sneak peek is not for the purpose of daytime shadowing, and it is impossible to perform visual photography. Furthermore, in this embodiment, it is assumed that only the specificity is close to 8 70 nm. In this case, it is possible to perform better scotopic photography for removing noise. The second filter 7 is for pre-banding only by infrared rays (in the present embodiment, the light is irradiated from the LED, and the infrared ray is blocked. In the other region, the other main surface 73 of the second filter 7 is formed on the transparent substrate 71 by the infrared ray 74 through the coating 74 (IR coating), and the anti-reflection film 77 is formed for the second filter. The other main surface 73 of the mirror 7 is a vacuum vapor deposition apparatus (not shown), a single layer formed by vacuum evaporation of g MgF2, a multilayer film formed of a1202 and Zr02 and MgF2 films, and Ti 2 and SiO 2 . Any of the membranes. The filter 7' corresponds to the corresponding LED illumination in a specific embodiment that is preset only by infrared rays. The wavelength of the light) The other bands of the line allow the photography under scotopic to have better effect as a transparent substrate. 7. Use visible light and over-infrared rays! 8 5 Onm with a peak of light 8 7 0 nm ) When the 5 axes 11 are on, the 2 filters 7 are not limited to the wavelength of the specific line set by the structure of the band) - the main surface is 2 2 shaped. Furthermore, Yu Qian 77. Reflection uses a well-known ferry to form a multi-layered layer based on this second band (in this case, the infrared ray is blocked.

-20- S 201245836 Clear transparent glass, for example, square thin glass with a thickness of 0.4mm~l.6mm. The infrared ray-passing coating layer 7 is a multilayer film in which a first film 7 made of a high refractive material and a 2nd 76th layer formed of a low refractive index material are stacked as shown in Fig. 7 . Further, in this embodiment, TiO 2 is used for the first film 75, SiO 2 is used for the second film 76, TiO 2 is the layer, and SiO 2 is even layer. However, the odd layer is SiO 2 and the layer is T i 0 2 . As a method of manufacturing the infrared ray-passing coating 74, using a main surface 72 of the substrate 71, TiO2 and SiO2 are alternately vacuum-deposited by a known vacuum evaporation apparatus (denotation) to form a red pass coating as shown in FIG. 74 method. In addition, the film thickness adjustment system of the first film 75 and the second thin film is subjected to a vapor deposition operation while monitoring the film thickness, and when it is set to a predetermined film thickness, the door adjacent to the vapor deposition source (not shown) is closed (omitted) In the figure, etc., the vapor deposition material (Ti02, SiO2) is stopped. Further, the infrared ray-passing coating layer 74 is composed of a plurality of layers which are sequentially defined by an ordinal number from the main surface 72 side of the permeable plate 71 as shown in Fig. 7, and is composed of one layer and two layers of 'three layers' in this embodiment. . Each of the first layer and the second layer is formed by laminating the first film 75 and the second film 76. The optical film thickness of the first film 75 and the second film 76 which are laminated is not the same (the thickness of each layer of the first film, the second layer, and the third layer) is different. Further, the film thickness is determined by the above formula 1 In the present embodiment, the second gantry mirror has a plate-like rate film at 860 nm, and the odd-numbered even-numbered transparent outline is used to implement the 763. Wavelength - 21 - 201245836 The transmittance of the band is 90% or more, the transmittance is 50% in the wavelength range of 8 50 nm, and the transmittance is less than 15 % at 840 nm. The number of layers of the infrared ray passage coating 74 and the optical film thickness of each layer are appropriately adjusted. The second filter 7 has a thickness of, for example, 0.4 mm to 1.6 mm. Then, the second filter 7 passes through the coating layer 74 by infrared rays. The light transmission property indicates that the transmittance in the wavelength band of 8 60 nm or more becomes the maximum 値, the transmittance in the wavelength band of 850 nm is 50%, and the transmittance in the wavelength of 830 nm is less than 5 % light transmission characteristics. Next, the wavelength characteristics of the first filter 4 and the second filter 5 are actually measured, Fig. 8 and Tables 1 and 2 show the results and the structure as an embodiment. A first filter 4 of the embodiment is a dispersion of copper as the infrared absorbing glass 51 in the first filter 4 of the present embodiment. a blue glass having a pigment such as an ion, a glass plate having a thickness of 0.8 mm and a refractive index of about 1.5 in the atmosphere of N. Then, a main surface 52 of the infrared absorbing glass 51 has a refractive index of 1.6 in the atmosphere of N. In the order of the Al 2 〇 3 film, the ZrO 2 film having a refractive index of 2.0 in the N atmosphere, and the MgF 2 film having a refractive index of 1.4 in the N atmosphere, each film constituting the anti-reflection film 54 is formed by vacuum deposition. Infrared absorber 5, the infrared absorber S has a light transmission characteristic as shown in L1 of Fig. 8. Further, in this embodiment, the incident angle of the light is set to 0 degree, that is, the light is incident vertically. .

S 201245836 As shown in FIG. 8, the infrared absorbing glass 51 indicates that the transmittance in the wavelength band of 400 nm to 5 5 Onm is 90% or more, and the transmittance in the wavelength band of 550 nm to 700 nm is decreased. The wavelength was about 50% in the wavelength of about 640 nm, and the transmittance was about 17% in the wavelength of 700 nm. As the transparent substrate 61 of the infrared ray reflector 6, a glass plate having a refractive index of 1.5 in N atmosphere and a thickness of 0.3 mm was used. Further, as the first film 65 constituting the infrared ray reflection film 64, TiO 2 having a refractive index of 2,300 in N atmosphere is used, and as the second film 66, SiO 2 having a refractive index of 1.46 in N atmosphere is used. The center wavelength is 688 nm. The method of manufacturing the infrared reflecting film 64 composed of the above-described 40 layers of the first film 65 and the second film 66 having the optical film thickness shown in Table 1 is formed on one main surface 62' of the transparent substrate 61. (Layer) The first film 65 and the second film 66 are obtained to obtain an infrared ray reflection film 6. -23- 201245836 Table 1 Refractive index of layer evaporation material N Optical film thickness Nd Center wavelength λ (nm) 1 Ti〇2 2.30 0.122 688 2 Si〇2 1.46 0.274 688 3 Τί〇2 2.30 1.296 688 4 Si〇2 1.46 1.279 688 5 Τί〇2 2.30 1.152 688 6 Si〇2 1.46 1.197 688 7 Τΐ〇2 2.30 1.115 688 8 Si〇2 1.46 1.180 688 9 Τί〇2 2.30 1.094 688 10 Si〇2 1.46 1.173 688 11 Τί〇2 2.30 1,089 688 12 Si〇2 1.46 1.176 688 13 Ti〇2 2.30 1.094 688 14 Si〇2 1.46 1.179 688 15 Ti〇2 2.30 1.096 688 16 Si〇2 1.46 1,187 688 17 Ti〇2 2.30 1.103 688 18 Si〇2 1.46 1.205 688 19 Ti〇2 2.30 1.142 688 20 Si〇2 1.46 1.234 688 21 Ti〇2 2.30 1.275 688 22 Si〇2 1.46 1.422 688 23 Ti〇2 2.30 1.437 688 24 Si〇2 1.46 1.486 688 25 Ti〇2 2.30 1.422 688 26 Si 〇2 1.46 1.475 688 27 Ti〇2 2.30 1.463 688 28 Si〇2 1.46 1.492 688 29 Ti〇2 2.30 1.424 688 30 Si〇2 1.46 1.472 688 31 Ti〇2 2.30 1.446 688 32 SiOz 1.46 1.488 688 33 Ti〇2 2.30 1.422 688 34 Si〇2 1.46 1.462 688 35 Ti〇2 2.30 1.424 688 36 Si 〇2 1.46 1,468 688 37 Ti〇2 2.30 1.396 688 38 Si〇2 1.46 1.424 688 39 Ti〇2 2.30 1,352 688 40 Si〇2 1.46 0.696 688 s -24- 201245836 Table 1 reveals the infrared reflection of the first filter 4. The composition of the film 64 and the optical film thickness of each of the films (the first film 65 and the second film 66). This infrared ray reflector 6 has a light transmitting property as L2 of FIG. That is, the light transmission property of the infrared ray reflection film 64 indicates that the transmittance in the wavelength band of 395 nm to 670 nm (wavelength including the wavelength band of 430 nm to 650 nm: band) is not more than 100% * the wavelength exceeds about 670 nm. In this case, the transmittance is drastically reduced and the transmittance becomes about 50% at a wavelength of about 680 nm, and the transmittance at a wavelength of 700 nm becomes a light transmission characteristic of about 4%. Then, as shown in Fig. 8, by the infrared absorbing glass 51 The other main surface 53, followed by the other main surface 63 of the transparent substrate 61, obtains the first filter 4 of the embodiment having a thickness of 1.1 mm. The first filter 4 has a light transmitting property as shown by L3 in Fig. 8 in which the light transmitting characteristics of the infrared ray absorbing body 5 and the infrared ray reflecting body 6 are combined. That is, the first filter 4 of the embodiment shows that the transmittance in the wavelength band of 400 nm to 550 nm is 90% or more, and the transmittance in the band of 550 nm to 700 nm is reduced, at about 640 nm. The transmittance in the wavelength is 50%, and the transmittance at a wavelength of 700 nm becomes a light transmission characteristic of about 〇%. In the first filter 4 of the present embodiment, the combination of the infrared absorber 5 and the infrared reflector 6 can be obtained at 400 nm to 5 50 nm as shown by the light transmission characteristics of the first filter 4 of the present embodiment. The maximum transmittance of the wavelength in the wavelength band of 90% or more in the wavelength band is 50% in the wavelength band of 620 nm to 660 nm, and the transmittance becomes about 0% in the wavelength of 7 〇〇 nm. Light transmission characteristics (less than 5%). That is, -25-201245836 can obtain a light transmission characteristic that is close to the infrared light domain from the visible field, the transmittance is slowly decreased, and the transmittance at a wavelength of 700 nm is about 〇% which is close to the sensitivity characteristic of the human eye. The comparison between the light transmission characteristic L3 of the second filter 4 of the embodiment shown in Fig. 8 and the light transmission characteristic L4 of the previous infrared cut filter is more specifically described. The conventional infrared ray blocking filter having the light transmitting property shown by L4 in Fig. 8 is composed of an infrared absorbing body in which an antireflection film is formed on both surfaces of the infrared absorbing glass. In the conventional infrared ray interrupting filter, the thickness of the infrared absorbing glass which is an infrared absorbing body is set to 1.6 mm, and the point at which the transmittance becomes 〇% is set to 700 nm. On the other hand, in the first filter 4 of the embodiment, half of the thickness of the previous infrared ray blocking filter (infrared absorbing body) indicating the light transmitting property of L4 is used, and in the visible region, particularly, 600 nm to 700 nm. In the wavelength band, the infrared absorber 5 having a higher transmittance than the previous infrared cut filter, that is, the infrared absorber 5 showing the light transmission characteristics indicated by L1, combines the infrared reflector 6 and The point at which the transmittance became 〇% was set to 700 nm. For this reason, the light transmission characteristic L3 of the first filter 4 of the embodiment is in the visible light domain, especially in the wavelength band of 600 nm to 700 nm, which is compared with the light transmission characteristic L4 of the previous infrared cut filter. Higher transmittance. Further, in the light transmission characteristic L3 of the first filter 4 of the embodiment, the light transmittance at a wavelength of 700 nm is closer to 〇% than the light transmission property L4 of the previous infrared ray interrupt filter.

-26- S 201245836 Specifically, in the light transmission characteristic L4 of the prior infrared ray interrupting filter, the transmittance at a wavelength of 600 nm is about 55%, and the transmittance at a wavelength of about 6 〇 5 nm is 5%. The transmittance was about 7.5% at a wavelength of 675 nm, and the transmittance was about 3% at a wavelength of 700 nm. On the other hand, in the light transmission characteristic L3 of the first filter 4 of the embodiment, the transmittance at a wavelength of 600 nm is about 75%, and the transmittance at a wavelength of about 64 〇 nm is 50% at 675 nm. The transmittance in the wavelength is about 20%, and the transmittance is about 0% in the wavelength of 700 nm. Thus, the light transmission characteristic L3 of the first filter 4 of the embodiment is in the wavelength band of 600 nm to 700 nm, especially in the wavelength band of 600 nm to 67 5 nm, compared with the light transmission characteristic L4 of the previous infrared blocking filter. The transmittance of the domain is high and the transmittance at a wavelength of 700 nm is close to 0%. In other words, in the first filter 4 of the embodiment, it is understood that the visible light of the red light having a wavelength of 600 nm to 700 nm can be sufficiently transmitted while sufficiently blocking the infrared rays of more than 700 nm. . Therefore, when the first filter 4 of the embodiment is mounted on the imaging device, the image sensor 9 can be used to image the image in comparison with the color which is strong in red in the past, and the image in the dark can be brightened. Camera. In the first filter 4 of the present embodiment, the infrared ray reflector 6 is combined with the infrared ray absorbing body 5 to suppress the amount of light reflected by the infrared ray reflector 6. For this reason, occurrence of ghosting due to reflection of the light of the infrared ray reflector 6 can be suppressed. Further, the half-wavelength of the first filter 4 is approximately the same as the half-wavelength of the infrared absorbing body 5, and the infrared ray reflector 6 is configured to represent 90% of the half-wavelength light of the infrared ray -27-201245836. In the above-mentioned transmittance, the infrared ray-shielding filter is provided with a light-transmitting characteristic of the infrared absorbing body 5 whose transmittance is gradually reduced at a wavelength of 550 nm to 700 nm, which is close to the sensitivity of the human eye, and the sensitivity characteristic close to the human eye can be obtained. Light transmission characteristics. Further, in the first filter 4 of the embodiment, the infrared absorbing body 5 can be configured to have a thickness smaller than that of the conventional infrared ray shielding filter having the light transmitting property indicated by L4. For this reason, the thickness of the first filter 4 can be set to be the same as or smaller than the previous infrared occlusion filter. A second filter 7 of the embodiment - In the second filter 7 of the present embodiment, as the transparent substrate 71, a glass plate having a refractive index of 1.5 in the atmosphere of N and a thickness of 1.1 mm is used. The first film 75 constituting the infrared ray-passing coating 74 is made of TiO 2 having a refractive index of 2.30 in the N atmosphere, and the second film 76 is made of SiO 2 having a refractive index of 1.46 in N atmosphere, and the center wavelength is 7 2 Onm. The main surface 72 of the transparent substrate 71 is formed by the method of manufacturing the infrared ray-passing coating 74 composed of the above-mentioned 48 layers of the first film 75 and the second film 76. The first film 75 and the second film 76 are formed (layered) to obtain the second filter 7.

-28- S 201245836 Table 2 Refractive index of layer evaporation material N Optical film thickness Nd Center wavelength λ (nm) 1 Ti〇2 2.30 0.117 720 2 Si〇2 1.46 1.169 720 3 Τί〇2 2.30 0.580 720 4 Si〇2 1.46 0.584 720 5 Ti〇2 2.30 0.588 720 6 Si〇2 1.46 0.455 720 7 Ti〇2 2.30 0.620 720 8 Si〇2 1.46 0.556 720 9 Ti〇2 2,30 0.396 720 10 Si〇2 1.46 0.667 720 11 Ti〇2 2.30 0.696 720 12 SiOz 1.46 0.694 720 13 Ti〇2 2.30 0.549 720 14 Si〇2 1,46 0.347 720 15 TiOz 2,30 0.677 720 16 Si〇2 1.46 0.556 720 17 Ti〇2 2.30 0.654 720 18 Si〇2 1.46 0.600 720 19 Ti〇2 2.30 0.598 720 20 Si〇2 1.46 1.032 720 21 Ti〇2 2.30 0.735 720 22 Si〇2 1.46 0.791 720 23 TiOz 2.30 0.734 720 24 Si〇2 1.46 0,551 720 25 Ti〇2 2.30 0.769 720 26 Si〇2 1.46 0.825 720 27 Ti〇2 2.30 0,876 720 28 Si〇2 1.46 0.848 720 29 Ti〇2 2.30 0.859 720 30 Si〇2 1.46 0,470 720 31 Ti〇2 2.30 0.771 720 32 Si〇2 1.46 0,662 720 33 Ti 〇2 2.30 0.946 720 34 Si〇2 1.46 0.993 720 35 Ti〇2 2.30 0.978 720 36 Si〇2 1.46 1.040 720 37 Ti〇2 2,30 1,007 720 38 Si〇2 1.46 0,967 720 39 Ti〇2 2.30 1.057 • 720 40 Si〇2 1,46 1,042 720 41 Ti〇2 2.30 0,995 720 42 Si〇2 1.46 0.974 720 43 Ti〇2 2.30 1.036 720 44 Si〇2 1.46 1.023 720 45 Ti〇2 2,30 0.982 720 46 Si〇2 1.46 0.886 720 47 Ti〇2 2.30 0.936 720 48 Si〇2 1.46 1.978 720 -29- 201245836 Table 2 The composition of the second filter 7 and the optical film thickness of each of the films (the first film 75 and the second film 76) are disclosed. This second filter 7 has a light transmitting property as shown in Fig. 5. Further, an anti-reflection film 77 is formed on the other main surface 73 of the transparent substrate 71. Further, in the above-described embodiment, the first filter 4 and the second filter 7 and the switching means (not shown) are provided in the optical filter module 3. However, the present invention is not limited thereto, and the module is not limited thereto. The first filter 4 and the second filter 7 and the switching means (not shown) are directly provided in the optical filter system shown in FIG. 9 of the imaging device 1 and can be constructed as a transparent substrate 61. The glass plate is not limited thereto, and may be any substrate that transmits light, for example, a crystal plate. Further, the transparent substrate 61 may be a birefringent plate, and a birefringent plate composed of a plurality of sheets may be used. Further, the crystal plate and the glass plate may be combined to form the transparent substrate 61. Further, in the embodiment, TiO 2 is used for the first film 65. However, the first film 65 is not limited thereto, and the first film 65 may be made of a high refractive material. For example, Zr02, Ta02, Nb202 or the like may be used. Further, Si 02 is used for the second film 66. However, the second film 66 is not limited thereto, and the second film 66 may be made of a low-refractive material. For example, MgF2 or the like may be used. Further, the first filter 4 of the embodiment is such that the infrared absorbing body 5 is disposed closer to the lens 2 side than the infrared ray reflector 6 in the imaging device. However, the present invention is not limited thereto. In other words, the first filter 4 may be disposed such that the infrared reflector 6 is located closer to the lens 2 than the infrared absorber 5. -30-

For example, in the image pickup apparatus, the first filter 4 is disposed such that the infrared absorber 5 is positioned on the side of the lens 2, and the infrared absorber 5 can absorb the light reflected by the infrared reflector 6. The arrangement of the infrared reflector 6 on the side of the lens 2 is smaller than the amount of light scattered by the infrared reflector 6 and scattered on the lens 2, and the occurrence of ghosting can be suppressed. On the other hand, in the case where the first filter 4 is disposed such that the infrared ray reflector 6 is positioned on the side of the lens 2, the infrared ray reflector 6 is disposed in comparison with the case where the infrared absorbing body 5 is disposed on the lens 2 side. Specifically, the distance between the foreign matter generated in the infrared reflector 6 and the imaging element 9 during the manufacturing process is reduced, so that deterioration of the image due to foreign matter can be suppressed. Further, in the embodiment, the infrared absorber 5 is used for forming the anti-reflection film 54 on one main surface 52 or both main surfaces 51 and 52 of the infrared absorbing glass 51. However, the infrared absorbing body in the present invention is used. 5 is not limited to this. For example, when the refractive index in the atmosphere of the infrared absorbing glass 51 is almost the same as the refractive index of the atmosphere, the anti-reflection film 54 may not be formed. In other words, as the infrared ray absorbing body, an infrared absorbing glass which does not form an antireflection film may be used. Further, in the embodiment, the infrared reflecting body 6 is used to form the infrared reflecting film 64 on one main surface 62 of the transparent substrate 61 of the other main surface 53 of the infrared absorbing glass 51. However, the present invention is The infrared reflector 6 in the middle is not limited to this. For example, as the infrared reflector, an infrared reflection film formed on the surface of the infrared absorbing glass may be used. In this case, it is easy to carry out the simplification and power saving of the miniaturization and switching mechanism of the optical filter module and the optical filter system. That is, in the embodiment, the film 64 is formed on one main surface 62 of the transparent substrate 61 on the other main surface 53 of the infrared ray, but the other main connection of the infrared absorbing glass 51 is formed as infrared rays. When the infrared ray reflection film 64 of the absorber is formed directly on the other main surface 53 of the infrared absorbing glass 51, the first filter 4 can be made thinner. Furthermore, the invention may be embodied without departing from the spirit and scope of the invention. For this reason, the above-described embodiments are merely illustrative and not limitative in various respects. The scope is based on the scope of the patent application and is not subject to the specification. Further, the modifications of the equal scope of the claims are within the scope of the invention. In addition, this application is based on the priority of Japan's Japanese Patent No. 2011-018751 on January 31, 2011. All of the above are incorporated into this application. [Industrial Applicability] The present invention is applicable to an optical filter used in an image pickup apparatus. [FIG. 1] FIG. 1 is a schematic diagram showing a schematic mode of an image pickup apparatus according to an embodiment. 2] Fig. 2 shows the first filter virgin glass 51 and the infrared ray reverse surface 53 of the embodiment. Such an infrared inverse characteristic, the state of the invention and the implementation of the present invention are limited and fully described in the present application.

S 201245836 Sexual map. Fig. 3 is a schematic diagram showing a schematic configuration of a first filter of the embodiment. Fig. 4 is a partially enlarged view showing a schematic structure of an infrared reflector of a first filter of the embodiment. Fig. 5 is a view showing the light transmission characteristics of the second filter of the embodiment. Fig. 6 is a schematic diagram showing a schematic configuration of a second filter of the embodiment. Fig. 7 is a partially enlarged view showing a schematic structure of an infrared ray transmitting body of a second filter of the embodiment. Fig. 8 is a view showing the light transmission characteristics of the infrared ray interrupt filter of the embodiment. Fig. 9 is a schematic diagram showing a schematic configuration of an image pickup apparatus according to another embodiment. [Fig. 10] Fig. 10 is a diagram showing the light transmission characteristics of the infrared absorbing glass [Description of main components] 1 : Image pickup device 11: Optical axis 2: Lens 3: Optical filter module 4: 1st filter - 33- 201245836 5 : Infrared absorber 5 1 : Infrared absorption glass 5 2, 5 3 : Main surface 54 : Anti-reflection film 6 : Infrared reflector 61 : Transparent substrate 62 , 63 : Main surface 64 : Infrared reflection film 65 : 1 film 66: second film 7: second filter 7 1 : transparent substrate 72, 73: main surface 7 4 : infrared light-passing coating 75: first film 76: second film 77: anti-reflection film 8: optical filter Mirror 8 1 : Anti-reflection film 9 : imaging element

S

Claims (1)

201245836 VII. Patent application scope: 1. An optical filter module is provided in the camera device, which can switch the optical filter module with a plurality of filters, wherein: the plurality of filters transmit visible light, at least interrupted. The first filter of the infrared ray and the second filter of only the infrared ray are arranged; the first filter and the second filter are arranged to be selectively switchable. The optical filter module according to the first aspect of the invention, wherein the second filter blocks another region of the infrared ray only by a predetermined band set in advance by infrared rays. 3. The optical filter module according to the first or second aspect of the invention, wherein the first filter comprises an infrared absorber that absorbs infrared rays and an infrared reflector that reflects infrared rays. 4. The optical filter module according to the third aspect of the invention, wherein the infrared absorber is a light transmission characteristic having a transmittance of 50% in a wavelength band of 620 nm to 660 nm; The reflector is a light transmission characteristic having a transmittance of 50% in a wavelength band of 670 nm to 690 nm; and a combination of the infrared absorber and the infrared reflector indicates a wavelength band of 620 nm to 660 nm. The transmittance in the wavelength is 50%, and the transmittance in the wavelength of 700 nm is less than 5%. 5. An optical filter system, which is arranged along the optical axis from the outside -35-201245836 body side' at least in sequence with a combined optical system that emits light from the outside, and an optical that can switch between the complex filters An optical filter system for an image pickup device of a filter system, an optical filter, and an imaging element, wherein: the plurality of filters transmit visible light, at least the first oven mirror that blocks infrared rays, and the second filter that passes only infrared rays One of the first filter and the second filter can be selectively switched and disposed on the optical axis. 6. The optical filter system according to claim 5, wherein the second filter blocks another region of the infrared ray only by a predetermined band set in advance by infrared rays. The optical filter system according to claim 5, wherein the first filter includes an infrared absorber that absorbs infrared rays and an infrared reflector that reflects infrared rays. 8. The optical filter system according to claim 7, wherein the infrared absorber is a light transmission characteristic having a transmittance of 50% in a wavelength band of 620 nm to 660 nm; The light body exhibits a light transmittance of 50% in a wavelength in a wavelength band of 670 nm to 690 nm; and the combination of the infrared absorber and the infrared reflector represents a wavelength in a wavelength band of 620 nm to 660 nm. The medium transmittance is 50%, and the transmittance at a wavelength of 700 nm is less than 5%. -36- S