KR20180015078A - Image pickup apparatus, lens cover, method of manufacturing lens cover - Google Patents

Abstract

Provided are an image pickup apparatus capable of more excellently acquiring an image of a target region by further suppressing dew condensation on an inner lateral side of a lens cover, the lens cover used for the same, and a method for manufacturing the lens cover. The image pickup apparatus (1) includes an image sensor (20), a lens (10) for picking up light from the target region on an image sensor, and the lens cover (310) covering the lens (10) from the outside. A hydrophilic film by a hydrophilic film forming agent containing a volatile hydrophilic compound (saturated vapor pressure (20°C) of 15 mmHg or more and 40 mmHg or less) is formed on the inner lateral side of the lens (10). The compound is in a volatilized state from the surface of the hydrophilic film.

Description

TECHNICAL FIELD [0001] The present invention relates to an imaging device, a lens cover, and a method of manufacturing a lens cover,

The present invention relates to an imaging device for imaging a target area, a lens cover used for the imaging device, and a manufacturing method for manufacturing the lens cover.

BACKGROUND ART [0002] An imaging apparatus for monitoring a situation such as a horizontal or an intersection is known. In this type of image pickup apparatus, the picked-up image is used for, for example, verification of a traffic accident. In the verification, the situation of the vehicle and the pedestrian, the lighting condition of the signaling device, and the like are confirmed. The imaging device captures a target area not only during the day but also at night after sunset.

In this type of image pickup apparatus, a lens cover for protecting a lens for taking in light of a target area is mounted so as to cover the lens from the outside. In this case, condensation may occur inside the lens cover due to the temperature difference between the inside of the apparatus and the outside of the apparatus. When dew condensation occurs in the lens cover, the condensation is reflected on the captured image, and the target area can not be captured well.

The following Patent Documents 1 to 3 disclose that the inner surface of the lens cover is subjected to a hydrophilic treatment or a hydrophilic film in order to solve the problem of condensation.

Japanese Laid-Open Patent Publication No. 2013-218114 Japanese Patent Application Laid-Open No. 2008-239017 Japanese Patent Application Laid-Open No. 2002-350966

As described above, when the inner surface of the lens cover is subjected to hydrophilic treatment or a hydrophilic film is formed, water droplets adhering to the inner surface due to condensation spread on the inner surface, so that the captured image is considered to be improved.

However, according to the examination by the inventors of the present invention, it was confirmed that even when a hydrophilic film was formed on the inner surface of the lens cover, the captured image was considerably unclear as compared with the case without condensation. Therefore, when the image pickup apparatus is used for monitoring purposes as described above, it has been found that there is a possibility that verification of an accident or the like can not be appropriately performed due to unclearness of such an image.

In view of the above problems, the present invention provides an imaging apparatus capable of further suppressing condensation on the inner surface of the lens cover to obtain an image of the target area more satisfactorily, a lens cover used in the imaging apparatus, and a method of manufacturing the lens cover .

As a result of intensive studies, the inventors of the present invention have found that a solvent for diluting a hydrophilic material has a high affinity to water (hydrophilicity) and a volatile compound (hereinafter referred to as a volatile hydrophilic compound, for example, isopropyl Alcohol) to form a hydrophilic film, it is possible to effectively suppress the condensation on the inside of the lens cover.

A first embodiment of the present invention relates to an image pickup apparatus. The imaging apparatus according to the present embodiment includes an image sensor, a lens for imaging light from the target area on the image sensor, and a lens cover for covering the lens from the outside. Here, in the lens cover, a volatile hydrophilic compound (having a saturated vapor pressure (20 DEG C) of 15 mmHg or more and 40 mmHg or less (preferably 25 mmHg or more and 35 mmHg or less) The hydrophilic film is formed and the volatile hydrophilic compound is volatilized from the surface of the hydrophilic film.

According to the image pickup apparatus of the present embodiment, since the hydrophilic film formed on the inner surface of the lens cover contains the volatile hydrophilic compound, the inner surface of the lens cover is prevented from being blurred by condensation . That is, since the volatile hydrophilic compound contained in the hydrophilic coating has a high affinity with water and is volatile, the volatile hydrophilic compound is volatilized in a state mixed with the water droplets generated by the condensation, whereby the number is subdivided . The microscopic droplets thus subdivided evaporate inside the image pickup device, and a part thereof remains on the image pickup device without evaporation and is attached to the inner surface of the lens cover. However, since the adhered water droplets are considerably finer in water, they are spread thinly by the hydrophilic coating formed on the inner surface. Therefore, blurring of the inner surface is suppressed, and the visibility of the captured image can be satisfactorily secured.

In the imaging device according to the present embodiment, for example, the hydrophilic film is formed using a hydrophilic film-forming agent having a content of isopropyl alcohol as the volatile hydrophilic compound of not less than 10% and not more than 80%. According to this configuration, condensation on the inner surface of the lens cover can be suppressed and the image quality of the captured image can be effectively increased, as is evident from the verification in the following embodiments. Therefore, even when the image pickup apparatus is used for the purpose of monitoring, it is possible to appropriately verify an accident or the like.

In this case, the content of isopropyl alcohol in the hydrophilic film-forming agent is preferably not less than 15% and not more than 60%. This makes it possible to more effectively suppress the condensation on the inner surface of the lens cover and to significantly improve the image quality of the captured image, as is evident in the verification in the embodiment.

In this case, the content of isopropyl alcohol in the hydrophilic film-forming agent is more preferably 20% or more and 40% or less. By doing so, condensation on the inner surface of the lens cover can be suppressed more effectively, and the image quality of the captured image can be increased to the same degree as in the case of no condensation, as is evident in verification in the embodiment.

In the image pickup apparatus according to the present embodiment, it is preferable that a hydrophilic film is formed on the outer surface of the lens cover opposite to the lens using a hydrophilic film-forming agent containing a volatile hydrophilic compound. By doing so, condensation on the outer surface of the lens cover is suppressed, so that the image quality of the captured image can be further enhanced. Also in this case, isopropyl alcohol can be used as the volatile hydrophilic compound, similarly to the above. In this case, the content of isopropyl alcohol in the hydrophilic film-forming agent is preferably not less than 10% and not more than 80%, more preferably not less than 15% and not more than 60%, more preferably not less than 20% and not more than 40% Is more preferable.

It is preferable that the image pickup apparatus according to the present embodiment further includes a heater for raising the temperature of the inner surface of the lens cover. By doing so, the water droplets subdivided by the action of the volatile hydrophilic compound in the vicinity of the inner surface of the lens cover are more likely to evaporate, and adhesion of the water droplets to the inner surface of the lens cover can be suppressed.

A second embodiment of the present invention relates to a lens cover for covering and protecting a lens. The lens cover according to this embodiment is characterized in that a hydrophilic film is formed on the inner surface of the lens side using a hydrophilic film forming agent containing a volatile hydrophilic compound and the volatile hydrophilic compound is volatilized from the surface of the hydrophilic film .

By using the lens cover according to the present embodiment in the image pickup apparatus, the same effect as that of the first embodiment can be exhibited.

Also in this embodiment, isopropyl alcohol can be used as a volatile hydrophilic compound as in the first embodiment. In this case, the content of isopropyl alcohol in the hydrophilic film-forming agent is preferably not less than 10% and not more than 80%, more preferably not less than 15% and not more than 60%, more preferably not less than 20% and not more than 40% Is more preferable.

A third embodiment of the present invention relates to a method of manufacturing a lens cover for covering and protecting a lens. A manufacturing method of a lens cover according to this embodiment is characterized by comprising a step of applying a hydrophilic film-forming agent containing a volatile hydrophilic compound to at least a side surface of a transparent and plate-like base member facing the lens, And drying the film forming agent. The hydrophilic film forming agent contains a hydrophilic material (for example, amorphous silica) for forming a hydrophilic film and a solvent for dispersing or dissolving the hydrophilic material, and the volatile hydrophilic compound acts as a solvent, Remains. The hydrophilic film-forming agent used in the present invention may contain, as a solvent, a solvent (methanol, ethanol, etc.) having a higher saturated vapor pressure than the volatile hydrophilic compound and a solvent having a lower saturated vapor pressure (normal propanol etc.) in addition to the volatile hydrophilic compound ≪ / RTI > In the drying step, at least a part of the solvent having a high saturated vapor pressure is volatilized.

By using the lens cover manufactured by the manufacturing method according to the present embodiment in the image pickup apparatus, the same effect as that of the first embodiment can be exhibited.

Also in this embodiment, isopropyl alcohol can be used as a volatile hydrophilic compound as in the first embodiment. In this case, the content of isopropyl alcohol in the hydrophilic film-forming agent is preferably not less than 10% and not more than 80%, more preferably not less than 15% and not more than 60%, more preferably not less than 20% and not more than 40% Is more preferable.

In the present invention, a hydrophilic compound having a saturated vapor pressure (20 ° C) of 15 mmHg or more and 40 mmHg or less may be used as the volatile hydrophilic compound, preferably a hydrophilic compound having a saturated vapor pressure (20 ° C) of 25 mmHg or more and 35 mmHg or less Isopropyl alcohol) can be used. If the saturated vapor pressure is too high, it tends to be difficult to remain in the hydrophilic film, and if the saturated vapor pressure is too low, it tends to be difficult to volatilize from the hydrophilic film.

As described above, according to the present invention, it is possible to provide an imaging device capable of further suppressing condensation on the inner surface of the lens cover to obtain an image of the target area, a lens cover used in the imaging device, and a manufacturing method of the lens cover have.

The effect or significance of the present invention will become more apparent from the description of the embodiments described below. It should be noted, however, that the embodiments described below are merely examples for practicing the present invention, and the present invention is not limited to what is described in the following embodiments.

Fig. 1 (a) is a diagram showing an external configuration of an image management system according to the embodiment.
1 (b) is a diagram showing an example of a picked-up image according to the embodiment.
Fig. 1 (c) is a view schematically showing a configuration on the front side of a lens barrel of an image pickup apparatus according to the embodiment.
2 is a cross-sectional view showing the structure of an image pickup apparatus according to the embodiment.
3 (a) is a flowchart showing a process of forming a hydrophilic film according to the embodiment.
Fig. 3 (b) and Fig. 3 (c) are diagrams schematically showing a manufacturing process of the lens cover according to the embodiment.
Figs. 4 (a) to 4 (d) schematically show the dew condensation suppression effect of the hydrophilic coating film of the lens cover according to the embodiment. Fig.
5 (a) shows the state of the front face of the imaging device immediately after it was left for one hour while operating the imaging device under an environment of -10 deg. C in accordance with Comparative Example 1 (no hydrophilic coating film) It is a photograph which shows.
Fig. 5 (b) is an image obtained by actually photographing a landscape in the image pickup apparatus immediately after taking out under a normal temperature environment according to Comparative Example 1. Fig.
Fig. 5 (c) is a photograph showing the state of the front face of the imaging device when five minutes elapsed after taking out under an ambient temperature environment according to Comparative Example 1. Fig.
Fig. 6 (a) is a graph showing the results of a comparison between the results of (a), (b) and (c) of Fig. 6 after leaving for 1 hour while operating the imaging device under the environment of -10 캜 according to Comparative Example 2 (with hydrophilic coating and no addition of isopropyl alcohol) Is a photograph showing the state of the front face of the imaging device immediately after the imaging operation.
Fig. 6 (b) is an image obtained by actually photographing a landscape in the image pickup apparatus immediately after taking out under an ambient temperature environment according to Comparative Example 2. Fig.
Fig. 6 (c) is a photograph showing the state of the front face of the imaging device when five minutes have elapsed after being taken out under an ambient temperature environment according to Comparative Example 2. Fig.
Fig. 7 (a) is a graph showing the results of measurement of the film thickness of the film after leaving the film for 1 hour while operating the imaging device under an environment of -10 deg. C according to Example 1 (base film forming agent: isopropyl alcohol (weight ratio) = 2: Is a photograph showing the state of the front surface of the imaging device immediately after being taken out under the environment.
Fig. 7 (b) is an image obtained by actually photographing a landscape in the image capturing apparatus immediately after taking out under an ambient temperature environment according to the first embodiment.
Fig. 7 (c) is a photograph showing the state of the front face of the imaging device when five minutes have elapsed after taking out under an ambient temperature environment according to the first embodiment. Fig.
Fig. 8 (a) is a graph showing the results of measurement of the film thickness of the film after leaving for 1 hour while operating the imaging device under an environment of -10 deg. C according to Example 2 (base film forming agent: isopropyl alcohol (weight ratio) = 1: Is a photograph showing the state of the front surface of the imaging device immediately after being taken out under the environment.
Fig. 8 (b) is an image obtained by actually photographing a landscape in the image pickup device immediately after taking out under an ambient temperature environment according to the second embodiment. Fig.
Fig. 8 (c) is a photograph showing the state of the front face of the imaging device when five minutes have elapsed after taking out under an ambient temperature environment according to the second embodiment. Fig.
Fig. 9 (a) is a graph showing the results of measurement of the temperature at room temperature (-10 DEG C) after leaving the imaging device in an environment of -10 DEG C according to Example 3 (base film forming agent: isopropyl alcohol (weight ratio = 1: Is a photograph showing the state of the front surface of the imaging device immediately after being taken out under the environment.
Fig. 9 (b) is an image obtained by actually photographing a landscape in the image capturing apparatus immediately after taking out under a normal temperature environment according to the third embodiment.
Fig. 9 (c) is a photograph showing the state of the front face of the imaging device when five minutes have elapsed after taking out under an ambient temperature environment according to the third embodiment. Fig.
Fig. 10 (a) is a graph showing the results of measurement of the film thickness of the film after leaving the film for 1 hour while operating the imaging device under an environment of -10 deg. C according to Example 4 (base film forming agent: isopropyl alcohol (weight ratio) = 1: 3) Is a photograph showing the state of the front surface of the imaging device immediately after being taken out under the environment.
Fig. 10 (b) is an image obtained by actually photographing a landscape in the image capturing apparatus immediately after taking out under an ambient temperature environment according to the fourth embodiment.
10 (c) is a photograph showing the state of the front face of the imaging device when five minutes have elapsed after being taken out under an ambient temperature environment according to the fourth embodiment.
Fig. 11 (a) is a graph showing the results of measurement of the film thickness of the film after leaving for 1 hour while operating the imaging device under an environment of -10 deg. C according to Example 5 (base film forming agent: isopropyl alcohol (weight ratio) = 4: Is a photograph showing the state of the front surface of the imaging device immediately after being taken out under the environment.
Fig. 11 (b) is an image obtained by actually photographing a landscape in the image pickup apparatus immediately after taking out under an ambient temperature environment according to the fifth embodiment.
11 (c) is a photograph showing the state of the front face of the imaging device when 5 minutes have elapsed after taking out under an ambient temperature environment according to the fifth embodiment.
Fig. 12 (a) is a graph showing the results of measurement of the film thickness of the film after leaving for 1 hour while operating the imaging device under an environment of -10 deg. C according to Example 6 (base film forming agent: isopropyl alcohol (weight ratio) = 7: Is a photograph showing the state of the front surface of the imaging device immediately after being taken out under the environment.
Fig. 12 (b) is an image obtained by actually photographing a landscape in the image pickup apparatus immediately after taking out under an ambient temperature environment according to the sixth embodiment. Fig.
12 (c) is a photograph showing the state of the front face of the imaging device when five minutes have elapsed after taking out under an ambient temperature environment according to the sixth embodiment.
Fig. 13 (a) is a graph showing the results of measurement of the film thickness of the film at room temperature for one hour while operating the imaging device under an environment of -10 deg. C according to Example 7 (base film forming agent: isopropyl alcohol (weight ratio) = 9: Is a photograph showing the state of the front surface of the imaging device immediately after being taken out under the environment.
Fig. 13 (b) is an image obtained by actually photographing a landscape in the image pickup device immediately after taking out under an ambient temperature environment according to the seventh embodiment.
Fig. 13 (c) is a photograph showing the state of the front face of the imaging device when 5 minutes passed after taking out under an ambient temperature environment according to the seventh embodiment. Fig.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the drawings.

Fig. 1 (a) is a diagram showing an external configuration of an image management system according to the embodiment.

As shown in Fig. 1 (a), the image management system includes an image capture device 1 and an external device 2. [ The image capturing apparatus 1 is a surveillance camera and is provided in the fixture 3 so as to capture a horizontal or crossing point including a signal unit. The fixture 3 is, for example, an outer wall or a roof structure such as a building or a pole. The image pickup apparatus 1 frequently records the captured image on an internal recording medium. The external device 2 is a portable personal computer. In addition, the external device 2 may be another portable information terminal such as a mobile phone or a tablet.

The image recorded in the image pickup apparatus 1 is appropriately retrieved to the external apparatus 2. [ The imaging device 1 and the external device 2 can communicate by wireless LAN. The external device 2 establishes the communication path by the wireless LAN and downloads the image from the imaging device 1. [ The communication between the image capture device 1 and the external device 2 is not limited to the wireless LAN and may be another communication method such as Bluetooth (registered trademark).

Fig. 1 (b) is a diagram showing an example of a picked-up image picked up by the image pickup apparatus 1. Fig. Here, the intersection 5 including the signal device 4 is set as the target area. For the sake of convenience, only the signal device 4 facing the direction of the image pickup device 1 is shown in Fig. 1 (b). An image picked up by the image pickup apparatus 1 is used for verification of a traffic accident, for example, after it is collected in the external apparatus 2. [ In this verification, the lighting situation of the signal device 4 is confirmed except for the situation of the vehicle or the pedestrian proceeding at the intersection 5. That is, it is confirmed which color of the signal device 4 is lit in red, blue, or yellow at the time of an accident.

Fig. 1 (c) is a view schematically showing the configuration of the front side of the barrel of the image pickup device 1. Fig.

As shown in Fig. 1 (c), the image pickup apparatus 1 is provided with a plurality of light emitting diodes 101 around the lens 10 and one illuminance sensor 102 for detecting illuminance of a target area . Under a low illuminance condition such as nighttime, the light emitting diode 101 is turned on and the target area is illuminated. The light emitting diode 101 is an illuminating light source that illuminates a target area by infrared light.

On the front side of the lens 10, a lens cover 310 (see Fig. 2) for covering the lens 10 and protecting the lens 10 is disposed. An LED cover 320 (see FIG. 2) for covering and protecting all the light emitting diodes 101 is disposed on the front side of the light emitting diode 101. The LED cover 320 simultaneously covers the light intensity sensor 102, in addition to all the light emitting diodes 101.

Fig. 2 is a cross-sectional view schematically showing the internal structure of the image pickup apparatus 1. Fig. This sectional view is obtained when the imaging device 1 is cut in a plane parallel to the optical axis of the lens 10. The lens barrel 310, the LED cover 320, and the holder 400 are hatched only for the sake of convenience.

The case 201 has a hollow cylindrical shape. The rear portion of the case 201 is closed by the lid 202. A lens cover 310 and an LED cover 320 are mounted on a front portion of the case 201 through a holder 400. A circuit board unit 203 for driving and controlling each section, a support substrate 204 for supporting the light emitting diode 101 and the light intensity sensor 102, a heater 205, And a communication module 206 for communicating with the external device 2 are accommodated. A power supply line 207 for supplying commercial power is connected to the power supply control board in the circuit board unit 203 via the lid 202. [

The lens cover 310 is made of a transparent and disc-shaped member. The diameter of the lens cover 310 is slightly larger than the diameter of the lens 10. As described later, the lens cover 310 is provided with a hydrophilic coating on the inner surface on the lens 10 side and on the outer surface opposite to the lens 10, respectively.

The LED cover 320 is made of a transparent plate member. In plan view, the LED cover 320 has a ring shape. The inner diameter of the LED cover 320 is larger than the diameter of the lens cover 310 and the outer diameter of the LED cover 320 is substantially equal to the inner diameter of the entire case 201. [

The holder 400 has a lens cover holding portion 401 for holding the lens cover 310 at the center and an LED cover holding portion 402 for holding the LED cover 320 thereon do. The lens cover holding portion 401 and the LED cover holding portion 402 are integrally connected by a bridge portion (not shown) passing through the gap between the light emitting diodes 101 adjacent in the circumferential direction.

The lens cover holding portion 401 has a cylindrical shape. The lens cover 310 is held in the lens cover holding portion 401 by being fitted in the inner diameter region A1 of the lens cover holding portion 401. [ In addition, the LED cover holding portion 402 has a cylindrical shape larger in diameter than the lens cover holding portion 401. The LED cover 320 is held in the LED cover holding portion 402 by being fitted in the ring shaped area A2 between the lens cover holding portion 401 and the LED cover holding portion 402. [

The holder 400 is fitted in a ring-shaped groove formed on the front side of the case 201. As a result, the front side of the case 201 is closed by the lens cover 310 and the LED cover 320. In this state, the lens barrel 11 holding the lens 10 is sandwiched inside the lens cover holder 401. The inner surface of the lens cover 310 faces the sealed space.

The image sensor 20 on the side of the circuit board unit 203 is disposed at a position facing the lens 10. [ The image sensor 20 is, for example, a CMOS image sensor. The lens 10 images the light from the target area on the image pickup surface of the image sensor 20. The light emitting diode 101 and the illuminance sensor 102 are disposed inside the LED cover 320.

The heater 205 is for raising the temperature of the inner surface of the lens cover 310. As a result, as described later, the water droplets subdivided near the inner surface of the lens cover 310 are liable to evaporate due to the action of the volatile hydrophilic compound (isopropyl alcohol) contained in the hydrophilic coating. The heater 205 is ON / OFF controlled by a control circuit provided in the circuit board unit 203. For example, the heater 205 is driven when the detected value of the temperature sensor for detecting the outside air is 0 DEG C or lower, and is controlled to be in the non-driven state when the detected value of the temperature sensor exceeds 0 DEG C.

However, in the configuration shown in Fig. 2, condensation may occur inside the lens cover 310 due to the temperature difference between the inside of the apparatus and the outside of the apparatus. That is, when the image pickup apparatus 1 starts the image pickup operation, the temperature inside the apparatus is raised by the heat from the circuit board unit 203. At this time, if the temperature of the outside air is lower than the inside of the apparatus, the air inside the apparatus is separated from the inside of the lens cover 310, so that the amount of saturated water vapor in the vicinity is lowered, Lt; / RTI > When dew condensation occurs on the inner surface of the lens cover 310 as described above, the condensation is reflected on the captured image, and the target area can not be captured well. Further, when the temperature of the outside air is higher than the temperature inside the apparatus, condensation may occur on the outer surface of the lens cover 310 due to the same phenomenon.

Thus, in the present embodiment, a hydrophilic film is formed on the inner and outer surfaces of the lens cover 310, respectively.

3 (a) is a flowchart showing a process of forming a hydrophilic coating film.

As shown in Fig. 3 (a), first, a hydrophilic film-forming agent is applied to one side of a transparent and plate-shaped base member (S101), and the applied hydrophilic film-forming agent is dried (S102). As a result, a hydrophilic film is formed on the surface of the base member. Thereafter, a hydrophilic film-forming agent is applied to the other surface of the base member (S103), and the applied hydrophilic film-forming agent is dried (S104). As a result, a hydrophilic film is formed on the other surface of the base member. In the drying step (S101, S104) of the hydrophilic film-forming agent, a solvent (methanol, ethanol, etc.) having a high saturated vapor pressure volatilizes preferentially and a hydrophilic film containing a volatile hydrophilic compound (isopropyl alcohol) is formed.

The hydrophilic film-forming agent can be obtained by, for example, mixing a material (amorphous silica or silane compound) constituting the hydrophilic film with a solvent such as an alcohol (ethanol, normal propanol, methanol, etc.) or propylene glycol monomethyl ether And the hydrophilic film-forming agent used in the present invention contains a volatile hydrophilic compound (such as isopropyl alcohol).

Figs. 3 (b) and 3 (c) are diagrams schematically showing a manufacturing process of the lens cover 310. Fig.

In the present embodiment, a hydrophilic film-forming agent to which a volatile hydrophilic compound is added to a hydrophilic film-forming agent (base film-forming agent) not containing the volatile hydrophilic compound (isopropyl alcohol) is applied to the base member. For example, a commercially available hydrophilic film-forming agent is used as the base film-forming agent, and isopropyl alcohol is used as the volatile hydrophilic compound. 3 (b), a hydrophilic film-forming agent containing a volatile hydrophilic compound is applied to the upper surface of the transparent base member 311 with a predetermined thickness by a spin coating method.

That is, the base member 311 is mounted on the rotating device 6 and rotated at a predetermined speed. In this state, the hydrophilic film former is dropped to the center of the base member 311. As a result, the hydrophilic film-forming agent spreads on the upper surface of the base member 311 by the centrifugal force. Thus, a hydrophilic film-forming agent is applied to the upper surface of the base member 311 to a predetermined thickness.

The base member 311 is made of, for example, a resin material having excellent light transmittance (for example, polycarbonate). The base member 311 has a circular shape in plan view.

After the hydrophilic film-forming agent is applied by the above-mentioned coating step, the drying step shown in Fig. 3 (c) is performed. That is, the base member 311 is placed under a high-temperature environment for a certain period of time, and the hydrophilic film-forming agent on the upper surface of the base member 311 is dried by heat. As a result, a film-forming agent (hydrophilic material) is fixed on the upper surface of the base member 311, and a hydrophilic film 312 having a predetermined thickness (for example, about 2 탆) is formed. In the formed hydrophilic film 312, isopropyl alcohol added to the base film-forming agent remains. Therefore, from the formed hydrophilic film 312, isopropyl alcohol is volatilized.

4 (a) to 4 (d)) is formed on the surface opposite to the base member 311 by the same step as that of the hydrophilic film 313 .

Figs. 4 (a) to 4 (d) schematically show the dew condensation suppression action of the hydrophilic coating 312 of the lens cover 310. Fig. Here, the hydrophilic film 312 is disposed on the inner side of the imaging device 1, that is, on the lens 10 side.

When the image pickup apparatus 1 starts the image pickup operation, the temperature inside the apparatus is raised by the heat from the circuit board unit 203. At this time, if the temperature of the outside air is lower than the inside of the apparatus, as shown in Fig. 4 (a), a water droplet 500 due to condensation is generated on the inner surface of the lens cover 310.

On the other hand, the hydrophilic film 312 contains isopropyl alcohol as described above, and from the surface of the hydrophilic film 312, isopropyl alcohol is volatilized as indicated by the broken arrow in FIG. 4 (a) have. Here, the isopropyl alcohol has high affinity with water and is volatile, so that isopropyl alcohol is volatilized in a state mixed with the water droplets 500 generated by the dew condensation, whereby the isopropyl alcohol as shown in Fig. 4 (b) Likewise, the numerical character 500 is subdivided into minute numerals 501.

The microscopic water drops 501 refined in this way evaporate in the image pickup device 1 but a part thereof remains in the image pickup device 1 without evaporation and is reflected by the lens cover 310 As shown in Fig. At this time, since the attached water droplets 501 are considerably finer in water, they are affinity with the hydrophilic film 312 formed on the inner surface, and as shown in Fig. 4 (d), the surface of the hydrophilic film 312 is thin It spreads. Therefore, fogging of the inner surface of the lens cover 310 is suppressed, and the visibility of the captured image is satisfactorily secured.

<Verification>

The inventors of the present invention conducted experiments to determine whether or not the inner surface of the lens cover 310 can be prevented from being blurred by condensation by adding isopropyl alcohol to the base film forming agent as described above. More specifically, the hydrophilic coatings 312 and 313 are formed on the inner and outer surfaces of the lens cover 310, respectively, and the hydrophilic coatings 312 and 313, which are included in the hydrophilic coating formulation used for forming the hydrophilic coatings 312 and 313, The content of the compound (isopropyl alcohol) was varied to compare the state in which the inner surface of the lens cover 310 was blurred by condensation. (Containing 31% by weight of ethanol, 26% by weight of normal propyl alcohol, 26% by weight of propylene glycol monomethyl ether, 5% by weight of methanol and 5% by weight of water) comprising a commercially available hydrophilic material and a base solvent, , 3% of amorphous silica, 3% of silane compound, and other minor components) was used. Ethanol and methanol are more volatile (saturated vapor pressure (20 ° C)) than isopropyl alcohol, and normal propyl alcohol and propylene glycol monomethyl ether are less volatile (saturated vapor pressure (20 ° C)) than isopropyl alcohol. A solution obtained by diluting the base film-forming agent with isopropyl alcohol (additive) having a purity of 99% was applied to the base member 311 to form the hydrophilic films 312 and 313. The thickness of the hydrophilic coatings 312 and 313 was set to about 2 mu m.

In the experiment, the lens was allowed to stand for 1 hour under the environment of -10 deg. C in the state in which the image pickup apparatus 1 was operated (in a state in which the imaging operation was actually performed, the light emitting diode was not turned on) The condition of the cover 310 was observed. Observation was performed immediately after taking out the image pickup device 1 under a room temperature environment and at a time point five minutes elapsed from that point. In order to show the verification result, at the two points in time, an image of the entire surface of the image capture device 1 was captured and a captured image was acquired. In order to verify the blurring state of the lens cover 310, immediately after taking out the image capturing apparatus 1 under a room temperature environment, the image capturing apparatus 1 actually picked up a landscape to obtain a captured image.

In addition, since the image capturing apparatus 1 is operated while being left in an environment of -10 deg. C for one hour, the temperature inside the image capturing apparatus 1 is higher than the external temperature (-10 deg. Therefore, it can be assumed that dew condensation occurs in the vicinity of the inner surface of the lens cover 310 in advance. In each experiment, how blurring due to this condensation occurred was confirmed by observing at the above-mentioned two viewpoints and by capturing a landscape image.

As Comparative Example 1, the same experiment was carried out on the image pickup apparatus 1 equipped with the lens cover 310 on which the hydrophilic films 312 and 313 were not formed. As Comparative Example 2, for the image pickup device 1 equipped with the lens cover 310 on which the hydrophilic films 312 and 313 were formed using only the base film forming agent without adding the additive (isopropyl alcohol) The same experiment was carried out.

5 (a) to 10 (c) show experimental results. The upper and lower ends of each sheet including three images are arranged in such a manner that immediately after taking out the image pickup apparatus 1 under a room temperature environment and at a time point five minutes elapsed from that point, (Middle stage) is a picked-up image obtained by picking up an image of a landscape in the image pickup apparatus 1 immediately after taking out the image pickup apparatus 1 under a room temperature environment.

5 (a) to 5 (c) are graphs showing experimental results of Comparative Example 1.

As shown in Fig. 5 (a), in Comparative Example 1, considerable fogging occurs in the lens cover 310 immediately after the image pickup apparatus 1 is taken out under a room temperature environment. As shown in Fig. 5 (c), in Comparative Example 1, considerable fogging occurs in the lens cover 310 even after 5 minutes have elapsed from immediately after taking out the image pickup apparatus 1 under a room temperature environment . 5 (b), in Comparative Example 1, a captured image obtained by actually photographing a landscape with the image pickup device 1 immediately after taking out the image pickup device 1 under a normal temperature environment can be displayed The blur is reflected to the extent that there is not enough.

Figs. 6 (a) to 6 (c) are diagrams showing experimental results of Comparative Example 2. Fig.

As shown in Fig. 6 (a), in Comparative Example 2, although fogging occurred in the lens cover 310 immediately after taking out the image pickup apparatus 1 under a room temperature environment, . As shown in Fig. 6 (c), in Comparative Example 2, it is assumed that cloudiness still remains in the lens cover 310 at the time point five minutes have elapsed from immediately after taking out the image pickup apparatus 1 under a room temperature environment However, the degree of fogging is smaller than that of Comparative Example 1. Therefore, it was confirmed from the result of this verification that the cloudiness due to condensation can be suppressed by forming the hydrophilic coatings 312 and 313 on the lens cover 310.

However, as shown in Fig. 6 (b), in Comparative Example 2, the photographed image obtained by actually photographing the landscape with the image pickup device 1 immediately after taking out the image pickup device 1 under a room- It is difficult to visually recognize the scenery yet, and the captured image is considerably blurred. Therefore, when the image pickup apparatus 1 is used for monitoring purposes, if the hydrophilic films 312 and 313 are formed using only the base film forming agent as in Comparative Example 2, It has been confirmed that there is a possibility that verification can not be performed properly.

Figs. 7 (a) to 7 (c) are diagrams showing experimental results of Example 1. Fig.

(Isopropyl alcohol) was added to the base film-forming agent of the hydrophilic material so that the amount of the additive (isopropyl alcohol) was 2: 1 in the base film forming agent in Example 1 (hereinafter referred to as base solvent, To prepare a hydrophilic film-forming agent. Therefore, the content of the additive (isopropyl alcohol) in the hydrophilic film-forming agent was 33.3%.

As shown in Fig. 7 (a), in the first embodiment, almost no fogging occurs in the lens cover 310 immediately after the image pickup apparatus 1 is taken out under a room temperature environment. As shown in Fig. 7 (c), in Example 1, almost no blurring occurs in the lens cover 310 even after five minutes have elapsed from immediately after taking out the image capturing apparatus 1 under a room temperature environment . Therefore, from the results of the verification, it is possible to form the hydrophilic films 312 and 313 on the lens cover 310 using the hydrophilic film forming agent to which the additive (isopropyl alcohol) is added in the above ratio, It can be confirmed that it can be suppressed.

As shown in Fig. 7 (b), in the first embodiment, a captured image obtained by actually photographing a landscape in the image capturing apparatus 1 immediately after taking out the image capturing apparatus 1 under a room temperature environment, And a clear image is formed in the substantially entire area. Therefore, even when the image pickup device 1 is used for monitoring purposes, the hydrophilic film forming agent (312) containing the additive (isopropyl alcohol) in the above ratio in the base film- , And 313 are formed, it is confirmed that the captured image is not damaged by condensation, and verification of an accident or the like can be appropriately performed using the captured image.

8 (a) to 8 (c) are diagrams showing experimental results of the second embodiment.

In Example 2, an additive (isopropyl alcohol) was added to the base film-forming agent of the hydrophilic material so that the base film-forming agent and the additive (isopropyl alcohol) were 1: 1, to prepare a hydrophilic film-forming agent. Therefore, the content of the additive (isopropyl alcohol) in the hydrophilic film-forming agent was 50.0%.

As shown in Fig. 8 (a), in Example 2, slightly clouding occurred in the lens cover 310 immediately after the image pickup apparatus 1 was taken out under a room temperature environment. However, Is suppressed. As shown in Fig. 8 (c), in Example 2, when the lens cover 310 slightly fogged at the point in time when five minutes elapsed immediately after taking out the image pickup apparatus 1 under a room temperature environment However, compared to Comparative Example 2, fogging is suppressed. Therefore, from the results of these tests, the hydrophilic films 312 and 313 are formed on the lens cover 310 using the hydrophilic film forming agent to which the additive (isopropyl alcohol) is added in the above ratio, It was confirmed that clouding caused by the above-mentioned defects can be suppressed.

As shown in Fig. 8 (b), in the second embodiment, a captured image obtained by actually photographing a landscape in the image capturing apparatus 1 immediately after taking out the image capturing apparatus 1 under a room- Although blurring is observed, a clear image is obtained in other areas. Therefore, as in Example 2, by forming the hydrophilic films 312 and 313 using the hydrophilic film-forming agent containing the additive (isopropyl alcohol) in the above ratio in the base film-forming agent, It is possible to suppress deterioration of the sharpness of the picked-up image due to condensation, and it is possible to more appropriately perform an inspection such as an accident using the picked-up image.

Figs. 9 (a) to 9 (c) are diagrams showing experimental results of Example 3. Fig.

In Example 3, an additive (isopropyl alcohol) was added to the base film-forming agent of the hydrophilic material so that the base film-forming agent: the additive (isopropyl alcohol) = 1: 2, to prepare a hydrophilic film-forming agent. Therefore, the content of the additive (isopropyl alcohol) in the hydrophilic film-forming agent was 66.6%.

As shown in Fig. 9 (a), in Example 3, fogging occurred in the lens cover 310 immediately after taking out the image pickup apparatus 1 under a room temperature environment. However, Is suppressed. As shown in Fig. 9 (c), in the third embodiment, it is assumed that fogging occurs in the lens cover 310 at the time point five minutes have elapsed from immediately after taking out the image pickup apparatus 1 under a normal temperature environment However, compared to Comparative Example 2, fogging is suppressed. Therefore, from the results of these tests, the hydrophilic films 312 and 313 are formed on the lens cover 310 using the hydrophilic film forming agent to which the additive (isopropyl alcohol) is added in the above ratio, It was confirmed that clouding caused by the above-mentioned defects can be suppressed.

As shown in Fig. 9 (b), in the third embodiment, a picked-up image obtained by actually photographing a landscape in the image pickup apparatus 1 immediately after taking out the image pickup apparatus 1 under a room- A relatively clear image is obtained in other areas. Therefore, as in Example 3, by forming the hydrophilic films 312 and 313 using the hydrophilic film-forming agent containing the additive (isopropyl alcohol) in the above-described ratio in the base film-forming agent, It is possible to suppress the degradation of the sharpness of the captured image due to condensation, and it has been confirmed that the verification of an accident or the like using the captured image can be performed more appropriately.

10 (a) to 10 (c) are diagrams showing experimental results of the fourth embodiment.

In Example 4, an additive (isopropyl alcohol) was added to the base film forming agent of a hydrophilic material so that the base film forming agent and the additive (isopropyl alcohol) were 1: 3 to prepare a hydrophilic film forming agent. Therefore, the content of the additive (isopropyl alcohol) in the hydrophilic film forming agent was 75.0%.

As shown in Fig. 10 (a), in Example 4, although fogging occurred in the lens cover 310 immediately after taking out the image pickup apparatus 1 under a room temperature environment, It is thinned and the cloudiness is suppressed. As shown in Fig. 10C, in Example 4, it is assumed that fogging occurs in the lens cover 310 at the point in time when five minutes have elapsed from immediately after taking out the image pickup apparatus 1 under a room temperature environment However, compared to Comparative Example 2, the fog was thin and the fog was suppressed. Therefore, from the results of these tests, the hydrophilic films 312 and 313 are formed on the lens cover 310 using the hydrophilic film forming agent to which the additive (isopropyl alcohol) is added in the above ratio, It was confirmed that clouding caused by the above-mentioned defects can be suppressed.

As shown in Fig. 10 (b), in the fourth embodiment, the captured image obtained by actually photographing the landscape in the image capturing apparatus 1 immediately after taking out the image capturing apparatus 1 under a normal temperature environment is clouded as a whole However, the reflected cloudiness is thinned, and as a whole, a relatively clear image is obtained. Therefore, as in Example 4, by forming the hydrophilic films 312 and 313 using the hydrophilic film-forming agent containing the additive (isopropyl alcohol) in the above-described ratio in the base film-forming agent, It is possible to suppress the degradation of the sharpness of the captured image due to condensation, and it has been confirmed that the verification of an accident or the like using the captured image can be performed more appropriately.

11 (a) to 11 (c) are diagrams showing experimental results of the fifth embodiment.

In Example 5, an additive (isopropyl alcohol) was added to the base film-forming agent of the hydrophilic material so that the base film-forming agent: the additive (isopropyl alcohol) = 4: 1 to prepare a hydrophilic film-forming agent. Therefore, the content of the additive (isopropyl alcohol) in the hydrophilic film-forming agent was 20.0%.

As shown in Fig. 11 (a), in the fifth embodiment, almost no fogging occurs in the lens cover 310 immediately after the image pickup apparatus 1 is taken out under a room temperature environment. 11 (c), in Example 5, almost no fogging occurs in the lens cover 310 even after 5 minutes have elapsed from immediately after taking out the image pickup apparatus 1 under a normal temperature environment . Therefore, from the results of these tests, the hydrophilic films 312 and 313 are formed on the lens cover 310 using the hydrophilic film forming agent to which the additive (isopropyl alcohol) is added in the above ratio, It can be confirmed that it can be suppressed.

As shown in Fig. 11 (b), in Embodiment 5, a captured image obtained by actually photographing a landscape in the image capturing apparatus 1 immediately after the image capturing apparatus 1 is taken out under a room- It is slightly sharper than that of the original image, but almost no fog is formed, and the image is almost clear in the entire area. Therefore, even when the image pickup device 1 is used for monitoring purposes, the hydrophilic film forming agent (312) containing the additive (isopropyl alcohol) in the above ratio in the base film- , And 313 are formed, it is confirmed that the captured image is not damaged by condensation, and verification of an accident or the like can be appropriately performed using the captured image.

Figs. 12 (a) to 12 (c) are diagrams showing experimental results of Example 6. Fig.

In Example 6, an additive (isopropyl alcohol) was added to the base film-forming agent of the hydrophilic material so that the base film-forming agent: the additive (isopropyl alcohol) = 7: 1 to prepare a hydrophilic film-forming agent. Therefore, the content of the additive (isopropyl alcohol) in the hydrophilic film-forming agent was 12.5%.

As shown in Fig. 12 (a), in Example 6, although slight cloudiness occurred in the lens cover 310 immediately after taking out the image pickup apparatus 1 under a room temperature environment, Is suppressed. As shown in Fig. 12 (c), in Example 2, when the lens cover 310 slightly fogged at 5 minutes after the imaging device 1 was taken out under a normal temperature environment However, compared to Comparative Example 2, fogging is suppressed. Therefore, from the results of these tests, the hydrophilic films 312 and 313 are formed on the lens cover 310 using the hydrophilic film forming agent to which the additive (isopropyl alcohol) is added in the above ratio, It was confirmed that clouding caused by the above-mentioned defects can be suppressed.

As shown in Fig. 12 (b), in Embodiment 6, a captured image obtained by actually photographing a landscape in the image capturing apparatus 1 immediately after taking out the image capturing apparatus 1 under a normal- Although the sharpness is somewhat inferior, the sharpness is secured to such an extent that the whole area can be recognized. Therefore, as in Example 6, by forming the hydrophilic films 312 and 313 using the hydrophilic film-forming agent containing the additive (isopropyl alcohol) in the above-described ratio in the base film-forming agent, It was confirmed that the sharpness of the captured image can be ensured and the verification of the accident or the like using the captured image can be appropriately performed.

Figs. 13 (a) to 13 (c) are diagrams showing experimental results of Example 7. Fig.

In Example 7, an additive (isopropyl alcohol) was added to the base film-forming agent of the hydrophilic material so that the base film-forming agent: the additive (isopropyl alcohol) = 9: 1, to prepare a hydrophilic film-forming agent. Therefore, the content of the additive (isopropyl alcohol) in the hydrophilic film-forming agent was 10.0%.

As shown in Fig. 13 (a), in Example 7, fogging occurs in the lens cover 310 immediately after the image pickup apparatus 1 is taken out under a room temperature environment. However, Is suppressed. As shown in Fig. 13 (c), in the seventh embodiment, it is assumed that fogging occurs in the lens cover 310 at the time point five minutes have elapsed from immediately after taking out the image pickup apparatus 1 under a normal temperature environment However, compared with Comparative Example 2, fogging is suppressed. Therefore, from the results of these tests, the hydrophilic films 312 and 313 are formed on the lens cover 310 using the hydrophilic film forming agent to which the additive (isopropyl alcohol) is added in the above ratio, It was confirmed that clouding caused by the above-mentioned defects can be suppressed.

As shown in Fig. 13 (b), in the seventh embodiment, a captured image obtained by actually photographing a landscape in the image capturing apparatus 1 immediately after taking out the image capturing apparatus 1 under a normal temperature environment is slightly clouded However, a viewable image is obtained in the entire area. Therefore, as in Example 7, by forming the hydrophilic films 312 and 313 using the film forming agent containing the additive (isopropyl alcohol) in the above ratio in the base film forming agent, compared with Comparative Example 2, It is possible to inhibit the sharpness of the captured image from being impaired by the image capturing apparatus and verify the accident or the like using the captured image more appropriately.

From the above experimental results, it has been confirmed that the addition of an additive (isopropyl alcohol) to the base film forming agent can suppress the condensation occurring in the lens cover 310, thereby improving the sharpness of the captured image.

Particularly, when the additive (isopropyl alcohol) is contained in the film forming agent in the range of content ratios shown in Examples 1 to 7, that is, in the range of 10.0% to 75.0% Condensation can be suppressed, and it is confirmed that the sharpness of the picked-up image can be increased. Therefore, by making the content ratio of the additive (isopropyl alcohol) to the film-forming agent at least 10.0% or more and 80.0% or less, condensation occurring in the lens cover 310 can be suppressed as compared with Comparative Example 2, It is possible to enhance the sharpness of the image.

Further, in the experimental results of Examples 1, 2 and 5, a clearer picked-up image is obtained as compared with the experimental results of the other examples. Therefore, the content of the additive (isopropyl alcohol) relative to the hydrophilic film-forming agent was in the range including the contents (33.3%, 50.0%, 20.0%) used in Examples 1, 2 and 5, that is, 15% It is more preferable to set it to about 60% or less.

In addition, in the experimental results of Examples 1 and 5, a more pronounced sharpness was obtained, and a clear picked-up image with almost no fogging was obtained. Therefore, the content of the additive (isopropyl alcohol) relative to the hydrophilic film-forming agent is in the range including the content (33.3%, 20.0%) used in Example 1, that is, in the range of 20% Is more preferable.

In the above experiment, isopropyl alcohol was used as an additive to be added to the base film-forming agent, but a compound capable of exerting the action described with reference to Figs. 4 (a) to 4 (d) It is supposed that an effect of enhancing the sharpness of a picked-up image by suppressing condensation occurring in the lens cover 310 is obtained when another compound is added as an additive .

&Lt; Effect of Embodiment >

According to the present embodiment, the following effects are exhibited.

Since the hydrophilic film 312 formed on the inner surface of the lens cover 310 contains a volatile hydrophilic compound (isopropyl alcohol), the inner surface of the lens cover 310 It is possible to suppress blurring due to condensation. That is, since the volatile hydrophilic compound (isopropyl alcohol) contained in the hydrophilic film 312 has high affinity with water and is volatile, the hydrophobic compound (isopropyl alcohol) ), Whereby the water droplet 500 is subdivided. The minute water droplets subdivided in this way evaporate in the image pickup device 1 and a part thereof remains in the image pickup device 1 without evaporation and is attached to the inner surface of the lens cover 310 . However, the attached water droplet 501 spreads thinly by the hydrophilic coating 312 formed on the inner surface of the lens cover 310, because it is a very fine water droplet. Therefore, blurring of the inner surface of the lens cover 310 is suppressed, and the visibility of the captured image can be satisfactorily secured.

Here, when isopropyl alcohol was used as the volatile hydrophilic compound, as shown in the above experimental results (Examples 1 to 7), the content of isopropyl alcohol in the hydrophilic film forming agent was 10% or more and 80% or less The condensation on the inner surface of the lens cover 310 can be suppressed and the image quality of the captured image can be effectively increased.

In this case, from the experimental results of Examples 1, 2, and 5, a clear captured image can be obtained by containing isopropyl alcohol in the hydrophilic film forming agent in a content ratio of 15.0% or more and 60.0% or less.

Further, from the results of the experiments of Examples 1 and 5, it can be seen that by containing isopropyl alcohol in the hydrophilic film forming agent in a content ratio of 20% or more and 40% or less, It is possible to obtain a clear picked-up image without a clear view.

In this embodiment, a hydrophilic film 313 is formed on the outer surface of the lens cover 310 opposite to the lens 10 by using a hydrophilic film-forming agent containing a volatile hydrophilic compound (isopropyl alcohol) The condensation on the outer surface of the lens cover 310 can be suppressed and the quality of the captured image can be further enhanced.

Further, in this embodiment, since the heater for raising the temperature of the inner surface of the lens cover 310 is disposed, it is possible to prevent the water surface of the lens cover 310 from being deformed by the action of the compound (isopropyl alcohol) The water droplet 501 is more likely to evaporate, and the water droplet 501 can be prevented from adhering to the inner surface of the lens cover 310. Therefore, it is possible to more effectively suppress blurring of the inner surface of the lens cover 310 due to condensation.

<Example of change>

In the above embodiment, the hydrophilic film 313 is formed on the inner surface and the outer surface of the lens cover 310 using a solvent added with a volatile hydrophilic compound (isopropyl alcohol) to the base film forming agent. However, The hydrophilic film 313 may be formed on the outer surface of the cover 310 using only the base film forming agent without adding the additive.

In the above embodiment, the hydrophilic film is not formed on the LED cover 320, but a hydrophilic film may be formed on the inner surface of the LED cover 320 in the same manner as the lens cover 310, A hydrophilic film may be formed on the outer surface of the lens cover 310 in the same manner as the lens cover 310.

2 shows only the lens 10 as a constitution of an optical system for taking in light from the target area. However, even if the image sensor 20 further includes a configuration other than the lens 10 in front of the image sensor 20 good. For example, an iris adjusting mechanism for restricting light from the outside or a filter for removing infrared light may be provided for the daytime and nighttime so that an appropriate amount of light enters the image sensor 20 in accordance with the intensity of light from the target area And a filter mechanism for inserting and separating the optical path of the optical system.

The number and arrangement of the light emitting diodes 101 are not limited to those shown in Fig. 1 (c), and the light emitting diodes 101 may be arranged in the image pickup apparatus 1 with different numbers and arrangements.

In the above embodiment, the image pickup apparatus 1 is transmitted to the external apparatus 2 by wireless communication, but the image pickup apparatus 1 may be transmitted to the external apparatus 2 by wire communication. Alternatively, a captured image may be recorded in a memory card mounted on the image capturing apparatus 1, the memory card may be detached from the image capturing apparatus 1 and mounted on the external apparatus 2 to capture the captured image into the external apparatus 2 .

In the above embodiment, the imaging apparatus 1 is provided on an outer wall, a roof structure, a pole, or the like of a building. However, the installation place of the imaging apparatus 1 is not limited to this. For example, the image capturing apparatus 1 may be provided on a traffic sign, or the structure of the image capturing apparatus 1 may be integrated into a streetlight or the like. The image pickup apparatus 1 may not necessarily be an image pickup apparatus used for monitoring purposes, or may be an image pickup apparatus that captures a landscape by carrying it.

In addition, various modifications can be appropriately made in the embodiment of the present invention within the scope of the technical idea shown in the claims.

1: Imaging device
10: Lens
20: Image sensor
310: Lens cover
311: Base member
312, 313: hydrophilic film

Claims (11)

An image sensor,
A lens for imaging light from the target area onto the image sensor,
And a lens cover which covers the lens from the outside,
Wherein the lens cover is provided with a hydrophilic film formed by a hydrophilic film forming agent containing a volatile hydrophilic compound (saturated vapor pressure (20 DEG C) of 15 mmHg or more and 40 mmHg or less) on the inner surface of the lens side, And the volatile hydrophilic compound is volatilized from the surface. The method according to claim 1,
Wherein the volatile hydrophilic compound is isopropyl alcohol and the content of isopropyl alcohol in the hydrophilic film forming agent is 10% or more and 80% or less. 3. The method of claim 2,
Wherein the content of isopropyl alcohol in the hydrophilic film-forming agent is 15% or more and 60% or less. 3. The method of claim 2,
Wherein the content of isopropyl alcohol in the hydrophilic film-forming agent is 20% or more and 40% or less. 5. The method according to any one of claims 1 to 4,
Wherein a hydrophilic film formed by a hydrophilic film-forming agent containing a volatile hydrophilic compound is formed on an outer surface of the lens cover opposite to the lens. 5. The method according to any one of claims 1 to 4,
Further comprising a heater for raising the temperature of the inner surface of the lens cover. A lens cover for covering and protecting a lens,
Wherein a hydrophilic film formed by a hydrophilic film forming agent containing a volatile hydrophilic compound (saturated vapor pressure (20 DEG C) of 15 mmHg or more and 40 mmHg or less) is formed on the inner side of the lens side, and the volatile Wherein the hydrophilic compound is in a volatile state. 8. The method of claim 7,
Wherein the volatile hydrophilic compound is isopropyl alcohol and the content of isopropyl alcohol in the hydrophilic film forming agent is 10% or more and 80% or less. A method of manufacturing a lens cover for covering and protecting a lens,
A step of applying a hydrophilic film forming agent containing a volatile hydrophilic compound (saturated vapor pressure (20 DEG C) of 15 mmHg or more and 40 mmHg or less) to at least a side surface of the base member which is transparent and plate-
And drying the applied hydrophilic film-forming agent. 10. The method of claim 9,
Wherein the content of isopropyl alcohol in the hydrophilic film-forming agent is 10% or more and 80% or less. 6. The method of claim 5,
Further comprising a heater for raising the temperature of the inner surface of the lens cover.

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