JP2015219330A - Camera apparatus and camera system using the same - Google Patents

Abstract

An object of the present invention is to remove stray light such as ghosts and flares that are reflected in a dome cover and significantly reduce the quality of a camera image, and to remove reflected S-polarized components from the outside. A camera apparatus that captures an image with light from an object to be imaged, the transmitting means transmitting at least part of the light from the object to be imaged, and the light transmitted through the transmitting means to a predetermined optical path An imaging unit that receives light as an image along with, a conversion unit that alternately converts the first polarization component and the second polarization component for each transmission, and transmits the first polarization component, and converts the second polarization component to Filter means for blocking, the converting means and the filter means on the predetermined optical path between the transmitting means and the imaging means, the transmitting means, the converting means, the filter means, and the imaging means The camera apparatus characterized by having arrange | positioned in order. [Selection] Figure 2

Description

  The present invention is a camera system having a dome cover for protecting a photographing camera, and has a function of removing internal reflections such as ghosts and flares, which significantly reduce the image quality generated by the dome cover, and removing external reflection S-polarized components. The present invention relates to a camera device having the same and a camera system using the same.

Many cameras that are installed mainly for security surveillance purposes, both outdoors and indoors, have lens and dust entry into the camera body, prevent the malicious person from destroying the camera, and A cover that is almost hemispherical for the purpose of alleviating the psychological burden on the side that is being covered and monitored by the entire hemispherical dome-shaped cover made of a resin such as colored resin that is transparent or difficult to see inside. Below, a dome cover) is installed.
Although these dome covers have many advantages, they are made of a transparent or colored resin material, and therefore have a higher refractive index than air. Due to this refractive index difference, about 4% surface reflection occurs on one side.

  When the reflected light is generated, the amount of transmitted light is reduced, and if there is reflected light from the lens surface or from the inside of the camera, a part of it is incident on the lens again and returns to the image sensor, which returns to the image sensor. The flare and ghost, such as blurring of the image (decrease in contrast) and a bright image of the aperture, resulting in harmful light called a ghost, leading to a decrease in image quality and a loss of information as a security image.

  The device disclosed in Patent Document 1 is a device in which a quarter-wave plate is rotatable with respect to a fixed polarizing plate. All incident light is linearly polarized light and can be matched with the vibration direction of the linearly polarized light. Optical attenuation is removed by installing a linear polarizer, and the transmitted light quantity can be adjusted by rotating a quarter-wave plate or linear polarizer, and the aperture diameter is reduced even when the incident light quantity is large. Therefore, it is possible to avoid the decrease in resolution such as diffraction.

  In addition, the apparatus disclosed in Patent Document 2 can convert light reflected from the back surface of the objective lens by a polarizing plate orthogonal to the observation position after converting light from the light source into linearly polarized light. The light that has passed through the objective lens and reflected by the surface of the eye to be examined can be adjusted in the direction of polarization vibration to pass through the orthogonal polarizing plate by passing through a quarter-wave plate twice. The optical isolator separates necessary light and unnecessary light by the reverse action.

Japanese Patent Laid-Open No. 2008-145889 Japanese Patent Application Laid-Open No. 08-052112

  However, in Patent Document 1, it is unclear whether a complicated mechanism such as rotating a quarter wavelength plate is incorporated, and further, an operation of converting all incident light into linearly polarized light can be realized. Moreover, it looks like it is lined with the linearly polarizing plate and the quarter-wave plate when viewed from the image pickup device side, but the purpose and function of removing stray light and removing external reflection are not discussed.

  Further, in Patent Document 2, two linear polarizing plates are required, the number of parts is increased as compared with known optical isolators for optical pickups, and the functions of necessary light and unnecessary light from the objective lens are provided. There were problems such as cost, performance, and equipment size (with light source and half mirror).

The camera device of the present invention is a camera device that captures an image with light from an object to be imaged,
Transmission means for transmitting at least part of light from the imaging target, imaging means for receiving light transmitted through the transmission means as an image along a predetermined optical path, a first polarization component and a second polarization component Conversion means for alternately converting each transmission, and filter means for transmitting the first polarization component and blocking the second polarization component, wherein the conversion means and the filter means are the transmission means The transmission means, the conversion means, the filter means, and the imaging means are arranged in this order on the predetermined optical path between the imaging means, and by taking such a configuration, The light reflected by the image sensor, further reflected by the transmission means, and further returning to the image sensor can be blocked.

  Further, the conversion means can be inserted into or withdrawn from the predetermined optical path, and when inserted, the conversion means can realize the function of blocking the returning light and can remove the ghost. Thus, when retracted, only the filter means remains in the camera device, and unnecessary reflection S-polarized components from the outside can be removed, and each function of the conversion means is on the predetermined optical path. It can be easily switched and realized by inserting or retracting vertically.

  Further, the conversion means can be inserted or withdrawn in accordance with a predetermined time, and in the time zone when the solar altitude is low in the morning and evening, the changing means is inserted to block the returning light. The ghost can be removed, and it is evacuated in the daytime when the solar altitude is high, leaving only the filter means in the camera device, and removing unnecessary reflected S-polarized components from the outside. The conversion means can be realized by switching easily by inserting or withdrawing the respective functions vertically with respect to the predetermined optical path according to the time zone.

  Further, the conversion means can be inserted or retracted in accordance with a predetermined shooting direction, and is inserted when shooting outdoors in the horizontal direction or upward, thereby realizing the function of blocking the above-mentioned returning light. The ghost can be removed, and when shooting in a direction other than the above-mentioned direction, it is retracted, leaving only the filter means in the camera device, and removing an unnecessary reflected S-polarized component from the outside. The converting means can be easily switched by inserting or withdrawing the respective functions vertically with respect to the predetermined optical path in accordance with the photographing direction.

  Further, the filter means can rotate about a direction along the predetermined optical path, and can maximize or optimize the action of removing the unnecessary S-polarized component. It is.

  Further, in the camera device that captures an image with light from the imaging target, a first conversion unit that alternately converts the first polarization component and the second polarization component for each transmission is transmitted from the imaging target. A transmission unit affixed to an incident surface side on which at least a part of light is incident; an imaging unit configured to receive light transmitted through the transmission unit as an image along a predetermined optical path; An optical module means integrally formed with a second converting means similar to the converting means, and a filter means for transmitting the first polarized component and blocking the second polarized component; Are arranged in the order of the transmission means, the optical module means, and the imaging means on the predetermined optical path between the transmission means and the imaging means. The dome cover and the lens When By interposing the optical module means between them, the action of blocking the light returning to the image sensor, the action of removing unnecessary reflected S-polarized components, and the attenuation of light by the linearly polarizing plate are avoided. It is possible to realize the action to be performed together.

  In addition, the first conversion means is arranged on substantially the entire outer peripheral portion of the transmission means, and has an effect of removing an unnecessary reflected S-polarized component and light of the filter means. The action of avoiding the attenuation can be maintained in all directions without being affected by the photographing direction of the camera device.

  The optical module means can be inserted into or withdrawn from the predetermined optical path, and can maximize or optimize the action of removing unnecessary S-polarized light components.

  The optical module means can be inserted or withdrawn in accordance with a predetermined time. In the time zone when the solar altitude is low in the morning and evening, the changing means is inserted to block the light that returns. The ghost can be removed by realizing the function, and the evacuation is performed in the daytime when the solar altitude is high, leaving only the filter means in the camera device, and unnecessary reflected S-polarized components from the outside. In accordance with the time zone, the respective functions can be easily switched and realized by inserting or evacuating the conversion means vertically with respect to the predetermined optical path. .

  Further, the optical module means is characterized in that it can be inserted or retracted in accordance with a predetermined photographing direction, and is inserted when performing outdoor horizontal direction or upward photographing so as to block the above-mentioned returning light. The ghost can be removed, and when shooting in a direction other than the above-described direction, the filter unit is retracted, leaving only the filter means in the camera device, and removing unnecessary reflected S-polarized components from the outside. Therefore, the conversion means can be realized by switching easily by inserting or withdrawing the respective functions perpendicularly to the predetermined optical path in accordance with the photographing direction.

  Passing unnecessary light called ghost or flare reflected by the imaging means, returning to the transmission means, and returning to the imaging means again through the linear polarization by the filter means and the conversion means. Rotate the plane of polarization of linearly polarized light by 90 degrees, and this time it can be cut off by the filter means. Furthermore, by removing the conversion means from the field of view of the lens, unnecessary reflection S-polarized components from the outside are removed. Two functions that can be realized as a small and simple structure.

1 is an overall perspective view of a camera device according to the present invention. Sectional drawing of the camera apparatus in Embodiment 1 of this invention Explanatory drawing of the S polarization component removal action in Embodiment 1 of the present invention Explanatory drawing of the internal ghost removal action in Embodiment 1 of the present invention Operational explanatory diagram of quarter-wave plate in Embodiment 1 of the present invention Operation flow diagram of quarter-wave plate in Embodiment 1 of the present invention The elements on larger scale of the linearly-polarizing plate in Embodiment 1 of this invention Operation flow diagram of linearly polarizing plate in embodiment 1 of the present invention Sectional drawing of the camera apparatus in Embodiment 2 of this invention Explanatory drawing of an internal ghost and S polarization component removal action in Embodiment 2 of the present invention

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
FIG. 1 is an overall perspective view of a camera apparatus according to the present invention, which includes a camera unit 11 for acquiring an image, a lens 13 inside the camera unit 11 and a substantially semicircular shape including the camera unit 11 and is transparent or transparent. This is a controlled translucent dome cover 12.

  The dome cover 12 is usually made of a resin such as acrylic or polycarbonate, and prevents the lens 13 and dust from entering the camera unit 11, prevents the malicious device from destroying the camera device 1, and the internal camera unit 11. It is installed for the purpose of alleviating the psychological burden on the monitored side and playing an important role.

  Next, FIG. 2 is a cross-sectional view of the camera apparatus according to Embodiment 1 of the present invention. The dome cover 21 includes a quarter-wave plate 28 that converts circularly polarized light into circularly polarized light, and a camera unit 22. The camera unit 22 further includes an imaging element 24 that converts an image of light into an electrical signal by a photoelectric action, and imaging. A cover glass 25 covering the element 24, a lens 23 for imaging light on the image sensor 24, a linearly polarizing plate 26 that transmits only a polarized component in a specific direction, and an infrared cut filter that transmits visible light without transmitting infrared light. 27.

  Next, the operation will be described in detail.

  3A is an explanatory diagram of the S-polarized light component removing action in the first embodiment of the present invention, and FIG. 3-2 is an explanatory diagram of the inner ghost removing action in the first embodiment of the present invention. This shows how light travels.

  31 is a dome cover, 32 is a lens, 33 is a linear polarizing plate, 34 is an infrared cut filter, 35 is a cover glass, 36 is an image sensor, and 37 is inserted / retracted perpendicular to the optical axis of the lens 32 1 / The four-wave plate is in a state of being retracted with respect to the optical axis in the case of the S polarization component removing action, and is inserted in a state perpendicular to the optical axis in the case of the internal ghost removing action.

  First, when the quarter-wave plate 37 is retracted, the dome cover 31 is made of a transparent resin such as polycarbonate as described above, and is usually a dielectric applied to the lens 32 or the like due to cost and difficulty in installation. A coating for preventing reflection by a single layer film or a multilayer film (hereinafter referred to as AR coating) is not applied. As a result, about 4% of the incident light from the outside is reflected and the amount of transmitted light is attenuated by that amount. Further, the inner surface of the dome cover 31 also has the same action to cover the image sensor 36 and the infrared cut filter. The internally reflected light from 34 becomes recursive reflected light reflected by the dome cover 31, and it returns to the image sensor 36 again. This retroreflected light is used when shooting in the horizontal direction in outdoor shooting where the sun altitude is low in the morning and evening, when shooting upwards outdoors such as airplanes and clouds during the day, and at low shooting positions such as car headlamps at night and at night. When a light source such as a streetlight or fireworks is turned on, or when the camera is turned on maliciously, the image becomes unnecessary and harmful light called ghost or flare, which reduces image quality and lacks image information. It will cause.

  In addition, the reflected light on the car's front glass, the surface of the leaves of trees, the polished floor surface, and the water surface, which is an unnecessary external reflection component, reduces the image quality as well as the ghost and flare. This is problematic in many respects, such as making it difficult to confirm the state of the image and causing loss of image information such as a change in hue.

  Such light includes many components (S-polarized light components) whose vibration surface is biased according to Brewster's law, which discusses reflection, transmission, and absorption on the surface of an object. Furthermore, when the incident angle of light is an angle called Brewster angle, all the P-polarized light components are absorbed, and the reflected light is only 100% S-polarized light components. This S-polarized light component is reflected by the windshield of the car, making it impossible to observe the interior. In order to remove this S-polarized component and make it easy to observe the inside, a linearly polarizing plate 33 having a polarization axis perpendicular to the S-polarized component placed in front of or behind the lens is effective.

  Since the quarter-wave plate 37 is retracted without being disposed on the front surface of the lens 32 and the linearly polarizing plate 33 is disposed so as to transmit only the P-polarized light component, an unnecessary reflection component outside, that is, S-polarized light. Ingredients can be removed.

  Next, when the quarter wavelength plate 37 is inserted perpendicular to the optical axis, the light transmitted through the dome cover 31 and transmitted through the lens 32 and the linear polarizing plate 33 is caused by the action of the linear polarizing plate 33. Converted to linearly polarized light. Further, a part of the light incident on the surface of the infrared cut filter 34 and / or the cover glass 35 is reflected from the light transmitted through the linear polarizing plate 33. The reflected light travels in the direction of the lens 32 and returns at the linear polarizing plate 33. This regressed light passes through the linear polarizing plate 33 as it is because the polarization oscillation direction is kept the same as that at the time of incidence.

  Further, the light transmitted through the lens 32 passes through the quarter wavelength plate 37 and reaches the inner surface of the dome cover 31. The linearly polarized light reflected at this time becomes circularly polarized light (the rotation direction is not specified) by the action of the quarter wavelength plate 37 and reaches the dome cover 31. A part of the circularly polarized light that has reached the dome cover 31 is reversed in the rotation direction of the circularly polarized light, returns to the quarter wavelength plate 37 again, and is converted into linearly polarized light by passing through. However, the vibration direction of the polarized light is rotated 90 degrees around the optical axis of the lens 32 and the previous polarized light. The polarized light rotated 90 degrees around the optical axis of the lens 32 further passes through the lens 32 and returns to the linearly polarizing plate 33. The returned light is linearly polarized light whose vibration direction is inclined by 90 degrees with respect to that at the time of emission, and therefore cannot pass through the linearly polarizing plate 33 and is blocked here.

  That is, the photographic image light that cannot return to the image pickup device 36 and cannot reach the image pickup device 36, is reflected by the infrared cut filter 34 and / or the cover glass 35, is reflected by the dome cover 31, and returns to the image pickup device 36. There is no light that degrades image quality such as ghosts and flares that are irrelevant to the image, and it is possible to prevent image quality degradation and image information loss. The reflection ghost and flare at the dome cover 31 can be removed by the above configuration and action.

  In this way, by inserting the quarter-wave plate 37 perpendicularly to the optical axis of the lens 32 or switching between retraction, when inserted, the above-described action of blocking the returning light is realized. When ghosts and flares are removed and retracted, only the linearly polarizing plate 33 is left in the field of view of the lens 32, and unnecessary reflected S-polarized light components from the outside can be removed.

  Further, means for realizing the above-described two actions, that is, a switching mechanism for inserting and retracting the quarter-wave plate will be described.

  FIG. 4 is a diagram for explaining the operation of the quarter-wave plate according to the first embodiment of the present invention. The quarter-wave plate 28 is held by the holder part 41, and the holder part 41 is supported at the fulcrum 43 by the arm 42. It is supported. The arm 42 can be rotated around the fulcrum 43 by using the driving force of the motor unit 44, that is, the holder unit 41 held by the arm 42 rotates the arm 42 about the fulcrum 43. The camera unit 22 can be inserted into or retracted from the front surface. Driving of the motor unit 44 is controlled by a predetermined operation flow, and appropriate insertion and retraction operations can be performed.

  FIG. 5 is an operation flow diagram of the quarter-wave plate in the first embodiment of the present invention, and is a flowchart of the operation of inserting and retracting the quarter-wave plate.

  In the morning and evening hours when the sun is low, strong rays of the sun go directly into the lens, and ghosts and flares occur strongly due to the internal infrared cut filter and / or reflection from the cover glass and retroreflection of the dome cover. . For this reason, a quarter-wave plate is inserted in front of the lens during this time period. In other times, that is, during daytime and nighttime, in order to remove harmful S-polarized components rather than ghosts and flares and ensure image quality and information, the quarter-wave plate is removed and linear polarizing plates are used. The configuration is arranged as it is.

  Therefore, the current time is first confirmed (S11), and then the above-mentioned morning and evening time periods when the sun is low (specifically, the setting is adjusted according to the season), and the current quarter-wave plate position. (S12), the time is compared with the preset position information (S13), and if the position of the quarter wavelength plate in the current time zone has already been matched, the quarter wavelength plate Is in a predetermined place, the drive mechanism does not work and is terminated (S19). If it does not coincide with the predetermined position (S14), the quarter-wave plate is driven from the current position (S15), and insertion or retraction is switched. Further, when the position is confirmed and coincides with the predetermined position (when an appropriate operation is performed), the driving is ended (S19). After the driving is completed, the confirmation of the time and the position of the quarter-wave plate is repeated and compared at a predetermined time (arbitrary interval time), and the position of the quarter-wave plate is corrected (S16). ).

  As a result, it is possible to automatically set the removal of ghost and flare caused by the morning and evening sun and the removal of harmful S-polarized light components during the day and night, and the image quality and image information can be maintained firmly.

  However, the operation parameters of the algorithm and the algorithm itself can be flexibly changed and reset in accordance with not only the time zone but also the scene such as the shooting target, season, and weather.

  Further, FIG. 6 is a partially enlarged view of the linearly polarizing plate according to Embodiment 1 of the present invention, in which a linearly polarizing plate 62 is arranged inside the holder portion 61, and rotates around the lens optical axis 63 at an arbitrary angle. And can be fixed. For the above-mentioned rotation, a rotation gear 65 for transmitting power to the motor unit 64 and a control unit 66 for adjusting the rotation of the motor unit 64 are provided.

  The S-polarized light component to be removed by the linear polarizing plate 62 is not an absolute component in space but is a relative one defined in each situation of the light source position and the direction of the reflecting surface, and changes for each observation target. That is, in order to efficiently remove the S-polarized light component, it is necessary to adjust the linearly polarizing plate in accordance with the state of the S-polarized light component, that is, to rotate around the lens optical axis.

  With the configuration described above, the rotation angle of the linearly polarizing plate that removes the reflected S-polarized light component to be removed can be optimally rotated to an arbitrary angle.

  In addition, the rotation is adjusted by a manual adjustment method and an algorithm that adds a polarization component and a screen brightness evaluation separately while an observer observes the monitor 67 and turns the rotation gear 65 while confirming the generation and removal of reflected light. There is an automatic adjustment method.

  With respect to the former manual method, the observer turns the turning gear 65 remotely while confirming the generation state of the reflected light while observing the monitor 67 in real time. It can be seen that the effect of removing unnecessary stray light (S-polarized light component) by the linearly polarizing plate 62 gradually changes by the turning operation. Stop and fix the rotation work at the maximum effect or at a position where the observation target is easily visible.

  Thereafter, when the observation object moves or changes its direction, or when the position of the light source (mainly the sun or the like) moves, the rotation angle is corrected while further monitoring.

  Furthermore, the latter automatic adjustment method will be described.

  FIG. 7 is an operation flow diagram of the linearly polarizing plate according to Embodiment 1 of the present invention, and is an operation flow that realizes optimization of the rotation angle of the linearly polarizing plate. First, the encoder for checking the image output and detecting the rotation angle of the linear polarizing plate is turned on (S21). Then, the rotation of the linear polarizing plate is started (S22), and is rotated once. The detection of this one rotation is also confirmed by the encoder. Further, after one rotation, the rotation of the linearly polarizing plate is stopped, and an average luminance value for each area that is divided into a large number of corners in advance in the screen area of the image sensor is detected (S23). When there is no change in the average luminance value in each part, it is determined that it is not necessary to adjust the rotation of the linear polarizing plate, and the rotation is stopped at that position. Further, when the pan operation of the lens is detected, it is determined that there is a need to adjust the rotation of the linear polarizing plate, and the process returns to the single rotation operation of the linear polarizing plate (S24).

  The average luminance value for each of the divided areas is detected, and if there is a change in the average luminance value in each part, it is determined that the rotation of the linear polarizing plate should be adjusted (S25). Reference is made to the fluctuation of the value and the output of the rotation angle of the encoder (S26). In this case, the average luminance value is further normalized by the maximum luminance in the area (S27), a place with a large fluctuation width is specified (S28), and the lowest output timing and encoder output are specified (S28). S29), the rotation of the linearly polarizing plate is started (S30). While monitoring the encoder output (S31), when the rotation angle coincides with the corresponding rotation angle, the rotation of the linear polarizing plate is stopped (S32).

  That is, in the area where the change in the normalized luminance is large, the smallest place of the output is the one where the S-polarized light component is removed most, and the rotation angle of the polarizing plate can be stopped at this position. It will be optimal.

  Further, when the pan operation is detected after the rotation is stopped (S33), there is a possibility that the pan position is deviated from the optimum position. Therefore, the rotation of the linearly polarizing plate is started once again, and the evaluation operation is repeated. This makes it possible to always update and maintain the optimum rotation angle of the linear polarizing plate.

  As described above, according to the first embodiment of the present invention, harmful ghosts and flares that are returned and incident on the image pickup device by reflection from the inside of the camera unit and further reflected by the dome cover are optically efficient. It can be removed by simple means, and it has a 1/4 wavelength plate insertion / retraction and a linear polarizing plate rotation mechanism, and removes harmful reflected S-polarized light components generated externally to the maximum or optimally. What can be achieved can be realized in a compact manner in the dome.

(Embodiment 2)
FIG. 8 is a cross-sectional view of the camera apparatus according to Embodiment 2 of the present invention. A dome cover 21 is provided with a quarter-wave plate 29 attached to or close to the incident surface side of light from the outside. The quarter wavelength plate 28 and the linear polarizing plate 26 are integrally formed and installed between the cover 21 and the camera unit 22, and the camera unit 22 converts an image of light into an electrical signal by a photoelectric action. An image sensor 24, a cover glass 25 that covers the image sensor 24, a lens 23 that focuses light on the image sensor 24, and an infrared cut filter 27 that transmits visible light without transmitting infrared light are provided.

  Next, the operation will be described in detail. FIG. 9 is an explanatory diagram of the internal ghost and S-polarized component removal action in Embodiment 2 of the present invention.

  When the light enters the infrared cut filter 34 and / or the cover glass 35, the light is converted into linearly polarized light by the linear polarizing plate 33. Since the vibration direction of the linearly polarized light is maintained, the linearly polarized light passes through the linearly polarizing plate 33 as it is after being reflected by the infrared cut filter 34 and / or the cover glass 35. Further, it passes through the quarter wavelength plate 37 and reaches the back surface of the dome cover 31.

  The light reflected by the dome cover 31 and returned by linearly polarized light passes through the quarter-wave plate 37 and is converted to circularly polarized light. That is, the further advanced light is reflected in a circularly polarized state on the back surface of the dome cover 31.

  Further, the light reflected on the back surface of the dome cover 31 is replaced with circularly polarized light that is reverse to the incident circularly polarized light, and is incident on the quarter wavelength plate 37 again, transmitted through the quarter wavelength plate 37, and emitted. The light is returned to linearly polarized light by the phase conversion action of the quarter-wave plate 37.

  However, the vibration direction of the polarized light is rotated 90 degrees around the optical axis of the previous polarized light and the lens 32. The polarized light rotated by 90 degrees around the optical axis of the lens 34 further returns to the linearly polarizing plate 33.

  Although the light reflected by the infrared cut filter 34 and / or the cover glass 35 could be transmitted as it was, the returned light passed through the linear polarizer 33 because the vibration direction was in a polarization state inclined by 90 degrees. You can't do it and you will be blocked here.

  That is, the lens 32 and the image sensor 36 cannot be returned or reached, reflected by the image sensor 36 and / or the infrared cut filter 34, reflected by the dome cover 31, and returned to the image sensor 36. Light that deteriorates image quality such as ghosts and flares that are unrelated to the target image is blocked.

  In addition, the second quarter-wave plate 38 is newly used to remove unnecessary S-polarized light components such as car front glass surface reflection, tree leaf reflection, and water surface reflection that are unnecessary external reflection components. It is affixed to the surface of the dome cover 31 or installed close to the surface. In order to remove this S-polarized component, the linearly polarizing plate 33 is configured to be perpendicular to the vibration direction so that it can be easily blocked and removed. I can do it. However, in this embodiment, in order to remove the internal reflection ghost, the quarter-wave plate 37 is inserted in front of the linear polarizing plate 33, so that the S polarizing component can be directly removed by the linear polarizing plate 33. Absent.

  The S-polarized component light reaching from the outside is once converted into circularly polarized light by a quarter-wave plate 38 that is attached to the surface of the dome cover 31 or placed close to the surface. The converted S-polarized component light passes through the dome cover 31 and is incident on a quarter-wave plate 37 installed inside. The incident circularly polarized light is returned to linearly polarized light again by the phase conversion action of the quarter wavelength plate 37.

  However, when the retardation effect of the quarter wavelength plate 37 is the same, this linearly polarized light is an apparent P-polarized component in which the vibration direction is substantially orthogonal to the unnecessary S-polarized component. This is equivalent to the action of passing through the half-wave plate by passing through the quarter-wave plates 38 and 37 twice, and the vibration direction of the linearly polarized light is rotated by 90 degrees, that is, S The light of the polarization component is replaced with the light of the P polarization component.

  By installing the linearly polarizing plate 33 around the optical axis of the lens 32 and in a direction perpendicular to the vibration direction of the P-polarized component, the P-polarized component, that is, the S-polarized component that should be removed outside the device is blocked. Is something you can do.

  In this case, it is possible to realize compactly at the same time without switching between the action of removing the ghost and flare generated inside the camera and the action of removing the externally unnecessary S-polarized light component.

  Further, in FIG. 8, the quarter-wave plate 28 and the linear polarizing plate 26 are integrated and move in a direction substantially perpendicular to the optical axis of the lens 23 while linking with the movement of the field of view of the lens 23. In other words, the field of view of the lens 23 is almost completely covered with the quarter-wave plate 28 and the linear polarizer 26, and the quarter-wave plate 28 and the linear polarizer 26 are retracted almost completely. The operation can be switched to the above state, and the operation is the same as that in FIG. In the case of the above-mentioned completely covering state, as described above, the ghost and flare removing operation and the external unnecessary S-polarized component removing operation can be realized simultaneously without switching, and will be described later. When fully retracted, the light transmittance reduced by the linearly polarizing plate 26 can be recovered, which is effective in a dark room or at night, or at a high shutter speed.

DESCRIPTION OF SYMBOLS 11 Camera part 12 Dome cover 13 Lens 21 Dome cover 22 Camera part 23 Lens 24 Image sensor 25 Cover glass 26 Linear polarizing plate 27 Infrared cut filter 28, 29 1/4 wavelength plate 30 Optical module part 31 Dome cover 32 Lens 33 Linear polarization Plate 34 Infrared cut filter 35 Cover glass 36 Image sensor 37, 38 1/4 wavelength plate 41 Holder part 42 Arm 43 Support point 44 Motor part 61 Holder part 62 Linearly polarizing plate 63 Lens optical axis 64 Motor part 65 Rotating gear 66 Control part 67 monitor

Claims (11)

A camera device that captures an image with light from an imaging target,
Transmissive means for transmitting at least part of the light from the imaging target;
Imaging means for receiving light transmitted through the transmission means as an image along a predetermined optical path;
Conversion means for alternately converting the first polarization component and the second polarization component for each transmission;
Filter means for transmitting the first polarization component and blocking the second polarization component;
The conversion means and the filter means are arranged in the order of the transmission means, the conversion means, the filter means, and the imaging means on the predetermined optical path between the transmission means and the imaging means. Camera device.   The camera device according to claim 1, wherein the conversion unit can be inserted into or retracted from the predetermined optical path.   The camera device according to claim 2, wherein the conversion unit can be inserted or withdrawn at a predetermined time.   The camera device according to claim 2, wherein the conversion unit can be inserted or retracted in accordance with a predetermined photographing direction.   The camera device according to claim 1, wherein the filter unit is rotatable about a direction along the predetermined optical path. A camera device that captures an image with light from an imaging target,
A transmission means for attaching a first conversion means for alternately converting the first polarization component and the second polarization component for each transmission to the incident surface side on which at least part of the light from the imaging target is incident;
Imaging means for receiving light transmitted through the transmission means as an image along a predetermined optical path;
A filter unit that is disposed inside the camera device and that transmits the first polarization component and blocks the second polarization component is formed integrally with a second conversion unit similar to the first conversion unit. An optical module means,
A camera apparatus, wherein the optical module means is arranged in the order of the transmission means, the optical module means, and the imaging means on the predetermined optical path between the transmission means and the imaging means.   The camera device according to claim 4, wherein the first conversion unit is disposed on substantially the entire outer periphery of the transmission unit. 8. The camera apparatus according to claim 6, wherein the optical module means can be inserted into or retracted from the predetermined optical path. 9. The camera apparatus according to claim 8, wherein the optical module means can be inserted or retracted in accordance with a predetermined time. 9. The camera apparatus according to claim 8, wherein the optical module means can be inserted or retracted in accordance with a predetermined photographing direction. A camera system comprising the camera device according to any one of claims 1 to 6.

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