JP6559031B2 - Imaging device or surveillance camera device - Google Patents

Description

  The present invention relates to an imaging apparatus, and more particularly to an apparatus connected to a network and a client, represented by a monitoring camera apparatus that enables subject recognition both day and night.

  In Patent Document 1, an actuator is attached to a filter frame provided with an infrared cut filter and a dummy glass in a surveillance camera device, and the position of the filter frame is moved with respect to an incident opening, whereby the infrared cut filter and the dummy glass are attached. A technique for switching is disclosed.

  In addition, polarized light that removes a specific polarization component contained in a large amount of reflected light in order to obtain a good image even when strong light such as sunlight is reflected on the water surface or window glass and the reflected light is incident. Some have a filter attached to the front of the camera lens. In Patent Document 2, in a camera device whose photographing direction is rotated, a polarizing filter is disposed in the light incident portion on the front surface of the camera unit, and the polarizing filter is set in the light transmission direction in a short time during the rotation of the camera device. On the other hand, a technique for removing unnecessary light by controlling rotation is disclosed.

  Further, in Patent Document 3, a polarizing filter is provided inside a camera lens device, and the polarizing filter interlocked with a diaphragm unit built in the lens device is rotated with respect to the light transmission direction. A technique for preventing deterioration in image quality due to reflected light is disclosed.

JP 2012-173523 A JP 2014-186302 A JP, 2014-160180, A

  However, in the prior art disclosed in Patent Document 2, a polarizing filter is disposed on the subject side front surface of the camera unit. For this reason, in a lens configuration of a surveillance camera that needs to capture a wide field angle range, the front lens is generally large, so that the polarizing filter is also large, which hinders downsizing of the apparatus.

  In the prior art disclosed in Patent Document 3, since a polarizing filter is inserted in conjunction with the aperture diameter of the diaphragm, there is a risk that the polarizing filter may be inserted when the aperture value is reduced at night when the amount of light is required. is there. And, if the aperture value is reduced, the depth of field can be increased, but since the total amount of light is reduced by the inserted polarizing filter, the sensitivity of the image sensor must be increased, resulting in a decrease in image quality. There is.

  In addition, it is known that the components constituting the transmission film of the polarizing filter are easily decomposed when irradiated with infrared rays, and the performance of the transmission film is likely to deteriorate. For this reason, in a device connected to a network and a client, such as a surveillance camera device that performs infrared illumination to recognize a distant subject at night, infrared light emitted at night accelerates the aging of the polarizing filter. There are challenges.

  Accordingly, an object of the present invention is to provide a small image pickup apparatus that can recognize a subject at daytime using an optical member having a polarization component in order to solve the above-described problems. In addition, an imaging apparatus is provided that prevents an insufficient amount of light due to an optical member having a polarization component, and prevents deterioration in image quality at night. Furthermore, an imaging apparatus is provided in which deterioration of an optical member having a polarization component is prevented.

  To achieve the above object, the present invention includes a lens, a plurality of infrared cut filters, a filter-like element glass, an optical member that can arbitrarily change the polarization direction of light with respect to the optical path of the lens, An image pickup apparatus comprising: an image pickup device, wherein the optical member is disposed between the infrared cut filter and the image pickup device.

  According to the present invention, it is possible to provide a small imaging device that can recognize a subject by removing strong reflected light in the daytime. In addition, it is possible to provide a small imaging device that prevents a shortage of light quantity at night and prevents deterioration in image quality. Furthermore, it is possible to provide a small imaging device that prevents deterioration of an optical member having a polarization component.

1 is an exploded perspective view of a network camera according to a first embodiment of the present invention. It is a disassembled perspective view of the front side lens-barrel part 1a of the lens apparatus 43 in 1st Example of this invention. It is a disassembled perspective view of the rear lens barrel 1b of the lens device 43 in the first embodiment of the present invention. It is a figure which shows the structure of the filter switching mechanism in 1st Example of this invention. It is a filter arrangement | positioning figure at the time of the daytime which inserted the infrared cut filter 3a with which the polarizing filter 7 in the 1st Example of this invention was attached. It is the filter arrangement | positioning figure at the time of the daytime which inserted the infrared cut filter 3b in 1st Example of this invention. It is the filter arrangement | positioning figure at the time of night which inserted the filter-shaped raw glass 4 in 1st Example of this invention. 1 is a block diagram illustrating a configuration of an imaging apparatus according to a first embodiment of the present invention. It is a flowchart figure of the filter switching operation | movement in 1st Example of this invention. It is a flowchart figure of the filter switching operation | movement in 1st Example of this invention. It is a figure which shows the structure of the filter switching mechanism of the lens apparatus in 2nd Example of this invention.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[First embodiment]
FIG. 1 is an exploded perspective view of a network camera (imaging device) according to a first embodiment of the present invention. A network camera represented by a monitoring camera device is a device to which a network and a client are connected. The network camera includes a dome cover 41, a dome 42, a lens device 43, and a pan / tilt rotation unit 44. The light incident on the network camera passes through the lens device 43 and irradiates an image sensor 9 described later to form an image and display an image.

  The lens device 43 is fixed to the pan / tilt rotation unit 44. The dome 42 is fixed to the pan / tilt rotation unit 44 by the dome cover 41 and the screw 40. The pan / tilt rotation unit 44 allows the lens device 43 and the dome 42 to rotate in the pan, tilt, and rotation directions. The dome cover 41 side is defined as the front side, and the pan / tilt rotation unit 44 side is defined as the rear side. The lens device 43 includes a front lens barrel portion 1a and a rear lens barrel portion 1b.

  FIG. 2 is an exploded perspective view of the front lens barrel 1a. The front lens barrel 1a includes a front fixed frame 16, a first group lens L1, an aperture unit 21, a second group lens L2, a rear fixed frame 26, and the like arranged in order from the front side. And the front side fixed frame 16 and the rear side fixed frame 26 are couple | bonded by the screw | thread 15 so that these members may be couple | bonded in the direction of the optical axis OL.

  As described above, the front lens barrel portion 1 a includes the two group lenses of the first group lens L 1 and the second group lens L 2, and the first group lens L 1 is held by the first movable frame 17. . The first movable frame 17 is provided with a sleeve 17s and a U-groove 17u. The sleeve 17s is engaged with a first guide bar 18 extending in the direction of the optical axis OL, and the U-groove 17u. Is engaged with the second guide bar 19 extending in the direction of the optical axis OL. The first group lens L1 is supported by the first guide bar 18 and the sleeve 17s so as to be movable in the direction of the optical axis OL, and is rotated around the first guide bar 18 by the second guide bar 19 and the U groove 17u. Is regulated.

  The first rack 20 is fixed to the first movable frame 17 while being biased in the direction of the optical axis OL and the rotation direction by a first rack spring (not shown), and is fixed to the rear fixed frame 26 with screws 27. Engage with the threaded portion of the stepping motor M17. The first rack 20 can move in the direction of the optical axis OL together with the first movable frame 17 by rotation of the screw portion. When the first movable frame 17 is moved, the first group lens L1 is moved in the direction of the optical axis OL, and a focusing operation is performed.

  The aperture unit 21 is fixed to the rear fixed frame 26 with screws (not shown), and the amount of light of the lens device 43 is adjusted by controlling the aperture unit 21.

  The second group lens L2 is held by the second movable frame 22. The second movable frame 22 is provided with a sleeve 22s and a U groove 22u. The sleeve 22s is engaged with a third guide bar 23 extending in the direction of the optical axis OL, and the U groove 22u. Is engaged with the fourth guide bar 24 extending in the direction of the optical axis OL. The second group lens L2 is supported by the third guide bar 23 and the sleeve 22s so as to be movable in the direction of the optical axis OL, and rotated around the third guide bar 23 by the fourth guide bar 24 and the U groove 22u. Is regulated.

  The second rack 25 is fixed to the second movable frame 22 while being biased in the direction of the optical axis OL and the rotational direction by a second rack spring (not shown), and is fixed to the rear fixed frame 26 with screws 27. Engage with the threaded portion of the stepping motor M22. The second rack 25 can move in the direction of the optical axis OL together with the second movable frame 22 by rotation of the screw portion. Then, when the second movable frame 22 moves, the second group lens L2 is moved in the direction of the optical axis OL, and a magnification changing operation is performed.

  The photo interrupters 28 and 29 are soldered to an unillustrated FPC (flexible printed circuit board) and are fixed to the rear fixed frame 26. The FPC is connected to stepping motors M17 and M22 fixed to the rear fixed frame 26, and the stepping motors M17 and M22 can be driven by energizing the FPC.

  The photo interrupter 28 is disposed on a moving area where the first movable frame 17 moves, and the position of the first movable frame 17 can be controlled by the output of the photo interrupter 28 and the rotation of the stepping motor M17. The photo interrupter 29 is disposed on a moving area where the second movable frame 22 moves, and the position of the second movable frame 22 can be controlled by the output of the photo interrupter 29 and the rotation of the stepping motor M22.

  As described above, stepping motors M17 and M22, photo interrupters 28 and 29, and the like are attached to the rear fixed frame 26, and the rear lens barrel portion 1b (in the downstream direction (rear side) of the optical axis OL is disposed. 3) is attached. In addition, the rear fixed frame 26 is provided with an incident opening 30 on the optical axis OL.

  Next, the configuration of the rear lens barrel 1b will be described. FIG. 3 is an exploded perspective view of the rear lens barrel 1b. The rear lens barrel 1b includes a stepping motor M2, a filter turret 2, a polarizing filter holding frame 6, a stepping motor M6, a sensor holder 8, an image sensor unit 10, an image processing unit 11, and the like arranged in order from the front side. Has been.

  The filter turret 2 includes a plurality of infrared cut filters 3 a and 3 b and a filter-shaped raw glass 4, and these filters are arranged on one plane of the filter turret 2. Such an arrangement of the filter contributes to downsizing of the imaging device. The UV cut coating is applied to the surface of one side of the infrared cut filters 3a and 3b, and the antireflection coating is applied to the surface of the other side. It is possible to reduce the influence and obtain a good image.

  A spacer 5 is fixed around the rear side of the infrared cut filter 3a of the filter turret 2, and a polarizing filter holding frame 6 that holds the polarizing filter 7 by the spacer 5 is around an axis parallel to the optical axis OL. It is arranged to be rotatable. That is, the polarizing filter 7 is disposed so as to overlap with one of the infrared cut filters 3a and 3b. The filter turret 2 can be rotated by a stepping motor M2. Thus, by attaching the polarizing filter 7 to one infrared cut filter 3a in advance, it is possible to reduce the size of the imaging device as compared with the case where each is provided separately.

  When the filter turret 2 is rotated by the stepping motor M2, the infrared cut filters 3a and 3b and the filter-shaped raw glass 4 are switched in the rotation direction of the filter turret 2 with respect to the optical axis OL. When the infrared cut filter 3a is arranged on the optical axis OL by the rotation of the filter turret 2, the polarizing filter 7 overlapping the infrared cut filter 3a includes the infrared cut filter 3a and a low-pass filter (not shown). Located between the image sensors 9. In this way, by using the infrared cut filter 3a to which the polarizing filter 7 is attached, the subject can be recognized at daytime. Further, as compared with the case where the polarizing member is positioned in the front side on the subject side of the camera unit as in the conventional imaging apparatus, the polarizing filter 7 is positioned between the infrared cut filter 3a and the imaging element 9 as in the present invention. When configured, the imaging apparatus can be reduced in size.

  When the filter turret 2 is further rotated, only the infrared cut filter 3b and only the filter-like raw glass 4 can be inserted into the optical axis OL. By rotating the filter turret 2, the infrared cut filters 3 a and 3 b are retracted from the optical axis OL, and a filter-like raw glass 4 is inserted instead, thereby preventing deterioration in image quality at night. Moreover, since the infrared cut filter 3a to which the polarizing filter 7 is attached is retracted from the optical axis OL, it is protected from infrared rays irradiated at night, and deterioration of the optical member having a polarization component is prevented. The polarizing filter holding frame 6 can be rotated by a stepping motor M6. A filter switching mechanism for switching the filter by rotating the filter turret 2 and a mechanism for rotating the polarizing filter holding frame 6 will be described later.

  The sensor holder 8 is fixed to the rear fixed frame 26 of the front lens barrel 1a by screws 12. An image sensor unit (sensor plate) 10 is fixed to the sensor holder 8 with an image sensor screw 13. The image sensor unit 10 is configured by integrating the image sensor 9 and a sheet metal, and is integrated with the lens device 43. An image processing unit 11 is fixed to the rear side of the image sensor unit 10.

  Next, the filter switching mechanism of the first embodiment will be described with reference to FIG. FIG. 4 is a view of the lens device 43 according to the first embodiment of the present invention as viewed from the rear side of the optical axis OL. For easy understanding, the sensor holder 8, the image sensor unit 10, and the image processing unit 11 are illustrated. Description is omitted.

  A gear M2G is provided on the rotation shaft of the stepping motor M2 that rotates the filter turret 2. The gear M2G meshes with the idler gear 2IG fixed to the rear fixed frame 26, and the idler gear 2IG meshes with the gear 2G formed on the outer periphery of the filter turret 2, whereby the rotation of the stepping motor M2 is transmitted to the filter turret 2. The filter turret 2 rotates about the rotation axis 2A of the filter turret 2, and the positions of the three filter elements, that is, the infrared cut filters 3a and 3b and the filter-shaped raw glass 4, are incident on the light incident opening 30 ( (See FIG. 3). The filter switching mechanism includes a stepping motor M2, a gear M2G, an idler gear 2IG, and a filter turret 2, and corresponds to the switching means of the present invention.

  Next, a mechanism for rotating the polarizing filter holding frame 6 to which the polarizing filter 7 is attached will be described. First, the filter turret 2 is rotated so that the infrared cut filter 3a is positioned at the light incident opening 30, and the gear 6G formed on the outer periphery of the polarizing filter holding frame 6 is engaged with the idler gear 6IG. The polarizing filter holding frame 6 is attached to the filter turret 2 with a spacer 5 (not shown) rotatable around an axis parallel to the optical axis OL. A gear M6G is provided on the output shaft of the stepping motor M6 that rotates the polarizing filter holding frame 6. The gear M6G meshes with an idler gear 6IG fixed to the rear fixed frame 26, and the idler gear 6IG meshes with the gear 6G of the polarizing filter holding frame 6, whereby the rotation of the stepping motor M6 is transmitted to the polarizing filter holding frame 6. Then, by rotating the polarizing filter holding frame 6, the polarizing filter 7 is set to a desired angle for polarizing incident light. In this way, the polarization direction of the polarizing filter 7 can be arbitrarily changed with respect to the optical path of the lens.

  When the filter turret 2 is rotated and the infrared cut filter 3a to which the polarizing filter 7 is attached is detached from the optical axis OL, the meshing between the idler gear 6IG and the gear 6G of the polarizing filter holding frame 6 is released. Then, the rotation of the stepping motor M6 is not transmitted to the polarizing filter holding frame 6. A mechanism for rotating the polarizing filter holding frame 6 to which the polarizing filter 7 is attached includes a stepping motor M6, a gear M6G, an idler gear 6IG, and the polarizing filter holding frame 6, and corresponds to a rotating means for rotating the optical member of the present invention. . In the first embodiment, the mechanism for rotating the polarizing filter holding frame 6 is driven independently of the filter switching mechanism.

  FIG. 5 is a diagram in which in the lens device 43 according to the first embodiment of the present invention, the filter turret 2 is rotated, and the infrared cut filter 3 a to which the polarizing filter 7 is attached is disposed in the region of the incident opening 30. is there. With this arrangement, the polarization filter 7 is positioned between the infrared cut filter 3 a and the image sensor 9. The light that has passed through the region of the incident opening 30 passes through the infrared cut filter 3 a and the polarization filter 7 and enters the image sensor 9. The arrangement shown in FIG. 5 is selected when reflected light generated by the reflection of strong light such as sunlight on the water surface or window glass is incident.

  FIG. 6 shows an arrangement of the infrared cut filter 3b in the lens device 43 according to the first embodiment of the present invention so that the filter turret 2 is rotated and the light from the incident aperture 30 is allowed to pass through the infrared cut filter 3b. FIG. With this arrangement, since the infrared cut filter 3a to which the polarizing filter 7 is attached is retracted from the incident opening 30, the light that has passed through the area of the incident opening 30 passes only through the infrared cut filter 3b. , The light does not enter the polarizing filter 7 and enters the image sensor 9. Since only the infrared cut filter 3b is disposed, it is necessary to correct the optical path length corresponding to the thickness of the polarization filter 7 with respect to the case where the infrared cut filter 3a and the polarization filter 7 are inserted. Therefore, a filter-like correction glass (not shown) having an optical path length corresponding to the thickness of the polarizing filter 7 is attached to the surface of the infrared cut filter 3b to correct the entire optical path length.

  The arrangement shown in FIG. 6 is selected when there is little reflected light containing a large amount of polarization components and priority is given to securing the amount of light. With this arrangement, the degree of freedom for photographing in the daytime is increased. In addition, although all of the infrared cut filters 3a and 3b use a filter in which the filter base material affects the filter thickness in this embodiment, a glass filter with a coating having infrared cut characteristics is used. May be used. When such a glass filter is used, it is not necessary to correct the optical path length with the correction glass as described above.

  FIG. 7 shows a filter-shaped elemental glass that rotates the filter turret 2 and allows the light from the incident opening 30 to pass through the elemental glass-shaped element 4 in the lens device 43 according to the first embodiment of the present invention. FIG. With this arrangement, since the polarizing filter 7 is retracted from the incident opening 30, the light that has passed through the region of the incident opening 30 passes only through the filter-like raw glass 4 and does not enter the polarizing filter 7. Incident on the image sensor 9. Since only the filter-shaped raw glass 4 is arranged, it is necessary to correct the optical path length of the thickness of the polarizing filter 7 with respect to the case where the infrared cut filter 3a to which the polarizing filter 7 is attached is inserted. Therefore, the thickness of the filter-shaped raw glass 4 is increased so as to be an optical path length corresponding to the thickness of the polarizing filter 7, and the entire optical path length is corrected.

  When the infrared cut filter 3a to which the polarizing filter 7 is attached is arranged by the filter switching mechanism as described above, only the infrared cut filter 3b is arranged, and only the filter-like raw glass 4 is arranged. Can be switched. Furthermore, at daytime, it is possible to select whether or not to switch the mechanism for rotating an optical member such as the polarizing filter 7 on an axis parallel to the optical axis OL of the lens. In addition, the polarizing filter 7 itself can be withdrawn at night or only the filter-like raw glass 4 can be selected. As a result, it is possible to prevent deterioration in image quality degradation at night. Further, it is possible to prevent the polarization filter 7 having a polarization component from deteriorating. In the first embodiment, the filter can be set by rotating the filter turret 2 and the polarizing filter 7 at the same time using the two stepping motors M2 and M6, so that the filter switching time can be increased. Have

  Next, a method for detecting the rotation angle of the filter turret 2 and the position of each filter, and a method for detecting the rotation angle of the polarizing filter 7 will be described with reference to FIG. A light shielding plate portion 2 </ b> C is provided on a part of the outer peripheral portion of the filter turret 2. Further, a light shielding plate part 6 </ b> C is also provided on a part of the outer peripheral portion of the polarizing filter holding frame 6. The sensor holder 8 (not shown) is provided with photo interrupters 2Pa, 2Pb, and 6P.

  The photo interrupters 2Pa and 2Pb acquire the value of the threshold voltage due to the passage of the light shielding plate 2C and detect the initial position of the filter turret 2. The filter position is calculated from the information on the initial position and the input value of the rotation angle of the stepping motor M2. Similarly, the photo interrupter 6P acquires the value of the threshold voltage due to the passage of the light shielding plate 6C and detects the initial position of the polarizing filter holding frame 6. The rotation angle of the polarizing filter 7 is calculated from the information on the initial position and the input value of the rotation angle of the stepping motor M6.

  Next, the configuration of the image pickup apparatus including the lens device 43 according to the first embodiment of the present invention will be described with reference to a block diagram shown in FIG. The imaging apparatus includes a camera unit 51 disposed outdoors and an operation unit 71 that operates the camera unit 51, and both are connected via a communication unit 81.

  The camera unit 51 includes a lens unit 63, an imaging unit 64, and a processing unit 65. The imaging unit 64 (corresponding to the imaging element 9 in FIG. 3) that has received the light transmitted through the lens unit 63 (corresponding to the first group lens L1 and the second group lens L2 in FIG. 2) converts the light into an electrical signal. Output as an image signal. The processing unit 65 (corresponding to the image processing unit 11 in FIG. 3) performs predetermined image processing such as defect correction and color correction on the output image signal. Further, the processing unit 65 can acquire the luminance of the image by calculating the image signal.

  Further, the camera unit 51 is provided with a control CPU 52 that controls the operation of the pan / tilt rotation unit 44 and the lens device 43 according to the operation of the operation unit 71. Connected to the control CPU 52 are a tilt driving unit 53, a pan driving unit 54, a diaphragm driving unit 55 for driving the diaphragm unit 21, a filter turret driving unit 56, a polarization filter driving unit 57, and a processing unit 65.

  The tilt driving unit 53 and the pan driving unit 54 drive the pan / tilt rotation unit 44. Further, the tilt driving unit 53 and the pan driving unit 54 have detection means (corresponding to pan / tilt detection means) for detecting the tilt angle and pan position of the camera, and the detection result is notified to the control CPU 52. The

  The filter turret drive unit 56 controls the stepping motor M2 and drives the filter turret 2. The filter turret driving unit 56 is connected to photo interrupters 2Pa and 2Pb as detection means for detecting the rotational angle position of the filter turret 2, and the detected value is notified to the control CPU 52. Similarly, the polarization filter driving unit 57 controls the stepping motor M6 and drives the polarization filter holding frame 6. The polarization filter driving unit 57 is connected to a photo interrupter 6P as detection means for detecting the rotational angle position of the polarization filter holding frame 6, and the detected value is notified to the control CPU 52.

  The control CPU 52 also includes a polarizing filter rotation angle storage unit 58 that stores the rotation angle step (angular resolution) of the polarizing filter 7, and a filter turret rotation angle storage unit 59 that stores the rotation angle step (angular resolution) of the filter turret 2. Is connected. The control CPU 52 can read information stored in the polarization filter rotation angle storage unit 58 and the filter turret rotation angle storage unit 59 as needed. Further, the control CPU 52 is connected with a polarization filter luminance calculation means 60 for grasping the luminance difference of the polarization component of the polarization filter 7 and a filter turret position calculation means 61 for calculating the rotation angle of the filter turret 2. In addition, information on the luminance of the image acquired by the processing unit 65 is notified to the control CPU 52.

  Further, the filter turret position calculation means 61 is connected to a polarization filter position calculation means 62 for calculating the rotation angle of the polarization filter 7. Based on the result of the calculation means, it is determined whether or not the optimum light from which the polarization component has been removed enters the image sensor 9.

  The operation unit 71 has an operation unit CPU 72, and the operation unit CPU 72 is instructed to operate the pan drive unit 54 and the tilt drive unit 53 of the camera unit 51 and the opening / closing operation of the aperture blades in the aperture drive unit 55. The unit 73 is connected. The operator (operator) can photograph a desired subject by operating the operation unit 73 and display the image on the display unit 74 while confirming an image photographed by the camera on a monitor (not shown).

  Next, the control of the rotation operation of the filter turret 2 and the polarizing filter 7 of the lens device 43 will be described with reference to the flowcharts of FIGS. Note that the image pickup apparatus of the present invention is initially set during the initial operation when the image pickup apparatus is turned on. As an initial setting operation, first, the filter turret 2 is rotated so that only the infrared cut filter 3b is positioned on the optical path of the lens (see FIG. 6). Then, the luminance of the entire image is calculated based on the image obtained by the light that has passed through only the infrared cut filter 3b. If there is a change (threshold value) that exceeds a certain value from the brightness value of the entire image, the initial setting is executed so as to switch to the filter-like raw glass 4 (see FIG. 7).

  When the filter setting process is started, a flow for determining a filter to be used is performed in step S101. This flow is a subroutine and will be described with reference to FIG. First, in step SS11, the luminance of the entire image is acquired. Note that the luminance may not be acquired for the entire image, but may be performed within a predetermined range designated by the user or the like. In addition to the luminance of the image, information such as the calendar and time held by the imaging device, the position of the sun, GPS, temperature, and humidity may be acquired and used. Such information may be acquired from the operation unit 71 or may be acquired from a dedicated detection means provided. Moreover, you may change the threshold value used for use filter determination using said information.

  Next, in step SS12, it is determined whether or not the brightness of the entire image is a value equal to or greater than a predetermined threshold value. This determination is performed based on whether the image of a subject that receives strong light such as sunlight is a daytime shooting that is highly likely to be incident on the imaging device or a nighttime shooting that is less likely to be performed. . When the brightness of the entire image is lower than the predetermined threshold value and it is determined that it is nighttime (determined as NO), the process proceeds to step SS17, and it is determined that the filter-like raw glass 4 on the filter turret 2 is inserted. Note that the determination means in step SS12 corresponds to the means for determining the daytime or nighttime of the present invention.

  On the other hand, when it is determined that the luminance of the entire image is higher than the predetermined threshold and is daytime (determined as YES), pixels having a luminance equal to or higher than the predetermined threshold in the image are counted in step SS13. For example, when the amount of light that has passed through the lens device 43 is large, the amount of electrons that can be stored in the image pickup pixels by the image pickup device 9 is saturated, and as a result, the pixels that appear white (out-of-white), that is, so-called saturation level pixels To do.

  Next, in step SS14, it is determined whether or not strong light is locally incident on the image. If the number of pixels having a luminance equal to or higher than the predetermined threshold counted in step SS13 is equal to or higher than the predetermined number, it is determined that strong light is incident, and otherwise, it is determined that strong light is not incident. If it is determined that strong light is incident (YES), the process proceeds to step SS15 and it is determined to insert the infrared cut filter 3a to which the polarizing filter 7 is attached. If it is determined that there is no strong light (determined as NO), the process proceeds to step SS16 and it is determined to insert the infrared cut filter 3b. Then, the flow for determining the use filter is terminated.

  The description returns to FIG. In step S102, the current rotation angle of the filter turret 2 is acquired. Next, in step S103, the filter turret 2 is driven so that the use filter determined in step S101 is inserted on the optical axis OL.

  In step S104, the filter turret 2 driven in step S103 determines whether or not the infrared cut filter 3a to which the polarizing filter 7 is attached is inserted on the optical axis OL. When it is determined that the infrared cut filter 3a to which the polarizing filter 7 is attached is not inserted (determined as NO), the process proceeds to step S110, the filter setting process is terminated, and the photographing operation or the like is started.

  If it is determined in step S104 that the infrared cut filter 3a to which the polarizing filter 7 is attached is inserted (YES), the process proceeds to step S105, and the current rotation angle of the polarizing filter 7 is acquired.

  In step S106, the polarizing filter 7 is driven with a constant angular resolution. Therefore, the polarizing filter 7 is held at that position after being rotated by a certain angle.

  In step S107, the luminance of the image that has passed through the polarizing filter 7 is acquired. Here, the image is divided into a plurality of blocks, and the luminance of each block is acquired. Note that the range to be acquired may not be the entire image, but may be acquired within a predetermined range, for example, near the center of the image.

  In step S108, the number of blocks whose luminance acquired in each block is equal to or higher than a predetermined value is counted. Then, the number of counted blocks and the polarization angle of the polarizing filter 7 at that time are stored together.

  Next, in step S109, it is determined whether or not the reflected light with strong luminance is removed. That is, when it is determined that the number of blocks stored in step S108 is equal to or less than a predetermined value (determined as YES), it is determined that the reflected light with high luminance has been removed, and the process proceeds to step S110 to complete the filter setting process. And start shooting. Otherwise, the process returns to step S106.

  In step S106, the polarizing filter 7 is driven to the next angular resolution. Then, the luminance acquisition of the image in step S107 and the luminance storage of the image in step S108 are executed, and the determination in step S109 is performed again. In addition, you may compare with the count value acquired before that instead of the comparison with a predetermined value. In this way, by obtaining the luminance while changing the polarization angle of the polarizing filter 7 for each angular resolution, and using the obtained luminance for the determination, the optimum position of the polarizing filter 7 can be determined.

  Note that information can be stored in advance in the polarization filter rotation angle storage unit 58 and the filter turret rotation angle storage unit 59, and the preset mode and the like can be set in advance by reading the information. According to the present invention, it is possible to provide the lens device 43 that can remove the reflected light during the daytime while securing the optimum light amount and can secure the light amount during the nighttime. Furthermore, compared to the conventional example in which a polarizing filter device or the like is disposed on the front surface of the lens, the device can be reduced in size because the polarizing filter 7 is disposed on the front surface of the imaging element 9 having a small light incident aperture 30. .

  A means for calculating the brightness of the incident light of the polarization component by the difference in contrast of the brightness of the incident light along with the rotation of the polarizing filter, and rotating the rotation angle position where the contrast of the image formed by the incident light of the polarization component is the lowest. May be used. Further, it is also possible to measure the external brightness using an illuminance sensor and use means for rotating the filter turret 2 to a rotation angle stored in advance according to the brightness. For example, when it is determined that it has become dark (determined as nighttime), the filter turret 2 is rotated to a predetermined rotation angle, while when it is determined that it has become brighter (determined as daytime), the filter turret 2 is similarly turned You may rotate to another determined rotation angle.

[Second Embodiment]
Hereinafter, a second embodiment of the present invention will be described with reference to FIG. Compared to the first embodiment, the second embodiment is common except for the filter switching mechanism and the mechanism for rotating the polarizing filter holding frame 6, and the description of the common basic configuration is omitted.

  FIG. 10 shows the configuration of the filter switching mechanism and the mechanism for rotating the polarizing filter holding frame 6 according to the second embodiment of the present invention. In the second embodiment, the filter turret 2 and the polarizing filter 7 are rotated by one stepping motor M. The stepping motor M is provided with a sun gear SG that rotates around the rotation axis of the stepping motor M. Further, a planetary gear PG that meshes with the sun gear SG and revolves around the sun gear SG is attached to the rotation shaft of the stepping motor M via the planetary arm AM.

  When the stepping motor M rotates counterclockwise, the sun gear SG rotates counterclockwise, and the planetary gear PG counterclockwise around the sun gear SG until it engages with the idler gear 2IG attached to the rear fixed frame 26. Revolve in the direction. The sun gear SG rotates the planetary gear PG, the rotation of the planetary gear PG is transmitted to the idler gear 2IG, and is transmitted to the filter turret 2 via the gear 2G formed on the outer periphery of the filter turret 2. The filter turret 2 rotates about the rotation shaft 2A, and the infrared cut filters 3a and 3b and the filter-shaped raw glass 4 are switched. The filter switching mechanism includes a stepping motor M, a sun gear SG, a planetary gear PG, a planetary arm AM, an idler gear 2IG, and a filter turret 2, and corresponds to the filter switching means of the present invention.

  Next, when the stepping motor M rotates in the clockwise direction, the planetary gear PG revolves in the clockwise direction around the sun gear SG to a position where the planetary gear PG meshes with the idler gear 6IG attached to the rear fixed frame 26. Then, the rotation of the planetary gear PG is transmitted to the idler gear 6IG, and is transmitted to the polarizing filter holding frame 6 through the gear 6G formed on the outer periphery of the polarizing filter holding frame 6. The polarizing filter holding frame 6 rotates around the sandwiched spacer 5, and the polarization angle of the polarizing filter 7 is changed. The mechanism for rotating the polarizing filter holding frame 6 includes a stepping motor M, a sun gear SG, a planetary gear PG, a planetary arm AM, an idler gear 6IG, and a polarizing filter holding frame 6, and is a rotating means for rotating the optical member of the present invention. Equivalent to.

  Further, the position where the planetary gear PG and the idler gear 2IG mesh with each other in the thickness direction is different from the position where the planetary gear PG and the idler gear 6IG mesh with each other in the thickness direction. With this configuration, when the polarizing filter holding frame 6 on the filter turret 2 is rotated, one planetary gear PG revolves through the planetary arm AM, and meshes with the idler gear 2IG or the idler gear 6IG depending on the revolution position. Can do.

  By rotating the stepping motor M clockwise or counterclockwise, the planetary arm AM and the planetary gear PG move, and the rotation of the planetary gear PG is transmitted to the gear 2G of the filter turret 2 or the gear 6G of the polarizing filter holding frame 6. can do. That is, the filter turret 2 or the polarizing filter holding frame 6 can be rotated by one stepping motor M. More specifically, after the filter turret 2 is rotated and the switching to the infrared cut filter 3a is completed, the polarization filter 7 can be rotated to change the polarization angle.

  As described above, it is possible to select only the infrared cut filter 3a, the infrared cut filter 3b, or the filter-shaped raw glass 4 to which the polarizing filter 7 is attached. The filter can be inserted into or retracted from the incident opening 30 on the incident light path of the light of the image sensor 9 depending on the purpose of use.

  In the second embodiment, the filter turret 2 and the polarizing filter holding frame 6 can be driven by the stepping motor M which is one driving member, and the first embodiment is driven by the two stepping motors M2 and M6. The cost can be reduced compared to As described above, the first embodiment has an advantage that the filter switching time can be increased, whereas the second embodiment has an advantage for cost.

  In both the first and second embodiments, the optical member of the present invention may be a member that polarizes a polarization component using a liquid crystal polarizing filter such as a polarizing shutter and a liquid crystal element. As mentioned above, although preferable embodiment of this invention was described, this invention is not limited to these embodiment, A various deformation | transformation and change are possible within the range of the summary.

2 Filter turret (switching means)
3a, 3b Infrared cut filter 4 Filter-like raw glass 6 Polarizing filter holding frame (rotating means)
7 Polarizing filter (optical member)
9 Image sensor 30 Incident aperture L1 1st group lens L2 2nd group lens OL Optical path, optical axis M Stepping motor (drive member)
SG sun gear PG planetary gear

Claims (14)

A lens,
A plurality of infrared cut filters;
A filter-like elemental glass,
An optical member capable of arbitrarily changing the polarization direction of light with respect to the optical path of the lens;
An image sensor;
Each of the plurality of infrared cut filters and a switching unit that enables switching of the filter-shaped raw glass with respect to the optical path ,
The optical member may be located between any one and the imaging element of the plurality of infrared cut filter is switched by the switching means, the imaging apparatus. The optical member may be provided in the first infrared cut filter of the plurality of infrared cut filter, the image pickup apparatus according to claim 1. A lens,
A first infrared cut filter;
A second infrared cut filter;
A filter-like elemental glass,
An optical member provided in the first infrared cut filter and capable of arbitrarily changing a polarization direction of light with respect to an optical path of the lens;
An image sensor;
A first state in which the first infrared cut filter and the optical member are inserted into the optical path, and the second infrared cut filter and the filter-shaped raw glass are retracted from the optical path;
A second state in which the second infrared cut filter is inserted into the optical path, and the first infrared cut filter, the optical member, and the filter-like raw glass are retracted from the optical path;
A third state in which the filter-shaped elemental glass is inserted into the optical path, and the first infrared cut filter, the optical member, and the second infrared cut filter are retracted from the optical path;
An image pickup apparatus comprising: switching means for switching between. Said first and infrared cut filter, and a second infrared cut filter not provided with the optical member, a front SL filter-like raw glass is arranged on one surface of the filter turret,
The Rukoto rotates the switching means the filter turret, the switching is equal to or to be made to the optical path, the imaging apparatus according to claim 2 or 3. Said switching means, and performs switching in response to said luminance of the image pickup apparatus according to claim 3 or 4. Means for determining daytime or nighttime according to the brightness of the image,
6. The switching means according to claim 5, wherein the switching means switches to the first infrared cut filter or the second infrared cut filter at daytime, and switches to the filter-like raw glass at nighttime. Imaging device. A rotation means,
Characterized in that it is possible to arbitrarily changed the polarization direction by rotating the optical member by the rotating means, the imaging apparatus according to any one of claims 2 to 6.   The imaging apparatus according to claim 7, wherein the switching unit is configured by a mechanism that can be driven independently of the rotating unit.   9. The imaging apparatus according to claim 7, wherein the switching unit and the rotation unit are configured by a mechanism that can be independently driven by one driving member. The one driving member is a stepping motor;
The imaging apparatus according to claim 9, wherein the switching unit and the rotating unit include a sun gear and a planetary gear driven by the stepping motor. A means for determining whether it is daytime or nighttime according to the brightness of the image,
Said switching means is characterized in that Ru presence selectable der of switching of the rotating means during the daytime, the image pickup apparatus according to any one of claims 7 to 10.   The imaging device according to claim 1, wherein the optical member is a polarizing filter. The optical member, characterized in that it is a liquid Akirahen optical filter, the image pickup apparatus according to any one of claims 1 to 11.   The imaging apparatus according to claim 1, wherein the imaging apparatus is a monitoring camera apparatus.

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