JP7342278B2 - Optical devices and imaging devices - Google Patents

Description

The technology of the present disclosure relates to an optical device and an imaging device.

Patent Document 1 discloses an image sensor that converts incident light into an electrical signal and outputs an image signal, an imaging lens that forms an image of a subject on the image sensor, and at least one optical element that transmits a specific wavelength band. A filter support part that holds the filter and allows the optical filter to be selectively inserted or removed in the middle of the optical axis that connects the imaging lens and the image sensor, and a filter support that allows the imaging lens to be inserted or removed from the optical axis according to the operation of inserting or removing the optical filter from the optical axis. An imaging device is described that includes a moving means for moving in a direction.

Patent Document 2 discloses an imaging device that includes an imaging optical system including a movable lens for adjusting the angle of view and a movable lens for adjusting the focus, and adjusts the focus by moving the movable lens for adjusting the focus to a focusing position. an image sensor that receives light from a subject and converts it photoelectrically; a focus adjustment control means that detects the in-focus position and controls the drive of a movable lens for adjusting the focus; and a position of the movable lens for adjusting the angle of view. information or the position information of the movable lens for focus adjustment is acquired to calculate the amount of correction for correcting the deviation of the focus position due to chromatic aberration of the imaging optical system, and also corrects the amount of correction to correct the coloration of the subject image due to chromatic aberration. An imaging apparatus is described that is characterized by comprising a correction unit that performs processing to suppress the correction amount and outputs the corrected correction amount to a focus adjustment control unit.

Patent Document 3 discloses an image sensor that captures an image of a subject, a variable filter placed in front of the image sensor that can be switched to multiple types of filters with different transmission wavelengths, and a variable filter that changes the wavelength range of light reflected from the subject. A wavelength band sorting means for sorting, and a focus adjustment means for adjusting the focus of an image sensor, and the filter of the variable filter is switched based on the selection result of the wavelength band sorting means, and the focus is adjusted by the focus adjustment means. An imaging device is described that is characterized by:

Japanese Patent Application Publication No. 2006-033716 JP2013-156540A Japanese Patent Application Publication No. 07-284111

One embodiment of the technology of the present disclosure provides an optical device and an imaging device that can reduce the time required to correct longitudinal chromatic aberration.

The optical device of the present disclosure includes a plurality of filters that selectively transmit light in a preset wavelength band, and includes a filter unit in which the plurality of filters are inserted into an optical path in a predetermined order, and a filter unit in which the plurality of filters are respectively inserted into an optical path. A correction lens that corrects longitudinal chromatic aberration of a plurality of types of transmitted light by moving along an optical axis, and the predetermined order is an order according to the moving direction of the correction lens.

Preferably, the predetermined order is an order in which the number of switching directions of movement is minimized.

Preferably, the predetermined order is an order in which the cumulative amount of movement of the correction lens is minimized.

Preferably, the camera further includes a zoom lens, and the predetermined order is based on a representative value of the amount of movement of the correction lens required to correct longitudinal chromatic aberration in the movement range of the zoom lens.

Preferably, the correction lens is a focus lens.

The correction lens further includes a zoom lens, and the correction lens is a focus lens and a master lens placed on the imaging side of the focus lens, and if the zoom lens is placed on the telephoto side with respect to a preset threshold, It is preferable that the focus lens moves to correct the axial chromatic aberration, and if the zoom lens is located on the wide-angle side of the threshold, the master lens moves to correct the axial chromatic aberration.

The filter unit has a configuration in which a plurality of filters are arranged in an annular shape, and it is preferable that the filter unit rotates in one direction to sequentially insert the plurality of filters into the optical path.

The plurality of filters include a starting filter inserted first into the optical path and a terminal filter inserted last into the optical path, and the filter unit has a configuration in which the plurality of filters are arranged in one direction. , by alternately repeating the first operation of moving from the position of the starting filter to the position of the terminating filter and the second operation of returning from the position of the terminating filter to the position of the starting filter, thereby sequentially inserting a plurality of filters into the optical path. is preferred.

Preferably, the predetermined order is an order in which the amount of movement of the correction lens becomes relatively large while the second operation is being performed.
It is preferable that the filter unit has a configuration in which a plurality of filters are arranged in an annular shape, and that the plurality of filters are sequentially inserted into the optical path by rotating the filter unit.
The filter unit is a rectangular flat plate in which a plurality of filters are arranged along the long side direction, and it is preferable that the filter unit reciprocates in the long side direction to sequentially insert the plurality of filters into the optical path.

The multiple filters include a blue filter that transmits light in the blue wavelength band, a green filter that transmits light in the green wavelength band, a red filter that transmits light in the red wavelength band, and a filter that transmits light in the infrared wavelength band. It is preferable to include an infrared filter that transmits light.

An imaging device of the present disclosure includes any of the optical devices described above.

It is a figure showing a camera. It is a figure showing a filter unit. 3 is a table showing an example of the amount of movement of the focus lens required to correct the axial chromatic aberration of each filter. 12 is a table showing candidates for each arrangement of filters, the movement direction of the focus lens when correcting axial chromatic aberration in each arrangement candidate, and the number of times the movement direction is switched. 12 is a table showing the actual amount of movement of the focus lens and the cumulative amount of movement of the focus lens in the cases of arrangement candidate 4 and arrangement candidate 10. 3 is a table showing the actual amount of movement of the focus lens and the cumulative amount of movement of the focus lens in the case of arrangement candidate 1; 7 is a table showing the actual amount of movement of the focus lens and the cumulative amount of movement of the focus lens in the case of arrangement candidate 2; It is a figure which shows another example of a filter unit. 9 is a diagram showing the transition of the operation of the filter unit in FIG. 8. FIG. 12 is a table showing candidates for each arrangement of filters, the movement direction of the focus lens when correcting axial chromatic aberration in each arrangement candidate, and the number of times the movement direction is switched. 7 is a table showing the actual amount of movement of the focus lens and the cumulative amount of movement of the focus lens in the case of arrangement candidate 2; 7 is a table showing the actual amount of movement of the focus lens and the cumulative amount of movement of the focus lens in the case of arrangement candidate 4; 7 is a table showing the actual amount of movement of the focus lens and the cumulative amount of movement of the focus lens in the case of arrangement candidate 7; 12 is a table showing the actual amount of movement of the focus lens and the cumulative amount of movement of the focus lens in the case of arrangement candidate 10; 7 is a table showing the amount of movement of the focus lens while the second operation is being performed in the case of each arrangement candidate. It is a figure which shows yet another example of a filter unit. It is a figure showing the camera of a 3rd embodiment. It is a flowchart which shows the operation procedure of the control part of 3rd Embodiment.

[First embodiment]
As an example, as shown in FIG. 1, a camera 10 is a surveillance camera installed in a factory or the like, and includes a lens barrel 11 and a main body 12. The lens barrel 11 is provided with a lens barrel side mount 13, and the main body 12 is provided with a main body side mount 14. The lens barrel 11 is attached to the main body 12 by the lens barrel side mount 13 and the main body side mount 14. An imaging optical system 20 is built into the lens barrel 11, and an image sensor 21 is built into the main body 12. The camera 10 is an example of an "imaging device" according to the technology of the present disclosure. Further, the lens barrel 11 is an example of an "optical device" according to the technology of the present disclosure.

The imaging optical system 20 includes a plurality of types of lenses for forming an image of subject light on the image sensor 21. Specifically, the imaging optical system 20 includes an objective lens 25, a focus lens 26, a zoom lens 27, and a master lens 28. These lenses 25 to 28 are arranged in this order from the object side (subject side) to the imaging side (image sensor 21 side). Each of the lenses 25 to 28 transmits light in a wavelength band from 400 nm to 1700 nm, that is, light in a wavelength band from visible light to near-infrared light. Although simplified in FIG. 1, each of the lenses 25 to 28 is actually a lens group in which a plurality of lenses are combined.

The imaging optical system 20 also has an aperture 30 and a filter unit 31. The aperture 30 is arranged between the zoom lens 27 and the filter unit 31. The filter unit 31 is arranged between the aperture 30 and the master lens 28.

The lens barrel 11 is provided with a focus lens drive mechanism 35, a zoom lens drive mechanism 36, an aperture drive mechanism 37, and a filter unit drive mechanism 38. As is well known, the focus lens drive mechanism 35 holds the focus lens 26 and rotates the focus cam ring around the optical axis OA, and the focus cam ring having a cam groove formed on the outer periphery. It includes a focusing motor that moves the cam ring along the optical axis OA. Similarly, the zoom lens drive mechanism 36 holds the zoom lens 27 and rotates the zoom cam ring around the optical axis OA, and the zoom cam ring having a cam groove formed on the outer periphery. It includes a zoom motor for moving along the optical axis OA. Note that in the following, the direction parallel to the optical axis OA and going from the object side to the imaging side will be referred to as the imaging side direction ID, and the direction parallel to the optical axis OA and going from the imaging side to the object side will be referred to as the object side. It is written as lateral direction OD. Parallel here refers to not only perfect parallelism but also parallelism that includes errors generally allowed in the technical field to which the technology of the present disclosure belongs.

The aperture drive mechanism 37 includes, as is well known, a motor that opens and closes a plurality of aperture blades of the aperture 30. The filter unit drive mechanism 38 includes a motor that rotates the filter unit 31 in one direction about its center.

The focus motor and the zoom motor are, for example, stepping motors. In this case, the positions of the focus lens 26 and the zoom lens 27 on the optical axis OA can be derived from the driving amounts of the focus motor and the zoom motor. Note that instead of the drive amount of the motor, a position sensor may be provided to detect the positions of the focus lens 26 and the zoom lens 27.

The filter unit drive mechanism 38 is provided with a rotational position sensor that detects the rotational position of the filter unit 31. The rotational position sensor is, for example, a rotary encoder.

Electrical components such as motors of each drive mechanism 35 to 38 are connected to lens barrel side contacts 40 provided on the lens barrel side mount 13. A main body side contact 41 is provided on the main body side mount 14 at a position corresponding to the lens barrel side contact 40 . A control section 45 is connected to the main body side contact 41 . When the lens barrel 11 is attached to the main body 12 via the lens barrel side mount 13 and the main body side mount 14, the lens barrel side contact 40 and the main body side contact 41 come into contact. Thereby, the electrical components of each of the drive mechanisms 35 to 38 and the control section 45 are electrically connected.

The control unit 45 is realized by, for example, a computer including a CPU (Central Processing Unit), memory, and storage. The memory is, for example, a RAM (Random Access Memory) or the like, and temporarily stores various information. The storage, which is a non-temporary storage medium, is, for example, a hard disk drive or a solid state drive, and stores various parameters and programs. The CPU loads a program stored in the storage into the memory and executes processing according to the program, thereby controlling the operation of each part of the camera 10 in an integrated manner. Note that the program may be recorded and distributed on an external recording medium (not shown), and installed by the CPU from the recording medium. Alternatively, the program may be stored in a server or the like connected to a network in a state that can be accessed from the outside, downloaded to a memory or storage by a CPU in response to a request, and installed and executed.

The electrical components of each drive mechanism 35 to 38 are driven under the control of a control section 45. More specifically, the control unit 45 emits a drive signal in response to an instruction from a user input via a monitor device (not shown) installed in a remote location away from the camera 10, for example, in a control room. The electrical components of each drive mechanism 35 to 38 are driven. For example, when an instruction to change the angle of view to the telephoto side is input via the monitor device, the control unit 45 issues a drive signal to the zoom motor of the zoom lens drive mechanism 36 to change the zoom lens 27 to the telephoto side. move it.

Further, the control unit 45 controls the axial chromatic aberration of multiple types of light transmitted through four filters F1, F2, F3, and F4, which will be described later, of the filter unit 31, to the focus lens 26 via the focus lens drive mechanism 35. Correction is made by moving along the optical axis OA. That is, the focus lens 26 is an example of a "correction lens" according to the technology of the present disclosure.

The focus motor and the zoom motor output drive amounts to the control section 45. The control unit 45 derives the positions of the focus lens 26 and the zoom lens 27 on the optical axis OA from the drive amount. Further, the rotational position sensor outputs the rotational position of the filter unit 31 to the control section 45. Thereby, the control section 45 grasps the rotational position of the filter unit 31.

The image sensor 21 has a light receiving surface that receives object light. The image sensor 21 is arranged such that the center of the light receiving surface coincides with the optical axis OA and the light receiving surface is orthogonal to the optical axis OA. The image sensor 21 has a light receiving surface made of indium gallium arsenide (InGaAs). Therefore, the image sensor 21 is capable of detecting a subject image based on light in a wavelength band from 400 nm to 1700 nm that has passed through the imaging optical system 20, that is, light in a wavelength band from visible light to near-infrared light. . Note that orthogonality here refers to not only complete orthogonality but also orthogonality that includes errors generally allowed in the technical field to which the technology of the present disclosure belongs.

The image sensor 21 is driven under the control of the control section 45. More specifically, when an instruction to start imaging is input via the monitor device, the control unit 45 causes the image sensor 21 to capture the subject light at a preset frame rate, for example, 30 fps (frames per second). let The image sensor 21 outputs an image obtained by capturing the subject light to the control unit 45. The control unit 45 stores the image from the image sensor 21 in a built-in memory (not shown) or transfers it to a monitor device.

As an example, as shown in FIG. 2, the filter unit 31 consists of a circular ring in which four filters F1 to F4, filters F1, F2, F3, and F4, are arranged at equal intervals (every 90 degrees in FIG. 2). It is a board. Filters F1, F2, F3, and F4 are examples of "a plurality of filters" according to the technology of the present disclosure. The filter unit 31 is rotated clockwise by a filter unit drive mechanism 38 in order to switch the filters F1 to F4 every frame. Clockwise is an example of "one direction" according to the technology of the present disclosure. The term "equal spacing" as used herein refers to not only perfectly equal spacing but also equal spacing that includes errors generally allowed in the technical field to which the technology of the present disclosure belongs. Note that the filter unit 31 may be rotated counterclockwise. Moreover, the filter unit 31 does not have to be a disk.

The filter unit 31 moves from a first position shown in the drawing in which the center of the filter F1 and the optical axis OA coincide with each other, to a second position shown in the figure in which the center of the filter F2 and the optical axis OA coincide with each other, and a filter F3. The filter F4 returns to the first position through a third position where the center of the filter F4 coincides with the optical axis OA, and a fourth position where the center of the filter F4 coincides with the optical axis OA. That is, the filters F1 to F4 are sequentially inserted into the optical path as the filter unit 31 rotates clockwise.

Each of the filters F1 to F4 selectively transmits light in a preset wavelength band. Filters F1 to F4 include, for example, a blue filter, a green filter, a red filter, and an infrared filter. The blue filter transmits light in the blue wavelength band. The green filter transmits light in the green wavelength band. The red filter transmits light in the red wavelength band. The infrared filter transmits light in the infrared wavelength band. The blue wavelength band is, for example, 400 nm to 490 nm, the green wavelength band is, for example, 490 nm to 550 nm, and the red wavelength band is, for example, 640 nm to 770 nm. Further, the infrared wavelength band is, for example, 1550±100 nm (1450 nm to 1650 nm). These blue filter, green filter, red filter, and infrared filter are arranged in an order according to the moving direction of the focus lens 26 when correcting axial chromatic aberration. Note that the numerical range expressed using "~" as described above means a range that includes the numerical values written before and after "~" as the lower limit and upper limit.

An image including a visible light image of the subject is obtained by the image sensor 21 capturing visible light that has passed through the blue filter, green filter, and red filter. Further, by the image sensor 21 capturing visible light and infrared rays that have passed through the infrared filter, an image including a visible light image and a radiation image of the subject is obtained.

As an example, as shown in Table 50 in FIG. 3, the amount of movement of the focus lens 26 required to correct the axial chromatic aberration of the red filter is set to 0 as a reference, and the amount of movement of the focus lens 26 required to correct the axial chromatic aberration of the infrared filter is 0. The amount of movement is -0.12mm. Similarly, the amount of movement of the focus lens 26 required to correct the axial chromatic aberration of the green filter is -0.115 mm, and the amount of movement of the focus lens 26 required to correct the axial chromatic aberration of the blue filter is -0.118 mm. Note that in the amount of movement of the focus lens 26, a negative value represents movement in the object side direction OD, and a positive value represents movement in the imaging side direction ID.

The axial chromatic aberration of each filter changes depending on the position of the zoom lens 27. Specifically, when the zoom lens 27 is located at the most telephoto side, the axial chromatic aberration of each filter is maximum, and when the zoom lens 27 is located at the widest angle side, the axial chromatic aberration of each filter is Minimum. In this example, the maximum value in the movement range of the zoom lens 27, that is, the movement amount when the zoom lens 27 is located at the most telephoto side, is used as the movement amount of the focus lens 26 required to correct longitudinal chromatic aberration. There is. The maximum value of the amount of movement of the focus lens 26 is an example of a "representative value" according to the technology of the present disclosure. Note that the average value of the amount of movement of the focus lens 26 required to correct longitudinal chromatic aberration within the movement range of the zoom lens 27 may be used as the representative value instead of the maximum value.

When any one of a blue filter, a green filter, a red filter, and an infrared filter is applied to filters F1 to F4, the number of arrangement candidates resulting from the combination is 4! = There are 24 ways. Table 55 in FIG. 4 shows arrangement candidate 1, arrangement candidate 2, arrangement candidate 4, and arrangement candidate 10 among the 24 arrangement candidates. Arrangement candidate 1 is a case where the filter F1 is an infrared filter, the filter F2 is a red filter, the filter F3 is a green filter, and the filter F4 is a blue filter. Arrangement candidate 2 is a case where the filter F1 is an infrared filter, the filter F2 is a red filter, the filter F3 is a blue filter, and the filter F4 is a green filter. Arrangement candidate 4 is a case where the filter F1 is an infrared filter, the filter F2 is a green filter, the filter F3 is a blue filter, and the filter F4 is a red filter. Arrangement candidate 10 is a case where the filter F1 is a red filter, the filter F2 is a blue filter, the filter F3 is a green filter, and the filter F4 is an infrared filter.

Table 56 shows the moving direction of the focus lens 26 when the filter unit 31 is rotated once and then further rotated to the fourth position of the second rotation, and is the movement direction of the focus lens 26 when correcting the axial chromatic aberration in each alignment candidate. 26 shows the direction of movement. In the case of arrangement candidate 1, first, the focus lens 26 moves in the object side direction OD when the filter F2 is inserted into the optical path. Next, when the filter F3 is inserted into the optical path, the focus lens 26 moves in the imaging side direction ID. Next, when the filter F4 is inserted into the optical path, the focus lens 26 moves in the object side direction OD. Next, when the filter F1 is inserted into the optical path, the focus lens 26 moves in the imaging side direction ID. Next, when the filter F2 is inserted into the optical path, the focus lens 26 moves in the object side direction OD. Next, when the filter F3 is inserted into the optical path, the focus lens 26 moves in the imaging side direction ID. Next, when the filter F4 is inserted into the optical path, the focus lens 26 moves in the object side direction OD. In this way, in the case of alignment candidate 1, the moving direction of the focus lens 26 is switched every time the filter inserted into the optical path changes. Therefore, the number of times the movement direction of the focus lens 26 is switched in the case of arrangement candidate 1 is 6 as shown in Table 57. In the case of arrangement candidate 2, first, the focus lens 26 moves in the object side direction OD when the filter F2 is inserted into the optical path. Next, when the filter F3 is inserted into the optical path, the focus lens 26 moves in the imaging side direction ID. Next, when the filter F4 is inserted into the optical path, the focus lens 26 moves in the imaging side direction ID. Next, when the filter F1 is inserted into the optical path, the focus lens 26 moves in the imaging side direction ID. Next, when the filter F2 is inserted into the optical path, the focus lens 26 moves in the object side direction OD. Next, when the filter F3 is inserted into the optical path, the focus lens 26 moves in the imaging side direction ID. Next, when the filter F4 is inserted into the optical path, the focus lens 26 moves in the imaging side direction ID. Therefore, the number of times the movement direction of the focus lens 26 is switched in the case of arrangement candidate 2 is 3 as shown in Table 57.

In the case of arrangement candidate 4, first, the focus lens 26 moves in the object side direction OD when the filter F2 is inserted into the optical path. Next, when the filter F3 is inserted into the optical path, the focus lens 26 moves in the object side direction OD. Next, when the filter F4 is inserted into the optical path, the focus lens 26 moves in the object side direction OD. Next, when the filter F1 is inserted into the optical path, the focus lens 26 moves in the imaging side direction ID. Next, when the filter F2 is inserted into the optical path, the focus lens 26 moves in the object side direction OD. Next, when the filter F3 is inserted into the optical path, the focus lens 26 moves in the object side direction OD. Next, when the filter F4 is inserted into the optical path, the focus lens 26 moves in the object side direction OD. Therefore, the number of times the movement direction of the focus lens 26 is switched in the case of arrangement candidate 4 is 2 as shown in Table 57. In the case of alignment candidate 10, first, when the filter F2 is inserted into the optical path, the focus lens 26 moves in the imaging side direction ID. Next, when the filter F3 is inserted into the optical path, the focus lens 26 moves in the imaging side direction ID. Next, when the filter F4 is inserted into the optical path, the focus lens 26 moves in the imaging side direction ID. Next, when the filter F1 is inserted into the optical path, the focus lens 26 moves in the object side direction OD. Next, when the filter F2 is inserted into the optical path, the focus lens 26 moves in the imaging side direction ID. Next, when the filter F3 is inserted into the optical path, the focus lens 26 moves in the imaging side direction ID. Next, when the filter F4 is inserted into the optical path, the focus lens 26 moves in the imaging side direction ID. Therefore, the number of times the movement direction of the focus lens 26 is switched in the case of arrangement candidate 10 is also 2 as shown in Table 57. Among the 24 arrangement candidates, the minimum number of switching is 2. Therefore, the sequence candidates with the smallest number of switching are sequence candidate 4 and sequence candidate 10.

In FIG. 5, table 60_4 shows the actual amount of movement of the focus lens 26 and the cumulative amount of movement of the focus lens 26 in the case of arrangement candidate 4. Further, Table 60_10 shows the actual amount of movement of the focus lens 26 and the cumulative amount of movement of the focus lens 26 in the case of the arrangement candidate 10. The cumulative amount of movement is the total amount of movement of the focus lens when the filter unit 31 switches from the fourth position in the first rotation to the fourth position in the third rotation. The cumulative amount of movement in the cases of alignment candidate 4 and alignment candidate 10 is both the minimum, 0.48 mm. In other words, the arrangement candidates with the smallest cumulative amount of movement are arrangement candidate 4 and arrangement candidate 10. Therefore, by arranging the blue filter, green filter, red filter, and infrared filter in the order of arrangement candidate 4 or arrangement candidate 10, the filters are arranged in the order that minimizes the number of switching times and the minimum cumulative amount of movement. be able to.

Therefore, the blue filter, green filter, red filter, and infrared filter are arranged in the order of arrangement candidate 4 or arrangement candidate 10. The order of the arrangement candidate 4 and the order of the arrangement candidate 10 are examples of a "predetermined order" according to the technology of the present disclosure. To repeat, arrangement candidate 4 is a case where the filter F1 is an infrared filter, the filter F2 is a green filter, the filter F3 is a blue filter, and the filter F4 is a red filter. Further, arrangement candidate 10 is a case where the filter F1 is a red filter, the filter F2 is a blue filter, the filter F3 is a green filter, and the filter F4 is an infrared filter.

Incidentally, as shown in Table 60_1 of FIG. 6, the cumulative amount of movement in the case of arrangement candidate 1 is 0.492 mm, which is larger than 0.48 mm. As shown in Table 60_2 in FIG. 7, the cumulative amount of movement in the case of the arrangement candidate 2 is 0.48 mm, which is the same as in the cases of the arrangement candidates 4 and 10. However, in the case of arrangement candidate 2, the number of times of switching is three, which is not the minimum, as shown in FIG. 4, so it is not adopted.

Next, the effect of the above configuration will be explained. The object light passes through the objective lens 25, focus lens 26, zoom lens 27, aperture 30, any of the filters F1 to F4 of the filter unit 31, and the master lens 28 of the imaging optical system 20 of the lens barrel 11, It reaches the light receiving surface of the image sensor 21. The image sensor 21 captures subject light under the control of the control unit 45 and outputs an image.

The filter unit 31 is rotated clockwise by the filter unit drive mechanism 38 that is driven under the control of the control section 45 . As a result, filters F1 to F4 are sequentially inserted into the optical path for each frame. The focus lens drive mechanism 35 driven under the control of the control unit 45 moves the focus lens 26 along the optical axis OA. As a result, the longitudinal chromatic aberration of the plurality of types of light transmitted through the filters F1 to F4 is corrected.

As shown in FIG. 2, the blue filter, green filter, red filter, and infrared filter are arranged in an order according to the moving direction of the focus lens 26 when correcting axial chromatic aberration. Therefore, it is possible to reduce the time required to correct longitudinal chromatic aberration by moving the focus lens 26 along the optical axis.

More specifically, as shown in FIG. 4, the blue filter, green filter, red filter, and infrared filter are arranged in the order that minimizes the number of times the focus lens 26 is switched in the moving direction. Therefore, the load applied to the focusing motor of the focus lens drive mechanism 35 when switching the moving direction can be reduced, and thereby the focus lens 26 can be smoothly moved along the optical axis OA. As a result, the time required to move the focus lens 26 can be reduced. Furthermore, as shown in FIG. 5, the blue filter, green filter, red filter, and infrared filter are arranged in the order that minimizes the cumulative amount of movement of the focus lens 26. This also reduces the time required to move the focus lens 26. Note that in the first embodiment, the plurality of filters are arranged in the order in which the number of times the movement direction of the focus lens 26 is switched is the minimum and the total amount of movement is the minimum, but the invention is not limited to this. A plurality of filters may be arranged in an order that minimizes the number of times the movement direction of the focus lens 26 is switched. Alternatively, a plurality of filters may be arranged in an order that minimizes the cumulative amount of movement of the focus lens 26.

As shown in FIG. 3, the blue filter, green filter, red filter, and infrared filter are arranged in the order based on the representative value of the amount of movement of the focus lens 26 required to correct longitudinal chromatic aberration within the movement range of the zoom lens 27. are arranged in Therefore, each filter can be arranged in an arrangement that roughly corresponds to the longitudinal chromatic aberration that changes depending on the position of the zoom lens 27.

In the first embodiment, a focus lens 26 is used as a lens for correcting axial chromatic aberration. Therefore, it is easy to correct longitudinal chromatic aberration.

As shown in FIG. 2, the filter unit 31 has a configuration in which filters F1 to F4 are arranged in an annular shape, and by rotating clockwise, the filters F1 to F4 are sequentially inserted into the optical path. Therefore, drive control of the filter unit drive mechanism 38 can be simplified.

As shown in FIG. 2, the filters F1 to F4 include a blue filter that transmits light in the blue wavelength band, a green filter that transmits light in the green wavelength band, and a red filter that transmits light in the red wavelength band. and an infrared filter that transmits light in an infrared wavelength band. Therefore, an image including a visible light image of the subject and an image including a visible light image and a radiation image of the subject can be obtained almost simultaneously.

Note that the imaging optical system 20 may include other optical elements such as a half mirror or a polarizing element. Furthermore, the filter unit 31 is not limited to being placed between the aperture 30 and the master lens 28, but may be placed, for example, between the zoom lens 27 and the aperture 30, or after the master lens 28. Furthermore, the filter unit 31 may be arranged not in the lens barrel 11 but in front of the image sensor 21 in the main body 12.

Although the camera 10 in which the lens barrel 11 and the main body 12 are removable has been illustrated, the present invention is not limited thereto. The lens barrel 11 and the main body 12 may be integral and cannot be removed.

[Second embodiment]
In the first embodiment, the filter unit 31 that rotates in one direction is illustrated, but the invention is not limited to this. As in the second embodiment shown in FIGS. 8 to 16, filter units 70 and 90 that reciprocate in two opposite directions may be used.

As an example, as shown in FIG. 8, the filter unit 70, like the filter unit 31 of the first embodiment, is a circular plate in which filters F1 to F4 are arranged at equal intervals in an annular shape. However, the filter unit 70 is provided with a cylindrical protrusion 71 between the filter F1 and the filter F4. The protrusion 71 abuts on two stoppers 72A and 72B provided on the lens barrel 11 (see also FIG. 9). Stoppers 72A and 72B are arranged at symmetrical positions with respect to the center of filter unit 70.

As an example, as shown in FIG. 9, the filter unit 70 sequentially inserts the filters F1 to F4 into the optical path by alternately repeating the first operation and the second operation. The first operation is an operation of moving from the starting position to the terminal position, and the second operation is an operation of returning from the terminal position to the starting position. In the example shown in FIG. 9, the first motion is a clockwise rotation of 90 degrees, and the second motion is a counterclockwise rotation of 270 degrees. The starting end position is a position where the protrusion 71 comes into contact with the stopper 72A, so that the center of the filter F1 and the optical axis OA coincide. The terminal position is a position where the protrusion 71 comes into contact with the stopper 72B, so that the center of the filter F4 and the optical axis OA are aligned. That is, the filter F1 is an example of "a starting filter inserted first into the optical path" according to the technology of the present disclosure. Further, the filter F4 is an example of "a terminal filter inserted last in the optical path" according to the technology of the present disclosure. The starting position is an example of the "position of the starting filter" according to the technology of the present disclosure. Further, the terminal position is an example of the "position of the terminal filter" according to the technology of the present disclosure. Note that angles such as 90° and 270° include errors that are generally allowed in the technical field to which the technology of the present disclosure belongs.

While the second operation is being performed, the image sensor 21 does not image the subject. That is, while the second operation is being performed, there is a blank period in which no image is output. Note that the following description will be made assuming that the amount of movement of the focus lens 26 required to correct the longitudinal chromatic aberration is the same as the value exemplified in the table 50 of FIG. 3.

Table 75 in FIG. 10 shows sequence candidate 7 in addition to sequence candidate 1, sequence candidate 2, sequence candidate 4, and sequence candidate 10 shown in table 55 of FIG. Arrangement candidate 7 is a case where the filter F1 is a red filter, the filter F2 is an infrared filter, the filter F3 is a green filter, and the filter F4 is a blue filter.

Table 76 shows the moving direction of the focus lens 26 when the first operation and the second operation are repeated twice, and shows the moving direction of the focus lens 26 when correcting the axial chromatic aberration in each alignment candidate. In the case of arrangement candidate 1, first, the focus lens 26 moves in the object side direction OD when the filter F2 is inserted into the optical path. Next, when the filter F3 is inserted into the optical path, the focus lens 26 moves in the imaging side direction ID. Next, when the filter F4 is inserted into the optical path, the focus lens 26 moves in the object side direction OD. Next, when the filter unit 70 performs a second operation and the filter F1 is inserted into the optical path, the focus lens 26 moves in the imaging side direction ID. Next, when the filter F2 is inserted into the optical path, the focus lens 26 moves in the object side direction OD. Next, when the filter F3 is inserted into the optical path, the focus lens 26 moves in the imaging side direction ID. Next, when the filter F4 is inserted into the optical path, the focus lens 26 moves in the object side direction OD. Next, when the filter unit 70 performs the second operation, the focus lens 26 moves in the imaging side direction ID. In this way, in the case of alignment candidate 1, the moving direction of the focus lens 26 is switched every time the filter inserted into the optical path changes. Therefore, the number of times the movement direction of the focus lens 26 is switched in the case of arrangement candidate 1 is 7 as shown in Table 77.

In the case of arrangement candidate 2, first, the focus lens 26 moves in the object side direction OD when the filter F2 is inserted into the optical path. Next, when the filter F3 is inserted into the optical path, the focus lens 26 moves in the imaging side direction ID. Next, when the filter F4 is inserted into the optical path, the focus lens 26 moves in the imaging side direction ID. Next, when the filter unit 70 performs a second operation and the filter F1 is inserted into the optical path, the focus lens 26 moves in the imaging side direction ID. Next, when the filter F2 is inserted into the optical path, the focus lens 26 moves in the object side direction OD. Next, when the filter F3 is inserted into the optical path, the focus lens 26 moves in the imaging side direction ID. Next, when the filter F4 is inserted into the optical path, the focus lens 26 moves in the imaging side direction ID. Next, when the filter unit 70 performs the second operation, the focus lens 26 moves in the imaging side direction ID. Therefore, the number of times the movement direction of the focus lens 26 is switched in the case of arrangement candidate 2 is 3 as shown in Table 77. In the case of arrangement candidate 4, first, the focus lens 26 moves in the object side direction OD when the filter F2 is inserted into the optical path. Next, when the filter F3 is inserted into the optical path, the focus lens 26 moves in the object side direction OD. Next, when the filter F4 is inserted into the optical path, the focus lens 26 moves in the object side direction OD. Next, when the filter unit 70 performs a second operation and the filter F1 is inserted into the optical path, the focus lens 26 moves in the imaging side direction ID. Next, when the filter F2 is inserted into the optical path, the focus lens 26 moves in the object side direction OD. Next, when the filter F3 is inserted into the optical path, the focus lens 26 moves in the object side direction OD. Next, when the filter F4 is inserted into the optical path, the focus lens 26 moves in the object side direction OD. Next, when the filter unit 70 performs the second operation, the focus lens 26 moves in the imaging side direction ID. Therefore, the number of times the movement direction of the focus lens 26 is switched in the case of arrangement candidate 4 is also 3 as shown in Table 77. In the case of arrangement candidate 7, first, when the filter F2 is inserted into the optical path, the focus lens 26 moves in the imaging side direction ID. Next, when the filter F3 is inserted into the optical path, the focus lens 26 moves in the object side direction OD. Next, when the filter F4 is inserted into the optical path, the focus lens 26 moves in the object side direction OD. Next, when the filter unit 70 performs a second operation and the filter F1 is inserted into the optical path, the focus lens 26 moves in the object side direction OD. Next, when the filter F2 is inserted into the optical path, the focus lens 26 moves in the imaging side direction ID. Next, when the filter F3 is inserted into the optical path, the focus lens 26 moves in the object side direction OD. Next, when the filter F4 is inserted into the optical path, the focus lens 26 moves in the object side direction OD. Next, when the filter unit 70 performs the second operation, the focus lens 26 moves in the object side direction OD. Therefore, the number of times the movement direction of the focus lens 26 is switched in the case of arrangement candidate 7 is also 3 as shown in Table 77. In the case of alignment candidate 10, first, when the filter F2 is inserted into the optical path, the focus lens 26 moves in the imaging side direction ID. Next, when the filter F3 is inserted into the optical path, the focus lens 26 moves in the imaging side direction ID. Next, when the filter F4 is inserted into the optical path, the focus lens 26 moves in the imaging side direction ID. Next, when the filter unit 70 performs a second operation and the filter F1 is inserted into the optical path, the focus lens 26 moves in the object side direction OD. Next, when the filter F2 is inserted into the optical path, the focus lens 26 moves in the imaging side direction ID. Next, when the filter F3 is inserted into the optical path, the focus lens 26 moves in the imaging side direction ID. Next, when the filter F4 is inserted into the optical path, the focus lens 26 moves in the imaging side direction ID. Next, when the filter unit 70 performs the second operation, the focus lens 26 moves in the object side direction OD. Therefore, the number of times the movement direction of the focus lens 26 is switched in the case of arrangement candidate 10 is also 3 as shown in Table 77. Among the 24 arrangement candidates, the minimum number of switching is 3. Therefore, the sequence candidates with the minimum number of switching are sequence candidate 2, sequence candidate 4, sequence candidate 7, sequence candidate 10, and the like.

Table 80_2 in FIG. 11 shows the actual amount of movement of the focus lens 26 and the cumulative amount of movement of the focus lens 26 in the case of arrangement candidate 2. Table 80_4 in FIG. 12 shows the actual amount of movement of the focus lens 26 and the cumulative amount of movement of the focus lens 26 in the case of arrangement candidate 4. Table 80_7 in FIG. 13 shows the actual amount of movement of the focus lens 26 and the cumulative amount of movement of the focus lens 26 in the case of arrangement candidate 7. Table 80_10 in FIG. 14 shows the actual amount of movement of the focus lens 26 and the cumulative amount of movement of the focus lens 26 in the case of the arrangement candidate 10. The cumulative amount of movement is the total amount of movement of the focus lens when the filter unit 31 moves from the start position of the first operation at the first time to the start end position of the second operation at the second time. The cumulative amount of movement in the case of alignment candidate 2, alignment candidate 4, alignment candidate 7, and alignment candidate 10 is all 0.48 mm, which is the minimum.

Table 85 shown in FIG. 15 shows the amount of movement of the focus lens 26 in cases such as row candidate 2, row candidate 4, row candidate 7, and row candidate 10, and shows the amount of movement of the focus lens 26 while the second operation is being performed. The amount of movement of 26 is shown. In the case of alignment candidate 2, the amount of movement of the focus lens 26 while the second operation is being performed is 0.115 mm. In the case of alignment candidate 4, the amount of movement of the focus lens 26 while the second operation is being performed is 0.12 mm. In the case of alignment candidate 7, the amount of movement of the focus lens 26 while the second operation is being performed is -0.002 mm. In the case of alignment candidate 10, the amount of movement of the focus lens 26 while the second operation is being performed is -0.12 mm. In other words, the arrangement candidates for which the amount of movement of the focus lens 26 during the second operation is relatively large are arrangement candidate 4 and arrangement candidate 10. Therefore, by arranging the blue filter, green filter, red filter, and infrared filter in the order of arrangement candidate 4 or arrangement candidate 10, the number of switching times is minimized, the total amount of movement is minimized, and the second operation is The filters can be arranged in the order in which the amount of movement of the focus lens 26 during the process is relatively large.

Therefore, in the second embodiment as well, the blue filter, green filter, red filter, and infrared filter are arranged in the order of arrangement candidate 4 or arrangement candidate 10, as in the first embodiment. Also in the second embodiment, the order of the line candidates 4 and the order of the line candidates 10 are examples of a "predetermined order" according to the technology of the present disclosure.

The filter unit 90 shown in FIG. 16 may be used instead of the filter unit 70. The filter unit 90 is a rectangular flat plate in which filters F1 to F4 are arranged along the long side direction. The filter unit 90 is reciprocated in the long side direction by the filter unit drive mechanism 38 to sequentially insert the filters F1 to F4 into the optical path. Specifically, the filter unit 90 moves along the direction of the left arrow parallel to the long side direction from the illustrated starting position where the center of the filter F1 and the optical axis OA coincide with each other, to the center of the filter F4. The first operation of moving to the end position arranged so that the optical axis OA coincides with the optical axis OA, and the second action of returning from the end position to the start end position along the direction of the right arrow parallel to the long side direction are alternately performed. repeat. The lens barrel 11 includes a stopper (not shown) that restricts the filter unit 90 from moving beyond the starting end position in the direction of the right arrow, and a stopper (not shown) that restricts the filter unit 90 from moving beyond the end position in the direction of the left arrow. A stopper (not shown) is provided. Parallel here refers to not only perfect parallelism but also parallelism that includes errors generally allowed in the technical field to which the technology of the present disclosure belongs.

In this way, in the second embodiment, the filter units 70 and 90 have a configuration in which the filters F1 to F4 are arranged in one direction, and the first operation of moving from the starting end position to the ending position and the ending position The filters F1 to F4 are sequentially inserted into the optical path by alternately repeating the first operation and the second operation of returning to the starting position. The blue filter, green filter, red filter, and infrared filter are arranged in order of increasing relative movement amount of the focus lens 26 during the second operation. Therefore, the period during which the second operation is performed, which is a blank period in which no image is output, can be effectively utilized for moving the focus lens 26, which requires a relatively long amount of time and requires a relatively large amount of movement. In the second embodiment, the number of times the movement direction of the focus lens 26 is switched is the minimum, the total amount of movement is the minimum, and furthermore, the movement amount of the focus lens 26 while the second operation is performed is relatively small. Although a plurality of filters are arranged in order of increasing size, the present invention is not limited to this. A plurality of filters may be arranged in an order that minimizes the number of times the movement direction of the focus lens 26 is switched. Alternatively, a plurality of filters may be arranged in an order that minimizes the cumulative amount of movement of the focus lens 26. Alternatively, a plurality of filters may be arranged in order of increasing relative movement amount of the focus lens 26 while the second operation is being performed.

[Third embodiment]
In the third embodiment shown in FIGS. 17 and 18, a master lens 28 is used in addition to the focus lens 26 to correct longitudinal chromatic aberration.

In FIG. 17, a camera 100 according to the third embodiment includes a lens barrel 101 and a main body 12. The lens barrel 101 has almost the same configuration as the lens barrel 11 of the first embodiment, except that a master lens drive mechanism 102 is connected to the master lens 28. Other parts that are the same as those in the first embodiment are designated by the same reference numerals, and descriptions thereof will be omitted.

Like the focus lens drive mechanism 35 and the zoom lens drive mechanism 36, the master lens drive mechanism 102 holds the master lens 28, and includes a master cam ring having a cam groove formed on its outer periphery, and a master cam ring that is connected to the optical axis. It includes a master motor that moves the master cam ring along the optical axis OA by rotating it around the OA. The master motor is driven under the control of the control unit 105. The master motor is a stepping motor, and the control unit 105 derives the position of the master lens 28 on the optical axis OA from the amount of drive of the master motor.

The control unit 105 corrects the longitudinal chromatic aberration of the plurality of types of light transmitted through the filters F1 to F4 by moving the focus lens 26 along the optical axis OA via the focus lens drive mechanism 35. Further, the control unit 105 corrects the longitudinal chromatic aberration of the plurality of types of light transmitted through the filters F1 to F4 by moving the master lens 28 along the optical axis OA via the master lens drive mechanism 102. That is, in the third embodiment, the master lens 28 in addition to the focus lens 26 is an example of a "correction lens" according to the technology of the present disclosure.

As shown in the flowchart of FIG. 18 as an example, the control unit 105 first detects the position of the zoom lens 27 (step ST100). If the detected position of the zoom lens 27 is closer to the telephoto side than the preset threshold, that is, if the zoom lens 27 is located closer to the telephoto side than the preset threshold (YES in step ST110). , the control unit 105 corrects the axial chromatic aberration by moving the focus lens 26 along the optical axis OA via the focus lens drive mechanism 35 (step ST120). On the other hand, if the detected position of the zoom lens 27 is on the wide-angle side of the threshold value, that is, if the zoom lens 27 is located on the wide-angle side of the threshold value (NO in step ST110), the control unit 105 Axial chromatic aberration is corrected by moving the master lens 28 along the optical axis OA via the master lens drive mechanism 102 (step ST130).

As described above, in the third embodiment, when the zoom lens 27 is located on the telephoto side than the preset threshold, the focus lens 26 moves to correct the axial chromatic aberration, and the zoom lens 27 is located on the wide-angle side, the master lens 28 moves to correct longitudinal chromatic aberration. When the zoom lens 27 is located on the telephoto side, the amount of movement required to correct longitudinal chromatic aberration is smaller for the focus lens 26 than for the master lens 28. Therefore, when the zoom lens 27 is located on the telephoto side with respect to a preset threshold value, the time required to correct the longitudinal chromatic aberration can be shortened by moving the focus lens 26. On the other hand, when the zoom lens 27 is located on the wide-angle side, the amount of movement required to correct the longitudinal chromatic aberration is smaller for the master lens 28 than for the focus lens 26. Therefore, when the zoom lens 27 is located at a wider angle side than a preset threshold value, the master lens 28 moves, thereby further reducing the time required to correct the longitudinal chromatic aberration. Note that axial chromatic aberration may be corrected by moving the focus lens 26 and the master lens 28 in parallel.

Note that if there are a plurality of arrangement candidates with the minimum number of times of switching of the movement direction of the correction lens, and if the cumulative amount of movement of the correction lens differs among the plurality of arrangement candidates, the arrangement candidate with the minimum cumulative amount of movement is selected.

The value of the amount of movement of the focus lens 26 required to correct longitudinal chromatic aberration shown in FIG. 3 is just an example. For this reason, the movement direction of the focus lens 26 shown in FIG. 4 etc., the total amount of movement of the focus lens 26 shown in FIG. 5 etc., and the focus lens 26 during the second operation shown in FIG. The amount of movement is also just an example. Therefore, arrangement candidate 4 and arrangement candidate 10 adopted as the arrangement of blue filters, green filters, red filters, and infrared filters are just examples, and depending on the value of the amount of movement of the focus lens 26 required to correct longitudinal chromatic aberration, change.

In each of the above embodiments, the cameras 10 and 100, which are surveillance cameras installed in a factory or the like, are shown as an example of an "imaging device" according to the technology of the present disclosure, but the invention is not limited thereto. Instead of cameras 10 and 100, digital cameras used by general users, smart devices, etc. may be used.

The number of filters is not limited to four. Further, instead of or in addition to the blue filter, green filter, red filter, and infrared filter, filters that transmit light in other wavelength bands may be included.

The computers configuring the control units 45 and 105 are, instead of or in addition to a CPU, a programmable logic device (PLD), which is a processor whose circuit configuration can be changed after manufacturing, such as an FPGA (Field-Programmable Gate Array). ), and/or an ASIC (Application Specific Integrated Circuit), which is a processor having a circuit configuration exclusively designed to execute a specific process.

The technology of the present disclosure can also be combined as appropriate with the various embodiments and/or various modifications described above. Moreover, it goes without saying that the present invention is not limited to the above-mentioned embodiments, and that various configurations can be adopted as long as they do not depart from the gist of the invention.

The descriptions and illustrations described above are detailed explanations of portions related to the technology of the present disclosure, and are merely examples of the technology of the present disclosure. For example, the above description regarding the configuration, function, operation, and effect is an example of the configuration, function, operation, and effect of the part related to the technology of the present disclosure. Therefore, unnecessary parts may be deleted, new elements may be added, or replacements may be made to the written and illustrated contents shown above without departing from the gist of the technology of the present disclosure. Needless to say. In addition, in order to avoid confusion and facilitate understanding of the parts related to the technology of the present disclosure, the descriptions and illustrations shown above do not include parts that require particular explanation in order to enable implementation of the technology of the present disclosure. Explanations regarding common technical knowledge, etc. that do not apply are omitted.

In this specification, "A and/or B" is synonymous with "at least one of A and B." That is, "A and/or B" means that it may be only A, only B, or a combination of A and B. Furthermore, in this specification, even when three or more items are expressed in conjunction with "and/or", the same concept as "A and/or B" is applied.

All documents, patent applications and technical standards mentioned herein are incorporated herein by reference to the same extent as if each individual document, patent application and technical standard was specifically and individually indicated to be incorporated by reference. Incorporated by reference into this book.

10, 100 Cameras 11, 101 Lens barrel 12 Main body 13 Lens barrel side mount 14 Main body side mount 20 Imaging optical system 21 Image sensor 25 Objective lens 26 Focus lens 27 Zoom lens 28 Master lens 30 Aperture 31, 70, 90 Filter unit 35 Focus Lens drive mechanism 36 Zoom lens drive mechanism 37 Aperture drive mechanism 38 Filter unit drive mechanism 40 Lens barrel side contacts 41 Body side contacts 45, 105 Control section 50, 55-57, 60, 75-77, 80, 85 Table 71 Protrusion 72A , 72B Stopper 102 Master lens drive mechanism F1 to F4 Filter ID Imaging side direction OA Optical axis OD Object side direction ST100, ST110, ST120, ST130 Step

Claims (12)

A filter unit having three or more filters that selectively transmit light in mutually different wavelength bands, and in which the three or more filters are inserted into an optical path in a predetermined order;
a correction lens that corrects longitudinal chromatic aberration of three or more types of light transmitted through the three or more filters by moving along the optical axis;
zoom lens and
Equipped with
The correction lens is a focus lens and a master lens disposed closer to the imaging side than the focus lens,
The predetermined order is an order according to a moving direction of the correction lens,
Correcting the longitudinal chromatic aberration by moving either the focus lens or the master lens depending on the position of the zoom lens;
optical equipment. 2. The optical device according to claim 1, wherein the predetermined order is an order in which the number of times the movement direction is switched is minimized. 3. The optical device according to claim 2, wherein the predetermined order is an order in which a total amount of movement of the correction lens is minimized. 4. The predetermined order is an order based on a representative value of the amount of movement of the correction lens required for correction of the longitudinal chromatic aberration in the movement range of the zoom lens. Optical device as described. If the zoom lens is located on a telephoto side than a preset threshold, the focus lens moves to correct the axial chromatic aberration,
The optical device according to any one of claims 1 to 4, wherein the master lens moves to correct the longitudinal chromatic aberration when the zoom lens is located on the wide-angle side of the threshold. The filter unit has a configuration in which the three or more filters are arranged in an annular shape, and the three or more filters are sequentially inserted into the optical path by rotating the filter unit in one direction. The optical device according to claim 5 . The three or more filters include a starting filter inserted first into the optical path and a terminal filter inserted last into the optical path,
The filter unit has a configuration in which the three or more filters are arranged in one direction, and includes a first operation of moving from the position of the starting filter to the position of the terminal filter, and a first operation of moving from the position of the terminal filter to the position of the terminal filter. The optical device according to any one of claims 1 to 5 , wherein the three or more filters are sequentially inserted into the optical path by alternately repeating the second operation of returning to the position of the starting filter. 8. The optical device according to claim 7 , wherein the predetermined order is an order in which the amount of movement of the correction lens increases relatively while the second operation is performed. The filter unit has a configuration in which the three or more filters are arranged in an annular shape, and the three or more filters are sequentially inserted into the optical path by rotating the filter unit . The optical device described in . The filter unit is a rectangular flat plate in which the three or more filters are arranged along the long side direction, and the three or more filters are sequentially moved by the filter unit reciprocating in the long side direction. The optical device according to claim 7 or 8 , which is inserted into an optical path. The three or more filters are
A blue filter that transmits light in the blue wavelength band,
a green filter that transmits light in the green wavelength band;
A red filter that transmits light in the red wavelength band,
The optical device according to any one of claims 1 to 10 , further comprising an infrared filter that transmits light in an infrared wavelength band. An imaging device comprising the optical device according to any one of claims 1 to 11 .