Imaging apparatus, imaging method and program

Abstract

To adjust a position of a relay lens group depending on temperature change, to suppress movement of an imaged image, and to reduce a sense of discomfort given by movement of the image.SOLUTION: An imaging apparatus comprises: a first lens tube that supports a focus lens group and a zoom lens group; a second lens tube that supports a relay lens group; imaging means that has an imaging surface on which light passing through a lens group forms an image; an enclosure in which the first lens tube, a second lens tube and an imaging surface are arranged inside; moving means that moves the second lens tube along a direction of an optical axis relative to the first lens tube in a state where the relay lens group is decentered for optical axes of the focus lens group and the zoom lens group; first determination means that determines a lens tube movement amount to move the second lens tube along a direction of the optical axis depending on change of temperature within the enclosure; second determination means that determines at least one of image movement amount on an imaging surface corresponding to the lens tube movement amount and correction amount for cancelling the image movement amount; and revolving means that revolves the enclosure by the correction amount.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to an imaging apparatus, an imaging method, and a program. [Background technology]

[0002] As imaging devices today become more highly precise, the amount of heat generated by the imaging device increases, and the temperature inside the housing of the imaging device tends to rise. Furthermore, when the external environment is hot or the imaging device is exposed to sunlight or other heat sources, the temperature inside the housing of the imaging device also rises. When components such as the lens barrel expand or contract with the change in temperature, the distance between the lenses changes, causing the image to become out of focus. Patent Document 1 discloses a technique for suppressing focus deviation by controlling the position of a focus lens in response to changes in temperature, but only discloses control of the position of the focus lens. Some imaging devices have a relay lens group, which may be intentionally decentered with respect to the other lens groups in order to adjust the aberration of the other lens groups (Patent Document 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2017-215574 A [Patent Document 2] Patent Publication No. 2021-196501 Summary of the Invention [Problem to be solved by the invention]

[0004] In an imaging device in which a relay lens group is decentered relative to the other lens groups, it is preferable not only to adjust the position of the relay lens group in response to temperature changes within the housing to suppress focus shifts, but also to suppress movement of the captured image that accompanies adjustment of the position of the relay lens group.

[0005] Therefore, an object of the present invention is to provide a technology that adjusts the position of a relay lens group in response to temperature changes inside the housing, suppresses movement of the captured image, and reduces the sense of discomfort caused by image movement. [Means for solving the problem]

[0006] An imaging device according to one aspect of the present invention includes a focus lens group, a zoom lens group, a relay lens group, a first barrel supporting the focus lens group and the zoom lens group, a second barrel supporting the relay lens group in a state in which the relay lens group is decentered with respect to an optical axis of the focus lens group and the zoom lens group, imaging means having an imaging surface on which light that has passed through the focus lens group, the zoom lens group, and the relay lens group is imaged, and imaging using the light imaged on the imaging surface, a housing in which the first barrel, the second barrel, and the imaging surface are disposed, and a housing for imaging the focus lens group and the zoom lens group. the second lens barrel relative to the first lens barrel in the direction of the optical axis with the relay lens group decentered with respect to the optical axis of the relay lens group; a measuring means for measuring a temperature inside the housing; a first determination means for determining a lens barrel movement amount by which the moving means should move the second lens barrel in the direction of the optical axis in response to a change in temperature measured by the measuring means; a second determination means for determining at least one of an image movement amount on the imaging plane corresponding to the lens barrel movement amount and a correction amount for offsetting the image movement amount; and a rotating means for rotating the housing by the correction amount so as to offset the image movement amount. Effect of the Invention

[0007] In one aspect of the present invention, the position of the relay lens group is adjusted in response to temperature changes within the housing, and image movement that accompanies the adjustment of the position of the relay lens group is suppressed, thereby reducing the discomfort felt by the movement of the captured image. [Brief description of the drawings]

[0008] [Figure 1] 1 is a perspective view showing an imaging device according to an embodiment of the present invention. [Diagram 2] 1 is a schematic diagram showing an imaging device according to an embodiment. [Diagram 3] FIG. 3 is a plan view showing a part of the imaging device in FIG. 2. [Figure 4] FIG. 13 is a schematic diagram showing an imaging device according to a modified example of the embodiment. [Diagram 5] 4A and 4B are diagrams illustrating image movement solved by the imaging apparatus according to the embodiment. [Figure 6] 5 is a diagram showing a deviation amount table used in the imaging apparatus according to the embodiment. [Figure 7] 5 is a diagram showing an image movement amount table used in the imaging apparatus of the embodiment. [Figure 8] 4 is a flowchart showing the operation of the imaging apparatus according to the embodiment. [Figure 9] 11A and 11B are diagrams showing modified examples of tables that can be used in the imaging device according to the embodiment. [Figure 10] 10 is a flowchart showing the operation of an imaging apparatus according to a modified example of the embodiment. [Figure 11] 13A and 13B are diagrams showing other modified examples of the table that can be used in the imaging device according to the embodiment. [Figure 12] 12 is a flowchart showing the operation of an imaging apparatus using the table illustrated in FIG. [Figure 13] 13A and 13B are diagrams showing other modified examples of the table that can be used in the imaging device according to the embodiment. [Figure 14] 14 is a flowchart showing the operation of an imaging apparatus using the table illustrated in FIG. 13. [Figure 15] FIG. 13 is a schematic diagram showing an imaging device according to another modified example of the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, the embodiment for carrying out the present invention will be described in detail with reference to the attached drawings. The embodiment described below is one example of a means for realizing the present invention, and should be appropriately modified or changed depending on the configuration of the device to which the present invention is applied and various conditions, and the present invention is not limited to the following embodiment.

[0010] <Configuration of imaging device> 1, an imaging device 1 according to an embodiment of the present invention has a housing 2 having a lens group and a camera device, and a pan head device 3 that supports the housing 2. The pan head device 3 has a tilt support section 3A that supports the housing 2 so that it can rotate in a tilt direction T, and a pan support section 3B that supports the tilt support section 3A together with the housing 2 so that it can rotate in a pan direction P. Although the illustrated housing 2 is substantially a rectangular parallelepiped, the shape of the housing 2 is not limited to a substantially rectangular parallelepiped shape. A tilt drive mechanism (not shown) for tilt rotating the housing 2 is provided inside the tilt support portion 3A, and a pan drive mechanism (not shown) for pan rotating the tilt support portion 3A is provided inside the pan support portion 3B. The imaging device 1 according to the embodiment is used for capturing moving images for movies, television, etc. However, the imaging device 1 may also be used for capturing private moving images.

[0011] 2, a lens device 4, an image sensor holder 8, a control device 10, a storage device 12, a thermometer 14, and a movement mechanism 16 are arranged inside the housing 2. The housing 2 has a substantially sealed structure to protect these internal elements from water and dust. The lens device 4 has a first lens barrel 5, a focus lens group, a zoom lens group, a second lens barrel 6, and a relay lens group.

[0012] The first barrel 5 supports a focus lens group (focus lenses 18a, 18b, and 18c in the illustrated example) and a zoom lens group (zoom lenses 20a and 20b in the illustrated example). The focus lens group is disposed closer to the subject than the zoom lens group. The focus lens group and the zoom lens group are disposed concentrically so as to share a common optical axis Ax. The zoom lens group is movable along the direction of the optical axis Ax by a mechanism not shown. The number and shapes of the focus lenses constituting the focus lens group are not limited to those shown in the illustrated example, and the number and shapes of the zoom lenses constituting the zoom lens group are also not limited to those shown in the illustrated example.

[0013] The second lens barrel 6 is supported at the rear end of the first lens barrel 5, and supports a relay lens group (relay lenses 22a, 22b, and 22c in the illustrated example). The relay lens group has an optical axis 6x that is decentered with respect to the optical axis Ax of the focus lens group and the zoom lens group. The common optical axis 6x of the relay lens group is parallel to the optical axis Ax of the focus lens group and the zoom lens group. In this way, in order to adjust the aberrations of the focus lens group and the zoom lens group, the relay lens group is intentionally decentered with respect to the focus lens group and the zoom lens group. In this embodiment, the outer peripheral surface of the second lens barrel 6 is concentric with the optical axis Ax, but the inner peripheral surface of the second lens barrel 6 is decentered with respect to the optical axis Ax, and the relay lens group arranged inside the second lens barrel 6 is decentered with respect to the optical axis Ax of the focus lens group and the zoom lens group. The number and shape of the relay lenses constituting the relay lens group are not limited to those shown in the figures.

[0014] The imaging element holder 8 is fixed to the rear end of the first barrel 5, and an imaging element 8A is disposed inside the imaging element holder 8. The imaging element 8A is, for example, a CMOS (Complementary Metal Oxide Semiconductor) image sensor or a CCD (Charge-Coupled Device) image sensor. The image sensor 8A has an image sensor surface 8B on which light passing through the focus lens group, the zoom lens group, and the relay lens group forms an image, and captures an image using the light formed on the image sensor surface 8B. That is, the image sensor 8A converts the subject image formed by the focus lens group, the zoom lens group, and the relay lens group into an image signal.

[0015] The control device 10 is electrically connected to the imaging element 8A and processes an image signal obtained by the imaging element 8A. The control device 10 is also electrically connected to a mechanism (not shown) for moving the zoom lens group and a mechanism for moving the relay lens group, and controls these mechanisms. The control device 10 is further connected to a tilt control mechanism 24 and a pan control mechanism 26 outside the housing 2 and controls these mechanisms. The tilt control mechanism 24 has the tilt drive mechanism and a control circuit that controls the tilt drive mechanism. The pan control mechanism 26 has the pan drive mechanism and a control circuit that controls the pan drive mechanism. The control device 10 is implemented by a processor such as a CPU (Central Processing Unit). Specifically, the processor executes a program read from the storage device 12 or another memory device (not shown) to process the image signal and control the zoom lens group, relay lens group, tilt control mechanism 24, and pan control mechanism 26.

[0016] The storage device 12 is a non-volatile memory device, and may be any of a ROM, a flash memory, or a magnetic storage device. The storage device 12 stores a misalignment amount table and an image movement amount table, which will be described later. The thermometer 14 measures the temperature inside the housing 2. The thermometer 14 may be a thermocouple, a thermistor, or the like. The thermometer 14 is electrically connected to the control device 10 so that the measurement result is supplied to the control device 10.

[0017] The movement mechanism 16 moves the second lens barrel 6 along the optical axis Ax relative to the first lens barrel 5 while maintaining the relay lens group decentered with respect to the optical axis Ax of the focus lens group and the zoom lens group. In this embodiment, the movement mechanism 16 moves the second lens barrel 6 along the optical axis Ax relative to the first lens barrel 5 while rotating the second lens barrel 6 about the optical axis Ax relative to the first lens barrel 5. Specifically, the moving mechanism 16 has a feed screw mechanism 16A, a ring 16B, a pin 16C, a gear 16D, a gear 16E, and a rotary motor 16F. The feed screw mechanism 16A is provided on the outer peripheral surface of the second barrel 6 and the inner peripheral surface of the first barrel 5. The feed screw mechanism 16A may be a trapezoidal screw, a ball screw, or one of various roller screws. The roller screw may be, for example, a planetary roller screw, a recirculating roller screw, or other roller screws. The feed screw mechanism 16A is coaxial with the optical axis Ax. Ring 16B is rotatably disposed around first barrel 5. Ring 16B is also coaxial with optical axis Ax. The pin 16C connects the ring 16B to the second barrel 6 and transmits the rotation of the ring 16B to the second barrel 6. An end of the barrel of the pin 16C is fixed to the second barrel 6. Gear 16D is fixed integrally to ring 16B. The gear 16E is fixed to the rotary shaft of the rotary motor 16F and is meshed with the gear 16D. The rotary motor 16F is electrically connected to the control device 10 and is driven by the control device 10.

[0018] With this configuration, when rotary motor 16F rotates, gears 16E and 16D and ring 16B rotate, and further second barrel 6 rotates around optical axis Ax. When second barrel 6 rotates relative to fixed first barrel 5, feed screw mechanism 16A moves second barrel 6 together with the relay lens group along the optical axis Ax. 2 and 3, a long hole 16Bh is formed in the ring 16B so that the second barrel 6 can move along the optical axis Ax relative to the ring 16B, and the body of the pin 16C is inserted into the long hole 16Bh. The length of the long hole 16Bh along the optical axis Ax is greater than the stroke of the second barrel 6 along the optical axis Ax. A circumferential groove 5g is formed in the first barrel 5, and the body of the pin 16C is inserted into the circumferential groove 5g so that the second barrel 6 is movable along the optical axis Ax relative to the first barrel 5 and rotatable around the optical axis Ax. The width of the circumferential groove 5g (the length along the optical axis Ax) is greater than the stroke of the second barrel 6 along the optical axis Ax.

[0019] The moving mechanism 16 may rotate the ring 16B using a belt and pulley mechanism instead of the gears 16D and 16E. In a modification of the embodiment shown in Fig. 4, the moving mechanism 16 has pulleys 16G and 16H instead of the gears 16D and 16E. The pulley 16G is fixed integrally to the ring 16B, and the pulley 16H is fixed to a rotating shaft of the rotary motor 16F. A belt 16I is stretched between the pulleys 16G and 16H. Therefore, when the rotary motor 16F rotates, the pulley 16H rotates, and the pulley 16G and the ring 16B are rotated by the belt 16I. The pulleys 16G and 16H may be toothed pulleys, and the belt 16I may be a toothed belt. As another modification, not shown, the moving mechanism 16 may rotate the ring 16B using a friction wheel or a chain and sprocket mechanism.

[0020] <Moving the image> When elements inside the housing 2 of the imaging device 1 generate heat, the temperature inside the housing 2 rises. Furthermore, when the external environment is hot or when the imaging device 1 is exposed to sunlight or other heat sources, the temperature inside the housing 2 of the imaging device 1 also rises. When members such as the lens barrels 5 and 6 expand and contract with changes in temperature, the distance between the lenses changes, causing the image to become out of focus. Therefore, the control device 10 corrects the focus deviation by moving the focus lens group along the optical axis Ax in response to a change in temperature measured by the thermometer 14, and also moving the relay lens group along the optical axis Ax. In the following explanation, the explanation of the movement of the focus lens group will be omitted, and the movement of the relay lens group will be explained in detail. The control device 10 determines the amount of barrel movement that the moving mechanism 16 should move the second barrel 6 along the direction of the optical axis Ax in response to the change in temperature measured by the thermometer 14, and drives the rotation motor 16F of the moving mechanism 16 an angle equivalent to the amount of barrel movement.

[0021] As described above, in order to adjust the aberrations of the focus lens group and the zoom lens group, the relay lens group is intentionally decentered with respect to the focus lens group and the zoom lens group, i.e., the relay lens group has an optical axis 6x that is decentered with respect to the optical axis Ax of the focus lens group and the zoom lens group. Therefore, when the second lens barrel 6 and the relay lens group are moved along the optical axis Ax to correct the focus deviation in response to the temperature change, the captured subject image 30 moves on the imaging surface 8B of the imaging element 8A, as shown in Fig. 5. This gives a strange feeling to the viewer of the captured moving image. In Fig. 5, the subject image 30 before the movement is shown by a virtual line, and the subject image 30 after the movement is shown by a solid line. In particular, in this embodiment, the moving mechanism 16 rotates the second lens barrel 6 relative to the first lens barrel 5 about the optical axis Ax, so that the relay lens group rotates about the optical axis Ax, causing the subject image 30 to move a large amount, which can cause a noticeable sense of discomfort to the viewer of the moving image.

[0022] Therefore, the control device 10 drives at least one of the tilt control mechanism 24 and the pan control mechanism 26 to rotate the housing 2 so as to cancel out the amount of image movement on the imaging surface 8B that occurs in response to the movement of the second lens barrel 6.

[0023] <Tables used by the imaging device> Fig. 6 shows a misalignment amount table used in the imaging device 1 of this embodiment. The misalignment amount table is stored in the storage device 12 (see Figs. 2 and 4). The misalignment table describes a number of temperatures and the amount of misalignment of the focus corresponding to these temperatures. The misalignment table depends on the model of the lens device 4 (specifically, the combination of lens groups), and the relationship between the temperature and the amount of misalignment of the focus is determined according to the model of the lens device 4. The control device 10 refers to the misalignment table to obtain the amount of misalignment of the focus corresponding to the temperature measured by the thermometer 14. The control device 10 then calculates the amount of movement of the lens barrel 6 that offsets the amount of misalignment of the focus (the amount by which the second lens barrel 6 should be moved relative to the first lens barrel 5 along the direction of the optical axis Ax).

[0024] 7 shows an image movement amount table used in the imaging device 1 of this embodiment. The image movement amount table is stored in the storage device 12. The image movement amount table describes a plurality of lens barrel movement amounts and the image movement amounts corresponding to these lens barrel movement amounts. In Fig. 7, the lens barrel movement amount is expressed as the drive angle of the rotation motor 16F. The image movement amount includes the image movement amount in the horizontal direction (X direction) and the image movement amount in the vertical direction (Y direction). The image movement amount table depends on the model of the lens device 4 (specifically, the combination of lens groups), and the relationship between the lens barrel movement amount and the image movement amount is determined according to the model of the lens device 4. The control device 10 refers to the image movement amount table to obtain the image movement amount corresponding to the lens barrel movement amount, and then calculates the correction amount for offsetting the image movement amount.

[0025] <Operation of the imaging device> The operation executed by the control device 10 of the imaging device 1 will be described with reference to the flowchart of FIG. First, in S1, the control device 10 determines whether or not a temperature change has occurred inside the housing 2. In S1, "a temperature change has occurred" means that there has been a change exceeding a certain threshold value (for example, 1°C) from the temperature measured immediately before. If it is determined that a temperature change has occurred inside the housing 2, the operation proceeds to S2, where the control device 10 refers to the misalignment amount table illustrated in FIG. 6 and obtains the focus misalignment amount corresponding to the current temperature from the misalignment amount table.

[0026] Next, in S3, the control device 10 calculates the necessary movement amount of the second lens barrel 6 that offsets the amount of focus deviation acquired in S2, i.e., the lens barrel movement amount. In this way, the lens barrel movement amount by which the movement mechanism 16 should move the second lens barrel 6 along the optical axis Ax is determined in response to the change in temperature measured by the thermometer 14. Next, in S4, the control device 10 starts the rotation of the rotary motor 16F of the movement mechanism 16 so that the second barrel 6 moves the barrel movement amount calculated in S3. Next, in S5, the control device 10 refers to the image movement amount table illustrated in FIG. 7 and obtains the image movement amount corresponding to the lens barrel movement amount calculated in S3 from the image movement amount table. In this way, the image movement amount on the imaging surface corresponding to the lens barrel movement amount is determined. Here, the "lens barrel movement amount calculated in S3" means the lens barrel movement amount itself calculated in S3 if the lens barrel movement amount calculated in S3 is in the image movement amount table. If the lens barrel movement amount calculated in S3 is not in the image movement amount table, the "lens barrel movement amount calculated in S3" means the lens barrel movement amount in the image movement amount table that is closest to the lens barrel movement amount calculated in S3.

[0027] Next, in S6, the control device 10 calculates the correction amount for offsetting the image movement amount acquired in S5, that is, the required pan drive amount and the required tilt drive amount. Next, in S7, the control device 10 sends command signals to the tilt control mechanism 24 and the pan control mechanism 26 to achieve the correction amount calculated in S7. As a result, the tilt control mechanism 24 and the pan control mechanism 26 swing the housing 2 relative to the camera platform device 3, thereby offsetting the amount of image movement. After this, the operation ends.

[0028] Through the above operations, the position of the relay lens group is adjusted in response to temperature changes within the housing 2, and unintended movement of the image caused by the adjustment of the relay lens group position is suppressed, thereby reducing the sense of incongruity caused by movement of the captured image. It is also possible to prevent erroneous recognition due to unintended movement of the image when recognizing from a moving image whether the subject is actually moving. To further reduce the sense of discomfort, the movement of the second barrel 6 that begins in S4 may be ended simultaneously with the swinging of the housing 2 in S7. Alternatively, S4 may be performed after S6 so that the movement of the second barrel 6 is performed in synchronization with the swinging of the housing 2 in S7. The above operation may be performed in parallel with the movement of the focus lens group in response to temperature changes.

[0029] <Modification> FIG. 9 shows a modified example of the table that can be used in the imaging device 1. This table is stored in the storage device 12. This table describes a number of temperatures, the amount of focus shift corresponding to these temperatures, and the amount of image movement corresponding to these temperatures. "The amount of image movement corresponding to these temperatures" refers to the amount of image movement corresponding to the amount of movement of the second lens barrel 6 required to offset the amount of focus shift corresponding to these temperatures. This table depends on the model of the lens device 4 (specifically, the combination of lens groups), and the relationship between temperature, amount of focus shift, and amount of image movement is determined depending on the model of the lens device 4. The control device 10 refers to this table to obtain the amount of focus deviation corresponding to the temperature measured by the thermometer 14. The control device 10 then calculates the amount of lens barrel movement that will offset the amount of deviation. Furthermore, the control device 10 refers to this table to obtain the amount of image movement corresponding to the temperature measured by the thermometer 14. Then, the control device 10 calculates the amount of correction for offsetting the amount of image movement. When the table of FIG. 9 is used, the amount of focus deviation corresponding to the current temperature of S2 in the flowchart of FIG. 8 can be obtained from this table, and the amount of image movement of S5 can also be obtained from this table.

[0030] 10 is a flowchart showing the operation of the imaging device 1 according to the modified embodiment. In this operation, the control device 10 determines the amount of image movement, and therefore the amount of correction, from an image captured by the imaging element 8A before the movement mechanism 16 moves the second barrel 6 and an image captured by the imaging element 8A after the movement mechanism 16 moves the second barrel 6. 10, the same steps as those in FIG. 8 are denoted by the same reference numerals, and the description thereof will be omitted.

[0031] If it is determined in S1 that a temperature change has occurred inside the housing 2, the operation proceeds to S1A, where the control device 10 records the current image data captured by the imaging element 8A. The recording medium for the image data may be the storage device 12 or another memory device (not shown). After executing S2 to S4, the operation proceeds to S5A, where the control device 10 again records the current image data captured by the imaging element 8A. Next, at S5B, the image data recorded at S5A is compared with the image data recorded at S1A, and the amount of image movement is determined by measuring the displacement of the positions of characteristic objects in the image data. Next, steps S6 and S7 are executed, and the operation ends.

[0032] Through the above operations, the position of the relay lens group is adjusted in response to temperature changes within the housing 2, and unintended movement of the image caused by the adjustment of the relay lens group position is suppressed, thereby reducing the sense of incongruity caused by movement of the captured image. It is also possible to prevent erroneous recognition due to unintended movement of the image when recognizing from a moving image whether the subject is actually moving. According to the operation of FIG. 10, the image movement amount table exemplified in FIG. 7 is not necessary, and the image movement amount can be offset by swinging the housing 2 based on the actual image movement amount.

[0033] FIG. 11 shows another modified example of the table that can be used in the imaging device 1. This table is stored in the storage device 12. This table describes a number of temperatures, the lens barrel movement amounts corresponding to these temperatures, and the correction amounts corresponding to these temperatures. The "lens barrel movement amounts corresponding to these temperatures" refer to the movement amounts of the second lens barrel 6 required to offset the amounts of focus deviation corresponding to these temperatures. The "correction amounts corresponding to these temperatures" refer to the correction amounts, i.e., the rotation amounts of the housing 2, required to offset the image movement amounts corresponding to the movement amounts of the second lens barrel 6 corresponding to these temperatures. This table depends on the model of the lens device 4 (specifically, the combination of lens groups), and the relationship between temperature, lens barrel movement amount, and correction amount is determined according to the model of the lens device 4. 11, the lens barrel movement amount is expressed as the drive angle of the rotary motor 16 F. The correction amount includes the pan drive angle of the pan control mechanism 26 and the tilt drive angle of the tilt control mechanism 24. The control device 10 refers to this table to obtain the amount of barrel movement corresponding to the temperature measured by the thermometer 14, and the control device 10 refers to this table to obtain the amount of correction corresponding to the temperature measured by the thermometer 14. Therefore, it is not necessary to calculate the lens barrel movement amount from the amount of focus deviation, it is not necessary to determine the image movement amount from the lens barrel movement amount, and it is not necessary to calculate the correction amount from the image movement amount.

[0034] The operation executed by the control device 10 of the imaging device 1 that uses the table illustrated in FIG. 11 will be described with reference to the flow chart of FIG. First, in S1, the control device 10 determines whether or not a temperature change has occurred inside the housing 2. If it is determined that a temperature change has occurred inside the housing 2, the operation proceeds to S2A, where the control device 10 refers to the table illustrated in FIG. 11 and obtains the required amount of movement of the second mirror tube 6, i.e., the amount of mirror tube movement, that corresponds to the current temperature. Next, in S4, the control device 10 starts the rotation of the rotary motor 16F of the movement mechanism 16 so that the second barrel 6 moves the barrel movement amount acquired in S2A. Next, in S6A, the control device 10 refers to the table illustrated in FIG. 11 and obtains the correction amounts corresponding to the current temperature, that is, the required pan drive amount and the required tilt drive amount. Next, in S7, the control device 10 sends command signals to the tilt control mechanism 24 and the pan control mechanism 26 to achieve the correction amount calculated in S7. As a result, the tilt control mechanism 24 and the pan control mechanism 26 swing the housing 2 relative to the camera platform device 3, thereby offsetting the amount of image movement. After this, the operation ends.

[0035] Through the above operations, the position of the relay lens group is adjusted in response to temperature changes within the housing 2, and unintended movement of the image caused by the adjustment of the relay lens group position is suppressed, thereby reducing the sense of incongruity caused by movement of the captured image. It is also possible to prevent erroneous recognition due to unintended movement of the image when recognizing from a moving image whether the subject is actually moving. To further reduce the sense of discomfort, the movement of the second barrel 6 that begins in S4 may be ended simultaneously with the swinging of the housing 2 in S7. Also, S4 may be performed after S6A so that the movement of the second barrel 6 is performed in synchronization with the swinging of the housing 2 in S7.

[0036] FIG. 13 shows another modified example of the table that can be used in the imaging device 1. This table is stored in the storage device 12. This table (lens barrel movement amount table) describes a number of temperatures and the lens barrel movement amount corresponding to these temperatures. In FIG. 13, the lens barrel movement amount is expressed as the drive angle of the rotation motor 16F. This table depends on the model of the lens device 4 (specifically, the combination of lens groups), and the relationship between the temperature and the lens barrel movement amount is determined depending on the model of the lens device 4. The control device 10 refers to this lens barrel movement amount table to obtain the lens barrel movement amount corresponding to the temperature measured by the thermometer 14. Similar to the operation of FIG. 10, the control device 10 determines the amount of image movement, and therefore the amount of correction, from the image captured by the imaging element 8A before the moving mechanism 16 moves the second barrel 6, and the image captured by the imaging element 8A after the moving mechanism 16 moves the second barrel 6.

[0037] The operation executed by the control device 10 of the imaging device 1 that uses the lens barrel movement amount table exemplified in FIG. 13 will be described with reference to the flowchart of FIG. First, in S1, the control device 10 determines whether or not a temperature change has occurred inside the housing 2. If it is determined that a temperature change has occurred within the housing 2, the operation proceeds to S1A, where the control device 10 records the current image data captured by the imaging device 8A. Next, in S2B, the control device 10 refers to the lens barrel movement amount table illustrated in FIG. 13, and obtains the required movement amount of the second lens barrel 6 that corresponds to the current temperature, that is, the lens barrel movement amount. Next, in S4, the control device 10 starts the rotation of the rotary motor 16F of the movement mechanism 16 so that the second barrel 6 moves the barrel movement amount acquired in S2B.

[0038] Next, in S5A, the control device 10 again records the current image data captured by the imaging element 8A. Next, at S5B, the image data recorded at S5A is compared with the image data recorded at S1A, and the amount of image movement is determined by measuring the displacement of the positions of characteristic objects in the image data. Next, steps S6 and S7 are executed, and the operation ends.

[0039] Through the above operations, the position of the relay lens group is adjusted in response to temperature changes within the housing 2, and unintended movement of the image caused by the adjustment of the relay lens group position is suppressed, thereby reducing the sense of incongruity caused by movement of the captured image. It is also possible to prevent erroneous recognition due to unintended movement of the image when recognizing from a moving image whether the subject is actually moving. According to the operation of FIG. 14, the data items of the pan drive angle and tilt drive angle exemplified in FIG. 11 are not necessary, and the amount of image movement can be offset by swinging the housing 2 based on the actual amount of image movement.

[0040] 15 shows an imaging device 1A according to another modified example of the embodiment. The imaging device 1A has a moving mechanism 46 instead of the moving mechanism 16. The moving mechanism 46 is disposed inside the housing 2. The movement mechanism 46 moves the second lens barrel 6 along the optical axis Ax relative to the first lens barrel 5 while maintaining the relay lens group decentered with respect to the optical axis Ax of the focus lens group and the zoom lens group. However, unlike the movement mechanism 16, the movement mechanism 46 does not rotate the second lens barrel 6 around the optical axis Ax relative to the first lens barrel 5. Specifically, the movement mechanism 46 has a pin 46A and a linear actuator 46B. The pin 46A is fixed to a movable part (piston) 46C of the linear actuator 46B. The pin 46A is inserted into an elongated hole 5h formed in the first lens barrel 5, and an end of the pin 46A is fixed to the second lens barrel 6.

[0041] With this configuration, when the linear actuator 46B is driven, the pin 46A and therefore the second barrel 6 move along the optical axis Ax together with the relay lens group. The length of the elongated hole 5h is greater than the stroke of the second barrel 6 along the optical axis Ax. A rack and pinion mechanism may be used in place of the linear actuator 46B. In the imaging device 1A illustrated in FIG. 15 in which the second lens barrel 6 moves straight ahead without rotating, the above-mentioned image movement problem may still occur, although not to the same extent as when the second lens barrel 6 is rotated. By suppressing the movement of the image by any of the above measures, the sense of discomfort caused by the movement of the captured image can be reduced in the imaging device 1A as well.

[0042] <Other Modifications> Although an embodiment of the present invention has been described above, the above description does not limit the present invention, and various modifications including deletion, addition, and substitution of components are possible within the technical scope of the present invention. For example, the imaging device according to the embodiment includes a focus lens group, a zoom lens group, and a relay lens group, but may include other lenses or lens groups.

[0043] In the above embodiment and modified examples, at least one table corresponding to the model of the lens device 4 (specifically, the combination of lens groups) is stored in the storage device 12. In other words, the storage device 12 stores at least one dedicated table corresponding to one model of the lens device 4. However, the storage device 12 may store a plurality of tables corresponding respectively to a plurality of models of lens devices. In this case, the control device 10 may read, for example, metadata from the lens device 4, recognize the model of the lens device 4, and read out the table corresponding to the model of the lens device 4 from the storage device 12. Alternatively, a user of the imaging device may input the model of the lens device 4 to the imaging device, causing the control device 10 to recognize the model of the lens device 4 and read out the table corresponding to the model of the lens device 4 from the storage device 12.

[0044] The present invention can be realized by supplying a program that realizes one or more functions of the processor of the embodiment to the processor via a network or a recording medium, and having the processor read and execute the program. In this case, the program (program code) itself read from the recording medium realizes the functions of the embodiment. Also, the recording medium on which the program is recorded can constitute the present invention. The control device 10 may be implemented as hardware. When implemented as hardware, for example, a specific compiler may be used to automatically generate a dedicated circuit on an FPGA from a program for implementing each step. FPGA is an abbreviation for Field Programmable Gate Array. Also, a gate array circuit may be formed in the same manner as an FPGA, and implemented as hardware. Also, it may be implemented by an ASIC (Application Specific Integrated Circuit).

[0045] The disclosure of the present specification includes the following configurations. (Configuration 1) A focus lens group; A zoom lens group; A relay lens group; a first lens barrel supporting the focus lens group and the zoom lens group; a second lens barrel that supports the relay lens group in a state in which the relay lens group is decentered with respect to the optical axis of the focus lens group and the zoom lens group; an imaging unit having an imaging surface on which light passing through the focus lens group, the zoom lens group, and the relay lens group is imaged, and imaging is performed using the light imaged on the imaging surface; a housing in which the first lens barrel, the second lens barrel, and the imaging surface are disposed; a moving means for moving the second lens barrel relative to the first lens barrel along the optical axis while the relay lens group is decentered with respect to the optical axes of the focus lens group and the zoom lens group; A measuring means for measuring a temperature inside the housing; a first determination means for determining a lens barrel movement amount by which the moving means should move the second lens barrel along the optical axis in response to a change in temperature measured by the measurement means; a second determination means for determining at least one of an image movement amount on the imaging surface corresponding to the lens barrel movement amount and a correction amount for offsetting the image movement amount; and a rotation means for rotating the housing by the correction amount so as to offset the image movement amount. 1. An imaging device comprising: (Configuration 2) The moving means moves the second lens barrel along the direction of the optical axis relative to the first lens barrel while rotating the second lens barrel about the optical axis relative to the first lens barrel. 2. The imaging device according to configuration 1,

[0046] (Configuration 3) The apparatus further includes a storage means for storing a table of a plurality of temperatures and a corresponding focus deviation amount, The first determination means refers to the deviation amount table to obtain the amount of focus deviation corresponding to the temperature measured by the measurement means, and calculates the amount of movement of the lens barrel that offsets the amount of focus deviation. 3. The imaging device according to configuration 1 or 2. (Configuration 4) Further comprising a storage means for storing an image movement amount table which describes a plurality of lens barrel movement amounts and image movement amounts corresponding to these lens barrel movement amounts; The second determination means refers to the image movement amount table, acquires the image movement amount corresponding to the lens barrel movement amount determined by the first determination means, and calculates the correction amount for offsetting the image movement amount. 3. The imaging device according to configuration 1 or 2. (Configuration 5) The present invention further includes a storage means for storing a misalignment amount table that describes a plurality of temperatures and corresponding defocus amounts, and an image movement amount table that describes a plurality of lens barrel movement amounts and corresponding image movement amounts, the first determination means refers to the deviation amount table to obtain a focus deviation amount corresponding to the temperature measured by the measurement means, and calculates the lens barrel movement amount that offsets the focus deviation amount; The second determination means refers to the image movement amount table, acquires the image movement amount corresponding to the lens barrel movement amount determined by the first determination means, and calculates the correction amount for offsetting the image movement amount. 3. The imaging device according to configuration 1 or 2.

[0047] (Configuration 6) The present invention further includes a storage means for storing a table that describes a plurality of temperatures, the amounts of focus deviation corresponding to these temperatures, and the amounts of image movement corresponding to these temperatures, the first determination means refers to the table to obtain an amount of focus deviation corresponding to the temperature measured by the measurement means, and calculates an amount of movement of the lens barrel that offsets the amount of focus deviation; The second determination means refers to the table to obtain the image movement amount corresponding to the temperature measured by the measurement means, and calculates the correction amount for offsetting the image movement amount. 3. The imaging device according to configuration 1 or 2. (Configuration 7) Further comprising a storage means for storing a lens barrel movement amount table which describes a plurality of temperatures and lens barrel movement amounts corresponding to these temperatures; The first determination means refers to the lens barrel movement amount table to obtain the lens barrel movement amount corresponding to the temperature measured by the measurement means. 3. The imaging device according to configuration 1 or 2. (Configuration 8) Further comprising a storage means for storing a table describing a plurality of temperatures, the lens barrel movement amounts corresponding to these temperatures, and the correction amounts corresponding to these temperatures; the first determination means refers to the table to obtain the lens barrel movement amount corresponding to the temperature measured by the measurement means; The second determination means refers to the table to obtain the correction amount corresponding to the temperature measured by the measurement means. 3. The imaging device according to configuration 1 or 2.

[0048] (Configuration 9) The second determination means determines the correction amount from an image captured by the imaging means before the moving means moves the second lens barrel and an image captured by the imaging means after the moving means moves the second lens barrel. 8. The imaging device according to any one of configurations 1 to 3 and 7,

[0049] (Configuration 10) capturing an image using light that has passed through a focus lens group, a zoom lens group, and a relay lens group and formed an image on an imaging surface; measuring a temperature inside a housing in which a first lens barrel supporting the focus lens group and the zoom lens group, a second lens barrel supporting the relay lens group in a state in which the relay lens group is decentered with respect to an optical axis of the focus lens group and the zoom lens group, and the imaging surface are disposed; determining a lens barrel movement amount by which the second lens barrel should be moved along the optical axis relative to the first lens barrel in response to the change in the measured temperature; moving the second lens barrel by the lens barrel movement amount along the optical axis direction relative to the first lens barrel in a state in which the relay lens group is decentered with respect to the optical axes of the focus lens group and the zoom lens group; determining at least one of an image movement amount on the imaging plane corresponding to the lens barrel movement amount and a correction amount for offsetting the image movement amount; and rotating the housing by the correction amount so as to offset the image movement amount. 13. An imaging method comprising: (Configuration 11) A program for causing a computer to function as the first determination means and the second determination means of the imaging device according to any one of configurations 1 to 9. [Explanation of symbols]

[0050] Reference Signs List 1, 1A...imaging device, Ax...optical axis, 2...housing, 5...first lens barrel, 6...second lens barrel, 6x...optical axis, 8A...imaging element, 8B...imaging surface, 10...control device, 14...thermometer, 16, 46...movement mechanism, 18a, 18b, 18c...focus lens, 20a, 20b...zoom lens, 22a, 22b, 22c...relay lens, 24...tilt control mechanism, 26...pan control mechanism

Claims

1. A focus lens group; A zoom lens group; A relay lens group; a first lens barrel supporting the focus lens group and the zoom lens group; a second lens barrel that supports the relay lens group in a state in which the relay lens group is decentered with respect to the optical axes of the focus lens group and the zoom lens group; an imaging unit having an imaging surface on which light passing through the focus lens group, the zoom lens group, and the relay lens group is imaged, and imaging is performed using the light imaged on the imaging surface; a housing in which the first lens barrel, the second lens barrel, and the imaging surface are disposed; a moving means for moving the second lens barrel relative to the first lens barrel along the optical axis while the relay lens group is decentered with respect to the optical axis of the focus lens group and the zoom lens group; A measuring means for measuring a temperature inside the housing; a first determination means for determining a lens barrel movement amount by which the moving means should move the second lens barrel along the optical axis in response to a change in temperature measured by the measurement means; a second determination means for determining at least one of an image movement amount on the imaging surface corresponding to the lens barrel movement amount and a correction amount for offsetting the image movement amount; and a rotation means for rotating the housing by the correction amount so as to offset the image movement amount.

1. An imaging device comprising:

2. The moving means moves the second lens barrel along the direction of the optical axis relative to the first lens barrel while rotating the second lens barrel about the optical axis relative to the first lens barrel.

2. The imaging device according to claim 1 .

3. The apparatus further includes a storage means for storing a table of a plurality of temperatures and a corresponding focus deviation amount, The first determination means refers to the deviation amount table to obtain the amount of focus deviation corresponding to the temperature measured by the measurement means, and calculates the amount of movement of the lens barrel that offsets the amount of focus deviation.

3. The imaging device according to claim 1, wherein the first and second lenses are arranged in a first direction.

4. Further comprising a storage means for storing an image movement amount table which describes a plurality of lens barrel movement amounts and image movement amounts corresponding to these lens barrel movement amounts; The second determination means refers to the image movement amount table, acquires the image movement amount corresponding to the lens barrel movement amount determined by the first determination means, and calculates the correction amount for offsetting the image movement amount.

3. The imaging device according to claim 1, wherein the first and second lenses are arranged in a first direction.

5. The present invention further includes a storage means for storing a misalignment amount table that describes a plurality of temperatures and corresponding defocus amounts, and an image movement amount table that describes a plurality of lens barrel movement amounts and corresponding image movement amounts, the first determining means refers to the deviation amount table to obtain a focus deviation amount corresponding to the temperature measured by the measuring means, and calculates a lens barrel movement amount that offsets the focus deviation amount; The second determination means refers to the image movement amount table, acquires the image movement amount corresponding to the lens barrel movement amount determined by the first determination means, and calculates the correction amount for offsetting the image movement amount.

3. The imaging device according to claim 1, wherein the first and second lenses are arranged in a first direction.

6. The camera further includes a storage means for storing a table that describes a plurality of temperatures, the amounts of focus deviation corresponding to these temperatures, and the amounts of image movement corresponding to these temperatures; the first determining means refers to the table to obtain an amount of focus deviation corresponding to the temperature measured by the measuring means, and calculates an amount of movement of the lens barrel that offsets the amount of focus deviation; The second determination means refers to the table to obtain the image movement amount corresponding to the temperature measured by the measurement means, and calculates the correction amount for offsetting the image movement amount.

3. The imaging device according to claim 1, wherein the first and second lenses are arranged in a first direction.

7. Further comprising a storage means for storing a lens barrel movement amount table which describes a plurality of temperatures and lens barrel movement amounts corresponding to these temperatures; The first determination means refers to the lens barrel movement amount table to obtain the lens barrel movement amount corresponding to the temperature measured by the measurement means.

3. The imaging device according to claim 1, wherein the first and second lenses are arranged in a first direction.

8. Further comprising a storage means for storing a table describing a plurality of temperatures, the lens barrel movement amounts corresponding to these temperatures, and the correction amounts corresponding to these temperatures; the first determination means refers to the table to obtain the lens barrel movement amount corresponding to the temperature measured by the measurement means; The second determination means refers to the table to obtain the correction amount corresponding to the temperature measured by the measurement means.

3. The imaging device according to claim 1, wherein the first and second lenses are arranged in a first direction.

9. The second determination means determines the correction amount from an image captured by the imaging means before the moving means moves the second lens barrel and an image captured by the imaging means after the moving means moves the second lens barrel.

3. The imaging device according to claim 1, wherein the first and second lenses are arranged in a first direction.

10. capturing an image using light that has passed through a focus lens group, a zoom lens group, and a relay lens group and formed an image on an imaging surface; measuring a temperature inside a housing in which a first lens barrel supporting the focus lens group and the zoom lens group, a second lens barrel supporting the relay lens group in a state in which the relay lens group is decentered with respect to an optical axis of the focus lens group and the zoom lens group, and the imaging surface are disposed; determining a lens barrel movement amount by which the second lens barrel should be moved along the optical axis relative to the first lens barrel in response to the measured temperature change; moving the second lens barrel by the lens barrel movement amount along the optical axis direction relative to the first lens barrel in a state in which the relay lens group is decentered with respect to the optical axes of the focus lens group and the zoom lens group; determining at least one of an image movement amount on the imaging plane corresponding to the lens barrel movement amount and a correction amount for offsetting the image movement amount; and rotating the housing by the correction amount so as to offset the image movement amount.

13. An imaging method comprising:

11. 3. A program for causing a computer to function as the first determination unit and the second determination unit of the imaging device according to claim 1.

Images