Lens device, imaging system, movable object, and control method

A lens device includes a first lens system including a first lens, a second lens system including a second lens, a moving member configured to move in an optical axis direction of the first lens, and a physical structure configured to move the first lens in the optical axis direction and move the moving member in a direction opposite to a movement direction of a center of gravity of a physical system that includes the first lens.

FIELD

The disclosed embodiments relate to a lens device, an imaging system, a movable object, and a control method.

BACKGROUND

In Japanese Unexamined Publication No. H08-022068, when a lens moves due to a zoom operation or a focus operation, a stabilizer disclosed in the application moves an auxiliary balance weight in the opposite direction from the movement direction of the lens. A structure for adjusting weight balance that is disclosed in Japanese Unexamined Publication No. 2010-39350 achieves weight balance by moving a weight in conjunction with a zoom action of a zoom lens.

When a dedicated motor is used to move a weight that inhibits a change in the position of the center of gravity of a physical system that includes a lens, reducing the size and weight of a lens device can be challenging.

The lens device according to an aspect of the present disclosure can include a first lens system for adjusting a focusing distance. The first lens system can include at least one first lens. The lens device can include a second lens system that includes at least one second lens. The lens device can include a first moving member capable of moving in an optical axis direction of the at least one first lens. The lens device can include a first physical structure for moving the at least one first lens in the optical axis direction, and also for moving the first moving member in the opposite direction from a movement direction of the center of gravity of a physical system that includes the at least one first lens.

The lens device can include a first lens holding member for holding the at least one first lens. The first physical structure can include a first cam portion provided to one of the first lens holding member and the first moving member. The first physical structure can include a first follower portion provided to the other of the first lens holding member and the first moving member, the first follower portion moving along a cam surface of the first cam portion and thereby causing the first lens holding member and the first moving member to move relative to each other.

The first moving member can be a first cam ring. The first moving member can be a material having a specific gravity greater than that of the at least one lens. The first moving member can be a metal.

The second lens system can be a single focus lens system. The second lens system can be a zoom lens system. The lens device can include a second moving member capable of moving in an optical axis direction of the at least one second lens. The lens device can include a second physical structure for moving the at least one second lens in the optical axis direction, and also for moving the second moving member in the opposite direction from a movement direction of the center of gravity of a physical system that includes the at least one second lens.

The lens device can include a second lens holding member for holding the at least one second lens. The second physical structure can include a second cam portion provided to one of the second lens holding member and the second moving member. The second physical structure can include a second follower portion provided to the other of the second lens holding member and the second moving member, the second follower portion moving along a cam surface of the second cam portion and thereby causing the second lens holding member and the second moving member to move relative to each other.

The second moving member can be a cam ring. The second moving member can be a material having a specific gravity greater than that of the at least one second lens. The second moving member can be a metal.

The lens device can include a light amount adjustment mechanism moving together with the one first lens or a portion of a plurality of first lenses, and adjusting an amount of light that passes through the at least one first lens. The second physical structure can move the second moving member in the opposite direction from a movement direction of the center of gravity of a physical system that includes the light amount adjustment mechanism. The light amount adjustment mechanism can include an aperture capable of modifying an opening diameter thereof. The light amount adjustment mechanism can include an actuator for driving the aperture and modifying the opening diameter.

The imaging system according to an aspect of the present disclosure can include a lens device. The imaging system can include an imaging device for imaging light focused by the lens device.

The imaging system can include a carrier for supporting at least one of the lens device and the imaging device. The carrier can support the lens device and the imaging device such that the lens device and the imaging device can rotate on a rotation axis running through a predetermined range of distance from the center of gravity of the physical system that includes the lens device and the imaging device. The carrier can support the lens device and the imaging device such that the lens device and the imaging device can rotate on a rotation axis running through the center of gravity of the physical system that includes the lens device and the imaging device.

A movable object according to an aspect of the present disclosure can include the imaging system. The movable object can be an unmanned aerial vehicle.

The imaging system can include a holding arm attached to the carrier.

A control method according to an aspect of the present disclosure can be a control method of a lens device that includes a first lens system for adjusting a focusing distance, the first lens system including at least one first lens; a second lens system that includes at least one second lens; and a first moving member capable of moving in an optical axis direction of the at least one first lens. The control method can include a first physical structure moving the at least one first lens in the optical axis direction, and also moving the first moving member in the opposite direction from a movement direction of the center of gravity of a physical system that includes the at least one first lens.

By moving the at least one first lens in the optical axis direction and also moving the first moving member in the opposite direction from the movement direction of the center of gravity of the physical system that includes the at least one first lens, a change in the position of the center of gravity of the physical system that includes a lens can be inhibited with a more simplified structure.

The features described above can also be arranged into a variety of sub-combinations.

DETAILED DESCRIPTION OF THE EMBODIMENTS

The present disclosure is described below using embodiments of the disclosure, but the embodiments below do not limit the disclosure according to the scope of the claims. Not all combinations of features described in the embodiments are necessary to achieve the disclosure.

The scope of the claims, specification, drawings, and abstract include matters subject to protection by copyright. The owner of copyright does not raise objections to duplication by any person of these documents if it is as displayed in the files or records of the Patent Office. However, in all other cases, all copyrights are reserved.

FIG. 1illustrates one example of an exterior of an unmanned aerial vehicle (UAV)100. The UAV100can include a UAV body101, a gimbal110, an imaging device140, and a lens device160. The gimbal110, the imaging device140, and the lens device160are one example of an imaging system. The gimbal110is one example of a carrier. The UAV100is one example of a movable object to which the imaging system is provided. The movable object can be a concept that includes, in addition to UAVs, other aerial vehicles moving in the air, vehicles moving on the ground, ships moving in the water, and the like.

The UAV body101can include a plurality of rotary wings. The UAV body101can cause the UAV100to fly by controlling the rotation of the plurality of rotary wings. For example, the UAV body101can cause the UAV100to fly by using four rotary wings. The number of rotary wings is not limited to four. Also, the UAV100can be a fixed-wing aircraft that does not have rotary wings.

The gimbal110can support the imaging device140and/or the lens device160. The imaging device140and/or the lens device160can be rotatably supported by the gimbal110. The gimbal110can also support the imaging device140and the lens device160such that the imaging device140and the lens device160can rotate on a rotation axis running through the center of gravity of a physical system that includes the imaging device140and the lens device160. For example, the gimbal110can rotatably support the imaging device140and the lens device160on a pitch axis that runs through the center of gravity of the physical system that includes the imaging device140and the lens device160. The gimbal110can further rotatably support the imaging device140and the lens device160such that the imaging device140and the lens device160can rotate centered on each of a roll axis and a yaw axis. The gimbal110can support the imaging device140, and can support the lens device160. The lens device160can also include the imaging device140. In such a case, the lens device160and the imaging device140together form a lens body.

The imaging device140can generate and record image data of optical images formed via the lens device160. The lens device160can be integrally provided with the imaging device140. The lens device160can be a so-called “interchangeable lens,” and can be detachably provided on the imaging device140.

FIG. 2illustrates one example of a function block of the UAV100. The UAV100can include a communication interface102, a UAV control unit104, a memory106, the gimbal110, the imaging device140, and the lens device160.

The communication interface102can communicate with an external transmitter. The communication interface102receives a variety of instructions from a remote transmitter. The UAV control unit104can control the flight of the UAV100following the instructions received from the transmitter. The UAV control unit104can control the gimbal110, the imaging device140, and the lens device160. The UAV control unit104can be configured from a microprocessor such as a CPU or MPU, a microcontroller such as an MCU, or the like. The memory106stores programs and the like necessary for the UAV control unit104to control the gimbal110, the imaging device140, and the lens device160. The memory106can be a computer-readable recording medium, and can include at least one from among SRAM, DRAM, EPROM, EEPROM, and flash memory such as USB memory. The memory106can be provided to the housing of the UAV100. The memory106can be provided such that it is removable from the housing of the UAV100.

The imaging device140can include an imaging control unit142, an imaging element144, and a memory146. The imaging device140can image light focused by the lens device160. The imaging element144can generate and output to the imaging control unit142image data of an optical image formed via the lens device160. The imaging element144can be configured from CCD or CMOS. The imaging control unit142can store image data output from the imaging element144in the memory146. The imaging control unit142can output image data to the memory106to be stored therein, via the UAV control unit104. The imaging control unit142can control the imaging device140and the lens device160according to action instructions for the imaging device140and the lens device160provided from the UAV control unit104. The imaging control unit142can be configured from a microprocessor such as a CPU or MPU, a microcontroller such as an MCU, or the like. The memory146can be a computer-readable recording medium, and can include at least one from among SRAM, DRAM, EPROM, EEPROM, and flash memory such as USB memory. The memory146can be provided inside the housing of the imaging device140. The memory146can be provided such that it is removable from the housing of the imaging device140.

The lens device160can include a memory161, a lens control unit162, an actuation mechanism164, a moving member200, a physical structure210, a plurality of lens holding members230, a plurality of lenses170, a light amount adjustment mechanism180, a plurality of lenses190, a plurality of lens holding members330, a physical structure310, a moving member300, and an actuation mechanism194. At least one, or all, of the plurality of lenses170can be disposed movably along an optical axis. The plurality of lenses170can be configured from a plurality of lens groups. The plurality of lenses170can function as a zoom lens system. The plurality of lenses170can also function as a varifocal lens. The plurality of lenses170can also function as a single focus lens system.

At least one, or all, of the plurality of lenses190can be disposed movably along an optical axis. The plurality of lenses190can be configured from a plurality of lens groups. The plurality of lenses190can also function as a focus lens system that can adjust a focusing distance.

The memory161can store a control value for the plurality of lenses170that are operated via the actuation mechanism164, a control value for the plurality of lenses190that are operated by the separate actuation mechanism194, and the like. The lens device160should include at least one lens170and at least one lens190. The lens device160can include any number of lenses according to the optical design of the lens device160.

Following lens action instructions from the imaging control unit142, the lens control unit162can drive the actuation mechanism164based on the control value stored in the memory161, and can move the plurality of lenses170in an optical axis direction. The lens control unit162can further drive the actuation mechanism194based on another control value stored in the memory161, and can move the plurality of lenses190in the optical axis direction. The lens control unit162can adjust the focusing distance by causing the plurality of lenses190to move in the optical axis direction in conjunction with the movement of the plurality of lenses170in the optical axis direction. The lens control unit162can cause the plurality of lenses190to function as a floating focus by causing the plurality of lenses190to move in the optical axis direction in conjunction with the movement of the plurality of lenses170in the optical axis direction. The lens control unit162can further adjust the focusing distance by causing the plurality of lenses190to move in the optical axis direction independently of the movement of the plurality of lenses170in the optical axis direction.

The lens holding members230can hold the lenses170. Each lens holding member230can hold one or a plurality of the lenses170. Each lens holding member230can move along the optical axis while holding one or a plurality of the lenses170. Each lens holding member230can be disposed to be movable along the optical axis within a lens barrel. The lens holding members330can hold the lenses190. Each lens holding member330can hold one or a plurality of the lenses190. Each lens holding member330can move along the optical axis while holding one or a plurality of the lenses190. Each lens holding member330can be disposed to be movable along the optical axis within the lens barrel.

The light amount adjustment mechanism180can move together with one or a portion of the plurality of lenses170, and can adjust the amount of light that passes through the one or plurality of lenses170. The light amount adjustment mechanism180can include an aperture capable of modifying an opening diameter thereof, and an actuator that drives the aperture and modifies the opening diameter.

The moving member200can be a member that inhibits a change in the position of the center of gravity of the physical system that includes the one or plurality of lenses170. The moving member200is one example of a second moving member. The moving member200can inhibit a change in the position of the center of gravity of the lens device160that is associated with the movement of the one or plurality of lenses170in the optical axis direction. The moving member200can move in the optical axis direction of the one or plurality of lenses170. The moving member200can also move parallel to the optical axis direction of the one or plurality of lenses170. The moving member200can also move in the opposite direction from the movement direction of the center of gravity of the physical system that includes the one or plurality of lenses170. The moving member200can move in the optical axis direction using power supplied by the actuation mechanism164. The moving member200can be configured by any material, so long as the member can inhibit a change in the position of the center of gravity of the lens device160. The moving member200can be a material having a specific gravity greater than that of the one or plurality of lenses170. The moving member200can be a metal. The moving member200can be, for example, a cam ring. The moving member200can also be a lens, and can also be a simple weight that is only used to constrain the position of the center of gravity of the lens device160. The moving member200can be disposed inside the lens barrel of the lens device160, or can be disposed outside the lens barrel of the lens device160.

The moving member300can be a member that inhibits a change in the position of the center of gravity of the physical system that includes the one or plurality of lenses190. The moving member300is one example of a first moving member. The moving member300can inhibit a change in the position of the center of gravity of the lens device160that is associated with the movement of the one or plurality of lenses190in the optical axis direction. The moving member300can move in the optical axis direction of the one or plurality of lenses190. The moving member300can also move parallel to the optical axis direction of the one or plurality of lenses190. The moving member300can also move in the opposite direction from the movement direction of the center of gravity of the physical system that includes the one or plurality of lenses190. The moving member300can move in the optical axis direction using power supplied by the actuation mechanism194. The moving member300can be configured by any material, so long as the member can inhibit a change in the position of the center of gravity of the lens device160. The moving member300can be a material having a specific gravity greater than that of the one or plurality of lenses190. The moving member300can be a metal. The moving member300can be, for example, a cam ring. The moving member300can also be a lens, and can also be a simple weight that is only used to constrain the position of the center of gravity of the lens device160. The moving member300can be disposed inside the lens barrel of the lens device160, or can be disposed outside the lens barrel of the lens device160.

The amount of movement of the moving member200and the moving member300can be determined based on the amount of movement of a movable element and the mass of the movable element. The movable element of the moving member200can be an element that is provided to the lens device160and that moves during a zoom action. The movable element of the moving member200can move in the optical axis direction during the zoom action. The movable element of the moving member200can include the one or plurality of lenses170, the light amount adjustment mechanism180, a cam ring, a linear guide ring, and the like. The amount of movement of the moving member200can indicate a distance of the moving member200from a baseline position. The amount of movement of the movable element of the moving member200can indicate the distance of the movable element from a baseline position. The baseline positions of the moving member200and of the movable element of the moving member200, respectively, can be the respective positions of the moving member200and the movable element at the wide angle end of the lens device160. The distance of the moving member200from the baseline position can be set such that a calculated value is no more than a predetermined value. The calculated value can be obtained by multiplying the distance of the movable element from the baseline position by the mass of the movable element to obtain a total physical quantity, then dividing this total physical quantity by the mass of the moving member200. The distance of the moving member200from the baseline position can be set such that a calculated value is no more than a predetermined value. The calculated value can be obtained by multiplying the distance of each of the one or plurality of lenses170from the baseline position by the mass of each of the one or plurality of lenses170to obtain respective physical quantities, then dividing the sum total of these physical quantities by the mass of the moving member200.

The movable element of the moving member300can move in the optical axis direction during a focus action and during the zoom action. The movable element of the moving member300can include the one or plurality of lenses190, and the like. The amount of movement of the moving member300can indicate a distance of the moving member300from a baseline position. The amount of movement of the movable element of the moving member300can indicate the distance of the movable element from a baseline position. The baseline positions of the moving member300and of the movable element of the moving member300, respectively, can be the respective positions of the moving member300and the movable element of the moving member300at a baseline focusing distance (for example, 500 mm). The distance of the moving member300from the baseline position can be set such that a calculated value is no more than a predetermined value. The calculated value can be obtained by multiplying the distance of the movable element from the baseline position by the mass of the movable element to obtain a total physical quantity, then dividing this total physical quantity by the mass of the moving member300. The distance of the moving member300from the baseline position can be set such that a calculated value is no more than a predetermined value. The calculated value can be obtained by multiplying the distance of each of the one or plurality of lenses190from the baseline position by the mass of each of the one or plurality of lenses190to obtain respective physical quantities, then dividing the sum total of these physical quantities by the mass of the moving member300.

The physical structure210can move the one or plurality of lenses170in the optical axis direction, and can also move the moving member200in the opposite direction from the movement direction of the center of gravity of the physical system that includes the one or plurality of lenses170. The physical structure210is one example of a second physical structure. The physical structure210can move the moving member200in the opposite direction from the movement direction of the center of gravity of the physical system that further includes the light amount adjustment mechanism180. The physical structure210moves the moving member200such that a component of the opposite direction from the movement direction of the center of gravity of the physical system that includes the one or plurality of lenses170is at least included in the movement direction of the moving member200.

The physical structure210can be physically linked with the moving member200and the lens holding members230. For example, when the moving member200moves in one optical axis direction, the physical structure210can move the lens holding members230in the other optical axis direction. The physical structure210can physically transmit to the lens holding members230a force generated by the moving member200rotating and moving in one optical axis direction, and can move the lens holding members230in the other optical axis direction.

The physical structure210can include a cam portion and a follower portion. The cam portion of the physical structure210is one example of a second cam portion. The follower portion of the physical structure210is one example of a second follower portion. The cam portion of the physical structure210can be provided to one of the moving member200and the lens holding members230. The follower portion of the physical structure210can be provided to the other of the moving member200and the lens holding members230. The force generated by the moving member200rotating and moving in one optical axis direction can be physically transmitted to the lens holding members230via the cam portion and the follower portion. The follower portion of the physical structure210can move along a cam surface of the cam portion and thereby cause the lens holding members230and the moving member200to move relative to each other.

The physical structure310can move the one or plurality of lenses190in the optical axis direction, and can also move the moving member300in the opposite direction from the movement direction of the center of gravity of the physical system that includes the one or plurality of lenses190. The physical structure310is one example of a first physical structure. The physical structure310moves the moving member300such that a component of the opposite direction from the movement direction of the center of gravity of the physical system that includes the one or plurality of lenses190is at least included in the movement direction of the moving member300.

The physical structure310can be physically linked with the moving member300and the lens holding members330. For example, when the moving member300moves in one optical axis direction, the physical structure310can move the lens holding members330in the other optical axis direction. The physical structure310can physically transmit to the lens holding members330a force generated by the moving member300rotating and moving in one optical axis direction, and can move the lens holding members330in the other optical axis direction.

The physical structure310can include a cam portion and a follower portion. The cam portion of the physical structure310is one example of a first cam portion. The follower portion of the physical structure310is one example of a first follower portion. The cam portion of the physical structure310can be provided to one of the moving member300and the lens holding members330. The follower portion of the physical structure310can be provided to the other of the moving member300and the lens holding members330. The force generated by the moving member300rotating and moving in one optical axis direction can be physically transmitted to the lens holding members330via the cam portion and the follower portion. The follower portion of the physical structure310can move along the cam surface of the cam portion and thereby cause the lens holding members330and the moving member300to move relative to each other.

With the configuration described above, the moving member200can, via the physical structure210, move in a direction that inhibits a change in the position of the center of gravity of the lens device160that is associated with the movement of the one or plurality of lenses170. By inhibiting a change in the position of the center of gravity of the lens device160associated with the zoom action of the lens device160, a change in drive torque on the pitch axis of the gimbal110associated with the zoom action of the lens device160can be inhibited. Furthermore, the moving member300can, via the physical structure310, move in a direction that inhibits a change in the position of the center of gravity of the lens device160that is associated with the movement of the one or plurality of lenses190. By inhibiting a change in the position of the center of gravity of the lens device160associated with the focus action of the lens device160, a change in drive torque on the pitch axis of the gimbal110associated with the focus action of the lens device160can be inhibited. Moreover, a change in the position of the center of gravity of the entire UAV100associated with the zoom action and/or the focus action of the lens device160can be inhibited, and the UAV100is able to achieve more stable flight.

FIG. 3illustrates examples of movement in a focus lens system in response to various focusing distances. The lens device160can include, in order from the body side, a first lens group171, a second lens group172, a third lens group173, a fourth lens group174, a first focus lens191, and a second focus lens192. Each of the plurality of lenses170can be classified as belonging to one of the first lens group171, the second lens group172, the third lens group173, and the fourth lens group174. Each of the plurality of lenses190can be classified as one of the first focus lens191and the second focus lens192.FIG. 3illustrates examples of the positions of the respective lens groups in cases where the zoom lens system is in a telephoto position and the focusing distance is co, 2000 mm, 1000 mm, 600 mm, and 500 mm. The “telephoto position” refers to the positions of each lens group in the zoom lens system at the telephoto end of the lens device160. The lenses of the first lens group171do not move in the optical axis direction. The lenses of the second lens group172, the third lens group173, and the fourth lens group174can move in the optical axis direction. An aperture182can be disposed between the second lens group172and the third lens group173. The aperture182can move in the optical axis direction in conjunction with the movement of the third lens group173. The first focus lens191and the second focus lens192can move in the optical axis direction, to conform with the movement associated with the zoom action of the second lens group172, the third lens group173, and the fourth lens group174in the optical axis direction. Furthermore, the first focus lens191and the second focus lens192can move in the optical axis direction as part of the focus action, independently of the movement of the second lens group172, the third lens group173, and the fourth lens group174in the optical axis direction.

FIG. 4illustrates examples of the movement of the lenses in each of the zoom lens system and the focus lens system in cases where the focusing distance is co, and the zoom lens system moves from a wide angle position to the telephoto position. The “wide angle position” refers to the positions of each lens group in the zoom lens system at the wide angle end of the lens device160. As illustrated inFIG. 4, the focus lens system moves in the optical axis direction in conjunction with the movement of the zoom lens system from the wide angle position to the telephoto position. Accordingly, any aberrations associated with the movement of the zoom lens system can be corrected.

FIG. 5is a perspective view of an exemplary exterior of the imaging device140and the lens device160supported on the gimbal110.FIG. 6is a perspective view of an exemplary interior appearance of the housing of the imaging device140and the lens device160supported on the gimbal110. The gimbal110can include a pitch axis rotation mechanism112that rotates the imaging device140and the lens device160centered on the pitch axis. The gimbal110can further include a roll axis rotation mechanism114and a yaw axis rotation mechanism116rotating the imaging device140and the lens device160centered on the roll axis and the yaw axis, respectively.

FIG. 7illustrates an exemplary perspective view of an exterior of a cam ring302in the focus lens system.FIG. 8illustrates an exemplary perspective view of an exterior of a displacement mechanism in the focus lens system. A fixed cylinder301can be fixed to a base168, which is provided with an electric circuit such as the imaging element144. The first focus lens191and the second focus lens192are disposed inside the fixed cylinder301. The first focus lens191is fixed to a first focus lens holding member195. The second focus lens192is fixed to a second focus lens holding member196. The cam ring302is disposed on an outer circumferential side of the fixed cylinder301, and is disposed so as to be rotatable and movable in the optical axis direction. A gear319is formed on a portion of the outer circumference on one end of the cam ring302. Power from a drive motor307can be transmitted to the gear319via a gear mechanism306, rotating the cam ring302.

A cam ring-operating cam groove312, a first focus lens-operating cam groove314, and a second focus lens-operating cam groove316can be formed on the cam ring302. A cam ring-operating cam pin311is provided on the outer circumference of the fixed cylinder301at a position corresponding to the cam ring-operating cam groove312. The cam ring-operating cam groove312cooperates with the cam ring-operating cam pin311and can guide the movement of the cam ring302in the optical axis direction. A first focus lens-operating cam pin313is provided to the lens holding member195. The first focus lens-operating cam groove314cooperates with the first focus lens-operating cam pin313and can guide the movement of the first focus lens191in the optical axis direction. A second focus lens-operating cam pin315is provided to the lens holding member196. The second focus lens-operating cam groove316cooperates with the second focus lens-operating cam pin315and can guide the movement of the second focus lens192in the optical axis direction.

As illustrated inFIG. 8, a guide support321and guide support322that extend parallel to the optical axis direction can be provided inside the cam ring302. The guide support321and the guide support322can be fixed to the base168. The lens holding member195and the lens holding member196can be guided by the guide support321and the guide support322to move in the optical axis direction. The first focus lens-operating cam pin313can be provided to a hole317provided in the lens holding member195. The second focus lens-operating cam pin315can be provided to a hole318provided in the lens holding member196.

The first focus lens-operating cam pin313can move within the first focus lens-operating cam groove314in association with the cam ring302rotating and moving in the optical axis direction. This movement of the first focus lens-operating cam pin313can cause the first focus lens191to move in the optical axis direction. The second focus lens-operating cam pin315can move within the second focus lens-operating cam groove316in association with the cam ring302rotating and moving in the optical axis direction. This movement of the second focus lens-operating cam pin315can cause the second focus lens192to move in the optical axis direction.

The cam ring302is one example of the moving member300. One example of the first cam portion can include the cam ring-operating cam groove312, the first focus lens-operating cam groove314, and the second focus lens-operating cam groove316. One example of the cam surface of the first cam portion can include side surfaces of each of the cam ring-operating cam groove312, the first focus lens-operating cam groove314, and the second focus lens-operating cam groove316. One example of the first follower portion can include the cam ring-operating cam pin311, the first focus lens-operating cam pin313, and the second focus lens-operating cam pin315.

The cam ring302can move in the opposite direction from the movement direction of the center of gravity of the physical system that includes the first focus lens191and the second focus lens192. This movement of the cam ring302can inhibit a change in the position of the center of gravity of the lens device160associated with the movement of the focus lens system accompanying the focus action and/or the zoom action.

FIG. 9illustrates one example of a movement trajectory of the focus lens system relative to the focusing distance.FIG. 9illustrates a movement trajectory of the focus lenses when the focusing distance is changed at the telephoto end of the lens device160. When the focusing distance changes from 500 mm and approaches 2000 mm, the first focus lens191approaches an image plane and the second focus lens192moves away from the image plane. The term “focus lens R2surface” indicates a surface of a focus lens that is on the same side of the focus lens as the image plane.

FIG. 10illustrates one example of a relationship between the focusing distance and the distance from the baseline position of the focus lens system in the wide angle position. InFIG. 10, the baseline position refers to the positions of the first focus lens191, the second focus lens192, and the cam ring302when the focusing distance is 500 mm. The distance from the baseline position uses a positive value to express a position closer to the image plane and a negative value to express a position closer to the body. The cam ring302can move in the opposite direction from the movement direction of the center of gravity of the physical system that includes the first focus lens191and the second focus lens192. In the example illustrated inFIG. 10, when the focusing distance changes from 500 mm and approaches co, the cam ring302moves so as to first approach the image plane, then move away from the image plane, and then approach the image plane once again. When the cam ring302moves in this way, a change in the position of the center of gravity of the lens device106accompanying the focus action can be inhibited. The movement trajectory illustrated inFIG. 10is merely exemplary, and the movement trajectory of the cam ring302may differ in response to the mass or movement trajectory of each focus lens.

FIG. 11illustrates one example of a relationship between the focusing distance and a physical quantity (moment) (g·mm) obtained by multiplying mass by the distance from the baseline position of the focus lens system in the wide angle position.FIG. 12illustrates one example of a relationship between the distance from the baseline position of the focus lens system in the wide angle position, the focusing distance, and the physical quantity (moment) (g·mm) obtained by multiplying mass by the distance from the baseline position. As inFIG. 10, the baseline position refers to the positions of the first focus lens191, the second focus lens192, and the cam ring302when the focusing distance is 500 mm.

Hereafter, the physical quantity obtained by multiplying mass by the distance from the baseline position is referred to as a physical quantity Bx. The cam ring302can move in a direction that inhibits a change in the position of the center of gravity of the physical system that includes the first focus lens191and the second focus lens192. The distance of the cam ring302from the baseline position can be set such that a calculated value is no more than a predetermined value. The calculated value can be obtained by adding a physical quantity B1of the first focus lens to a physical quantity B2of the second focus lens, then dividing the sum total of these physical quantities by the mass of the cam ring302. This distance can inhibit a change in the position of the center of gravity of the physical system (sum total) that includes the first focus lens191, the second focus lens192, and the cam ring302accompanying a change in the focusing distance. The distance of the cam ring302from the baseline position can also be set such that a calculated value is canceled out. The calculated value can be obtained by adding the physical quantity B1of the first focus lens191to the physical quantity B2of the second focus lens192, then dividing the sum total of these physical quantities by the mass of the cam ring302. This distance can prevent a change in the position of the center of gravity of the physical system due to a change in the focusing distance. A change in the position of the center of gravity associated with the movement of the first focus lens191and the second focus lens192accompanying the focus action and/or the zoom action can be inhibited.

The sum total of the physical quantity B1of the first focus lens191, the physical quantity B2of the second focus lens192, and a physical quantity BC of the cam ring302can be expressed as the sum total ΣB of a physical quantity Bx. In the examples illustrated inFIGS. 10 to 12, the cam ring302can move such that the sum total ΣB of a physical quantity Bx is always zero while the focusing distance is changed from the shortest distance (e.g., 500 mm) to the longest distance (e.g., ∞). However, the cam ring302does not necessarily need to move such that the sum total ΣB of a physical quantity Bx is always zero. This is because a drive range of the grooves in the cam ring302is restricted by, for example, a design restriction or the like. In such a case, the cam ring302can move such that, for example, the maximum value of the sum total ΣB of a physical quantity Bx for a case where the focusing distance is changed from the shortest distance to the longest distance is no more than one-third that of a case where the cam ring302does not restrict a change in the position of the center of gravity.

The cam ring302can move such that a width W of the change in position of the center of gravity of the lens device160when the focusing distance is changed from the shortest distance to the longest distance is less than 10% that of a case where the cam ring302does not restrict the change in the position of the center of gravity. In order to keep the optical axis of the lens device160horizontal, drive torque must be applied on the pitch axis of the gimbal110. This drive torque is expressed as C (N·mm). Given this, the cam ring302can move such that the maximum value of the drive torque C when the focusing distance is changed from the shortest distance to the longest distance is less than 10% that of a case where the cam ring302does not restrict the change in the position of the center of gravity.

As described above, a change in the position of the center of gravity of the lens device160associated with the movement of the focus lens system can be inhibited due to the movement of the cam ring302in the optical axis direction.

FIG. 13illustrates an exemplary perspective view of an exterior of a cam ring202of the zoom lens system.FIG. 14illustrates an exemplary perspective view of an exterior of a fixed cylinder232. The fixed cylinder232can be fixed to the base168, which is provided with an electric circuit such as the imaging element144. The fixed cylinder232holds a lens of the first lens group171. The cam ring202is disposed on an outer circumferential side of the fixed cylinder232, and is disposed so as to be rotatable and movable in the optical axis direction. A gear204is formed on a portion of the outer circumference on one end of the cam ring202. The gear204can interlock with a gear166. The gear166can be rotated by the drive motor165. Power from the drive motor165can be transmitted to the gear204via the gear166and, while rotating, the cam ring202can move in the optical axis direction along the outer circumference of the fixed cylinder232.

As illustrated inFIG. 14, a cam ring support pin234can be provided to the outer circumferential surface of the fixed cylinder232. The cam ring support pin234can guide the movement of the cam ring202in the optical axis direction. A linear guide groove236can be formed on the fixed cylinder232. The linear guide groove236can guide the optical-axis-direction movement of a second lens group cam pin220, a third lens group cam pin222, and a fourth lens group cam pin (not shown in the drawings). The second lens group cam pin220is provided to the lens holding members230that hold the lenses170of the second lens group172. The third lens group cam pin222is provided to the lens holding members230that hold the lenses170of the third lens group173. The fourth lens group cam pin is provided to the lens holding members230that hold the lenses170of the fourth lens group174.

As illustrated inFIG. 13, a cam ring-operating cam groove212that engages with the cam ring support pin234can be formed on the cam ring202. The cam ring-operating cam groove212is guided by the cam ring support pin234, and thereby the cam ring202can move in the optical axis direction while rotating. For example, the cam ring202can move in the direction of an arrow132while rotating in the direction of an arrow130. Furthermore, a second lens group-operating cam groove214that engages with the second lens group cam pin220, a third lens group-operating cam groove216that engages with the third lens group cam pin222, and a fourth lens group-operating cam groove (not shown in the drawings) that engages with the fourth lens group cam pin can be formed on the cam ring202. The second lens group cam pin220can move within the linear guide groove236and along the second lens group-operating cam groove214in association with the cam ring202rotating and moving in the optical axis direction. This movement of the second lens group cam pin220can cause the lenses in the second lens group172to move in the optical axis direction. The third lens group cam pin222can move within the linear guide groove236and along the third lens group-operating cam groove216in association with the cam ring202rotating and moving in the optical axis direction. This movement of the third lens group cam pin222can cause the lenses in the third lens group173to move in the optical axis direction. The fourth lens group cam pin can move within the linear guide groove236and along the fourth lens group-operating cam groove in association with the cam ring202rotating and moving in the optical axis direction. This movement of the fourth lens group cam pin can cause the lenses in the fourth lens group174to move in the optical axis direction.

The cam ring202is one example of the moving member200. One example of the second cam portion can include the linear guide groove236, the cam ring-operating cam groove212, the second lens group-operating cam groove214, the third lens group-operating cam groove216, and the fourth lens group-operating cam groove. One example of the cam surface of the second cam portion can include side surfaces of each of the linear guide groove236, the cam ring-operating cam groove212, the second lens group-operating cam groove214, the third lens group-operating cam groove216, and the fourth lens group-operating cam groove. One example of the second follower portion can include the cam ring support pin234, the second lens group cam pin220, the third lens group cam pin222, and the fourth lens group cam pin.

The cam ring202can move in the opposite direction from the movement direction of the center of gravity of the physical system that includes the lenses of the second lens group172, the lenses of the third lens group173, and the lenses of the fourth lens group174. Moreover, the cam ring202can move in the opposite direction from the movement direction of the center of gravity of the physical system that includes the lenses of the second lens group172, the lenses of the third lens group173, and the lenses of the fourth lens group174, and that also includes the light amount adjustment mechanism180including the aperture182and the actuator. This movement of the cam ring202can inhibit a change in the position of the center of gravity of the lens device160associated with the zoom action.

FIG. 15illustrates one example of a relationship between a rotation angle of the cam ring and a distance from the image plane of the imaging element144. The cam ring rotation angle is a rotation angle of the cam ring202from a baseline angle, where the rotation angle of the cam ring202at the wide angle end of the lens device160is treated as the baseline angle (0°). The distance from the image plane of the imaging element144is a distance from the image plane of the imaging element144to each lens group in the zoom lens system.FIG. 15depicts a change in the distance from the image plane of the imaging element144to each lens group in the zoom lens system in a case where the lens device160is changed from the wide angle end to the telephoto end.

FIG. 16illustrates one example of a relationship between the rotation angle of the cam ring and a distance from the wide angle position. The “wide angle position” refers to the positions of the cam ring202and of each lens group in the zoom lens system at the wide angle end of the lens device160.FIG. 16depicts a change in the distance from the wide angle position for the cam ring202and for each lens group in the zoom lens system in a case where the lens device160is changed from the wide angle end to the telephoto end.

FIG. 17illustrates one example of a relationship between the rotation angle of the cam ring and a physical quantity (g·mm) obtained by multiplying mass by the distance from the wide angle position. Hereafter, the physical quantity obtained by multiplying mass by the distance from the wide angle position is referred to as a physical quantity Ax. The cam ring202can move in a direction that inhibits changes in the position of the center of gravity of the physical system that includes the second lens group172, the third lens group173, and the fourth focus lens174. The distance of the cam ring202from the wide angle position can be set such that a calculated value is no more than a predetermined value. The calculated value can be obtained by adding a physical quantity A2of the second lens group172to a physical quantity A3of the third lens group173and a physical quantity A4of the fourth lens group174, then dividing the sum total of these physical quantities by the mass of the cam ring202. This distance can inhibit the position of the center of gravity of the physical system (sum total) that includes the first lens group171, the second lens group172, the third lens group173, the fourth lens group174, and the cam ring202from changing from the wide angle end of the lens device160to the telephoto end. The distance of the cam ring202from the wide angle position can be set such that a calculated value is canceled out. The calculated value can be obtained by adding the physical quantity A2of the second lens group172to the physical quantity A3of the third lens group173and the physical quantity A4of the fourth lens group174, then dividing the sum total of these physical quantities by the mass of the cam ring202. This distance can prevent a change in the position of the center of gravity of the physical system from the wide angle end to the telephoto end. The mass of the third lens group173, which is a parameter of the physical quantity A3of the third lens group173, can include the mass of the aperture182.

The sum total of the physical quantity A1of the first lens group171, the physical quantity A2of the second lens group172, the physical quantity A3of the third lens group173, the physical quantity A4of the fourth lens group174, and a physical quantity AC of the cam ring202can be expressed as the sum total ΣA of a physical quantity Ax. In the example illustrated inFIG. 17, the cam ring202can move such that the sum total ΣA of a physical quantity Ax is always zero while the lens device160is changed from the wide angle end to the telephoto end. However, the cam ring202does not necessarily need to move such that the sum total ΣA of a physical quantity Ax is always zero. This is because a drive range of the grooves in the cam ring202is restricted by, for example, a design restriction or the like. In such a case, the cam ring202can move such that, for example, the maximum value of the sum total ΣA of a physical quantity Ax for a case where the lens device160is changed from the wide angle end to the telephoto end is no more than one-third that of a case where the cam ring202does not restrict a change in the position of the center of gravity.

The cam ring202can move such that the width W of the change in position of the center of gravity of the lens device160when the lens device160is changed from the wide angle end to the telephoto end is less than 10% that of a case where the cam ring202does not restrict the change in the position of the center of gravity. In order to keep the optical axis of the lens device160horizontal, drive torque must be applied on the pitch axis of the gimbal110. This drive torque is expressed as C (N·mm). Given this, the cam ring202can move such that a maximum value of the drive torque C when the lens device160is changed from the wide angle end to the telephoto end is less than 10% that of a case where the cam ring202does not restrict the change in the position of the center of gravity.

As described above, a change in the position of the center of gravity of the lens device160associated with the zoom action can be inhibited due to the movement of the cam ring202in the optical axis direction.

In some embodiments, the gimbal110can hold the imaging device140and the lens device160so as to be rotatable on the pitch axis, which runs through the center of gravity of the physical system that includes the imaging device140and the lens device160. As illustrated inFIGS. 18 to 20, the gimbal110can rotate the imaging device140and the lens device160centered on the pitch axis and can hold the imaging device140and the lens device160at various attitudes. In addition, the lens device160can perform the zoom action and the focus action in various attitudes. However, the position of the center of gravity of the lens device160does not change due to the zoom action and the focus action. Therefore, when the position of the center of gravity of the physical system that includes the imaging device140and the lens device160is set on the pitch axis, even when the lens device160performs the zoom action and the focus action in various attitudes, the position of the center of gravity of the physical system that includes the imaging device140and the lens device160can be maintained on the pitch axis. Thus, the drive torque of the pitch axis rotation mechanism112does not change due to differences in the zoom action and the focus action of the lens device160.

The pitch axis of the gimbal110does not necessarily run through the center of gravity of the physical system that includes the imaging device140and the lens device160. The pitch axis of the gimbal110can be defined so as to be positioned within a predetermined range relative to the center of gravity of the physical system that includes the imaging device140and the lens device160. For example, as illustrated inFIG. 18, the predetermined range can be a range spanning from the center of gravity of the physical system to a distance that is one-fourth the total length (H) of the physical system (i.e., H/4).

FIG. 21is an exterior perspective view of one example of a stabilizer800. In the above, the UAV100with the imaging device140and the lens device160installed thereon was described. However, the imaging device140and the lens device160are not necessarily installed on the UAV100. The imaging device140and the lens device160can be installed on a moving body other than the UAV100. For example, a camera unit813provided to the stabilizer800is equivalent to the imaging device140and the lens device160.

The stabilizer800can include the camera unit813, a gimbal820, and a holding arm803. The gimbal820can rotatably support the camera unit813. The gimbal820can include a pan axis809, a roll axis810, and a tilt axis811. The gimbal820can rotatably support the camera unit813to rotate centered on the pan axis809, the roll axis810, and the tilt axis811. The gimbal820is one example of a carrier. The camera unit813is one example of a lens device, or of a lens device and imaging device. The camera unit813can include a slot812for inserting memory. The gimbal820is fixed to the holding arm803via a holder807.

The holding arm803can include various buttons for operating the gimbal820and the camera unit813. The holding arm803can include a shutter button804, a record button805, and an operation button806. By pressing down the shutter button804, a still image can be recorded by the camera unit813. By pressing down the record button805, a moving image can be recorded by the camera unit813.

A device holder801can be fixed to the holding arm803. The device holder801can hold a mobile device802such as a smart phone. The mobile device802can be connected to the stabilizer800via a wireless network such as WiFi, so as to be capable of communication. Thus, an image captured by the camera unit813can be displayed on a screen of the mobile device802.

The present disclosure is described using embodiments, but the technical scope of the disclosure is not limited to the scope in the above embodiments. It should be clear to a person skilled in the art that the above embodiments are open to various modifications or improvements. It should also be clear from the scope of the claims that forms having such modifications or improvements can be included in the technical scope of the present disclosure.

The order of each process in the operations, procedures, steps, stages, and the like of the devices, systems, programs, and methods in the scope of the claims, specification, and drawings is not specifically disclosed using “beforehand,” “in advance,” and the like, and any order is possible as long as a postprocess does not use the output of a preprocess. Even if “first,” “next,” and the like are used for convenience in describing the flow of operations in the scope of the claims, specification, and drawings, it is not meant that it must be executed in this order.

DESCRIPTION OF REFERENCE NUMERALS