WO2018109847A1

WO2018109847A1 - Control device, imaging device, mobile body, control method, and program

Info

Publication number: WO2018109847A1
Application number: PCT/JP2016/087126
Authority: WO
Inventors: 本庄謙一; 永山佳範
Original assignee: エスゼットディージェイアイテクノロジーカンパニーリミテッド
Priority date: 2016-12-13
Filing date: 2016-12-13
Publication date: 2018-06-21
Also published as: JPWO2018109847A1; JP6543878B2

Abstract

It may not be possible to obtain a desired effect when correcting the position of a focus lens according to temperature. This control device may comprise a determination unit that determines correction of the position of a focus lens of an imaging device on the basis of temperature if at least one of the following preset conditions is met: a condition pertaining to an evaluation value for an image captured by the imaging device; a condition pertaining to the distance between the imaging device and a subject; a condition pertaining to the altitude of the imaging device; a condition pertaining to the movement speed of the imaging device; a condition pertaining to the movement speed of the focus lens of the imaging device; and a condition pertaining to whether the imaging device is currently performing contrast AF.

Description

Control device, imaging device, moving body, control method, and program

The present invention relates to a control device, an imaging device, a moving body, a control method, and a program.

A change in temperature may cause a physical change in the imaging device, for example, and a focus position may shift. Therefore, the imaging device may correct the position of the focus lens according to the temperature. In Patent Document 1, when the elapsed time from the power-on to the image input device is included in the time range corresponding to the fluctuation period of the ambient temperature of the distance measuring sensor, the elapsed time corresponds to the stable period of the ambient temperature. It is described that the scanning range of the focus lens in autofocus is set wider than that included in the time range.
Patent Document 1 Japanese Patent No. 4226936

Challenges to be solved

Favorable effects may not be obtained by correcting the position of the focus lens according to the temperature.

General disclosure

A control device according to an aspect of the present invention includes a condition related to an evaluation value of an image captured by an imaging device, a condition related to a distance between the imaging device and a subject, a condition related to an altitude of the imaging device, a condition related to a moving speed of the imaging device, In the case where a predetermined condition including at least one of a condition regarding the moving speed of the focus lens and a condition regarding whether or not the imaging apparatus is performing contrast AF is satisfied, the position of the focus lens of the imaging apparatus is based on the temperature. You may provide the determination part which determines to correct | amend.

The evaluation value may be an evaluation value related to contrast derived by the contrast AF method. The determination unit may determine that the predetermined condition is satisfied when the change amount of the evaluation value per unit time is equal to or less than the threshold, and may determine to correct the position of the focus lens based on the temperature.

The evaluation value may be an evaluation value related to the phase difference derived by the phase difference AF method. The determination unit may determine that the predetermined condition is satisfied when the change amount of the evaluation value per unit time is equal to or less than the threshold, and may determine to correct the position of the focus lens based on the temperature.

The evaluation value may be an evaluation value related to the size of the subject in the image. The determination unit may determine that the predetermined condition is satisfied when the change amount of the evaluation value per unit time is equal to or less than the threshold, and may determine to correct the position of the focus lens based on the temperature.

The determination unit may determine that a predetermined condition is satisfied when the amount of change per unit time of the distance is equal to or less than a threshold, and may determine to correct the position of the focus lens based on the temperature.

The determination unit may determine that the predetermined condition is satisfied when the amount of change per unit time of the altitude is equal to or less than the threshold, and may determine to correct the position of the focus lens based on the temperature.

The determination unit may determine that a predetermined condition is satisfied when the moving speed of the imaging apparatus is equal to or less than a threshold value, and may determine to correct the position of the focus lens based on the temperature.

The determination unit may determine that a predetermined condition is satisfied when the moving speed of the focus lens of the imaging apparatus is equal to or less than a threshold, and may determine to correct the position of the focus lens based on the temperature.

The determining unit may determine that the predetermined condition is satisfied when the imaging apparatus is not performing the contrast AF, and may determine to correct the position of the focus lens based on the temperature.

The determination unit determines that the predetermined condition is satisfied when the other condition that the change amount from the reference temperature of the image pickup apparatus satisfies the condition is at least a threshold is satisfied, and the focus lens satisfies the predetermined condition. May be determined to be corrected based on temperature.

The determination unit may update the reference temperature based on the temperature when the amount of change from the reference temperature is greater than or equal to the threshold value.

The determination unit determines that a predetermined condition is satisfied when the other condition that the amount of movement according to the temperature from the reference position of the focus lens is equal to or greater than the threshold is satisfied. The focus lens position may be determined to be corrected based on the temperature.

The determination unit may update the reference position based on the position of the focus lens when the amount of movement from the reference position is equal to or greater than a threshold value.

An imaging device according to one embodiment of the present invention may include the control device. The imaging device may include a focus lens. The imaging apparatus may include a control unit that controls the focus lens to correct the position of the focus lens in response to the determination unit determining to correct the position of the focus lens based on the temperature.

A moving body according to one embodiment of the present invention is provided with the imaging device.

A control method according to an aspect of the present invention includes a condition related to an evaluation value of an image captured by an imaging apparatus, a condition related to a distance between the imaging apparatus and a subject, a condition related to an altitude of the imaging apparatus, a condition related to a moving speed of the imaging apparatus, In the case where a predetermined condition including at least one of a condition regarding the moving speed of the focus lens and a condition regarding whether or not the imaging apparatus is performing contrast AF is satisfied, the position of the focus lens of the imaging apparatus is based on the temperature. A step of determining to correct may be provided.

A program according to one embodiment of the present invention includes a condition related to an evaluation value of an image captured by an imaging apparatus, a condition related to a distance between the imaging apparatus and a subject, a condition related to an altitude of the imaging apparatus, a condition related to a moving speed of the imaging apparatus, When a predetermined condition including at least one of a condition regarding the moving speed of the focus lens and a condition regarding whether or not the imaging apparatus is performing contrast AF is satisfied, the position of the focus lens of the imaging apparatus is corrected based on the temperature. The computer may execute the step of determining to do.

It is possible to prevent an unfavorable effect from being caused by the imaging device correcting the position of the focus lens according to the temperature.

The above summary of the invention does not enumerate all the features of the present invention. A sub-combination of these feature groups can also be an invention.

It is a figure which shows an example of the external appearance of an unmanned aircraft. It is a figure which shows an example of the functional block of an unmanned aerial vehicle. It is a figure which shows an example of the relationship between the temperature according to a focal distance, and the position of a focus lens. It is a figure which shows an example for demonstrating contrast AF. It is a figure which shows an example for demonstrating contrast AF. It is a figure which shows an example for demonstrating the execution timing of temperature correction. It is a figure which shows an example for demonstrating the execution timing of temperature correction. It is a figure which shows an example for demonstrating the distance of an imaging device and a to-be-photographed object. It is a figure which shows an example for demonstrating the execution timing of temperature correction. It is a figure which shows an example for demonstrating the execution timing of temperature correction. It is a flowchart which shows an example of the execution procedure of temperature correction. 6 is a flowchart illustrating an example of a procedure in which the imaging apparatus performs temperature correction when the temperature changes beyond an allowable temperature range. It is a figure which shows an example of a hardware constitutions.

Hereinafter, the present invention will be described through embodiments of the invention. However, the following embodiments do not limit the invention according to the claims. In addition, not all the combinations of features described in the embodiments are essential for the solving means of the invention.

The claims, the description, the drawings, and the abstract include matters that are subject to copyright protection. The copyright owner will not object to any number of copies of these documents as they appear in the JPO file or record. However, in other cases, all copyrights are withheld.

Various embodiments of the present invention may be described with reference to flowcharts and block diagrams. The blocks in the flowcharts and block diagrams may represent (1) the stage of the process in which the operation is performed or (2) the “part” of the device responsible for performing the operation. Certain stages and “parts” are provided with dedicated circuitry, programmable circuitry supplied with computer readable instructions stored on a computer readable storage medium, and / or computer readable instructions stored on a computer readable storage medium. It may be implemented by a processor. Dedicated circuitry may include digital and / or analog hardware circuitry. Integrated circuits (ICs) and / or discrete circuits may be included. Programmable circuits may be logical products, logical sums, exclusive logical sums, negative logical products, negative logical sums, and other logical operations, such as field programmable gate arrays (FPGAs) and programmable logic arrays (PLA), for example. , Flip-flops, registers, and memory elements, including reconfigurable hardware circuitry.

A computer-readable storage medium may include any tangible device capable of storing instructions to be executed by a suitable device. As a result, a computer readable storage medium having instructions stored thereon comprises a product that includes instructions that can be executed to create a means for performing the operations specified in the flowcharts or block diagrams. Examples of computer readable storage media may include electronic storage media, magnetic storage media, optical storage media, electromagnetic storage media, semiconductor storage media, and the like. More specific examples of computer-readable storage media include floppy disks, diskettes, hard disks, random access memory (RAM), read only memory (ROM), erasable programmable read only memory (EPROM or flash memory). Electrically erasable programmable read only memory (EEPROM), static random access memory (SRAM), compact disc read only memory (CD-ROM), digital versatile disc (DVD), Blu-ray (registered trademark) disc, memory stick Integrated circuit cards and the like may be included.

The computer readable instructions may include either source code or object code written in any combination of one or more programming languages. The source code or object code includes a conventional procedural programming language. Conventional procedural programming languages include assembler instructions, instruction set architecture (ISA) instructions, machine instructions, machine dependent instructions, microcode, firmware instructions, state setting data, or Smalltalk, JAVA, C ++, etc. It may be an object-oriented programming language and a “C” programming language or a similar programming language.

Computer readable instructions may be directed to a general purpose computer, special purpose computer, or other programmable data processing device processor or programmable circuit locally or in a wide area network (WAN) such as a local area network (LAN), the Internet, etc. ). The processor or programmable circuit may execute computer readable instructions to create a means for performing the operations specified in the flowcharts or block diagrams. Examples of processors include computer processors, processing units, microprocessors, digital signal processors, controllers, microcontrollers, and the like.

FIG. 1 shows an example of the appearance of an unmanned aerial vehicle (UAV) 100. The UAV 100 includes a UAV main body 102, a gimbal 200, an imaging device 300, and a plurality of imaging devices 230. The UAV 100 is an example of a moving object. The moving body is a concept including, in addition to UAV, other aircraft that moves in the air, vehicles that move on the ground, ships that move on the water, and the like.

The UAV main body 102 includes a plurality of rotor blades. The UAV main body 102 flies the UAV 100 by controlling the rotation of a plurality of rotor blades. For example, the UAV main body 102 causes the UAV 100 to fly using four rotary wings. The number of rotor blades is not limited to four. Further, the UAV 100 may be a fixed wing aircraft that does not have a rotating wing.

The imaging device 300 is a camera for capturing a moving image or a still image. The plurality of imaging devices 230 are sensing cameras that image the surroundings of the UAV 100 in order to control the flight of the UAV 100. Two imaging devices 230 may be provided on the front surface that is the nose of the UAV 100. Two other imaging devices 230 may be provided on the bottom surface of the UAV 100. The two imaging devices 230 on the front side may be paired and function as a so-called stereo camera. The two imaging devices 230 on the bottom side may also be paired and function as a stereo camera. The distance from the UAV 100 to the object may be measured based on images captured by the plurality of imaging devices 230. Three-dimensional spatial data around the UAV 100 may be generated based on images captured by the plurality of imaging devices 230. The number of imaging devices 230 included in the UAV 100 is not limited to four. The UAV 100 only needs to include at least one imaging device 230. The UAV 100 may include at least one imaging device 230 on each of the nose, the tail, the side surface, the bottom surface, and the ceiling surface of the UAV 100. The angle of view that can be set by the imaging device 230 may be wider than the angle of view that can be set by the imaging device 300. The imaging device 230 may have a single focus lens or a fisheye lens.

FIG. 2 shows an example of functional blocks of the UAV100. The UAV 100 includes a UAV control unit 110, a communication interface 150, a memory 160, a gimbal 200, a rotating blade mechanism 210, an imaging device 300, an imaging device 230, a GPS receiver 240, an inertial measurement device (IMU) 250, a magnetic compass 260, and an atmospheric pressure. An altimeter 270 is provided.

The communication interface 150 communicates with an external transmitter. The communication interface 150 receives various commands for the UAV control unit 110 from a remote transmitter. The memory 160 stores programs necessary for the UAV control unit 110 to control the gimbal 200, the rotary blade mechanism 210, the imaging device 300, the imaging device 230, the GPS receiver 240, the IMU 250, the magnetic compass 260, and the barometric altimeter 270. Store. The memory 160 may be a computer-readable recording medium and may include at least one of flash memory such as SRAM, DRAM, EPROM, EEPROM, and USB memory. The memory 160 may be provided inside the UAV main body 102. The memory 160 may be provided so as to be removable from the UAV main body 102.

The gimbal 200 supports the imaging direction of the imaging device 300 so that it can be adjusted. The gimbal 200 supports the imaging device 300 rotatably around at least one axis. The gimbal 200 is an example of a support mechanism. The gimbal 200 may support the imaging device 300 rotatably about the yaw axis, the pitch axis, and the roll axis. The gimbal 200 may change the imaging direction of the imaging device 300 by rotating the imaging device 300 about at least one of the yaw axis, the pitch axis, and the roll axis. The rotary blade mechanism 210 includes a plurality of rotary blades and a plurality of drive motors that rotate the plurality of rotary blades.

The imaging device 230 captures the surroundings of the UAV 100 and generates image data. Image data of the imaging device 230 is stored in the memory 160. The GPS receiver 240 receives a plurality of signals indicating times transmitted from a plurality of GPS satellites. The GPS receiver 240 calculates the position of the GPS receiver 240, that is, the position of the UAV 100, based on the received signals. The inertial measurement device (IMU) 250 detects the posture of the UAV 100. The IMU 250 detects, as the posture of the UAV 100, acceleration in the three axial directions of the front, rear, left, and upper sides of the UAV 100, and angular velocity in the three axial directions of pitch, roll, and yaw. The magnetic compass 260 detects the heading of the UAV 100. The barometric altimeter 270 detects the altitude at which the UAV 100 flies.

The UAV control unit 110 controls the flight of the UAV 100 in accordance with a program stored in the memory 160. The UAV control unit 110 may be configured by a microprocessor such as a CPU or MPU, a microcontroller such as an MCU, or the like. The UAV control unit 110 controls the flight of the UAV 100 according to a command received from a remote transmitter via the communication interface 150.

The UAV control unit 110 may specify the environment around the UAV 100 by analyzing a plurality of images captured by the plurality of imaging devices 230. The UAV control unit 110 controls the flight while avoiding obstacles based on the environment around the UAV 100, for example. The UAV control unit 110 may generate three-dimensional spatial data around the UAV 100 based on a plurality of images captured by the plurality of imaging devices 230, and control the flight based on the three-dimensional spatial data.

The UAV control unit 110 may measure the distance between the UAV 100 and the object that is the subject by a triangulation method based on a plurality of images captured by the plurality of imaging devices 230. The UAV control unit 110 may measure the distance between the UAV 100 and the object using an ultrasonic sensor, an infrared sensor, a radar sensor, or the like.

The imaging apparatus 300 includes an imaging unit 301 and a lens unit 401. The lens unit 401 may be a lens unit that can be detached from the imaging unit 301. The imaging unit 301 includes an imaging control unit 310, an imaging element 330, and a memory 340. The imaging control unit 310 may be configured by a microprocessor such as a CPU or MPU, a microcontroller such as an MCU, or the like. The imaging control unit 310 may control the imaging device 300 in accordance with an operation command for the imaging device 300 from the UAV control unit 110.

The memory 340 may be a computer-readable recording medium and may include at least one of flash memory such as SRAM, DRAM, EPROM, EEPROM, and USB memory. The memory 340 may be provided inside the housing of the imaging unit 301. The memory 340 may be provided so as to be removable from the housing of the imaging unit 301.

The imaging device 330 may be configured by a CCD or a CMOS. The image pickup device 330 is held inside the housing of the image pickup apparatus 300 and outputs image data of an optical image formed through the plurality of lenses 432 to the image pickup control unit 310. The imaging control unit 310 performs a series of image processing such as noise reduction, demosaicing, gamma correction, and edge cooperation on the image data. The imaging control unit 310 stores image data after a series of image processing in the memory 340. The imaging control unit 310 may output and store the image data in the memory 160 via the UAV control unit 110. The imaging control unit 310 may perform an autofocus operation using image data.

The lens unit 401 includes a lens control unit 410, a memory 420, a lens moving mechanism 430, a plurality of lenses 432, a lens position detection unit 440, and a temperature sensor 450. The plurality of lenses 432 includes a zoom lens and a focus lens. The lens control unit 410 controls the movement of the plurality of lenses 432 in the optical axis direction via the lens moving mechanism 430 in accordance with a lens operation command from the imaging unit 301. The lens control unit 410 controls the movement of the plurality of lenses 432 via the lens moving mechanism 430. Some or all of the plurality of lenses 432 are moved along the optical axis by the lens moving mechanism 430. The lens control unit 410 moves at least one of the plurality of lenses 432 along the optical axis in accordance with a lens operation command from the imaging control unit 310. The lens control unit 410 performs at least one of a zoom operation and a focus operation by moving at least one of the plurality of lenses 432 along the optical axis. The lens position detection unit 440 detects the position of each of the plurality of lenses 432. The lens position detection unit 440 detects the current zoom position and focus position.

The memory 420 stores control values of a plurality of lenses 432 that move via the lens moving mechanism 430. The memory 420 stores, for example, lens specific information such as an F value, a focal length, and an individual number of the lens unit 401 as a control value. The memory 420 may include at least one of flash memory such as SRAM, DRAM, EPROM, EEPROM, and USB memory.

The temperature sensor 450 detects the temperature of the lens unit 401 as the temperature of the imaging device 300. The temperature sensor 450 may be provided in the lens barrel of the lens unit 401 or may be provided outside the lens barrel of the lens unit 401. The temperature sensor 450 may be provided in the housing of the imaging unit 301 or may be provided in the UAV main body 102.

The lens control unit 410 includes a temperature correction unit 412. The temperature correction unit 412 corrects the focus position of the focus lens according to the temperature via the lens moving mechanism 430. A lens barrel or the like constituting the lens unit 401 expands and contracts depending on the temperature. Due to such expansion and contraction, the focus position of the focus lens may shift. Therefore, the temperature correction unit 412 corrects the focus position of the focus lens based on the temperature information from the temperature sensor 450.

The temperature correction unit 412 may correct the focus position according to the temperature based on a predetermined relationship between the temperature and the lens position of the focus lens. For example, as illustrated in FIG. 3, the temperature correction unit 412 uses a function that is defined for each focal length (zoom position) of the lens unit 401 and indicates the relationship between the temperature and the lens position of the focus lens. Correct. The temperature correction unit 412 may correct the focus position by using a function corresponding to each shooting distance indicating the distance between the imaging apparatus 300 and the subject and each focal length. Each function may be stored in memory 420. The memory 420 may store a table indicating the relationship between temperature and lens position for each shooting distance and focal length. The temperature correction unit 412 may specify the lens position of the focus lens and correct the focus position by referring to a table corresponding to the shooting distance and the focal length.

The imaging control unit 310 includes an AF processing unit 312. The AF processing unit 312 may determine the focus position of the focus lens according to the contrast AF method or the phase difference AF method. The AF processing unit 312 may determine the focus position of the focus lens according to the image plane phase difference AF method. While moving the focus lens via the lens control unit 410, evaluation values relating to contrast or phase difference are sequentially derived from the image data output from the image sensor 330. The AF processing unit 312 determines the position of the focus lens when the evaluation value is the highest as the focus position.

For example, according to the contrast AF method, the AF processing unit 312 moves the focus lens from the closest end to the infinity end according to the contrast AF method, and the focus lens when the evaluation value is the highest in the so-called hill-climbing method is shown. Search for the location of. In parallel with the search for the focus position by the AF processing unit 312, the temperature correction unit 412 may execute the correction of the focus position according to the temperature. The degree of focus position correction by the temperature correction unit 412 according to the temperature change is large, and as shown in FIG. 5, there is a possibility that a part of the evaluation value becomes a discontinuous point (a part surrounded by a broken line 600). Due to the presence of such discontinuous points, the AF processing unit 312 may not be able to specify the focus position appropriately.

For example, since the imaging device 300 mounted on a moving body such as the UAV 100 often operates in an environment where the change in the ambient temperature is relatively large, the change in the temperature of the imaging device 300 may be large. Therefore, when contrast AF and temperature correction are performed simultaneously, there is a possibility of affecting the focus position specification.

Further, when the change in the distance between the imaging apparatus 300 and the subject is large, even if the focus position is finely adjusted by the temperature correction, the subject is not focused and the temperature correction effect may be hardly obtained.

Therefore, when it is preferable not to correct the position of the focus lens according to the temperature, the imaging apparatus 300 according to the present embodiment does not execute the temperature correction by the temperature correction unit 412 even if the temperature changes. As a result, the temperature correction unit 412 does not unnecessarily perform temperature correction, thereby reducing the processing burden on the imaging apparatus 300. For example, when the imaging apparatus 300 is mounted on the UAV 100, the temperature varies greatly depending on the altitude. In such a situation, when the imaging apparatus 300 is used, temperature correction may be frequently performed. As a result, the processing load of the imaging apparatus 300 increases, and there is a possibility that problems such as an increase in power consumption or an increase in the amount of heat generated by the CPU or the like may occur. By reducing the frequency with which the temperature correction unit 412 performs the temperature correction, it is possible to reduce the processing load of the imaging apparatus 300 and to prevent such a problem from occurring. Since the contrast AF and the temperature correction are performed in parallel, it is possible to prevent the occurrence of a trouble in specifying the focus position.

In order to control the execution of the temperature correction, the imaging control unit 310 and the determination unit 316 are included. The determination unit 316 includes a condition related to an evaluation value of an image captured by the imaging apparatus 300, a condition related to the distance between the imaging apparatus 300 and the subject, a condition related to the altitude of the imaging apparatus 300, a condition related to the moving speed of the imaging apparatus 300, It is determined whether or not a predetermined condition including at least one of a condition relating to a moving speed of the focus lens and a condition relating to whether or not the imaging apparatus 300 is performing contrast AF is satisfied. The determination unit 316 determines whether or not to correct the position of the focus lens of the imaging device 300 based on the temperature, depending on whether or not a predetermined condition is satisfied. When the determination unit 316 determines that the predetermined condition is satisfied, the determination unit 316 may determine to correct the position of the focus lens based on the temperature.

The evaluation value may be an evaluation value related to contrast derived by the AF processing unit 312 using the contrast AF method. The evaluation value may be an evaluation value related to the phase difference derived by the phase difference AF method in the AF processing unit 312. For example, as illustrated in FIG. 6, the determination unit 316 may determine that the change amount per unit time of the evaluation value of the contrast or the phase difference does not satisfy the predetermined condition in the period T1 higher than the threshold value. The determination unit 316 may determine that a predetermined condition is satisfied in a period in which the evaluation value other than the period T1 is stable. The evaluation value may be an evaluation value related to the distance to the subject derived by the DFD (Depth From Defocus) method.

The evaluation value may be an evaluation value related to the size of the subject in the image captured by the imaging apparatus 300. The determination unit 316 may determine that a predetermined condition is satisfied when the amount of change in the evaluation value per unit time is equal to or less than a threshold value. For example, as shown in FIG. 7, when transitioning from image (A) to image (B), the subject frame 610 of the subject in the image (A) and the subject frame 612 of the subject 500 in the image (B). Since the size does not change, the determination unit 316 determines that a predetermined condition is satisfied. On the other hand, when the image (A) transitions to the image (C), the subject frame 610 of the subject 500 in the image (A) and the subject frame 612 of the subject 500 in the image (B) change in size. The determination unit 316 determines that a predetermined condition is not satisfied.

As illustrated in FIG. 8, the determination unit 316 determines that a predetermined condition is satisfied when the change amount per unit time of the shooting distance X indicating the distance between the subject 500 and the imaging device 300 is equal to or less than a threshold value. You can do it. As illustrated in FIG. 9, the determination unit 316 determines that the predetermined condition is not satisfied in the period T2 and the period T3 in which the shooting distance X changes as the UAV 100 moves or the subject 500 moves. It's okay. On the other hand, the determination unit 316 may determine that a predetermined condition is satisfied in a period other than the period T2 and the period T3.

Even when the altitude of the imaging apparatus 300 changes, the distance between the imaging apparatus 300 and the subject 500 is highly likely to change significantly. Accordingly, the determination unit 316 may determine that a predetermined condition is satisfied when the change amount per unit time of the altitude of the imaging apparatus 300 is equal to or less than a threshold value.

Even when the moving speed of the imaging apparatus 300 is fast, there is a high possibility that the distance between the imaging apparatus 300 and the subject 500 will change significantly. Therefore, the determination unit 316 may determine that a predetermined condition is satisfied when the moving speed of the imaging apparatus 300 is equal to or less than a threshold value.

When the subject being imaged by the imaging device 300 is switched to another subject having a different distance from the imaging device 300 in a relatively short time, the focus position of the imaging device 300 changes greatly. In such a case, there are cases where the effect obtained even if the focus position is corrected by the temperature is small. That is, when the moving speed of the focus lens of the imaging apparatus 300 is fast, there are few effects obtained even if the focus position is corrected by the temperature. Therefore, the determination unit 316 may determine that a predetermined condition is satisfied when the moving speed of the focus lens of the imaging apparatus 300 is equal to or less than a threshold value.

温度 If temperature correction is executed during contrast AF, there may be a problem in specifying the focus position. Therefore, the determination unit 316 may determine that a predetermined condition is satisfied when the imaging apparatus 300 is not performing contrast AF.

If the determination unit 316 satisfies at least one of the above-described conditions and satisfies another condition that the amount of change in the temperature of the imaging apparatus 300 from the reference temperature is equal to or greater than a threshold, You can judge. The determination unit 316 may update the reference temperature based on the temperature when the amount of change from the reference temperature is equal to or greater than the threshold value. Thereby, when the temperature change is small, the temperature correction is not performed, and therefore the frequency of execution of the temperature correction can be suppressed.

The determination unit 316 satisfies a predetermined condition when the other condition that the amount of movement according to the temperature from the reference position of the focus lens satisfies at least one of the above-described conditions and is greater than or equal to the threshold value is satisfied. You may judge. The determination unit 316 may update the reference position based on the position of the focus lens when the amount of movement from the reference position is greater than or equal to the threshold value. Accordingly, when the temperature change is small and the amount of movement of the focus lens is small, the temperature correction is not performed, so that the frequency of performing the temperature correction can be suppressed.

For example, as shown in FIG. 10, an allowable temperature range that is allowed without performing temperature correction due to a temperature change is ± 4 [° C.] with respect to the reference temperature. The determining unit 316 determines that a predetermined condition is satisfied when the temperature change from the reference temperature is ± 4 [° C.] or more. Alternatively, the allowable movement amount of the focus lens without performing the temperature correction due to the temperature change is set as the allowable width σ. The determination unit 316 determines that a predetermined condition is satisfied when the amount of movement of the focus lens from the reference position at the reference temperature is equal to or larger than the allowable width σ.

FIG. 11 is a flowchart showing an example of a temperature correction execution procedure by the imaging apparatus 300.

The determining unit 316 acquires lens information of the lens unit 401 from the lens unit 401 (S100). The lens unit 401 may provide the lens information stored in the memory 340 to the determination unit 316. The memory 340 may store information indicating whether or not the lens is compatible with temperature correction, in addition to the F value and the focal length, as lens information. The determining unit 316 determines whether or not the lens unit 401 is a temperature correction compatible lens based on the lens information (S102).

If the lens unit 401 is a lens that does not support temperature correction, the determination unit 316 ends the process. On the other hand, if the lens unit 401 is a temperature correction compatible lens, the determination unit 316 determines whether or not a predetermined condition for executing temperature correction is satisfied (S104). The determination unit 316 includes a condition related to an evaluation value of an image captured by the imaging apparatus 300, a condition related to the distance between the imaging apparatus 300 and the subject, a condition related to the altitude of the imaging apparatus 300, a condition related to the moving speed of the imaging apparatus 300, It may be determined whether or not a predetermined condition including at least one of a condition relating to a moving speed of the focus lens and a condition relating to whether or not the imaging apparatus 300 is performing contrast AF is satisfied.

If the predetermined condition is not satisfied, the determination unit 316 determines not to correct the position of the focus lens based on the temperature, and instructs the lens unit 401 to interrupt the temperature correction (S110). The temperature correction unit 412 interrupts temperature correction in response to an instruction to interrupt temperature correction.

On the other hand, when the predetermined condition is satisfied, the determination unit 316 determines to correct the position of the focus lens based on the temperature, and instructs the lens unit 401 to execute the temperature correction (S106). When the temperature correction unit 412 receives an instruction to execute the temperature correction and interrupts the temperature correction, the temperature correction unit 412 starts the temperature correction. If the temperature correction is already being executed, the temperature correction unit 412 receives the instruction to execute the temperature correction and continues the temperature correction as it is (S108).

The imaging apparatus 300 repeats the processing from step S104 to step S112 until the imaging processing by the lens unit 401 is completed (S112).

As described above, according to the present embodiment, when it is preferable not to correct the position of the focus lens according to the temperature, the imaging apparatus 300 does not perform temperature correction. Therefore, the frequency of temperature correction can be reduced, and the processing burden on the imaging apparatus 300 can be reduced. By suppressing the frequency of the temperature correction, it is possible to reduce the flicker of the image captured by the imaging apparatus 300 and to prevent the user from feeling uncomfortable.

FIG. 12 is a flowchart illustrating an example of a procedure in which the imaging apparatus 300 performs temperature correction when the temperature changes beyond the allowable temperature range. The imaging apparatus 300 may execute the procedure illustrated in FIG. 12 at a predetermined cycle, for example, at an interval of 1/60 sec.

The determination unit 316 acquires the temperature information Tc in the lens detected by the temperature sensor 450 via the lens control unit 410 (S200). The determination unit 316 derives a difference (Tc−To) between the reference temperature To and the temperature Tc as a temperature change ΔT (S202). The determination unit 316 determines whether or not the magnitude of the temperature change ΔT is 4 ° C. or more (S204). If the magnitude of the temperature change ΔT is within 4 ° C., the determination unit 316 determines that the predetermined condition is not satisfied and ends the process.

On the other hand, if the magnitude of the temperature change ΔT is 4 ° C. or more, then the determination unit 316 determines whether or not the contrast AF is being performed (S206). If the contrast AF is being executed, the determination unit 316 updates the reference temperature To to the temperature Tc and ends the process.

If the contrast AF is not being executed, the determination unit 316 determines that a predetermined condition is satisfied. The determination unit 316 instructs execution of temperature correction. The temperature correction unit 412 corrects the focus position of the focus lens based on the temperature Tc (S208). The determination unit 316 updates the reference temperature To to the temperature Tc and ends the process.

As described above, when the temperature change is small, the temperature correction is not executed, so that the frequency of the temperature correction can be reduced and the processing load on the imaging apparatus 300 can be reduced.

FIG. 13 illustrates an example of a computer 1200 in which aspects of the present invention may be embodied in whole or in part. A program installed in the computer 1200 can cause the computer 1200 to function as an operation associated with the apparatus according to the embodiment of the present invention or as one or more “units” of the apparatus. Alternatively, the program can cause the computer 1200 to execute the operation or the one or more “units”. The program can cause the computer 1200 to execute a process according to an embodiment of the present invention or a stage of the process. Such a program may be executed by CPU 1212 to cause computer 1200 to perform certain operations associated with some or all of the blocks in the flowcharts and block diagrams described herein.

The computer 1200 according to this embodiment includes a CPU 1212 and a RAM 1214, which are connected to each other by a host controller 1210. The computer 1200 also includes a communication interface 1222 and an input / output unit, which are connected to the host controller 1210 via the input / output controller 1220. Computer 1200 also includes ROM 1230. The CPU 1212 operates according to programs stored in the ROM 1230 and the RAM 1214, thereby controlling each unit.

The communication interface 1222 communicates with other electronic devices via a network. A hard disk drive may store programs and data used by CPU 1212 in computer 1200. The ROM 1230 stores therein a boot program executed by the computer 1200 at the time of activation and / or a program depending on the hardware of the computer 1200. The program is provided via a computer-readable recording medium such as a CR-ROM, a USB memory, or an IC card or a network. The program is installed in the RAM 1214 or the ROM 1230 that is also an example of a computer-readable recording medium, and is executed by the CPU 1212. Information processing described in these programs is read by the computer 1200 to bring about cooperation between the programs and the various types of hardware resources. An apparatus or method may be configured by implementing information operations or processing in accordance with the use of computer 1200.

For example, when communication is performed between the computer 1200 and an external device, the CPU 1212 executes a communication program loaded in the RAM 1214 and performs communication processing on the communication interface 1222 based on the processing described in the communication program. You may order. The communication interface 1222 reads transmission data stored in a RAM 1214 or a transmission buffer area provided in a recording medium such as a USB memory under the control of the CPU 1212 and transmits the read transmission data to a network, or The reception data received from the network is written into a reception buffer area provided on the recording medium.

In addition, the CPU 1212 allows the RAM 1214 to read all or necessary portions of a file or database stored in an external recording medium such as a USB memory, and executes various types of processing on the data on the RAM 1214. Good. The CPU 1212 may then write back the processed data to an external recording medium.

Various types of information such as various types of programs, data, tables, and databases may be stored in the recording medium and subjected to information processing. The CPU 1212 describes various types of operations, information processing, conditional judgment, conditional branching, unconditional branching, and information retrieval that are described throughout the present disclosure for data read from the RAM 1214 and specified by the instruction sequence of the program. Various types of processing may be performed, including / replacement, etc., and the result is written back to RAM 1214. In addition, the CPU 1212 may search for information in files, databases, etc. in the recording medium. For example, when a plurality of entries each having an attribute value of the first attribute associated with the attribute value of the second attribute are stored in the recording medium, the CPU 1212 specifies the attribute value of the first attribute. The entry that matches the condition is searched from the plurality of entries, the attribute value of the second attribute stored in the entry is read, and thereby the first attribute that satisfies the predetermined condition is associated. The attribute value of the obtained second attribute may be acquired.

The program or software module described above may be stored in a computer-readable storage medium on the computer 1200 or in the vicinity of the computer 1200. In addition, a recording medium such as a hard disk or a RAM provided in a server system connected to a dedicated communication network or the Internet can be used as a computer-readable storage medium, whereby the program is transferred to the computer 1200 via the network. provide.

As mentioned above, although this invention was demonstrated using embodiment, the technical scope of this invention is not limited to the range as described in the said embodiment. It will be apparent to those skilled in the art that various modifications or improvements can be added to the above-described embodiment. It is apparent from the scope of the claims that the embodiments added with such changes or improvements can be included in the technical scope of the present invention.

The execution order of each process such as operations, procedures, steps, and stages in the apparatus, system, program, and method shown in the claims, the description, and the drawings is particularly “before” or “prior”. It should be noted that they can be implemented in any order unless the output of the previous process is used in the subsequent process. Regarding the operation flow in the claims, the description, and the drawings, even if it is described using “first”, “next”, etc. for the sake of convenience, it means that it is essential to carry out in this order. is not.

100 UAV
102 UAV main body 110 UAV control unit 150 Communication interface 160 Memory 200 Gimbal 210 Rotor wing mechanism 230 Imaging device 240 GPS receiver 260 Magnetic compass 270 Barometric altimeter 300 Imaging device 301 Imaging unit 310 Imaging control unit 312 AF processing unit 316 Determination unit 330 Imaging Element 340 Memory 401 Lens unit 410 Lens control unit 412 Temperature correction unit 420 Memory 430 Lens movement mechanism 432 Lens 440 Lens position detection unit 450 Temperature sensor 1200 Computer 1210 Host controller 1212 CPU
1214 RAM
1220 Input / output controller 1222 Communication interface 1230 ROM

Claims

A condition relating to an evaluation value of an image taken by the imaging device, a condition relating to a distance between the imaging device and a subject, a condition relating to an altitude of the imaging device, a condition relating to a moving speed of the imaging device, and a moving speed of a focus lens of the imaging device If a predetermined condition including at least one of a condition and a condition regarding whether or not the imaging apparatus is performing contrast AF is satisfied, the position of the focus lens of the imaging apparatus is corrected based on the temperature. And a control unit.
The evaluation value is an evaluation value related to contrast derived by a contrast AF method,
The determination unit determines that the predetermined condition is satisfied when the amount of change per unit time of the evaluation value is equal to or less than a threshold, and determines to correct the position of the focus lens based on temperature. The control device according to claim 1.
The evaluation value is an evaluation value related to a phase difference derived by a phase difference AF method,
The determination unit determines that the predetermined condition is satisfied when the amount of change per unit time of the evaluation value is equal to or less than a threshold, and determines to correct the position of the focus lens based on temperature. The control device according to claim 1.
The evaluation value is an evaluation value related to the size of a subject in the image,
The determination unit determines that the predetermined condition is satisfied when the amount of change per unit time of the evaluation value is equal to or less than a threshold, and determines to correct the position of the focus lens based on temperature. The control device according to claim 1.
The determination unit determines that the predetermined condition is satisfied when a change amount of the distance per unit time is equal to or less than a threshold, and determines to correct the position of the focus lens based on temperature. Item 2. The control device according to Item 1.
The determination unit determines that the predetermined condition is satisfied when the amount of change per unit time of the altitude is equal to or less than a threshold, and determines to correct the position of the focus lens based on temperature. Item 2. The control device according to Item 1.
2. The determination unit according to claim 1, wherein the determination unit determines that the predetermined condition is satisfied when the moving speed of the imaging apparatus is equal to or less than a threshold value, and determines to correct the position of the focus lens based on temperature. The control device described.
The determination unit determines that the predetermined condition is satisfied when the moving speed of the focus lens of the imaging apparatus is equal to or less than a threshold, and determines to correct the position of the focus lens based on temperature. Item 2. The control device according to Item 1.
2. The determination unit according to claim 1, wherein when the imaging apparatus is not performing contrast AF, the determination unit determines that the predetermined condition is satisfied and determines to correct the position of the focus lens based on temperature. The control device described.
The determination unit determines that the predetermined condition is satisfied when satisfying another condition that the change amount of the temperature of the imaging apparatus from a reference temperature is equal to or greater than a threshold value, satisfying at least one of the conditions. The control device according to claim 1, wherein the control device determines to correct the position of the focus lens based on temperature.
The control device according to claim 10, wherein the determination unit updates the reference temperature based on a temperature when an amount of change from the reference temperature is equal to or greater than a threshold value.
The determination unit satisfies the predetermined condition when satisfying at least one of the conditions and satisfying another condition that a movement amount according to a temperature from the reference position of the focus lens is equal to or greater than a threshold value. The control device according to claim 1, wherein the control device determines that the position of the focus lens is to be corrected based on temperature.
The control device according to claim 12, wherein the determination unit updates the reference position based on a position of the focus lens when a movement amount from the reference position is equal to or greater than a threshold value.
A control device according to any one of claims 1 to 13,
The focus lens;
An imaging apparatus comprising: a control unit that controls the focus lens to correct the position of the focus lens in response to the determination unit determining to correct the position of the focus lens based on temperature.
A moving body that moves with the imaging device according to claim 14.
A condition relating to an evaluation value of an image taken by the imaging device, a condition relating to a distance between the imaging device and a subject, a condition relating to an altitude of the imaging device, a condition relating to a moving speed of the imaging device, and a moving speed of a focus lens of the imaging device If a predetermined condition including at least one of a condition and a condition regarding whether or not the imaging apparatus is performing contrast AF is satisfied, the position of the focus lens of the imaging apparatus is corrected based on the temperature. A control method comprising the step of:
A condition relating to an evaluation value of an image taken by the imaging device, a condition relating to a distance between the imaging device and a subject, a condition relating to an altitude of the imaging device, a condition relating to a moving speed of the imaging device, and a moving speed of a focus lens of the imaging device If a predetermined condition including at least one of a condition and a condition regarding whether or not the imaging apparatus is performing contrast AF is satisfied, the position of the focus lens of the imaging apparatus is corrected based on the temperature. A program that causes a computer to execute the steps to be performed.