JP6659085B2 - Imaging device and control method - Google Patents

Description

  The present invention relates to an imaging device and a control method.

  2. Description of the Related Art An imaging apparatus such as a digital camera generally includes an electric zoom. The electric zoom is driven in accordance with an instruction from an operation member such as a zoom operation lever or a rotating ring. When the pointing member is a rotating ring, the user rotates the rotating ring to drive the zoom lens and adjust the zoom magnification. To address such a problem, an imaging apparatus has been proposed in which the user can freely adjust the operation torque of the rotating ring in order for the user to set a unique operation feeling of the zoom ring. Patent Literature 1 discloses a lens that adjusts a force by which an actuator of a zoom lens presses a suppressing member against a rotating ring, and changes a direction and a magnitude of an auxiliary torque by changing a frictional force generated by the pressing to adjust an operation torque. An apparatus is disclosed.

JP 2013-50686 A

  In a digital camera, a driving amount of a zoom lens with respect to an operation amount of a rotating ring is uniformly determined for each device. Therefore, depending on the user, the change amount of the zoom lens with respect to the operation amount of the rotating ring may feel small or large. How the user perceives the amount of change of the zoom lens with respect to the amount of operation of the rotating ring by the user also differs depending on the shooting situation.

  Moreover, in the lens device disclosed in Patent Document 1, a member for suppressing torque and an actuator for generating torque are required for torque adjustment, which increases costs and power consumption. In addition, since this lens device is mechanically suppressed by the operation member, there is a possibility that the lens will be damaged when the rotating ring rotates at high speed due to generation of high torque.

  An object of the present invention is to provide an imaging apparatus that can be driven at a moving speed of a zoom lens corresponding to a rotation speed of a rotating ring according to a user's preference or a shooting situation.

An imaging device according to an embodiment of the present invention includes an operation member provided concentrically with respect to a lens optical axis of a zoom lens, a detection unit configured to detect a rotation speed of the operation member, and Determining means for determining a conversion rate used to convert a rotation speed to a moving speed of the zoom lens, wherein the determination means is detected by the detection means when the operation member is rotated by a user. The conversion rate is determined based on the rotation speed of the operating member.

  According to the imaging apparatus of the present invention, it is possible to drive the zoom lens at a moving speed corresponding to the rotation speed of the rotating ring according to the user's preference and the shooting situation.

FIG. 2 is a diagram illustrating a configuration example of an imaging device according to the present embodiment. This is a configuration for controlling driving of a zoom lens by operating a zoom ring. FIG. 3 is a diagram illustrating an example of detection of a moving speed of a zoom lens. FIG. 4 is a diagram illustrating a relationship between a zoom ring speed and a zoom lens speed. 9 is a flowchart illustrating a process of assigning a rotation speed of a zoom ring to a movement speed of a zoom lens. 9 is a flowchart illustrating a process of assigning a rotation speed of a zoom ring to a movement speed of a zoom lens. 9 is an example of a relationship between a rotation speed of a zoom ring and a moving speed of a zoom lens during moving image shooting and still image shooting.

(Example 1)
FIG. 1 is a diagram illustrating a configuration example of an imaging device according to the present embodiment.
The imaging apparatus according to the present embodiment has a function of instructing movement of a zoom lens by a zoom ring. The zoom ring is an operation member provided concentrically with respect to the lens optical axis of the zoom lens.
The imaging device includes a lens barrel 101 to a memory card 111. The lens barrel 101 has a built-in zoom lens for adjusting the angle of view, a focus lens for adjusting the focus, a shutter for controlling the exposure time, and a diaphragm for adjusting the amount of light received by the image sensor 102 (brightness of the image). ing.

  The image sensor 102 converts an optical image obtained by the lens barrel 101 into an electric signal. The imaging signal processing unit 103 converts a video signal transmitted from the imaging element 102 into a signal suitable for storing in the memory card 111. The drive controller 104 controls the drive of each actuator built in the lens barrel 101. The system controller 105 controls the entire imaging device. The camera operation unit 106 is an operation unit used by a user to perform operations such as shooting. When the camera is started, the program compressed in the flash memory 107 is decompressed / expanded in the program memory 108, operates according to the program in the program memory 108, and performs various control operations described below. The image memory 109 temporarily stores the captured image. The display 110 displays a captured image.

  Light from the subject is focused on the image sensor 102 through the lens barrel 101 controlled by the lens barrel control unit 105 through a focus, a zoom lens, and the like existing inside the lens barrel 101. The subject image formed on the image sensor 102 is photoelectrically converted into an electric signal. The photoelectrically converted image from the image sensor 102 is read at a predetermined cycle, and is subjected to signal processing by the image signal processor 103 so as to become a standard image signal.

  The signal processed by the imaging signal processing unit 103 is temporarily stored in the image memory 109 as a standard digital image at a predetermined cycle, and is simultaneously sent to the display 110 to display the captured image. (Shooting standby state). In this photographing standby state, photographing is performed by pressing a photographing button (not shown) included in the camera operation unit 106. When the photographing button is pressed, the image is read out from the image sensor 102 for a preset exposure time and temporarily stored in the image memory 109. The stored image is converted into optimal data for storage by the imaging signal processing unit 103 and then recorded on the memory card 111. In FIG. 1, the memory card 111 for storing captured images may be an optical disk, a hard disk, a magneto-optical disk, or the like, or may be a random accessible memory composed of a solid-state semiconductor memory such as a FLASH memory or an SRAM / DRAM. Good.

FIG. 2 illustrates a configuration for controlling the driving of the zoom lens by operating the zoom ring in the camera operation unit included in the imaging apparatus according to the present embodiment.
The system controller 105 controls the entire imaging device. Specifically, the system controller 105 notifies a drive command to the motor controller 1041 in accordance with the operation status of the lens barrel 101 and the image sensor 102, and the actuator 1011 inside the lens barrel 101 performs a predetermined operation. To execute the control for the operation. The drive controller 104 includes a motor control controller 1041, a PWM generation circuit 1042, and a driver circuit 1043. The motor controller 1041 transmits an output command to the PWM generation circuit 1042 according to a drive command from the system controller 105.

  The PWM generation circuit 1042 outputs a PWM signal to the driver circuit 1043 based on the output command received from the motor controller 1041. The driver circuit 1043 generates a drive waveform for driving each actuator inside the 101 from the PWM signal from the PWM generation circuit 1042.

  Here, the actuator incorporated in the lens barrel 101 will be described. USM 1011a is a vibration type motor for driving the zoom lens 1012b. The DC solenoid 1011b drives the shutter 1012b. The stepping motor 1011c drives the focus lens 1012c. The stepping motor 1011d drives the aperture 1012d.

  The motor controller 1041 determines driving conditions such as the driving speed, the driving amount, and the moving direction of each actuator according to a driving command from the system controller 105. Further, the motor controller 1041 controls the driving state of each actuator in the lens barrel 101 so as to satisfy the driving condition according to the driving command from the system controller 105.

  When the user rotates the zoom ring 1061, rotation information of the zoom ring detected by an encoder (not shown) inside the zoom ring 1061 is notified to the system controller 105. The system controller 105 determines the movement information of the zoom lens 1012a based on the rotation information of the zoom ring 1061. The movement information includes, for example, a moving direction, a moving speed, and a moving distance. The system controller 105 notifies the motor control controller 1041 of a drive command including the determined movement information as a drive condition.

  The motor controller 1041 determines the driving frequency of the USM 1011a so as to drive the zoom lens 1012a under the driving conditions included in the driving command notified from the system controller 105. The motor control controller 1041 instructs the PWM generation circuit 1042 to generate a PWM waveform of the determined drive frequency. Then, the motor controller 1041 drives the USM 1012a by applying a drive waveform to the USM 1011a via the driver circuit 1043. The zoom lens 1012a is provided with an encoder for detecting a driving amount of the lens. An encoder signal detected by the encoder is notified to the motor controller 1041. The motor controller 1041 converts the encoder signal into movement information of the zoom lens. Then, based on the converted movement information of the zoom lens 1012a and the movement information included in the drive command from the system controller 105, the motor control controller 1041 determines the drive frequency of the drive signal applied to the USM 1011a in the next control cycle. I do.

FIG. 3 is a diagram illustrating an example of detecting the moving speed of the zoom lens.
FIG. 3 shows a binarized analog signal output from a two-phase encoder for detecting a zoom speed when the zoom lens 1012a is driven under a predetermined driving condition. FIG. 3A shows a binarized signal of ENCA which is one of the two-phase encoders. FIG. 3B shows a binarized signal of ENCB which is one of the two-phase encoders. FIG. 3C shows an operation clock of the motor control controller 1041.

  The system controller 105 detects the moving speed of the zoom lens with reference to the rising and falling edges of ENCA and ENCB. Specifically, the system controller 105 detects how many control clocks of the motor control controller 1041 have taken between each encoder edge, and calculates the moving speed of the zoom lens based on the detection result.

An example of calculating the moving speed V _ZM (unit: rps) from the ENCA cycle T1 shown in FIG. 3 will be described. The clock frequency f _clk of the motor control controller in the present embodiment is 10 kHz. The number of pulses _Pc per encoder phase output per rotation of the motor is 100. According to FIG. 3, the count number C _ZM of the operation clock of the motor control controller detected during the period T1 is 10. Based on these conditions, the moving speed V _ZM is calculated according to the following equation (1).

  Next, an example of detecting the moving direction of the zoom lens will be described. The system controller 105 detects the moving direction of the zoom lens based on which of the encoder waveforms ENCA and ENCB has been output first. In this embodiment, the direction in which the pulse of ENCB is output first is the direction in which the zoom lens 1012a extends, and conversely, the case in which ENCA is output first is the direction in which it is advanced. In the example shown in FIG. 3, the zoom lens 1012a is driven in the extending direction.

  Next, an example of detection of the moving distance of the zoom lens will be described. The system controller 105 counts the falling and rising edges of the ENCA and ENCB encoders taking into account the moving direction of the zoom lens, and detects the moving distance of the zoom lens using the integrated value of the count.

  In this embodiment, the rising edge and the falling edge of each encoder edge are counted. That is, when the zoom lens is driven for one cycle of the encoder in the extending direction, the number of pulses increases by four. Conversely, when the zoom lens is driven for one cycle of the encoder in the rewinding direction, the number of pulses is reduced by 4 pulses. As described above, the moving distance of the zoom lens is managed by adding or subtracting the edge count of the encoder signal output at the time of driving, taking into account the rotation direction of the encoder. When driving the zoom lens 1012a, the driving amount is determined according to a zoom operation instruction from the camera operation unit 106, and the zoom lens is driven while controlling at a specified moving speed until the driving amount is reached.

The method for detecting the rotational speed of the rotating ring is basically the same as the method for detecting the moving speed of the zoom lens. The system controller 105 binarizes a two-phase encoder signal output when the rotating member is rotated, and calculates a rotation speed from the binarized signal. As an example, the clock frequency f _{clk_sys} of the system controller 105 that detects the binarized signal is _set to 10 MHz. The count number C _r of the operation clock detected between encoder edges to 5000. Further, the number of pulses P _r of the encoder per phase output per motor revolution and 1000. The rotation speed V _r (unit is rps) is calculated as follows.

  When driving the zoom lens 1012a by rotating the zoom ring, it is necessary to associate the rotation speed of the zoom ring with the moving speed of the zoom lens. Hereinafter, the association between the rotation speed of the zoom ring and the moving speed of the zoom lens will be described.

FIG. 4 is a diagram showing the relationship between the zoom ring speed and the zoom lens speed.
Let the minimum rotation speed of the zoom ring be V _{rg_min} . Let the minimum rotation speed of the zoom ring be V _{rg_max} . The minimum moving speed of the zoom lens is set to _{Vzm_min} . Let the maximum speed of the zoom lens be _{Vzm_max} . The minimum movement speed V _{rg_min} of the zoom ring is determined by the ability of a detection system that detects the rotation speed of the zoom ring.

  When speed detection is performed using an encoder signal, it is necessary to detect how many clocks the edge interval of each encoder is an operation clock and store it in a register. The slower the speed, the longer the interval between each edge of the encoder and the greater the number of clocks counted between edges. Therefore, when the zoom ring is rotated at a low speed, the count value may exceed the maximum value that can be represented by the register. In this case, the speed will not be accurately represented. In order to prevent such a situation, the system controller 105 sets the rotation speed of the zoom ring that does not exceed the maximum value of the register as the minimum speed.

The system controller 105 sets the maximum zoom ring speed V _{rg_max} based on the maximum detectable zoom ring rotational speed. The rotation speed, rotation amount, and rotation direction of the zoom ring are detected based on the information of the two-phase encoder. Therefore, accurate information on the edge interval of the encoder signal is required to guarantee the zoom ring operation. However, when the speed of the zoom ring is increased, there is a possibility that a state in which an accurate edge interval cannot be detected, that is, so-called skipping may occur. Therefore, when setting the maximum speed of the zoom ring, the system controller 105 sets in advance a rotation speed equal to or lower than the rotation speed of the zoom ring from which rotation information can be accurately detected.

On the other hand, the minimum speed and the maximum speed on the zoom lens side are determined in consideration of both the hardware aspects such as the maximum output and power consumption of the actuator (USM in this embodiment) for driving the zoom lens and the user's feeling of use. Is determined. The system controller 105 associates the rotation speed of the zoom ring with the movement speed of the zoom lens. Specifically, when driven at a speed less than the minimum speed of the zoom ring, the zoom lens is driven at the minimum speed, and when driven at a speed higher than the maximum speed, the zoom lens is driven at the maximum speed. (See Equation (4)). When the rotation speed of the zoom ring is equal to or higher than the minimum speed of the zoom lens and equal to or lower than the maximum speed, that is, when the user moves the zoom ring at a speed between the minimum speed and the maximum speed, the system controller 105 performs the following processing. Execute That is, the system controller 105 converts the rotation speed of the zoom ring into the moving speed of the zoom lens using the speed change rate R shown in Expression (3) and Expression (4).

FIG. 5 is a flowchart illustrating a process of assigning the maximum rotation speed and the minimum rotation speed of the zoom ring to the maximum movement speed and the minimum movement speed of the zoom lens.
First, in step S501, the system controller 105 determines whether the current mode of the imaging device is the speed assignment mode. The speed assignment mode is a mode for assigning the rotation speed of the zoom ring corresponding to the maximum movement speed and the minimum movement speed of the zoom lens.

If the current mode is not the speed assignment mode, the process returns to S501. If the current mode is the speed assignment mode, the process proceeds to S502.
In step S502, when the zoom ring is rotated by the user, the system controller 105 functions as a detection unit that detects the rotation speed of the zoom ring. Specifically, the system controller 105 reads the maximum rotation speed of the zoom ring. The system controller 105 sets the average rotation speed when rotating the zoom ring for a predetermined time from the start of rotation of the zoom ring as the maximum rotation speed of the zoom ring.

  Next, in step S503, the system controller 105 determines whether the maximum rotation speed of the zoom ring set in step S502 is within the range of the settable rotation speed. The speed range of the rotation speed of the zoom ring is predetermined in accordance with whether the rotation speed can be accurately detected in consideration of the standard of the detection system when the ring is rotated at that speed.

  If the maximum rotation speed of the zoom ring set in S502 is out of the range of the settable rotation speed, the process returns to S502. If the maximum rotation speed of the zoom ring set in S502 is within the range of the settable rotation speed, the process proceeds to S504. In step S504, the system controller 105 assigns the rotation speed of the zoom ring set in step S502 to the maximum movement speed of the zoom lens, and stores the rotation speed in the flash memory.

  Next, in S505, when the user rotates the zoom ring, the system controller 105 reads the minimum rotation speed of the zoom ring. The system controller 105 sets the average rotation speed when rotating the zoom ring for a predetermined time from the start of rotation of the zoom ring as the minimum rotation speed of the zoom ring.

  In step S506, the system controller 105 determines whether the minimum rotation speed of the zoom ring set in step S505 is within the range of the settable rotation speed. If the minimum rotation speed of the zoom ring set in S505 is out of the range of the settable rotation speed, the process returns to S505. If the minimum rotation speed of the zoom ring set in S505 is within the range of the settable rotation speed, the process proceeds to S507. In step S507, the system controller 105 assigns the rotation speed of the zoom ring set in step S505 to the minimum moving speed of the zoom lens and stores the rotation speed in the flash memory.

  Next, in step S508, the system controller 105 determines a conversion rate used to convert the rotation speed of the zoom ring into the movement speed of the zoom lens. Specifically, the system controller 105 determines the minimum rotation speed and the maximum rotation speed of the zoom ring, the maximum movement speed of the zoom lens stored in step S504, and the minimum movement speed of the zoom lens stored in step S504. The speed change rate R is calculated using the equation (3). As shown in Expression (3), the speed change rate R is a ratio of the difference between the maximum movement speed and the minimum movement speed of the zoom lens to the difference between the maximum rotation speed and the minimum rotation speed of the zoom ring. Subsequently, in step S509, the speed change rate R is stored in the flash memory. Then, in S510, the mode is shifted to the photographing mode before the speed allocation mode is canceled and the speed allocation mode is entered. The processing for setting the rotation speed of the zoom ring corresponding to the moving speed of the zoom lens has been described above.

  As described above, according to the present embodiment, the rotation speed of the zoom ring corresponding to the moving speed of the zoom lens can be changed to the one intended by the user. Therefore, the moving speed of the zoom lens corresponding to the rotation speed of the zoom ring can be freely changed according to the preference of the user, and as a result, the usability as an imaging device can be improved.

(Example 2)
The imaging apparatus according to the second embodiment separately sets the speed change rate when shooting a moving image and the speed change rate when shooting a still image.

FIG. 6 is a flowchart illustrating processing for assigning the rotation speed of the zoom ring to the moving speed of the zoom lens according to the second embodiment.
Steps S601 and S603 to 611 in FIG. 6 are the same as steps S501 to S510 in FIG. In S602 in FIG. 6, the system controller 105 selects one of the still image shooting mode (first shooting mode) and the moving image shooting mode (second shooting mode). Then, the system controller 105 sets the rotation speed of the zoom ring corresponding to the moving speed of the zoom lens according to the selected shooting mode through the processing of S603 to S608.

  Normally, in an imaging apparatus capable of shooting a moving image and a still image, the moving speed of the zoom lens when the zoom lens is driven is different between when shooting a moving image and when shooting a still image. At the time of high-speed driving, the driving sound generated when driving the zoom lens becomes large. Therefore, when the zoom lens is driven at high speed during moving images, the driving sound of the zoom lens is recorded. As a countermeasure, the moving speed of the zoom lens during moving image shooting tends to be set lower than that of still images.

FIG. 7 is an example of the relationship between the rotation speed of the zoom ring and the moving speed of the zoom lens during moving image shooting and still image shooting.
If the moving speed of the zoom lens is different between movie shooting and still image shooting, if the rotation speed of the zoom ring corresponding to the moving speed of the zoom lens is the same for still image shooting and movie shooting, FIG. As shown, the speed range that does not respond to the rotation speed of the zoom ring increases.

  The rotation speed of the zoom ring that can correspond to the maximum movement speed of the zoom lens when the conversion rate when converting to the movement speed of the zoom lens is determined based on the maximum movement speed of the zoom lens when shooting still images Range becomes narrower. In such a state, if the movement speed of the zoom lens is adjusted by changing the rotation speed of the zoom ring, fine adjustment of the speed becomes difficult. Therefore, at the time of moving image shooting, it is desirable to assign the rotation speed of the zoom ring set based on the maximum moving speed of the zoom lens at the time of moving image shooting.

  In the present embodiment, the rotation speed of the zoom ring corresponding to the moving speed of the zoom lens and the speed change rate R expressed by equation (3) are set at the time of shooting a still image and at the time of shooting a moving image, respectively. At the time of shooting a moving image and at the time of shooting a still image, the rotation speed of the zoom ring is converted into the movement speed of the zoom lens using the parameters set for each. In this way, by changing the rotation speed of the zoom ring corresponding to the moving speed of the zoom lens between moving image shooting and still image shooting, the work of fine-tuning the speed during moving image shooting is This can be performed more easily than when no change is made during video shooting.

  As described above, the present invention has been described in detail based on the preferred embodiments. However, the present invention is not limited to these specific embodiments, and various forms that do not depart from the gist of the present invention are also included in the present invention. included. Some of the above-described embodiments may be appropriately combined.

(Other embodiments)
The present invention supplies a program for realizing one or more functions of the above-described embodiments to a system or an apparatus via a network or a storage medium, and one or more processors in a computer of the system or the apparatus read and execute the program. This processing can be realized. Further, it can be realized by a circuit (for example, an ASIC) that realizes one or more functions.

  105 System controller

Claims (11)

An operation member provided concentrically with respect to the lens optical axis of the zoom lens,
Detecting means for detecting a rotation speed of the operation member;
Determining means for determining a conversion rate used to convert the detected rotation speed of the operation member into the movement speed of the zoom lens,
The imaging device according to claim 1, wherein the determination unit determines the conversion rate based on a rotation speed of the operation member detected by the detection unit when the operation member is rotated by a user. A rotation speed of the operation member corresponding to a maximum movement speed of the zoom lens, based on the operation of the user, and a rotation speed of the operation member corresponding to a minimum movement speed of the zoom lens. The imaging apparatus according to claim 1, further comprising a setting unit configured to set a minimum rotation speed of the operation member, which is a speed. The determination unit determines the conversion rate based on the maximum rotation speed and the minimum rotation speed set by the setting unit, and the maximum movement speed and the minimum movement speed of the zoom lens. The imaging device according to claim 2, wherein: A storage unit configured to store a maximum rotation speed of the operation member and a minimum rotation speed of the operation member set by the setting unit,
The said determination means determines the ratio of the difference of the maximum movement speed and the minimum movement speed of the said zoom lens with respect to the difference between the maximum rotation speed and the minimum rotation speed of the said operation member as said conversion rate. Alternatively, the imaging device according to claim 3. The rotation device according to claim 2, wherein the setting unit sets a rotation speed of the operation member detected when the operation member is rotated by a user as a maximum rotation speed and a minimum rotation speed of the operation member. The imaging device according to claim 1. The imaging device has a still image shooting mode and a moving image shooting mode,
The determination unit separately determines the conversion rate when the shooting mode of the imaging device is the still image shooting mode and the conversion rate when the shooting mode of the imaging device is the moving image shooting mode. The imaging device according to claim 1, wherein: An imaging device having a still image shooting mode and a moving image shooting mode,
An operation member provided concentrically with respect to the lens optical axis of the zoom lens,
Detecting means for detecting a rotation speed of the operation member;
Determining means for determining a conversion rate used to convert the detected rotation speed of the operation member into the movement speed of the zoom lens,
The conversion rate determined by the determining unit is different between a case where the shooting mode of the imaging device is the still image shooting mode and a case where the shooting mode of the imaging device is the moving image shooting mode. Imaging device. The imaging apparatus according to claim 1, further comprising a control unit configured to drive and control the zoom lens based on a moving speed of the zoom lens. 9. The apparatus according to claim 1, further comprising: a conversion unit configured to convert a rotation speed of the operation member into a movement speed of the zoom lens based on the conversion rate determined by the determination unit. 10. Imaging device. A control method of an imaging device including an operation member provided concentrically with respect to a lens optical axis of a zoom lens,
A detection step of detecting a rotation speed of the operation member,
Determining a conversion rate used to convert the detected rotation speed of the operation member to the movement speed of the zoom lens,
In the determining step, when the user rotates the operation member, the conversion rate is determined based on a rotation speed of the operation member detected in the detection step . A control method of an imaging device including an operation member provided concentrically with respect to a lens optical axis of a zoom lens,
A detection step of detecting a rotation speed of the operation member,
Determining a conversion rate used to convert the detected rotation speed of the operation member to the movement speed of the zoom lens,
The control method according to claim 1, wherein the conversion rate determined in the determining step is different between a case where a still image shooting mode is set and a case where a moving image shooting mode is set.

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