JP2016161739A - Imaging device and control method of same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an imaging device that can drive a zoom lens driven at a movement velocity of the zoom lens corresponding to a rotation velocity of a rotation ring in accordance with a taste of a user or shooting situation.SOLUTION: An imaging device is provided that includes a zoom ring provided in a concentric circular shape with respect to a lens optical axis of a zoom lens. The imaging device is configured to: detect a rotation velocity of the zoom ring in responce to an operation of a user; and determine a conversion rate to be used in conversion of the detected rotation velocity of the zoom ring to a movement velocity of the zoom lens.SELECTED DRAWING: Figure 1

Description

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

  An imaging apparatus such as a digital camera is generally provided with an electric zoom. The electric zoom is driven in accordance with an instruction from an operation member such as a zoom lever or a rotating ring. When the indicating member is a rotating ring, the user rotates the rotating ring to drive the zoom lens and adjust the zoom magnification. In order to solve 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 Document 1 discloses a lens that adjusts the operation torque by adjusting the force with which the actuator of the zoom lens presses the restraining member against the rotating ring, and changing the direction and magnitude of the auxiliary torque by changing the frictional force generated by the pressing. An apparatus is disclosed.

JP2013-50686A

  In a digital camera, the driving amount of the zoom lens with respect to the operation amount of the 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. The manner in which the amount of change of the zoom lens with respect to the amount of operation of the rotating ring by the user also varies depending on the shooting situation.

  Further, the lens device disclosed in Patent Document 1 requires a restraining member and an actuator for generating torque for adjusting the torque, resulting in an increase in cost and power consumption. Further, since this lens device is mechanically suppressed by the operation member, there is a possibility that the lens device may be damaged when the rotating ring rotates at a 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 rotating speed of a rotating ring in accordance with a user's preference and shooting conditions.

  An imaging apparatus 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 that detects a rotation speed of the operation member, and the detected operation member. Determining means for determining a conversion rate used for converting a rotation speed into a movement speed of the zoom lens;

  According to the imaging apparatus of the present invention, the zoom lens can be driven at the moving speed corresponding to the rotating speed of the rotating ring in accordance with the user's preference and shooting situation.

It is a figure which shows the structural example of the imaging device of this embodiment. This is a configuration for controlling the driving of the zoom lens by operating the zoom ring. It is a figure explaining an example of the detection of the moving speed of a zoom lens. It is a figure which shows the relationship between a zoom ring speed and a zoom lens speed. It is a flowchart explaining the process which allocates the rotational speed of a zoom ring to the moving speed of a zoom lens. It is a flowchart explaining the process which allocates the rotational speed of a zoom ring to the moving speed of a zoom lens. It is an example of the relationship between the rotational speed of the zoom ring and the moving speed of the zoom lens during moving image shooting and still image shooting.

Example 1
FIG. 1 is a diagram illustrating a configuration example of an imaging apparatus according to the present embodiment.
The imaging apparatus according to the present embodiment is equipped with a function for instructing movement of the zoom lens using a zoom ring. The zoom ring is an operation member provided concentrically with the lens optical axis of the zoom lens.
The imaging apparatus includes a lens barrel 101 to a memory card 111. The lens barrel 101 includes a 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 (image brightness). ing.

  The image sensor 102 converts the optical image obtained by the lens barrel 101 into an electric signal. The imaging signal processing unit 103 converts the video signal transmitted from the imaging element 102 into a signal suitable for storing in the memory card 111. The drive controller 104 performs drive control of each actuator built in the lens barrel 101. A system controller 105 controls the entire imaging apparatus. The camera operation unit 106 is an operation unit used for a user to perform operations such as shooting. When the camera is activated, the program compressed in the flash memory 107 is decompressed / expanded in the program memory 108 and operates according to the program in the program memory 108, and various control operations described below are performed. The image memory 109 temporarily stores captured images. 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, 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. A photoelectric conversion image from the image sensor 102 is read at a predetermined cycle, and is subjected to signal processing by the image signal processing unit 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 period, and simultaneously sent to the display 110 to display the captured image. (Standby standby). In this shooting standby state, shooting is performed by pressing a shooting button (not shown) included in the camera operation unit 106. When the shooting button is pressed, it is read out from the image sensor 102 with a preset exposure time and temporarily stored in the image memory 109. The accumulated image is recorded in the memory card 111 after being converted into optimum data for storage by the imaging signal processing unit 103. In FIG. 1, the memory card 111 for storing the captured image may be an optical disk, a hard disk, a magneto-optical disk, or the like, or a randomly accessible memory composed of a solid-state semiconductor memory such as a FLASH memory or an SRAM / DRAM. Good.

FIG. 2 is a configuration for controlling the driving of the zoom lens by operating the zoom ring in the camera operation unit of the imaging apparatus of the present embodiment.
A system controller 105 controls the entire imaging apparatus. Specifically, the system controller 105 notifies the motor controller 1041 of a drive command 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 control for The drive controller 104 includes a motor control controller 1041, a PWM generation circuit 1042, and a driver circuit 1043. The motor control controller 1041 transmits an output command to the PWM generation circuit 1042 in accordance with the 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 control controller 1041. The driver circuit 1043 generates a drive waveform for driving each actuator in the 101 from the PWM signal from the PWM generation circuit 1042.

  Here, an actuator built in the lens barrel 101 will be described. The 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 drive conditions such as the drive speed, drive amount, and movement direction of each actuator in response to a drive command from the system controller 105. The motor controller 1041 controls the drive state of each actuator in the lens barrel 101 so that the drive condition according to the drive command from the system controller 105 is satisfied.

  When the zoom ring 1061 is rotated by the user, zoom system rotation information detected by an encoder (not shown) in the zoom ring 1061 is notified to the system controller 105. The system controller 105 determines movement information of the zoom lens 1012a based on the rotation information of the zoom ring 1061. The movement information includes, for example, a movement direction, a movement speed, and a movement 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 control controller 1041 determines the drive frequency of the USM 1011a so as to drive the zoom lens 1012a under the drive condition included in the drive command notified from the system controller 105. The motor controller 1041 instructs the PWM generation circuit 1042 to generate a PWM waveform having the determined drive frequency. Then, the motor controller 1041 applies a drive waveform to the USM 1011a via the driver circuit 1043 to drive the USM 1012a. The zoom lens 1012a is provided with an encoder for detecting the driving amount of the lens. The encoder signal detected by the encoder is notified to the motor controller 1041. The motor controller 1041 converts the encoder signal into zoom lens movement information. The motor controller 1041 determines the drive frequency of the drive signal applied to the USM 1011a in the next control cycle 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. To do.

FIG. 3 is a diagram illustrating an example of detection of the moving speed of the zoom lens.
FIG. 3 shows binarized analog signals output from the two-phase encoder for detecting the 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 binary signal of ENCB which is one of the two-phase encoders. FIG. 3C shows an operation clock of the motor controller 1041.

  The system controller 105 detects the moving speed of the zoom lens based on the rising and falling edges of ENCA and ENCB. Specifically, the system controller 105 detects how many control clocks of the motor controller 1041 took between the encoder edges, 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 controller in the present embodiment is 10 kHz. The number _Pc of pulses per encoder phase output per motor rotation is 100. From FIG. 3, the count number C _ZM of the operation clock of the motor 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 depending on which of the ENCA and ENCB encoder waveforms is output first. In this embodiment, when the ENCB pulse is output first, the zoom lens 1012a extends, and conversely, the ENCA pulse is output first. In the example shown in FIG. 3, the zoom lens 1012a is driven in the extending direction.

  Next, an example of detecting 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 in consideration of the moving direction of the zoom lens, and detects the moving distance of the zoom lens using the integrated value of the counts.

  In the present embodiment, the rising and falling edges of each encoder edge are counted. That is, when the zoom lens is driven for one encoder cycle in the extending direction, the number of pulses increases by four. Conversely, when the zoom lens is driven for one encoder cycle in the carry-in direction, four pulses are reduced. 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 in consideration of the rotation direction of the encoder. When driving the zoom lens 1012a, the drive amount is determined according to the zoom operation instruction from the camera operation unit 106, and the zoom lens is driven while being controlled at a designated moving speed until the drive 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 the two-phase encoder signal output when the rotating member is rotated, and calculates the 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 10 MHz. An operation clock count C _r detected between encoder edges is set 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 the zoom lens 1012a is driven by rotating the zoom ring, it is necessary to associate the rotation speed of the zoom ring with the movement speed of the zoom lens. Hereinafter, the association between the rotation speed of the zoom ring and the movement 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 V _{rg_min} be the minimum rotation speed of the zoom ring. Let V _{rg_max} be the minimum rotation speed of the zoom ring. The minimum moving speed of the zoom lens is V _{zm_min} . Let V _{zm_max be} the maximum speed of the zoom lens. The minimum moving speed V _{rg — min} of the zoom ring is determined by the ability of the detection system to detect the rotation speed of the zoom ring.

  When speed detection is performed using an encoder signal, it is necessary to detect the number of clocks using the edge interval of each encoder as an operation clock and store it in a register. The slower the speed, the longer the interval between the edges of the encoder and the greater the number of clocks counted between the edges. Therefore, when the zoom ring is rotated at a low speed, this count value may exceed the maximum value that can be represented by the register. In this case, the speed is not accurately expressed. 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 rotation speed of the zoom ring that can be detected. The rotation speed, rotation amount, and rotation direction of the zoom ring are detected based on information from the two-phase encoder. Therefore, in order to ensure the zoom ring operation, accurate information on the edge interval of the encoder signal is required. However, when the speed of the zoom ring is increased, there is a possibility that a state where 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 a rotation speed equal to or lower than the rotation speed of the zoom ring that can accurately detect rotation information in advance.

On the other hand, the minimum speed and the maximum speed on the zoom lens side take into consideration both the user's feeling of use and the hardware aspect such as the maximum output and power consumption of the actuator (USM in this embodiment) that drives the zoom lens. Determined. The system controller 105 associates the rotation speed of the zoom ring with the movement speed of the zoom lens. Specifically, the zoom lens is driven at the lowest speed when driven at a speed lower than the minimum speed of the zoom ring, and the zoom lens is driven at the highest speed when driven at a speed higher than the maximum speed. Associating is performed as described above (see equation (4)). When the rotation speed of the zoom ring is not less than the minimum speed and not more than the maximum speed of the zoom lens, 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 movement speed of the zoom lens using the speed change rate R shown in Expression (3) and Expression (4).

FIG. 5 is a flowchart for explaining processing for 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 S501, the system controller 105 determines whether the current mode of the imaging apparatus is the speed allocation 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 allocation mode, the process returns to S501. If the current mode is the speed allocation mode, the process proceeds to S502.
In 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 the zoom ring is rotated for a predetermined time from the start of rotation of the zoom ring as the maximum rotation speed of the zoom ring.

  In step S503, the system controller 105 determines whether the maximum rotation speed of the zoom ring set in step S502 is within a settable rotation speed range. The speed range of the rotation speed of the zoom ring is determined in advance depending on whether or not the rotation speed can be accurately detected in consideration of the detection system standard when the ring is rotated at that speed.

  If the maximum rotation speed of the zoom ring set in S502 is outside the settable rotation speed range, the process returns to S502. If the maximum rotation speed of the zoom ring set in S502 is within the settable rotation speed range, 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 moving speed of the zoom lens and stores it in the flash memory.

  In step 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 the zoom ring is rotated 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 a settable rotation speed range. If the minimum rotation speed of the zoom ring set in S505 is outside the settable rotation speed range, the process returns to S505. If the minimum rotation speed of the zoom ring set in S505 is within the settable rotation speed range, 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 movement speed of the zoom lens and stores it in the flash memory.

  In step S <b> 508, the system controller 105 determines a conversion rate used for converting 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 S504, and the minimum movement speed of the zoom lens stored in S504. The speed change rate R is calculated using Equation (3). As shown in Expression (3), the speed change rate R is a ratio of the difference between the maximum moving speed and the minimum moving speed of the zoom lens to the difference between the maximum rotating speed and the minimum rotating speed of the zoom ring. In step S509, the speed change rate R is stored in the flash memory. In S510, the mode is shifted to the shooting mode before the speed allocation mode is canceled and the speed allocation mode is entered. The process 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 user's preference, and as a result, the feeling of use as the imaging device can be improved.

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

FIG. 6 is a flowchart illustrating a process of assigning the rotation speed of the zoom ring to the movement speed of the zoom lens in the second embodiment.
S601 and S603 to 611 in FIG. 6 are the same as S501 to S510 in FIG. In S602 of 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 photographing mode by the processing of S603 to S608.

  Usually, in an imaging apparatus capable of shooting a moving image and a still image, the moving speed of the zoom lens when driving the zoom lens differs between moving image shooting and still image shooting. When driving at a high speed, the driving sound generated when driving the zoom lens becomes loud. Therefore, when the zoom lens is driven at a 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 a still image.

FIG. 7 shows 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 moving image shooting and still image shooting, the rotation speed of the zoom ring corresponding to the moving speed of the zoom lens is set to the same speed during still image shooting and moving image shooting. 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 moving speed of the zoom lens by determining the conversion rate when converting to the moving speed of the zoom lens based on the maximum moving speed of the zoom lens during still image shooting The range of becomes narrower. In such a state, if it is attempted to adjust the moving speed of the zoom lens 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 based on the maximum moving speed of the zoom lens at the time of moving image shooting.

  In this 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 during still image shooting and moving image shooting, respectively. Then, at the time of moving image shooting and still image shooting, the rotation speed of the zoom ring is converted into the moving speed of the zoom lens using the set parameters. 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 task of performing fine adjustment of the speed during moving image shooting is This can be performed more easily than when no change is made at the time of moving image shooting.

  The present invention has been described in detail based on the preferred embodiments thereof, but the present invention is not limited to these specific embodiments, and various forms within the scope of the present invention are also included in the present invention. included. A part of the above-described embodiments may be appropriately combined.

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

  105 System controller

Claims (8)

An operation member provided concentrically with respect to the optical axis of the zoom lens;
Detecting means for detecting the rotational speed of the operating member;
An imaging apparatus comprising: a determining unit that determines a conversion rate used for converting the detected rotation speed of the operating member into a moving speed of the zoom lens. The imaging apparatus according to claim 1, further comprising a control unit that drives and controls the zoom lens based on a moving speed of the zoom lens. The determining means includes
The rotational speed of the operating member corresponding to the minimum moving speed of the zoom lens is the maximum rotational speed of the operating member, and the rotational speed of the operating member corresponding to the minimum moving speed of the zoom lens is the minimum rotational speed of the operating member. As stored in the storage means,
The ratio of the difference between the maximum movement speed and the minimum movement speed of the zoom lens with respect to the difference between the maximum rotation speed and the minimum rotation speed of the operation member is determined as the conversion rate. The imaging device described. 4. The determination unit according to claim 3, wherein the rotation speed of the operation member detected when the operation member is rotated by a user is set to a maximum rotation speed and a minimum rotation speed of the operation member. Imaging device. The imaging device has a still image shooting mode and a moving image shooting mode,
The determining 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 image pickup apparatus according to claim 1, wherein the image pickup apparatus is an image pickup apparatus. 6. 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. Imaging device. When the rotation speed of the operation member is not less than the minimum speed of the operation member and not more than the maximum speed of the operation member, the conversion means converts the rotation speed of the operation member based on the conversion rate of the zoom lens. The imaging device according to any one of claims 1 to 6, wherein the imaging device is converted into a moving speed. A method for controlling an imaging apparatus 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;
A determining step of determining a conversion rate used for converting the detected rotational speed of the operating member into a moving speed of the zoom lens.

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