JP2013024962A - Lens controller, photographic lens, imaging device, and lens control program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control mechanism capable of appropriately driving a focus lens even when there is an instruction input from a user through a general-purpose operation member, since when the function of driving a focus lens is additionally assigned to an operation member to which other functions are assigned, the operation specifications for driving a focus lens is naturally limited to strike a balance with the other functions.SOLUTION: To solve the problem above, a lens control device comprises: an acquisition part that acquires a pulse number per unit time that is outputted by operating an operation member; and an actuator control part that determines that a drive amount per one pulse of an actuator driving a lens in the optical axis direction is a first drive amount when the pulse number per unit time is smaller than a prescribed threshold value, and that the drive amount is a second drive amount greater than the first drive amount when the pulse number is greater than the threshold value.

Description

  The present invention relates to a lens control device, a photographing lens, an imaging device, and a lens control program.

When the focus lens is moved by motor drive to focus the subject image, the continuous drive mode that drives continuously according to the operation time of the operation member by the user, and the minute drive that drives the drive amount determined by one operation A lens control device having a driving mode is known.
[Prior art documents]
[Patent Literature]
[Patent Document 1] JP-A-3-163422

  If an operation member for driving the focus lens can be provided exclusively, an operation member that satisfies various requirements for driving the focus lens can be provided. However, recent cameras have become smaller and lighter, and as much as possible the operation member There is a request to reduce this. Therefore, it is often the case that one operation member accepts operations for a plurality of functions. However, if the focus lens driving function is additionally assigned to the operation member to which another function is assigned, the operation specification is naturally limited due to the balance with the other function. Therefore, there has been a demand for a control mechanism suitable for driving the focus lens even when an instruction is input from a user by a general-purpose operation member.

  In order to solve the above-described problem, the lens control device according to the first aspect of the present invention includes an acquisition unit that acquires the number of pulses per unit time output by operating the operation member, and a pulse per unit time. When the number is smaller than a predetermined threshold value, the driving amount per pulse of the actuator for moving the lens in the optical axis direction is set as the first driving amount. When the number is equal to or larger than the threshold value, the driving amount is larger than the first driving amount. And an actuator control unit as a second drive amount.

  In order to solve the above problem, a photographic lens according to the second aspect of the present invention includes the lens control device described above.

  In order to solve the above problem, an imaging device according to a third aspect of the present invention includes the lens control device described above.

  In order to solve the above problem, the lens control program according to the fourth aspect of the present invention includes an acquisition step of acquiring the number of pulses per unit time output by operating the operation member, and the number of pulses is The driving amount per pulse of the actuator that moves the lens in the optical axis direction is set as the first driving amount when the threshold is smaller than the predetermined threshold, and the second driving amount that is larger than the first driving amount when the threshold is equal to or larger than the threshold. And causing the computer to execute an actuator control step as a driving amount.

  It should be noted that the above summary of the invention does not enumerate all the necessary features of the present invention. In addition, a sub-combination of these feature groups can also be an invention.

It is a back perspective view of the single-lens reflex camera concerning this embodiment. 1 is a block diagram schematically showing a system configuration of a single-lens reflex camera. It is explanatory drawing of the pulse which generate | occur | produces by operation of a rotary dial. It is a flowchart which concerns on switching of a low speed mode and a high speed mode. It is a flowchart of the focus lens drive in power focus. It is explanatory drawing explaining a depth of focus. It is explanatory drawing explaining application of the high speed mode with respect to a different interchangeable lens. It is a flowchart in the case of performing power focus after AF operation. It is a flowchart which concerns on switching of the low speed mode and high speed mode at the time of using a focus evaluation value.

  Hereinafter, the present invention will be described through embodiments of the invention, but 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.

  FIG. 1 is a rear perspective view of a single-lens reflex camera 10 according to the present embodiment. The single-lens reflex camera 10 is configured by mounting an interchangeable lens 20 on a camera body 30. A plurality of interchangeable lenses 20 having different focal lengths, open F values, and the like are attached to the camera body 30 in a replaceable manner.

  The interchangeable lens 20 is provided with a focus lens group in the lens barrel for adjusting the focus of the transmitted subject light beam. The focus lens group adjusts the focal point on the light receiving surface of the image sensor by moving along the optical axis direction. The focus lens group is moved by driving a focus lens motor provided in the lens barrel.

  A rotary dial 31 is provided on the back surface of the camera body 30. The rotary dial 31 can rotate clockwise and counterclockwise around a rotation axis parallel to the optical axis of the interchangeable lens 20 and plays a role as an operation member by the user. The rotary dial 31 is configured such that a click feeling is obtained each time the rotary dial 31 is rotated by a certain angle, and the user can give one input pulse to the camera body 30 for this one click. In the present embodiment, a click feeling is obtained at intervals of 45 °. Therefore, the user can give eight input pulses to the camera body 30 by rotating the rotary dial 31 once.

  An enter button 32 is provided at the center of the rotary dial 31, and the user presses the enter button 32 to set and execute the selected menu item on the camera body 30. A liquid crystal display unit 33 is provided on the back surface of the camera body 30. The liquid crystal display unit 33 displays various setting information, menu items, and the like regarding various settings of the single-lens reflex camera 10 in addition to the image display of the captured image data. Therefore, the user selects and executes a specific item while displaying the image data, menu items, and the like sequentially on the liquid crystal display unit 33 by operating the rotary dial 31, the determination button 32, and other operation members. An instruction to perform can be given to the camera body 30.

  A release button 34 is disposed at a position where the index finger is applied when the user holds the camera body 30 with the right hand. The release button 34 is composed of push buttons that can be detected in two steps in the pressing direction, and executes AF, AE, etc., which are photographing preparation operations, upon detection of SW1, which is the first step pressing, and the second step. The acquisition operation of the subject image as the actual captured image by the image sensor is executed by the detection of SW2 which is the depression of.

  Here, an outline of the focus adjustment by the movement of the focus lens group will be described. As a focus adjustment mode, an autofocus mode, a power focus mode, and a combination mode in which these are used together are prepared. Prior to shooting, the user selects and sets one of the focus adjustment modes by menu selection.

  In the autofocus mode, when the camera body 30 detects SW1 of the release button 34, the focus lens group is automatically moved to a position where the focus lens motor is driven and brought into focus by a known contrast detection method, for example. To do. More specifically, subject images are sequentially acquired while continuously moving the focus lens group, and a focus evaluation value corresponding to the ratio of the high frequency component is calculated from each image, and the focus evaluation value becomes a maximum value. Autofocus is realized by moving the focus lens group to the position. The user can visually recognize the in-focus process by the subject images continuously displayed on the liquid crystal display unit 33.

  In the power focus mode, the camera body 30 detects the rotation operation of the rotary dial 31 by the user, and drives the focus lens motor according to the rotation amount, thereby moving the focus lens group. For example, when the user rotates the rotary dial 31 clockwise, the focus lens group moves from the close end side to the infinite end side. Conversely, when the user rotates counterclockwise, the focus lens group moves from the infinite end side to the close end side. Move to. During this time, the camera body 30 continuously acquires subject images, and the acquired subject images are sequentially displayed on the liquid crystal display unit 33. Therefore, the user can confirm the in-focus state by displaying the liquid crystal display unit 33 while operating the rotary dial 31. Of course, a strict focusing operation can be performed by enlarging a specific subject area using the enlargement display function. Further, the focus evaluation value can be calculated by using continuously obtained subject images and visualized by the liquid crystal display unit 33, thereby assisting the user in focusing work. Specific control of the power focus mode will be described later.

  The combined mode is a mode that allows fine adjustment by power focus after a focusing operation by autofocus. For example, when the user is autofocused on the nose of the person who is the subject, the user can perform fine adjustment such that the eyes are focused by operating the rotary dial 31.

  FIG. 2 is a block diagram schematically showing the system configuration of the single-lens reflex camera 10. The system of the single-lens reflex camera 10 includes a lens control system centered on the lens system control unit 120 and a camera control system centered on the camera system control unit 130 corresponding to each of the interchangeable lens 20 and the camera body 30. Is done. The lens control system and the camera control system exchange various data and control signals with each other via a connection unit connected by the lens mount 121 and the camera mount 131.

  An image processing unit 136 included in the camera control system processes an imaging signal photoelectrically converted by the imaging element 135 into image data in accordance with a command from the camera system control unit 130. The image data processed in the main photographic image is sent to the display control unit 134 and displayed on the liquid crystal display unit 33 for a certain time after shooting, for example. In parallel with this, the processed image data is processed into a predetermined image format and recorded in the external memory via the external connection IF 137.

  The camera memory 132 is a non-volatile memory such as a flash memory, for example, and plays a role of storing a program for controlling the single-lens reflex camera 10, various parameters, and the like. The work memory 133 is a memory that can be accessed at high speed, such as a RAM, and plays a role of temporarily storing image data being processed.

  The operation input unit 138 detects that operation members such as the rotary dial 31, the determination button, the release button 34, and the like have been operated, and outputs them to the camera system control unit 130. The timer 139 is responsible for various timings related to the execution of the program by the camera system control unit 130, starts timing by a reset signal from the camera system control unit 130, and delivers the elapsed time according to the call. The timer 139 can execute a plurality of times in parallel. The focus evaluation unit 140 calculates the focus evaluation value FE from the ratio of the high frequency component of the acquired subject image. A higher focus evaluation value FE means that the contrast of the subject image is higher. That is, it represents a state in which the subject is in focus. Conversely, when the focus evaluation value FE is low, it is determined that the image is a blurred image.

  The lens system control unit 120 receives various control signals from the camera system control unit 130 and executes various operations. The lens memory 122 stores lens-specific information, a program executed by the lens system control unit 120, and the like. The motor drive circuit 123 receives a control signal from the camera system control unit 130 received by the lens system control unit 120 and processes the drive signal, and drives a focus lens motor as an actuator that moves the focus lens group.

  FIG. 3 is an explanatory diagram of pulses generated by operating the rotary dial 31. On / off of the rotary dial 31 is detected by contact or non-contact between the metal brush that rotates together with the rotary member and the fixed contact pattern. Two sets of such metal brushes and contact patterns are prepared as A phase and B phase.

  As shown in the figure, the A phase and the B phase are set to be shifted by a quarter wavelength. That is, the on / off timings associated with the rotation are set so as to deviate from each other. As a result, when the rotary dial 31 is rotated in the clockwise CW direction, the B-phase pulse 302 is detected after the A-phase pulse 301, and the A-phase pulse 301 is detected again with a slight delay. . Conversely, when the rotary dial 31 is rotated counterclockwise in the CCW direction, the A-phase pulse 301 is detected continuously after the B-phase pulse 302, and the B-phase pulse 302 is detected again with a slight delay. . Therefore, the camera system control unit 130 determines the rotation direction and the number of input pulses from the timing pattern and number of such detection pulses received from the operation input unit 138.

  The number of input pulses is counted as one pulse when each of the A-phase pulse 301 and the B-phase pulse 302 is detected once. Further, as described above, when the rotary dial 31 is rotated once, eight input pulses are generated. Therefore, the contact patterns of the A phase and the B phase are also formed at 45 ° intervals.

Next, details of the power focus mode will be described. Power focusing mode according to this embodiment, depending on whether the number of pulses per unit of output time by rotating the dial 31 is operated is greater or smaller than the threshold value p ₀ a predetermined focus per pulse Change the driving amount of the lens motor. More specifically, the amount of movement of the focus lens per click is increased when the rotary dial 31 is rotated quickly, and is decreased when the rotary dial 31 is rotated slowly. That is, the camera system control unit 130 detects the speed at which the rotary dial 31 is turned, and switches the drive of the focus lens motor between the low speed mode and the high speed mode.

  FIG. 4 is a flowchart relating to switching between the low speed mode and the high speed mode. The flow is started when the camera system control unit 130 detects one pulse from the non-operating state of the rotary dial 31.

  When the camera system control unit 130 detects that one pulse is sent from the rotary dial 31, it substitutes 1 for the speed mode flag fg in step S401. The speed mode flag fg being 1 indicates that the low speed mode is selected as the drive mode of the focus lens motor.

Subsequently, the camera system control unit 130 substitutes 1 for the input pulse counter p in step S402, transmits a reset signal to the timer 139 in step S403, and starts the timer t. In step S404, the camera system control unit 130 subsequently determines whether there is a pulse input. If there is a pulse input, the process proceeds to step S405, and the camera system control unit 130 increments the input pulse counter p. This is repeated until the timer t reaches the unit time _{t 0} (step S406). The unit time _{t 0} is set to, for example, about 50 msec.

Upon reaching the unit time _{t 0} at step S406, the process proceeds to step S407, the camera system control unit 130 determines whether the input pulse counter p exceeds the threshold value _{p 0.} Threshold p ₀ is set to, for example, about 3 pulses. If the threshold is exceeded _{p 0,} the process proceeds to step S408, substituting 2 to speed mode flag fg. The speed mode flag fg being 2 indicates that the high speed mode is selected as the drive mode of the focus lens motor. When the input pulse counter p is the threshold value _{p 0} or less, the process proceeds to step S409, the substitutes 1 for speed mode flag fg. If the speed mode flag fg is originally 1, the value of 1 is maintained as it is.

  Then, the camera system control unit 130 proceeds to step S410, and further determines whether or not the rotary dial 31 is operated depending on whether or not there is a pulse input. If it is determined that it has been operated, the process returns to step S402 again, and a series of operations are repeated. When it is determined that the operation has been completed, the series of flows is ended.

  Next, how the focus lens group is moved according to the drive mode of the focus lens motor switched in this way will be described. FIG. 5 is a flowchart of focus lens drive in power focus.

  In the power focus mode, since the focus lens group is driven by the focus lens motor in accordance with the operation of the rotary dial 31, the flow is when the camera system control unit 130 detects one pulse from the non-operating state of the rotary dial 31. Start with. That is, it starts in parallel with the flow of FIG.

  In step S501, the camera system control unit 130 checks whether or not the current speed mode flag fg is 1. In the flow of FIG. 4, 1 is assigned as the default value of the speed mode flag fg in step S401, but the confirmation in step S501 is performed with a slight delay from step S401 in terms of timing. If the speed mode flag fg is 1, it is determined that the low speed mode is selected as the drive mode of the focus lens motor, and in step S502, the camera system control unit 130 moves the focus lens group in the low speed mode.

In the low speed mode, the camera system control unit 130 sends to the lens system control unit 120 a control signal corresponding to mv ₁ which is a predetermined drive amount with respect to one pulse input. When the lens system control unit 120 receives a control signal from the camera system control unit 130, the lens system control unit 120 reads out the characteristics of the focus lens motor stored in the lens memory 122 and generates a drive signal corresponding to mv ₁ . The motor drive circuit 123 receives the drive signal generated by the lens system control unit 120 and drives the focus lens motor by mv ₁ . The focus lens group moves in the optical axis direction according to the drive amount mv ₁ of the focus lens motor. The direction of movement is determined from the infinite end side to the near end side or from the close end side to the infinite end side depending on the rotation direction of the rotary dial 31.

Various types of focus lens motors are employed for the interchangeable lens 20 in accordance with the lens characteristics and the like. For example, when a DC motor is employed, the lens system control unit 120 calculates a rotation amount and a rotation angle corresponding to mv ₁ as the driving amount of the focus lens group. At this time, the type of the focus lens motor, the output reduction ratio, and the like are stored in the lens memory 122 as the characteristics of the focus lens motor.

  In step S501, if the speed mode flag fg is not 1, it is determined to be 2, and it is determined that the high speed mode is selected as the drive mode of the focus lens motor. In step S503, the camera control system 130 moves the focus lens group in the high speed mode.

In the high-speed mode, the camera system control unit 130 sends a control signal corresponding to mv ₂ that is a predetermined driving amount to the input of one pulse to the lens system control unit 120. mv ₂ is set to a value larger than mv ₁ , and for example, about 3 times is set as a constant multiple. Lens system control unit 120 receives a control signal from the camera system control unit 130 reads out the characteristics of the focus lens motor or the like stored in the lens memory 122, it generates a drive signal corresponding to mv _2. The motor drive circuit 123 receives a drive signal generated by the lens system control unit 120 drives the focus lens motor by mv _2.

When the focus lens motor is driven in accordance with the input of one pulse, mv _{1 in} the low speed mode or mv _{2 in the} high speed mode, the camera system control unit 130 continues in step S504 depending on whether or not there is further pulse input. It is determined whether or not the rotary dial 31 is operated. If it is determined that it has been operated, the process returns to step S501 again, and a series of operations are repeated. At this time, since the switching between the low speed mode and the high speed mode shown in the flow of FIG. 4 is executed in parallel, the determination in step S501 is sequentially changed according to the result. If it is determined in step S504 that the operation has been completed, the series of processing ends.

The driving amount mv ₁ may be a fixed value determined in advance, or may be dynamically changed according to the characteristics of the interchangeable lens, the shooting situation, and the like. However, in order to focus the subject image by power focus, the amount of movement of the focus lens group by the drive amount mv ₁ must be less than the depth of focus. This is because if the amount of movement of the focus lens group by the drive amount mv ₁ exceeds the depth of focus, the focus lens group may not be stationary at a position where it is evaluated as in-focus. FIG. 6 is an explanatory diagram for explaining the depth of focus.

  The subject light flux 12 transmitted through the focus lens group 21 along the optical axis 11 is limited by the diaphragm 22 and forms an image near the light receiving surface. At this time, if the circle when the subject light beam is cut in a plane perpendicular to the optical axis is smaller than the allowable circle of confusion δ, it can be evaluated that the subject image in that plane is in focus. That is, if the light receiving surface of the image sensor 135 exists between the DOFs defined along the optical axis direction by the allowable circle of confusion δ, the subject image can be evaluated as being in focus.

  As shown in the figure, the depth of focus DOF varies depending on the focal length of the interchangeable lens, the aperture value, and the distance to the subject. Specifically, the focal depth DOF increases as the aperture value increases, decreases as the focal length increases, and decreases as the subject is closer. If the focusing operation is performed with the aperture open, it also depends on the open F value of the interchangeable lens.

Therefore, the driving amount mv ₁ is a depth of focus DOF ₀ when most reduced at its interchangeable lens 20 as a reference, the driving pitch of the focus lens group is preferably set so that the DOF ₀ or less. Alternatively, the drive amount mv ₁ may be dynamically changed in accordance with the magnitude of the focal depth DOF that varies as described above.

Since the low-speed mode is a mode for strictly adjusting the focus of the subject, it is desirable that the drive amount mv ₁ is determined based on the depth of focus DOF as described above. On the other hand, the high-speed mode is a mode intended to move the focus lens group greatly with a small amount of operation in consideration of the user's intention to rotate the rotary dial 31 vigorously. Therefore, how to determine the drive amount mv ₂ preferable for the high-speed mode will be described.

  FIG. 7 is an explanatory diagram for explaining the application of the high-speed mode to different interchangeable lenses 20. As described above, the user can attach different interchangeable lenses 20 to the camera body 30 in accordance with the shooting intention. Each of the interchangeable lenses 20 differs in characteristics such as a focal length, an open F value, and a shortest shooting distance. Further, the interchangeable lens 20 extends from a close end for focusing on a subject at the shortest shooting distance to an infinite end for focusing on a subject at infinity. The amount of movement of each focus lens group also varies.

For example, as shown in the figure, when trying to move the focus lens group from the infinite end to the close end, the focus lens motor of the interchangeable lens A reaches 1320 rotations, and the interchangeable lens B reaches 2040 rotations. In the case of the interchangeable lens C, it reaches 2400 revolutions. However, if the drive amount mv ₂ is constant regardless of the interchangeable lens, the operation amount from the infinite end to the close end varies for each interchangeable lens. Such a feeling of operation is not preferable for the user.

Therefore, regardless of which interchangeable lens 20 is attached, the drive amount mv ₂ is adjusted so that the operation amount of the rotary dial 31 for moving the focus lens group from the infinite end to the closest end is constant. For example, if the user turns the rotary dial 31 three times, the focus lens group can be moved from the infinite end to the closest end regardless of which interchangeable lens is mounted.

Specifically, the lens system control unit 120 acquires the amount of rotation of the focus lens motor from the infinite end to the closest end from the lens memory 122 and divides it by 24 pulses, which is the number of pulses corresponding to 3 rotations. The driving amount mv ₂ is determined by That is, the driving amount mv ₂ that is the amount of rotation per pulse from the rotary dial 31 is determined to be 55 rotations for the interchangeable lens A, 85 rotations for the interchangeable lens B, and 100 rotations for the interchangeable lens C. If the drive amount mv ₂ is determined in this way, the power focus is easy to operate for the user.

  Next, the combined mode will be described. FIG. 8 is a flowchart when power focus is executed after the AF operation. The flow is started when the focus adjustment by autofocus is completed.

When the focus adjustment by autofocus is completed, the camera system control unit 130 transmits a reset signal to the timer 139 in step S801 to start the timer t. In step S802, it is determined whether there is a pulse input. Without pulse input flow proceeds to step S803, whether the timer off time t ₁ the predetermined has elapsed, it is determined by calling the time measured by the timer 139. If it has not yet elapsed, the process returns to step S802 again. That waits between pulses input to the timer off-time t _1. Timer off time t ₁ is as it is and the series of processing is terminated after the lapse.

  After confirming the pulse input in step S802, the camera system control unit 130 proceeds to step S804 and substitutes 1 for the speed mode flag fg. Then, the process proceeds to step S805, and waits for the user's operation of the rotary dial 31 to end, and the series of processing ends. That is, according to the flow of FIG. 4, the number of pulses per unit time is counted and it is determined whether 1 or 2 is substituted for the speed mode flag fg. Regardless of the number of pulses, the speed mode flag fg is set to 1. That is, the focus lens motor is driven in the low speed mode. In the combined mode, the focus adjustment has already been almost completed by the autofocus, and the user only performs fine adjustment. Therefore, it is better for the user to feel the operation when the focus lens group is moved in the low-speed mode in which the focus lens group is prohibited from being largely moved and the focus of the subject can be strictly adjusted.

  Next, an application example in which the calculation result of the focus evaluation value FE is applied in the power focus mode will be described. FIG. 9 is a flowchart relating to switching between the low speed mode and the high speed mode when the focus evaluation value FE is used. The flow is started when the camera system control unit 130 detects one pulse from the non-operating state of the rotary dial 31.

  When the camera system control unit 130 detects that one pulse has been sent from the rotary dial 31, the camera system control unit 130 acquires the focus evaluation value FE from the focus evaluation unit 140 in step S <b> 901. Note that it is assumed that the subject to be measured for the focus evaluation value FE is determined in advance by a manual operation by the user or that the camera automatically determines the subject to be measured. As a method for the user to determine in advance by manual operation, for example, a method of determining a subject existing in the focus detection area designated by the user as a measurement subject from a plurality of focus detection areas, or a touch panel screen is provided. In the case of a camera, for example, a method of performing a touch operation on a subject displayed on a touch panel screen and determining the subject may be used. On the other hand, as a method for automatic determination by the camera, for example, there is a method for determining a subject (face) detected by well-known face recognition (face detection) as a measurement target subject, or the closest to the camera. For example, a method of determining a subject as a measurement target can be given.

Then, in step S902, the determining whether greater or not than the reference evaluation value FE ₁ determined in advance. The reference evaluation value FE ₁ is a threshold value that can be determined to be about the fine adjustment even when the focus adjustment is performed in the in-focus state. Therefore, when the acquired focus evaluation value FE is larger than the reference evaluation value FE _1, the process proceeds to step S903, 1 is substituted for the speed mode flag fg.

In step S902, the case where the acquired focus evaluation value FE is equal to or less than the reference evaluation value FE _1, the camera system controller 130 proceeds to step S904, the more the obtained focus evaluation value FE reference evaluation value FE ₂ It is determined whether or not it is too small. Reference evaluation value FE ₂ is set from the reference evaluation value FE ₁ to a smaller value, the object image is in a state of a large blur, it is necessary to move the large focusing lens group when performing the focus adjustment It is a threshold value that can be determined. Therefore, when the acquired focus evaluation value FE is smaller than the reference evaluation value FE _2, the process proceeds to step S905, substituting 2 to speed mode flag fg.

In step S904, the case where the acquired focus evaluation value FE is determined as a reference greater than the evaluation value FE _2, the process proceeds to step S906, performs normal processing described with reference to FIG. Then, in step S907, the camera system control unit 130 proceeds to step S908 after driving the focus lens motor in response to one pulse input by mv _{1 in} the low speed mode or mv _{2 in the} high speed mode. Determine if the operation is continuing. If the operation is continued, the process returns to step S901 to execute a series of processes again. That is, the camera system control unit 130 acquires the focus evaluation value FE every time the focus lens group is moved by the drive amount of mv ₁ or mv ₂ , and resets the speed mode. By obtaining the evaluation values in this way, strict focus adjustment and high-speed movement of the focus lens group can be executed smoothly.

If the camera system control unit 130 determines in step S908 that the operation of the rotary dial 31 by the user has ended, the series of processing ends. By processing as described above, if the subject image blur state, even if the number of pulses per unit time is threshold p ₀ or less is set high speed mode, also, substantially focused state object image If so, the low-speed mode is set even when the number of pulses per unit time is larger than the threshold value p _0, so that the in-focus state can be reached quickly.

In the above embodiments, the camera system control unit 130 obtains the number of pulses p per unit time which is output by the rotary dial 31 is operated, whether the pulse number p is greater than the threshold value p ₀ Thus, it was determined whether the driving amount per pulse of the focus lens motor that moves the focus lens group in the optical axis direction is mv ₁ or mv ₂ . That is, the role as the lens control device has been described as being played by the camera system control unit 130 included in the camera body 30. However, the lens system control unit 120 included in the interchangeable lens 20 as a photographing lens may play this role. In this case, a pulse from the rotary dial 31 provided in the camera body 30 is delivered to the lens system control unit 120 via the camera mount 131 and the lens mount 121. Note that the rotary dial 31 may be provided on the interchangeable lens 20 side.

  When the single-lens reflex camera 10 is connected to a computer such as a PC by wire or wirelessly and remotely operated, the remotely operated computer can also serve as a lens control device. In the above-described embodiment, the single-lens reflex camera 10 has been described as an example. However, a mirrorless single-lens camera, a compact camera, or a video camera may be used. Recent imaging devices often have a moving image shooting function, but the power focus is also compatible with moving image shooting. In the above-described embodiment, the movement of the focus lens group has been described as an example. However, the zoom lens group may be similarly moved using another operation member. Further, the operation member is not limited to the rotary dial, and may be, for example, a slide switch as long as the operation member can define the operation amount.

  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 order of execution 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 to”. It should be noted that the output can be realized 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 convenience, it means that it is essential to carry out in this order. It is not a thing.

DESCRIPTION OF SYMBOLS 10 Single-lens reflex camera, 11 Optical axis, 12 Subject light beam, 20 Interchangeable lens, 21 Focus lens group, 22 Aperture, 30 Camera body, 31 Rotation dial, 32 Decision button, 33 Liquid crystal display part, 34 Release button, 120 Lens system control , 121 Lens mount, 130 Camera system control unit, 131 Camera mount, 132 Camera memory, 133 Work memory, 134 Display control unit, 135 Image sensor, 136 Image processing unit, 137 External connection IF, 138 Operation input unit, 301 A Phase pulse, 302 B phase pulse

Claims (13)

An acquisition unit for acquiring the number of pulses per unit time output when the operation member is operated;
When the number of pulses per unit time is smaller than a predetermined threshold, the driving amount per pulse of the actuator that moves the lens in the optical axis direction is set as the first driving amount. A lens control device comprising: an actuator control unit configured to make a second drive amount larger than the first drive amount.   The lens control device according to claim 1, wherein the lens is a focus lens.   The lens control device according to claim 2, wherein the actuator control unit determines the first drive amount based on a depth of focus.   The lens control device according to claim 2, wherein the actuator control unit determines the second drive amount as a constant multiple of the first drive amount.   The actuator control unit determines, as the second drive amount, a value obtained by dividing a drive amount from the closest end to the infinite end of the focus lens in each of a plurality of different photographing lenses by a predetermined number of pulses. Item 5. The lens control device according to any one of Items 2 to 4.   The actuator control unit may move the first drive amount regardless of the number of pulses per unit time when the focus lens is moved by operating the operation member continuously after moving the focus lens by automatic focus adjustment. The lens control device according to any one of claims 2 to 5.   The actuator control unit obtains a focus evaluation value of a predetermined subject area, and when the focus evaluation value satisfies a predetermined condition, the first controller regardless of the number of pulses per unit time. The lens control device according to claim 2, wherein the driving amount and the second driving amount are switched.   The lens control device according to claim 7, wherein the actuator control unit acquires the focus evaluation value every time the focus lens is moved by the first drive amount or the second drive amount.   When the focus evaluation value is smaller than a predetermined evaluation value, the actuator control unit sets the drive amount to the second drive amount even when the number of pulses per unit time is smaller than the threshold value. The lens control device according to claim 7 or 8.   When the focus evaluation value is greater than a predetermined evaluation value, the actuator control unit determines the drive amount as the first drive amount even when the number of pulses per unit time is equal to or greater than the threshold value. The lens control device according to any one of claims 7 to 9.   A photographic lens including the lens control device according to claim 1.   An imaging device including the lens control device according to claim 1. An acquisition step of acquiring the number of pulses per unit time output by operating the operation member;
When the number of pulses is smaller than a predetermined threshold value, the driving amount per pulse of the actuator that moves the lens in the optical axis direction is set as a first driving amount. When the number of pulses is equal to or larger than the threshold value, the first driving is performed. The lens control program which makes a computer perform the actuator control step which makes the 2nd driving amount larger than the amount.

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