Drive control device, system and method, lens device, and storage medium

Abstract

This invention relates to a drive control device, system, and method, a lens assembly, and a storage medium. The drive control device controls an actuator that causes relative movement between a vibrator and a contact body in contact with the vibrator, causing the vibrator to vibrate by applying a first signal and a second signal having a phase difference. The drive control device includes: a first determining unit configured to determine the phase difference; and a second determining unit configured to determine the voltage amplitude of the electrical power supplied to the actuator, such that the voltage amplitude decreases as the absolute value of the phase difference decreases.

Description

[0001] This application is a divisional application of the invention patent application filed on December 11, 2020, with application number 202011460671.8 and invention title "Drive control device, system and method, lens device and storage medium". Technical Field

[0002] This invention relates to a drive control device, a drive control system, a lens device, a drive control method, and a storage medium. Background Technology

[0003] A vibration actuator includes a vibrator that vibrates by applying two-phase frequency signals with a phase difference, causing the vibrator to vibrate in a manner similar to elliptical motion, and the vibrator moves relative to a contact body in contact with the vibrator. As methods for controlling the drive of a vibration actuator, frequency control by changing the frequency of the two-phase frequency signals and phase difference control by changing the phase difference between the two-phase frequency signals are known. Frequency control and phase difference control are frequently used to drive vibration actuators at high and low speeds, respectively.

[0004] Japanese Patent Application Publication No. 2014-153497 discloses a lens tube in which, when the phase difference is changed during start-up, reversal of the drive direction, or stop of drive, the drive voltage is lower than the drive voltage during normal drive of the vibrating wave motor, so as to suppress noise when the phase difference is changed.

[0005] However, in the lens barrel described in JP 2014-153497, the ratio between the amplitude of the elliptical motion in the direction of travel and the amplitude of the elliptical motion in the direction perpendicular to the direction of travel varies depending on the phase difference. Therefore, as the phase difference decreases, the amplitude in the direction perpendicular to the direction of travel may relatively increase, potentially leading to unwanted vibrations. Although frequency control can suppress vibrations in the direction perpendicular to the direction of travel, power consumption may increase. Summary of the Invention

[0006] The present invention provides a drive control device, a drive control system, a lens device, a drive control method, and a storage medium, which can suppress noise and unwanted vibration and reduce power consumption when the vibration actuator is driven at low speed.

[0007] According to one aspect of the invention, a drive control device controls an actuator that causes a vibrator and a contact body in contact with the vibrator to move relative to each other, and causes the vibrator to vibrate by applying a first signal and a second signal having a phase difference. The drive control device includes: a first determining unit configured to determine the phase difference; and a second determining unit configured to determine the voltage amplitude of the power supplied to the actuator such that the voltage amplitude decreases as the absolute value of the phase difference decreases.

[0008] Other aspects of the present invention include a drive control system comprising the aforementioned drive control device, a drive control method corresponding to the aforementioned drive control device, and a storage medium storing computer programs that enable a computer to be used as various units of the drive control device.

[0009] Other features of the invention will become clear from the following description of exemplary embodiments with reference to the accompanying drawings. Attached Figure Description

[0010] Figure 1 This is a block diagram illustrating the drive control system according to the first embodiment.

[0011] Figure 2 This is a construction diagram showing a vibration actuator according to the first embodiment.

[0012] Figure 3 This is a graph showing the relationship between the drive signal and the speed for a vibration actuator according to the first embodiment.

[0013] Figure 4A and Figure 4B This is a diagram illustrating an example of the relationship between phase difference and duty cycle according to the first embodiment.

[0014] Figure 5 This is a flowchart illustrating a method for driving a vibration actuator by controlling a phase difference according to a first embodiment.

[0015] Figure 6 This is a block diagram illustrating the drive control system according to the second embodiment.

[0016] Figure 7 This is a block diagram illustrating a lens-interchangeable digital single-lens reflex camera as an example of a camera device according to the second embodiment.

[0017] Figure 8A and Figure 8B This is a diagram illustrating an example of the relationship between phase difference and duty cycle according to the second embodiment.

[0018] Figure 9 This is a flowchart illustrating a method for driving a vibration actuator by phase difference control according to a second embodiment.

[0019] Figure 10 This is a block diagram illustrating a drive control system according to a third embodiment.

[0020] Figures 11A to 11C This is a diagram illustrating an example of the relationship between velocity, acceleration, and duty cycle according to the third embodiment.

[0021] Figure 12This is a flowchart illustrating a method for driving a vibration actuator by phase difference control according to a third embodiment.

[0022] Figure 13 This is a block diagram illustrating the drive control system according to the fourth embodiment.

[0023] Figure 14A and Figure 14B This is a diagram illustrating an example of the relationship between phase difference and duty cycle according to the fourth embodiment.

[0024] Figure 15 This is a flowchart illustrating a method for driving a vibration actuator by phase difference control according to a fourth embodiment. Detailed Implementation

[0025] The embodiments of the invention will now be described with reference to the accompanying drawings. Corresponding elements in the drawings will be indicated by the same reference numerals, and their descriptions will be omitted.

[0026] First Embodiment

[0027] Figure 1 This is a block diagram illustrating a drive control system 101 according to this embodiment. The drive control system 101 includes a drive control device 102, a detector 111, and a vibration actuator 112.

[0028] Figure 2 This is a block diagram illustrating a vibration actuator 112 according to this embodiment. The vibration actuator 112 includes a contact body 201 and a vibrator 205. The contact body 201 and the vibrator 205 are pressurized and in contact with each other. The vibrator 205 includes a metallic elastomer 203 with protrusions 202 and an electromechanical energy conversion element (piezoelectric element) 204 engaged with the metallic elastomer 203. A two-phase drive signal having a phase difference and changing periodically is applied to the piezoelectric element 204, thereby causing elliptical motion vibration. The drive signal is a square wave signal, and the ratio of the pulse width of the square wave to one period is called the duty cycle. When the duty cycle increases, the voltage amplitude of the power supplied to the vibration actuator 112 increases. When the duty cycle decreases, the voltage amplitude of the power supplied to the vibration actuator 112 decreases.

[0029] The vibration actuator 112 is driven at a low speed by phase difference control and at a high speed by frequency control. Figure 3 This is a graph showing the relationship between the drive signal of the vibration actuator 112 and the speed. The horizontal axis represents frequency, and the vertical axis represents speed. Figure 3Three phase differences of 90 degrees, 60 degrees, and 30 degrees are shown. During phase difference control, the frequency is fixed at the starting frequency, and the vibration actuator 112 is driven by changing the phase difference. The phase difference is a value with a sign, and the sign indicates the direction of travel of the vibration actuator 112. During frequency control, the phase difference is fixed, and the vibration actuator 112 is driven by changing the frequency from the starting frequency.

[0030] In this embodiment, phase difference control with a phase difference of -90 degrees to 90 degrees is performed in the low-speed region below v301. In the high-speed region above v301, frequency control is performed to fix the phase difference at 90 degrees or -90 degrees. In frequency control, the phase difference can be set to another value. The voltage amplitude of the power supplied to the vibration actuator 112 is adjusted by the ratio of the pulse width, i.e., the duty cycle. The voltage amplitude can be adjusted by methods other than pulse width modulation. In addition to pulse width modulation, a linear method can also be used as a method for adjusting the voltage amplitude. In the following description, an example of adjusting the voltage amplitude by adjusting the duty cycle is described, but the duty cycle can be simply understood as the voltage amplitude.

[0031] Vibration actuator 112 in Figure 2 It moves in the x-direction.

[0032] The drive control device 102 includes a controller 103, a signal generator 108, and a drive circuit 109. The detector 111 includes a position sensor configured to detect the position of the vibration actuator 112. The position sensor is an optical encoder comprising an optical scale with a striped pattern and an optical sensor that receives light emitted from a light emitter and reflected by the optical scale.

[0033] The controller 103 includes a CPU, etc., which is configured to periodically execute various processes and to control the frequency, phase difference, duty cycle, etc. of the two-phase drive signals (first signal and second signal) applied to the vibration actuator 112. The controller 103 includes a target value input unit 104, a control quantity calculator 105, a phase difference frequency determiner 106 as a first determiner, a duty cycle determiner 107 as a second determiner, and a position calculator 110.

[0034] The target value input unit 104 is configured to set a target position to which the vibration actuator 112 will move. The target position is a command value that changes over time and is calculated periodically until the vibration actuator 112 moves to the final stop position.

[0035] The position calculator 110 is configured to calculate position information about the position of the vibration actuator 112 by using a digital signal acquired by an AD converter that converts an analog signal output from a detector 111.

[0036] The control quantity calculator 105 is configured to calculate the control quantity using PID control based on the difference between the target position of the vibration actuator 112, which is periodically obtained from the target value input unit 104, and the current position of the vibration actuator 112, which is input from the position calculator 110. P represents proportional control, I represents integral control, and D represents derivative control.

[0037] The phase difference frequency determiner 106 is configured to determine the frequency and phase difference of the two-phase drive signal used to control the drive of the vibration actuator 112 by using the control quantity calculated by the control quantity calculator 105.

[0038] Duty cycle determiner 107 is configured to determine the duty cycle based on the phase difference determined by phase difference frequency determiner 106. By determining the duty cycle, the voltage amplitude of the power supplied to vibration actuator 112 is determined.

[0039] The signal generator 108 is configured to generate two-phase drive signals based on the frequency, phase difference and duty cycle set by the controller 103, and is configured to output the two-phase drive signals to the drive circuit 109.

[0040] Since the two-phase drive signal obtained from the signal generator 108 is insufficient to drive the vibration actuator 112, the drive circuit 109 amplifies the voltage and power and applies the two-phase drive signal to the vibration actuator 112.

[0041] In the following text, reference will be made to Figure 4A and Figure 4B Describe a method for determining the duty cycle based on the phase difference. Figure 4A and Figure 4B This is a diagram illustrating an example of the relationship between phase difference and duty cycle. Figure 4A In the diagram, the horizontal axis represents the control quantity calculated by the control quantity calculator 105, and the vertical axis represents the phase difference. Figure 4B In the diagram, the horizontal axis represents the control quantity calculated by the control quantity calculator 105, and the vertical axis represents the duty cycle.

[0042] When the control quantity is the value indicated by the dashed line 401 (= zero), the phase difference is zero. At this time, the duty cycle is d41. As the control quantity increases from zero, the phase difference increases. The duty cycle increases linearly with the increase in phase difference. When the control quantity is the value indicated by the dashed line 403, the duty cycle is d42. When the control quantity becomes greater than the value indicated by the dashed line 403, the drive control device 102 changes the drive control method of the vibration actuator 112 from phase difference control to frequency control. In frequency control, the phase difference is constant at 90 degrees, and the duty cycle is also constant at d42.

[0043] As the control quantity decreases from zero, the phase difference decreases and becomes negative. The sign of the phase difference indicates the direction of travel, and a negative phase difference indicates the opposite direction of travel. When the phase difference is negative, the duty cycle is determined based on the absolute value of the phase difference. That is, the duty cycle increases as the phase difference decreases. When the control quantity is the value indicated by the dashed line 402, the duty cycle is d42. When the control quantity becomes less than the value indicated by the dashed line 402, the drive control device 102 switches the drive control method of the vibration actuator 112 from phase difference control to frequency control. In frequency control, the phase difference is constant at -90 degrees, and the duty cycle is also constant at d42.

[0044] As described above, in this embodiment, the duty cycle decreases as the absolute value of the phase difference decreases. That is, as the absolute value of the phase difference decreases, the voltage amplitude of the power supplied to the vibration actuator 112 decreases.

[0045] As the absolute value of the phase difference decreases, the elliptical motion moves in a direction perpendicular to the direction of travel of the vibration actuator 112. Figure 2 The direction of the x-direction in ( Figure 2 The vibration component in the y-direction increases. In this embodiment, as the absolute value of the phase difference decreases, the duty cycle decreases, that is, the voltage amplitude decreases, making it possible to suppress the vibration component of the elliptical motion in the direction perpendicular to the direction of travel. By suppressing the vibration component in the direction perpendicular to the direction of travel, noise and unwanted vibration can be suppressed, and power consumption can be reduced.

[0046] In the following text, reference will be made to Figure 5 The process is described as follows: When the vibration actuator 112 is moved to the final stop position (i.e. the final target position), the phase difference and duty cycle are determined by phase difference control and a drive signal is output. Figure 5 This is a flowchart illustrating a method for driving a vibration actuator 112 by phase difference control according to this embodiment. As described above, in phase difference control, the frequency is fixed at the starting frequency.

[0047] In step S501, the target value input unit 104 sets the target position to which the vibration actuator 112 is moved.

[0048] In step S502, the controller 103 calculates the difference, i.e., the deviation, between the target position to which the vibration actuator 112 is moved and the position of the vibration actuator 112 obtained from the position information detected by the detector 111.

[0049] In step S503, the control quantity calculator 105 uses PID control to calculate the control quantity based on the difference calculated in step S502.

[0050] In step S504, the phase difference frequency determiner 106 determines the phase difference based on the control quantity calculated in step S503.

[0051] In step S505, the duty cycle determiner 107 uses... Figure 4A and Figure 4B The relationship shown is used to determine the duty cycle based on the phase difference determined in step S504. In this embodiment, the duty cycle is used. Figure 4A and Figure 4B The relationship shown can be used with... Figure 4A and Figure 4B The relationships shown are different.

[0052] In step S506, the signal generator 108 generates a two-phase drive signal with a phase difference based on the phase difference, frequency, and duty cycle, and outputs the two-phase drive signal to the drive circuit 109. The controller 103 stores the phase difference, frequency, and duty cycle as set values.

[0053] As described above, when the vibration actuator 112 is driven at a low speed, this embodiment can reduce power consumption and suppress noise and unnecessary vibration by controlling the duty cycle according to the phase difference.

[0054] Second Embodiment

[0055] Figure 6 This is a block diagram illustrating a drive control system 101 according to this embodiment. The controller 103 of this embodiment includes a phase difference duty cycle interlock control execution determiner 601. The phase difference duty cycle interlock control execution determiner 601 is configured to determine whether to determine the duty cycle based on the phase difference, depending on whether the vibration actuator 112 is to be operated or the operating mode of the vibration actuator 112. Since other configurations of the drive control system 101 of this embodiment are the same as those of the drive control system 101 of the first embodiment, their detailed description will be omitted.

[0056] Figure 7 This is a block diagram illustrating a lens-interchangeable digital SLR camera, an example of a camera device with a drive control system 101. In this embodiment, the drive control system 101 is used to drive a focusing lens unit 753, which is an optical unit described later. The digital SLR camera includes a camera body 701 and a lens assembly 750. The camera body 701 is mechanically and electrically connected to the lens assembly 750 and supplies power to the lens assembly 750 via a power terminal.

[0057] First, the structure of the main body 701 of the digital single-lens reflex camera will be described.

[0058] The imaging unit 704 includes an image sensor such as a CCD or CMOS sensor, and is configured to convert an optical image, whose light intensity is adjusted by the shutter 703, into an electrical signal. The A / D converter 705 is configured to convert the analog signal output from the imaging unit 704 into a digital signal. The image processor 708 is configured to perform pixel interpolation, resizing, or color conversion processing on data from the A / D converter 705 or data from the memory controller 709. The image processor 708 is configured to perform predetermined calculations using captured still image data. The camera system controller 702 is configured to perform exposure control and focus detection control using the calculation results obtained from the image processor 708. It performs TTL (through-the-lens) AF (autofocus), AE (auto exposure), and EF (pre-flash) processing. The image processor 708 performs predetermined calculations using captured still image data to perform TTL (automatic white balance) processing based on the acquired calculation results.

[0059] Output data from A / D converter 705 is written to memory 710 via image processor 708 and memory controller 709, or via memory controller 709. Memory 710 is configured to store still image data from A / D converter 705 and still image data to be displayed on display 707. Memory 710 also serves as a memory for displaying still images (video memory). D / A converter 706 is configured to convert the still image data stored in memory 710 into an analog signal and supply the analog signal to display 707. The still image data stored in memory 710 is displayed on display 707 via D / A converter 706.

[0060] The display 707 is a display such as an LCD, and is configured to display based on analog signals from a D / A converter 706. An A / D converter 705 performs A / D conversion on the digital signals. A memory 710 accumulates the digital signals. Subsequently, the digital signals are converted from analog to analog by the D / A converter 706, sequentially sent to the display 707, and displayed, thereby enabling the display of a through-still image, i.e., live view display.

[0061] The non-volatile memory 712 is a memory that is an electrically erasable and recordable medium, such as an EEPROM. The non-volatile memory 712 stores constants, programs, etc., used for the operation of the camera system controller 702.

[0062] The camera system controller 702 includes at least one CPU or circuitry and is configured to control the entire digital single-lens reflex camera. The camera system controller 702 is configured to execute a program recorded in non-volatile memory 712. System memory 711 is, for example, RAM. In system memory 711, constants, variables, programs, etc., read from non-volatile memory 712 are expanded for the operation of the camera system controller 702. The camera system controller 702 is configured to control the display by controlling the image processor 708, memory controller 709, and memory 710.

[0063] The operation unit 713, shutter button 715, and mode selection switch 716 are operation units used to input various operation commands to the camera system controller 702. Through the operation mode selection switch 716, the operation mode of the camera system controller 702 can be switched to any of the following: still image recording mode, motion image recording mode, playback mode, etc. Still image recording modes include, for example, automatic recording mode, automatic scene detection mode, manual mode, various scene modes for recording settings in various shooting scenarios, program AE mode, and custom mode.

[0064] During the operation of shutter button 715, the first shutter switch 720 is activated by a so-called half-press, which serves as a camera preparation command, and a first shutter switch signal SW1 is generated. When the first shutter switch signal SW1 is generated, operations such as AF processing, AE processing, AWB processing, and EF processing begin.

[0065] When the operation of the shutter button 715 is completed, the second shutter switch 721 is activated by a so-called full press, which serves as a recording command, and a second shutter switch signal SW2 is generated. When the second shutter switch signal SW2 is generated, the camera system controller 702 begins a series of operations for image processing, from reading signals from the imaging unit 704 to writing still image data to the recording medium 724.

[0066] When various function icons displayed on the display 707 are selected and operated, functions are appropriately assigned to each operation component of the operation unit 713 for each scenario, and each operation component is used as a function button.

[0067] The power switch 717 is an operating unit configured to switch the power on / off of the main body 701 of the digital single-lens reflex camera. The power controller 718 includes a battery detection circuit, a DC-DC converter, a switching circuit for switching which blocks are to be powered, etc., to detect whether a battery is installed, the battery type, and the remaining battery power. The power controller 718 is configured to control the DC-DC converter based on the detection results and instructions from the camera system controller 702, and to supply the required voltage to each unit, including the recording medium 724, during the required time period. The power supply unit 719 includes primary batteries such as alkaline and lithium batteries, secondary batteries such as NiCd, NiMH, and Li batteries, an AC adapter, etc.

[0068] Recording medium I / F 723 is an interface to recording medium 724, such as a memory card or a hard disk. Recording medium 724 is a recording medium such as a memory card for recording captured still images, and includes semiconductor memory, optical disc, magnetic disk, etc.

[0069] The camera communicator 714 is configured to give desired operating instructions, such as instructions for driving the focusing lens and aperture, to the lens assembly 750 via the lens communicator 759, and is configured to send / receive necessary information.

[0070] Next, the construction of the lens assembly 750 will be described.

[0071] The lens assembly 750 includes a camera optical system having an aperture 752, a focusing lens unit 753, a zoom lens unit 754, and a front lens unit 755.

[0072] The lens system controller 751 is a computer including a CPU, and is configured to control the entire lens assembly 750, including an aperture driver 756, a focus driver 757, a focus detector 758, a lens communicator 759, and a memory 760. The lens system controller 751 is configured to send information to / receive information from the digital SLR camera body 701 via the lens communicator 759.

[0073] The aperture driver 756 is configured to control the aperture 752 and perform light adjustment operations according to instructions from the lens system controller 751.

[0074] The focus driver 757 includes a drive control system 101 and is configured to drive the focusing lens unit 753 in the optical axis direction, which is the x-direction, according to instructions from the lens system controller 751, in order to adjust the focus.

[0075] The operation switch 763 includes a manual operation switch for zooming and focusing, an aperture switch, and a setting switch for switching between automatic and manual modes.

[0076] The focal length detector 758 is configured to detect the focal length of the camera optics by using a zoom position sensor, such as a variable resistor, to detect the position of the zoom lens unit 754.

[0077] The memory 760 includes ROM, RAM, etc., and is configured to store the product model, serial number, focal length information, focus sensitivity information, etc. of the lens device 750.

[0078] Temperature detector 761 can detect the environment using lens device 750.

[0079] The orientation detector 762 is configured to detect the orientation, i.e., position, of the lens assembly 750 relative to the direction of gravity, which is the y-direction. An accelerometer or similar sensor can be used as the orientation detector 762. Based on the orientation detected by the orientation detector 762, it can be determined whether the lens assembly 750 is in a horizontal or vertical position.

[0080] For example, when the shutter button 715 is half-pressed and an operation for detecting focus is performed, the camera system controller 702 sends a drive command for the focusing lens unit 753 to the lens system controller 751 via the camera communicator 714 and the lens communicator 759. The drive command for the focusing lens unit 753 is calculated based on the amount of movement and speed of the focusing lens unit 753 towards the focus position, taking into account the amount of defocusing corresponding to the phase difference of the signal from the subject image. When the lens system controller 751 receives the drive command for the focusing lens unit 753, it moves the focusing lens unit 753 to the focus position via the focus driver 757. The lens system controller 751 then sends information about the shooting mode to the focus driver 757.

[0081] In the following description, the drive control of the focusing lens unit 753 will be described with the still image mode or the motion image mode selected using the mode selection switch 716. The image mode selected by the mode selection switch 716 is transmitted to the lens assembly 750 via the camera communicator 714 and the lens communicator 759. The still image mode requires a wide speed range from low to high. In the motion image mode, the speed can be relatively low, but quiet operation is required.

[0082] The control of duty cycle relative to phase difference will be described according to the camera mode. Figure 8 is a diagram illustrating an example of the relationship between phase difference and duty cycle in this embodiment. Since the relationship between phase difference and duty cycle in the still camera mode is the same as described in the first embodiment... Figure 4A and Figure 4BThe relationships shown are the same, so their detailed description will be omitted. In motion camera mode, since the duty cycle is not controlled based on the phase difference, the duty cycle is always constant at d81, regardless of the phase difference.

[0083] Figure 9 This is a flowchart illustrating a method for driving a vibration actuator 112 through phase difference control according to this embodiment. In this embodiment, the method will be described in conjunction with... Figure 5 Different parts of the sequence.

[0084] The lens system controller 751 moves the focusing lens unit 753 to the focusing position via the focus driver 757 and sends information about the shooting mode to the focus driver 757.

[0085] In step S901, the phase difference duty cycle interlock control execution determiner 601 determines whether to determine the duty cycle based on the phase difference according to the camera mode. When a static camera mode is set, it is determined that the duty cycle is determined based on the phase difference, and the process proceeds to step S505. When a moving camera mode is set, it is determined that the duty cycle is not determined based on the phase difference, and the process proceeds to step S902.

[0086] In step S902, the duty cycle determiner 107 determines the duty cycle independently of the phase difference.

[0087] As described above, according to the construction of this embodiment, in addition to the effects of the first embodiment, the vibration actuator 112 can also be appropriately driven by selecting the relationship between the phase difference and the duty cycle according to the operating mode.

[0088] When the motion camera mode is set, this embodiment determines the duty cycle independently of the phase difference, but the duty cycle can be determined based on the phase difference. In this case, the minimum duty cycle is set to be less than the minimum duty cycle in the motion camera mode.

[0089] This embodiment determines whether to determine the duty cycle based on the phase difference according to the camera mode.

[0090] However, the present invention is not limited thereto. The operating command of the vibration actuator 112 can be used for determination. For example, a command value related to the amount of movement to the final target position given to the vibration actuator 112 can be used for determination. Specifically, when the command value for the amount of movement is less than a predetermined value, the duty cycle can be determined without considering the phase difference. When the command value for the amount of movement is greater than the predetermined value, the duty cycle can be determined based on the phase difference. This can be determined using a command value related to the speed of the vibration actuator 112. When the command value related to the speed of the vibration actuator 112 is greater than the predetermined value, the duty cycle can be determined without considering the phase difference. When the command value related to the speed of the vibration actuator 112 is less than the predetermined value, the duty cycle can be determined based on the phase difference.

[0091] Third Embodiment

[0092] Figure 10 This is a block diagram of the drive control system 101 of this embodiment. When the focusing lens unit 753 is driven at a low speed, stopping accuracy is required while suppressing unnecessary vibrations. However, stopping accuracy may deteriorate due to friction, etc. In this embodiment, the controller 103 includes a deceleration state determiner 1001, which is configured to determine the operating state of the vibration actuator 112 such that the vibration actuator 112 stops at a stop position with high accuracy. The controller 103 is configured to use the determination result of the deceleration state determiner 1001 to determine whether the vibration actuator 112 needs to decelerate from the current speed. Since the other configurations of the drive control system 101 of this embodiment are the same as those of the drive control system 101 of the first embodiment, their detailed description will be omitted. Since the configuration of the digital single-lens reflex camera having the drive control system 101 of this embodiment is the same as that of the digital single-lens reflex camera of the second embodiment, its detailed description will also be omitted.

[0093] Figures 11A to 11C This is a diagram illustrating an example of the relationship between velocity, acceleration, and duty cycle in this embodiment. Figures 11A to 11C In the various graphs, the horizontal axis represents time. Vibration actuator 112 begins operation at time t1, reaches velocity v111 at time t2, begins deceleration at time t3, and stops at the final target position at time t4. From time t1 to t2, the acceleration of vibration actuator 112 is set to a111, causing the velocity to increase to v111. From time t1 to t2, the duty cycle increases from d41 to d42. From time t2 to t3, the acceleration of vibration actuator 112 is set to zero. Thus, vibration actuator 112 is driven at a constant velocity, and the phase difference also remains constant. From time t3 to t4, the acceleration of vibration actuator 112 is set to -a111, causing the vibration actuator to decelerate. From time t3 to t4, the duty cycle remains at d42 without being updated.

[0094] Figure 12 This is a flowchart illustrating a method for driving a vibration actuator 112 through phase difference control according to this embodiment. In this embodiment, the method will be described in conjunction with... Figure 5 Different parts of the sequence.

[0095] In step S1201, the deceleration state determiner 1001 determines the operating state of the vibration actuator 112. In this embodiment, when the acceleration of the vibration actuator 112 is negative, it is determined that the operating state of the vibration actuator 112 is in a deceleration state. When the acceleration of the vibration actuator 112 is not negative, it is determined that the operating state of the vibration actuator 112 is not in a deceleration state.

[0096] In step S1202, the controller 103 determines whether the vibration actuator 112 needs to be decelerated based on the operating state of the vibration actuator 112 determined in step S1201. When the vibration actuator 112 is in a deceleration state and deceleration of the vibration actuator 112 is required, the process proceeds to step S505. When the vibration actuator 112 is not in a deceleration state and deceleration of the vibration actuator 112 is not required, the process proceeds to step S1203.

[0097] In step 1203, the duty cycle determiner 107 determines the currently held value as the duty cycle regardless of the phase difference, that is, maintains the value of the duty cycle.

[0098] As described above, in addition to the effects of the first embodiment, the configuration of this embodiment also enables the vibration actuator 112 to stop with high precision.

[0099] Fourth embodiment

[0100] Figure 13 This is a block diagram illustrating the drive control system 101 of this embodiment. The controller 103 of this embodiment includes a phase difference duty cycle interlock control relationship determiner 1301. The phase difference duty cycle interlock control relationship determiner 1301 is configured to select an appropriate relationship from multiple relationships between phase difference and duty cycle based on the state of the digital single-lens reflex camera. In this embodiment, the phase difference duty cycle interlock control relationship determiner 1301 selects the relationship between phase difference and duty cycle using information from the orientation detector 762 of the lens assembly 750. Since the other configurations of the drive control system 101 of this embodiment are the same as those of the drive control system 101 of the first embodiment, their detailed description will be omitted. Since the configuration of the digital single-lens reflex camera including the drive control system 101 in this embodiment is the same as that of the digital single-lens reflex camera of the second embodiment, its detailed description will also be omitted.

[0101] The driving direction of the vibration actuator 112 ( Figure 2 (x-direction) and optical axis direction ( Figure 7 The x-direction is parallel to the optical axis, which is the driving direction of the focusing lens unit 753. The driving direction of the vibration actuator 112 is perpendicular to the direction of gravity, i.e. Figure 7 The y-direction in the image. When the driving direction of the vibration actuator 112 is perpendicular to the direction of gravity, the vibration actuator 112 is easily affected by gravity, and it may be difficult to stop the driving of the focusing lens unit 753. Therefore, in this embodiment, depending on the orientation of the lens device 750 during use, specifically, by comparing the y-direction in the image. Figure 7 The angle θ in the x-direction and the threshold θt are used to change the relationship between the phase difference and the duty cycle.

[0102] Figure 14A and Figure 14B These are diagrams illustrating examples of the relationship between phase difference and duty cycle in this embodiment. When the angle θ is less than a threshold θt, the duty cycle varies based on a first relationship. Since the first relationship is consistent with that in the first embodiment... Figure 4A and Figure 4B The relationships shown are the same, so their detailed description will be omitted. When the angle θ is greater than the threshold θt, the duty cycle changes based on the second relationship. In the second relationship, when the control quantity is the value indicated by the dashed line 401 (= zero), the duty cycle is d141, which is greater than d41, and d41 is the minimum duty cycle in the first relationship. As the control quantity increases from zero, the duty cycle increases linearly. When the control quantity is the value indicated by the dashed line 403, the duty cycle is d42. When the control quantity becomes greater than the value indicated by the dashed line 403, the drive control device 102 changes the drive control method of the vibration actuator 112 from phase difference control to frequency control. In frequency control, the phase difference is constant at 90 degrees, and the duty cycle is also constant at d42. As the control quantity decreases from zero, the phase difference decreases and becomes negative. The sign of the phase difference indicates the direction of travel, and a negative phase difference indicates the opposite direction of travel. When the phase difference is negative, the duty cycle is determined based on the absolute value of the phase difference. That is, the duty cycle increases as the phase difference decreases. When the control quantity is the value indicated by the dashed line 402, the duty cycle is d42. When the control quantity becomes less than the value indicated by the dashed line 402, the drive control device 102 changes the drive control method of the vibration actuator 112 from phase difference control to frequency control. In frequency control, the phase difference is constant at -90 degrees, and the duty cycle is also constant at d42.

[0103] Figure 15 This is a flowchart illustrating a method for driving a vibration actuator 112 through phase difference control according to this embodiment. In this embodiment, the method will be described in conjunction with... Figure 5 Different parts of the sequence.

[0104] The lens system controller 751 moves the focusing lens unit 753 to the focusing position via the focus driver 757 and sends the orientation information (angle θ) of the lens assembly 750 to the focus driver 757.

[0105] In step S1501, the phase difference duty cycle interlock control relationship determiner 1301 determines whether to control the duty cycle based on the phase difference by using the orientation information (angle θ) of the lens device 750 obtained from the lens system controller 751. When angle θ is less than the threshold θt, the process proceeds to step S1502. When angle θ is greater than the threshold θt, the process proceeds to step S1503. When angle θ equals the threshold θt, the step to proceed can be arbitrarily set.

[0106] In step S1502, the duty cycle determiner 107 uses... Figure 14A and Figure 14B The first relationship shown determines the duty cycle based on the phase difference determined in step S504.

[0107] In step S1503, the duty cycle determiner 107 uses... Figure 14A and Figure 14B The second relationship shown determines the duty cycle based on the phase difference determined in step S504.

[0108] As described above, according to the construction of this embodiment, in addition to the effects of the first embodiment, the vibration actuator 112 can be stopped with high precision.

[0109] In this embodiment, even when the orientation information (angle θ) is greater than the threshold θt, the duty cycle is controlled based on the phase difference. However, the duty cycle may not be controlled, that is, the duty cycle may be determined independently of the phase difference.

[0110] In this embodiment, the phase difference duty cycle interlock control relationship determiner 1301 selects the relationship between phase difference and duty cycle based on the orientation of the lens assembly 750 as the state of using a digital single-lens reflex camera. However, the invention is not limited to this. For example, in a low-temperature environment, when lubricating oil or the like is used on the driven component, the load acting on the vibration actuator 112 may change due to viscosity variations. The relationship between phase difference and duty cycle can be selected based on the temperature environment of the digital single-lens reflex camera. In this case, information from the temperature detector 761 can be used to select the relationship between phase difference and duty cycle. That is, when the value of the indicated temperature environment from the temperature detector 761 is greater than a predetermined value, a first relationship can be used, and when the value of the indicated temperature environment from the temperature detector 761 is less than a predetermined value, a second relationship can be used.

[0111] Besides temperature, humidity can be used to determine the relationship between phase difference and duty cycle. For example, in high humidity environments, friction may change, and stopping accuracy may deteriorate. A first relationship can be used when the indicated humidity level from a humidity detector (not shown) is less than a predetermined value. A second relationship can be used when the indicated humidity level from the humidity detector is greater than the predetermined value.

[0112] The above embodiments can provide a drive control device, a drive control system, a lens device, a drive control method, and a storage medium. When the vibration actuator is driven at a low speed, each of them can suppress noise and unnecessary vibration and reduce power consumption.

[0113] Although the invention has been described with reference to exemplary embodiments, it should be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the appended claims should be given the broadest interpretation to cover all such variations and equivalent structures and functions.

Claims

1. A drive control device for a camera lens, the drive control device controlling an actuator that causes relative movement between a vibrator and a contact body in contact with the vibrator, and causing the vibrator to vibrate by applying a first signal and a second signal having a phase difference, the drive control device comprising: A first determining unit is configured to determine the phase difference; as well as The second determining unit is configured to determine the voltage amplitude of the power supplied to the actuator, such that the voltage amplitude decreases as the absolute value of the phase difference decreases.

2. The drive control device according to claim 1, wherein The second determining unit determines the voltage amplitude based on the orientation of the device with the actuator.

3. The drive control device according to claim 2, wherein When the indicated orientation value is less than a predetermined value, the second determining unit determines the voltage amplitude such that the voltage amplitude decreases as the absolute value of the phase difference decreases, and Specifically, when the value of the indicated orientation is greater than a predetermined value, the second determining unit determines the voltage amplitude such that the voltage amplitude decreases as the absolute value of the phase difference decreases, and the minimum value of the voltage amplitude is greater than the minimum value of the voltage amplitude when the value of the indicated orientation is less than the predetermined value.

4. The drive control device according to claim 1, wherein, The second determining unit determines the voltage amplitude based on the temperature environment.

5. The drive control device according to claim 4, wherein When the indicated temperature value is greater than a predetermined value, the second determining unit determines the voltage amplitude such that the voltage amplitude decreases as the absolute value of the phase difference decreases, and Specifically, when the value of the indicated temperature environment is less than a predetermined value, the second determining unit determines the voltage amplitude such that the voltage amplitude decreases as the absolute value of the phase difference decreases, and the minimum value of the voltage amplitude is greater than the minimum value of the voltage amplitude when the value of the indicated temperature environment is less than the predetermined value.

6. The drive control device according to claim 1, wherein The second determining unit determines the voltage amplitude based on the humidity environment during use.

7. The drive control device according to claim 6, wherein When the indicated humidity value is less than a predetermined value, the second determining unit determines the voltage amplitude such that the voltage amplitude decreases as the absolute value of the phase difference decreases, and Specifically, when the value of the indicated humidity environment is greater than a predetermined value, the second determining unit determines the voltage amplitude such that the voltage amplitude decreases as the absolute value of the phase difference decreases, and the minimum value of the voltage amplitude is greater than the minimum value of the voltage amplitude when the value of the indicated humidity environment is less than the predetermined value.

8. A drive control system comprising a drive control device applied to a camera lens, the drive control device controlling an actuator configured to cause relative movement between a vibrator and a contact body in contact with the vibrator, and causing the vibrator to vibrate by applying a first signal and a second signal having a phase difference, the drive control device comprising: A first determining unit is configured to determine the phase difference; as well as The second determining unit is configured to determine the voltage amplitude of the power supplied to the actuator, such that the voltage amplitude decreases as the absolute value of the phase difference decreases.

9. A lens device, comprising: The drive control system according to claim 8; as well as An optical unit driven by a drive control system.

10. A drive control method for a camera lens, the drive control method controlling an actuator that causes relative movement between a vibrator and a contact body in contact with the vibrator, and causing the vibrator to vibrate by applying a first signal and a second signal having a phase difference, the drive control method comprising the following steps: Determine the phase difference; as well as The voltage amplitude of the power supplied to the actuator is determined such that the voltage amplitude decreases as the absolute value of the phase difference decreases.

11. A non-transitory computer-readable storage medium storing computer programs that enable a computer to use as various units of a drive control device according to any one of claims 1 to 7.

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