JP2016118600A - Lens control device and imaging device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a free movement of a lens in a non-electrification state of an actuator not having halt retaining force in a non-electrification state.SOLUTION: A lens control device 120 is used in an imaging device in which a lens barrel 101 including a lens 104 and an actuator 122 actuating the lens in an optical axis direction is operative to collapse from a state where the lens barrel extends with respect to an imaging device main body 120. The lens control device has: control means that performs electrification with respect to the actuator so that the lens is actuated to a prescribed position in the collapse operation, and halts the electrification with respect to the actuator after the lens is actuated to the prescribed position; and pose detection means that detects a pose of the imaging device, in which the control means is configured to change the prescribed position in accordance with the detected pose thereof.SELECTED DRAWING: Figure 1

Description

The present invention relates to an imaging apparatus in which a lens barrel is retracted in an apparatus main body.

  An imaging device (hereinafter referred to as a camera) such as a digital camera or a video camera has a retracted state that is extended from the camera body to the object side (subject side) at the time of shooting, and a retracted state that is housed in the camera body when not in use. Some have a retractable lens barrel. In such a camera, the total length of the lens barrel in the retracted state determines the thickness of the camera. For this reason, in the retracted state, the distance between the plurality of lenses arranged inside the lens barrel in the optical axis direction is narrower than that in the extended state so that the total length of the lens barrel is as short as possible. To the image side. However, depending on the structure of the lens barrel, there may remain a space in which any lens can move to some extent in the optical axis direction in the lens barrel in the retracted state. When this movable lens is driven by an actuator that does not generate a stop holding force that holds the lens at a stop position in a non-energized state, such as a voice coil motor (VCM), Problems arise.

  For example, consider a case where the lens barrel is retracted from the extended state in a state where the camera is in a downward posture (a posture in which the tip of the lens barrel faces downward). Until the lens barrel changes from the extended state to the retracted state, the lens in the lens barrel is driven to a predetermined position on the image side by the energized actuator. However, if this actuator is not energized and does not have a stop holding force, the lens will fall from the predetermined position in the space due to its own weight due to the stop of energization to the actuator, and will be positioned below the lens. Colliding with other members. As a result, there is a risk that a collision sound may be generated or a malfunction may occur in the lens barrel due to an impact.

  In Patent Document 1, a lens holding member and another member (VCM yoke) are brought into contact with each other to generate a frictional force. When the VCM is not energized, the lens holding member is held at the stop position by the frictional force. Thus, a configuration in which the free movement of the lens holding member is prevented is disclosed.

JP 2013-142798 A

  However, in the configuration in which the lens holding member is held at the stop position by the frictional force between the lens holding member and another member as in Patent Document 1, the actuator (VCM) is used when the lens holding member is driven from the stop state. It is necessary to generate a driving force that exceeds the frictional force. For this reason, compared with the case where there is no such frictional force, the power consumption in an actuator increases. Further, since the lens holding member does not move until the driving force exceeding the frictional force is generated in the actuator after the energization of the actuator is started, there is a possibility that the response of the lens driving is deteriorated.

  According to the present invention, the freedom of a lens in a non-energized state of an actuator that does not have a stop holding force in a non-energized state without causing an increase in power consumption of the actuator used for driving the lens or a decrease in the response of the drive. An imaging apparatus capable of preventing movement is provided.

  A lens control device according to one aspect of the present invention is used in an imaging device that performs a retraction operation from a state in which a lens barrel including a lens and an actuator that drives the lens in the optical axis direction is extended to the imaging device body. The lens control device detects the attitude of the imaging device and a control unit that energizes the actuator so that the lens is driven to a predetermined position during the retracting operation, and stops energization of the actuator after the lens is driven to the predetermined position. Posture detecting means. And a control means changes a predetermined position according to the said attitude | position, It is characterized by the above-mentioned.

  According to another aspect of the present invention, there is provided a lens control device that performs a retraction operation from a state in which a lens barrel including a lens and an actuator that drives the lens in the optical axis direction is extended from the image pickup device body. Used for. The lens control device detects the attitude of the imaging device and a control unit that energizes the actuator so that the lens is driven to a predetermined position during the retracting operation, and stops energization of the actuator after the lens is driven to the predetermined position. Posture detecting means. And a control means changes the decreasing rate of the energization amount at the time of stopping energization with respect to an actuator according to the said attitude | position, It is characterized by the above-mentioned.

  Note that an imaging apparatus that performs a retraction operation from a state in which a lens barrel including a lens and an actuator that moves the lens in the optical axis direction is extended with respect to the imaging apparatus main body, and the imaging apparatus that includes the lens control device, It constitutes another aspect of the present invention.

  According to another aspect of the present invention, there is provided a lens control method in which a lens barrel including a lens and an actuator that drives the lens in the optical axis direction is retracted from a state where the lens barrel is extended with respect to the imaging device body. Used for. The lens control method includes a control step of energizing the actuator so that the lens is driven to a predetermined position in the retracting operation, and stopping the energization to the actuator after the lens is driven to the predetermined position, and detecting the attitude of the imaging device. A step of performing. In the control step, the predetermined position is changed according to the posture.

  According to another aspect of the present invention, there is provided a lens control method in which a lens barrel including a lens and an actuator that drives the lens in the optical axis direction is retracted from a state where the lens barrel is extended with respect to the imaging device body. Used for. The lens control method includes a control step of energizing the actuator so that the lens is driven to a predetermined position in the retracting operation, and stopping the energization to the actuator after the lens is driven to the predetermined position, and detecting the attitude of the imaging device. A step of performing. In the control step, the reduction rate of the energization amount when the energization to the actuator is stopped is changed according to the posture.

  A lens control program that is a computer program that causes a computer of the imaging apparatus to execute processing corresponding to the lens control method also constitutes another aspect of the present invention.

  In the present invention, when the energization to the actuator is stopped after the lens is driven to the predetermined position by the retracting operation, the predetermined position is changed according to the attitude of the imaging device, or the decrease rate of the energization amount is changed. As a result, even when the actuator does not have a stop holding force in a non-energized state, the lens holding member can be freely moved in a non-energized state without causing an increase in power consumption of the actuator or a decrease in drive response. Can be prevented. Therefore, it is possible to prevent the occurrence of a collision sound due to the lens falling in the lens barrel and colliding with another member depending on the posture of the imaging apparatus, and the occurrence of a malfunction of the lens barrel due to the impact.

1 is a block diagram illustrating a configuration of a digital camera that is Embodiment 1 of the present invention. 6 is a flowchart showing a collapsible process in the camera of Embodiment 1. 9 is a flowchart showing a collapsible process in a camera that is Embodiment 2 of the present invention. 9 is a flowchart showing focus energization stop processing in the camera of Embodiment 2. FIG. 3 is a cross-sectional view showing a retractable lens barrel in the camera of Embodiment 1. FIG. 3 is a diagram illustrating an acceleration sensor in the camera according to the first embodiment.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 shows a configuration of a digital camera (hereinafter simply referred to as a camera) 100 as an image pickup apparatus that is Embodiment 1 of the present invention. 5A and 5B show a camera main body (imaging device main body) 150 of the camera 100 and a retractable lens barrel (can be retracted) with respect to the camera main body 150. The schematic structure of the lens 101 will be described below.

  As shown in these drawings, the lens barrel 101 has a plurality (three) of lenses 102 to 104 constituting a photographing optical system therein. OA indicates an optical axis of a photographing optical system to be described later. In the following description, the direction in which the optical axis OA extends is referred to as an optical axis direction.

  The lens 102 disposed on the most object side (tip side) and the lens 103 disposed on the image side of the lens barrel 101 are a first group mirror that holds them as shown in FIGS. 5 (a) and 5 (b). This is a zoom lens that moves in the optical axis direction together with the cylinder 4 and the second group lens barrel 5 and performs zooming. A lens 104 arranged on the image side of the zoom lens 103 moves in the direction of the optical axis together with the third group barrel 6 that holds the lens 104 as shown in FIGS. 5A and 5B, and performs focus adjustment. It is a lens. Further, as shown in FIG. 1, an aperture / shutter 105 that performs light amount adjustment and exposure control is disposed on the image side of the focus lens 104.

  Although not shown, the lens barrel 101 has an anti-vibration lens that moves (shifts) in a direction orthogonal to the optical axis direction to reduce image blur caused by camera shake such as camera shake. May be. Further, in order to detect camera shake, an angular velocity sensor (such as a gyro sensor) 119 may be provided in the camera 100 as shown in parentheses in FIG.

  5A shows the extended state in which the lens barrel 101 is extended toward the object side with respect to the camera main body 150, and FIG. 5B shows the lens barrel 101 housed in the camera main body 150 (collapsed). The retracted state is shown. The lens barrel 101 holds the first group barrel 4, the second group barrel 5 and the third group barrel 6, the image sensor (image sensor) 106, and the low-pass filter 7 disposed in front of the image sensor 106. A sensor holder 9 and a fixed cylinder 10 fixed to the sensor holder 9.

  In FIG. 1, light incident on the photographing optical system from a subject forms an image on the light receiving surface of the image sensor 106. The image sensor 106 is constituted by a CCD sensor, a CMOS sensor, or the like, and converts a subject image formed on the light receiving surface into an electrical signal. An imaging signal as an electrical signal output from the imaging element 106 is input to the image processing circuit 107. The image processing circuit 107 performs image processing such as pixel interpolation processing and color conversion processing on the imaging signal to generate an image signal. The image signal is stored as image data in an internal memory 108 constituted by DRAM, SRAM or the like.

  The display unit 109 is configured by a display element such as an LCD, and displays image data that is sequentially stored in the internal memory 108 and sequentially read out as a live view image, and displays various types of information related to photographing. The image data stored in the internal memory 108 is compressed by the compression / decompression processing unit 110, and a recording medium such as a memory card attached to the camera 100 via the storage unit 111 or a non-volatile built in the camera 100. Recorded in the memory.

  The aperture shutter driver 112 calculates an exposure control value (aperture value and shutter speed) based on the luminance information of the image signal generated by the image processing circuit 107, and drives the aperture / shutter 105 based on the calculation result. . Thereby, automatic exposure (AE) control is performed.

  The focus lens driving unit 114 drives the third group barrel 6 holding the focus lens 104 in the optical axis direction via a voice coil motor (hereinafter referred to as VCM) 122 which is an actuator for driving the focus lens. The VCM 122 is provided with a focus position detection unit that detects the position of the focus lens 104 and the third group barrel 6 (hereinafter referred to as a focus position) using an optical scale and an optical sensor (not shown). The focus lens driving unit 114 controls driving of the VCM 122 so that the focus position acquired from the position detection unit follows the target position instructed from the system control unit 120. Specifically, the focus lens drive unit 114 generates a drive waveform to be given to the VCM 122 based on the deviation between the focus position obtained from the position detection unit and the target position instructed from the system control unit 120, and outputs the drive waveform to the VCM 122. .

  When performing autofocus (AF) control by the contrast detection method, the system control unit 120 acquires the contrast evaluation value of the image signal while moving the focus lens 104, and places the focus lens 104 at a position where the contrast evaluation value is highest. Move. In addition, when performing the AF control by the phase difference detection method, the system control unit 120 calculates a phase difference between a pair of image signals for phase difference calculation obtained from the image sensor 106, and uses the phase difference to obtain a photographing optical system. The defocus amount of is calculated. Then, the focus lens 104 is moved based on the defocus amount.

  The zoom lens driving unit 115 is configured to hold the zoom lenses 102 and 103 through a DC motor (hereinafter referred to as DCM) 121 that is an actuator for driving the zoom lens in response to a zoom instruction from the user. 4 and 5 are driven in the optical axis direction. Although not shown, the DCM 121 is composed of two photo interrupters and a light shielding propeller capable of shielding each of the four interrupters so as to generate an output pulse whose phase is 45 degrees out of phase with each other. A zoom position detector is provided. The two photo interrupters output the output pulse in accordance with light shielding and non-light shielding by the light shielding propeller accompanying the rotation of the DCM 121. The zoom lens driving unit 115 detects the positions of the zoom lenses 102 and 103 (hereinafter referred to as zoom positions) by counting these output pulses, and controls the driving of the DCM 121 (that is, the zoom lenses 102 and 103). .

  The system control unit 120 is configured by a computer including a CPU and the like, and controls the entire camera 100. The system control unit 120 executes various control programs stored in the internal memory 108 to perform charge accumulation / reading of the image sensor 106, AE / AF control, zoom control, and the like. Further, the system control unit 120 controls the feeding operation and the retracting operation of the lens barrel 101 with respect to the camera body 150 by controlling the driving of the DCM 121 and the VCM 122. The system control unit 120 is a lens control device and functions as a control unit.

  The operation unit 116 includes a release switch 117 for a user to instruct AF control and photographing, a retraction instruction switch 118 for instructing the retraction of the lens barrel 101, and operation buttons and zoom levers for performing various settings. The collapsible instruction switch 118 is a power switch for turning on / off the power of the camera 100 (instructed to retract when the power is turned off) or a reproduction for shifting the camera 100 from a photographing mode for photographing to a reproduction mode for reproducing a photographed image. It is also provided as a mode transition button.

  In addition, the camera 100 is provided with an acceleration sensor 123 that detects acceleration applied to the camera 100, and the acceleration sensor 123 is connected to the system control unit 120. The acceleration sensor 123 is, for example, a capacitance-type acceleration sensor, and can detect acceleration in a three-dimensional space by dividing it into components in the X, Y, and Z directions that are orthogonal to each other. Based on the acceleration data detected by the acceleration sensor 123, the system control unit 120 detects the posture of the camera 100 by calculation using a predetermined value and a calculation formula stored in the internal memory 108 in advance. That is, the system control unit 120 functions as a posture detection unit that detects the posture of the camera 100 using the acceleration sensor 123.

  FIG. 6 shows the relationship between the camera 100 and the acceleration sensor 123 in the three-axis directions. In this embodiment, the optical axis OA is the Z axis, and two axes that are orthogonal to the Z axis and orthogonal to each other are the X axis (horizontal axis) and the Y axis (vertical axis). When the camera 100 is in a downward posture in which the tip of the lens barrel 101 faces downward, the direction of gravitational acceleration acting on the lens barrel 101 is mainly the Z-axis direction. Therefore, whether or not the camera 100 is in the downward posture can be determined based on the output from the acceleration sensor 123 according to the acceleration component in the Z-axis direction.

  As can be seen from FIG. 5B, the total length of the lens barrel 101 in the retracted state determines the thickness of the camera 100 (camera body 150) in the optical axis direction. For this reason, in order to make the camera 100 compact, it is necessary to shorten the total length of the lens barrel in the retracted state. In the present embodiment, the third group lens barrel 6 moves to a position approaching the low-pass filter 7 disposed in front of the image sensor 106. The first group barrel 4 and the second group barrel 5 move toward the sensor holder 9 and stop at a position where the distance between the lenses 101 to 103 is as small as possible.

  However, in such a retracted state, a space S in which the third group barrel 6 can freely move in the optical axis direction (second group barrel 5 side) is formed in the lens barrel 101. In the present embodiment, the third group barrel 6 is driven by the VCM 122, but the VCM 122 does not generate a stop holding force for holding the third group barrel 6 at the stop position in a non-energized state. For this reason, when the lens barrel 101 is retracted from the extended state with the camera 100 in the downward posture and the energization to the VCM 122 is stopped as shown in FIG. Falls in the space S due to its own weight and collides with the second group barrel 5 at the position 6 '. In the collapsing process described below, such a collision is avoided. 5C shows a posture in which the front end of the lens barrel 101 faces downward as the downward posture of the camera 100. In the following description, the “downward posture” refers to the tip of the lens barrel 101. It is not limited to a posture facing directly downward, but also includes a posture facing downward (obliquely downward) from the horizontal direction.

  Next, the collapsing process performed by the system control unit 120 in this embodiment will be described with reference to the flowchart of FIG. The system control unit 120 executes the retracting process according to a lens control program that is a computer program. Here, the description of the collapsing process is started assuming that the power source of the camera 100 is on and the lens barrel 101 is in the extended state. In the following description, the focus lens 104 and the third group lens barrel 6 that holds the focus lens 104 are collectively referred to as a focus lens, and the zoom lenses 102 and 103 and the first group and second group lens barrels 4 and 5 that hold these are summarized. This is called a zoom lens.

  In step S <b> 200, the system control unit 120 determines whether or not a collapsing instruction has been given by the user turning off the power switch (collapse instruction switch 118). The system control unit 120 proceeds to step S201 when there is a retracting instruction, and repeats the determination at step S200 when there is no retracting instruction. When the above-described playback mode transition switch also serves as the retracting instruction switch 118, the system control unit 120 determines whether or not a retracting instruction has been made by operating the playback mode transition switch.

  In step S <b> 201, the system control unit 120 detects the posture of the camera 100 based on the output (acceleration data) from the acceleration sensor 123. The processing in this step corresponds to posture detection processing.

  Next, in step S202, the system control unit 120 describes the orientation of the camera 100 detected in step S201 as a downward orientation in which the tip of the lens barrel 101 faces downward (in FIG. 2, “the lens is downward”: It is determined whether the same applies to the step). The system control unit 120 proceeds to step S203 when the posture of the camera 100 is the downward posture, and proceeds to step S204 when the posture of the camera 100 is not the downward posture.

  In step S203, the system control unit 120 drives the VCM 122 through the focus lens drive unit 114, and drives the focus lens to the first retracted position as the first predetermined position in the retracted direction. Specifically, the system control unit 120 drives the VCM 122 (energizes the VCM 122) so that the focus position detected using the output from the focus position detection unit provided in the VCM 122 matches the first retracted position. Control. The first retracted position of the focus lens is a position closest to the object side, that is, the feeding side where the focus lens can be located when the zoom lens is driven to the retracted position thereafter. In other words, the first retracted position is the position 6 ′ in contact with the zoom lens in the space S or a position close thereto as shown in FIG. When the driving of the focus lens to the first retracted position is completed, the system control unit 120 proceeds to step S205.

  On the other hand, in step S204, the system control unit 120 drives the VCM 122 through the focus lens driving unit 114, and drives the focus lens to the second retracted position as the second predetermined position in the retracted direction. Specifically, the system control unit 120 drives the VCM 122 (energizes the VCM 122) so that the focus position detected using the output from the focus position detection unit provided in the VCM 122 matches the second retracted position. Control. The second retracted position of the focus lens is the position closest to the image side, that is, the retracted side where the focus lens can be located when the zoom lens is driven to the retracted position thereafter. In other words, the second retracted position is a position closest to the image sensor 106 (color filter 7 and sensor holder 9) in the space S or a position in contact with the sensor holder 9 as shown in FIG. . When the driving of the focus lens to the second retracted position is completed, the system control unit 120 proceeds to step S205. The processing of step 203 and step S204 and the processing of step 209 and step S210 described later correspond to the control processing.

  As described above, in this embodiment, when the lens barrel 101 is retracted in a state where the camera 100 is in the downward posture, the first retracted position that is the movable end in the direction in which the gravitational acceleration acts on the focus lens is set. Drive the focus lens. For this reason, even if energization to the VCM 122 is stopped thereafter, the amount by which the focus lens falls to the zoom lens side can be minimized. Accordingly, it is possible to prevent a collision with the zoom lens or other members due to the focus lens described with reference to FIG.

  On the other hand, when the lens barrel 101 is retracted in a state where the camera 100 is in a posture other than the downward posture, for example, in an upward posture in which the tip of the lens barrel 101 faces upward (or obliquely upward), the focus lens is moved to the second position. Drive to the retracted position. That is, the focus lens is driven to the second retracted position that is a movable end in the direction in which the gravitational acceleration acts on the focus lens. For this reason, even if energization to the VCM 122 is stopped thereafter, the amount of the focus lens falling to the image sensor 106 side can be minimized. Thereby, the collision with the sensor holder 9 and other members due to the drop of the focus lens toward the image sensor 106 can be prevented.

  In step S205, the system control unit 120 drives the DCM 121 through the zoom lens driving unit 115 to start driving the zoom lens to a preset zoom retracted position. The zoom retracted position is a position of the zoom lens where the entire length of the lens barrel 101 is the shortest.

  In step S206, the system control unit 120 determines whether the zoom position detected using the output from the zoom position detection unit provided in the DCM 121 matches the zoom retraction position (the zoom lens has reached the zoom retraction position). Determine whether or not. The system control unit 120 proceeds to step S208 when the zoom lens has reached the zoom retracted position, and proceeds to step S207 when the zoom lens has not reached the zoom retracted position.

  In step S207, the system control unit 120 continues to drive the zoom lens to the zoom retracted position.

  In step S208, the system control unit 120 determines whether the posture of the camera 100 detected in step S201 is a horizontal posture in which the lens barrel 101 (optical axis OA) is horizontal. The system control unit 120 proceeds to step S209 if the posture of the camera 100 is a horizontal posture, and proceeds to step S210 if it is not a horizontal posture (that is, an upward posture or a downward posture).

  In step S209, the system control unit 120 stops energization of the VCM 122 for driving the focus lens. The energization stop here is performed immediately (instantly) instead of gradually decreasing as in step S210 described later.

  In step S210, the system control unit 120 gradually decreases the energization amount (voltage) to the VCM 122 for driving the focus lens at a predetermined decrease rate. When the energization amount finally becomes zero, the system control unit 120 applies the voltage to the VCM 122. Stop energization. The predetermined decrease rate is a second decrease rate smaller than the first decrease rate when the decrease rate of the energization amount when the energization is immediately stopped in step S209 is the first decrease rate. , A reduction rate for reducing the energization amount so that the falling speed of the VCM 122 becomes slow.

  Here, the process of step S209 and step S210 is demonstrated. When the camera 100 is in a horizontal posture, the gravitational acceleration does not act to move the focus lens in the optical axis direction, so that the focus lens falls due to gravity even when the power to the VCM 122 is stopped. Absent. Therefore, the system control unit 120 that has determined that the camera 100 is in the horizontal posture in step S208 immediately stops energization of the VCM 122 in step S209. On the other hand, when the camera 100 is not in a horizontal posture, the gravitational acceleration acts to move the focus lens in the direction of the optical axis. Therefore, if the energization to the VCM 122 is stopped immediately, the focus lens may fall due to gravity. There is.

  In this embodiment, in step S203 and step S204, the retracted position of the focus lens is changed to the first and second retracted positions according to the posture of the camera 100, so that the focus lens when the energization of the VCM 122 is stopped is changed. Minimize the amount of fall. However, depending on the manufacturing variation of the lens barrel 101 and the accuracy of position control of the focus lens, the drop amount may not be sufficiently small, and a collision due to the drop may occur. Accordingly, when the system control unit 120 determines in step S208 that the camera 100 is not in the horizontal posture, the focus lens is dropped by gradually decreasing the energization amount to the VCM 122 at a predetermined decrease rate in step S210. Even so, the fall speed is reduced. Thereby, the occurrence of a collision is prevented.

  As described above, in this embodiment, the position at which the focus lens is driven in the retracting direction is changed by the VCM 122 according to the posture of the camera 100 when the lens barrel 101 is retracted. Furthermore, the method for stopping energization of the VCM 122 is changed according to the posture of the camera 100 when the lens barrel 101 is retracted. Accordingly, by stopping energization to the VCM 122 that has driven the focus lens after the lens barrel 101 reaches the retracted state, the focus lens falls so as to collide with other members, and the collision sound or the lens barrel 101 can be prevented from occurring.

  Next, a second embodiment of the present invention will be described. When energizing the VCM 122 is stopped when the lens barrel 101 reaches the retracted state, if a large vibration is applied to the camera 100, the focus lens may move due to the vibration and collide with another member. There is. In the present embodiment, this is avoided.

  The configuration of the camera is the same as that of the first embodiment, and the same components as those of the first embodiment are denoted by the same reference numerals as those of the first embodiment. The flowchart of FIG. 3 shows the collapsing process performed by the system control unit 120 in this embodiment. Also in the present embodiment, the system control unit 120 executes the retracting process according to a lens control program that is a computer program. Also here, the description of the collapsing process is started assuming that the power source of the camera 100 is on and the lens barrel 101 is in the extended state.

  Steps S300 to S307 are the same as steps S200 to S207 described in the first embodiment, and thus description thereof is omitted.

  The system control unit 120 that determines that the zoom lens has reached the zoom retracted position in step S306 performs a focus energization stop process different from steps S208 to 210 of the first embodiment in step S307. The focus energization stop process will be described with reference to the flowchart of FIG.

  In step S400, the system control unit 120 determines whether or not the focus energization stop process to be performed is performed in response to the power switch off operation. When the focus energization stop process is performed in response to the power switch off operation, the system control unit 120 proceeds to step S407, and is performed in response to an operation other than the power switch off operation (for example, a playback mode transition switch operation). In this case, the process proceeds to step S401.

  In step S401, the system control unit 120 detects the magnitude of vibration (vibration amount) applied to the camera 100 based on the output from the angular velocity sensor 119 shown in parentheses in FIG. That is, the system control unit 120 functions as a vibration detection unit together with the angular velocity sensor 119.

  Next, in step S402, the system control unit 120 determines whether or not the magnitude of vibration detected in step S401 is greater than or equal to a predetermined value (or greater than a predetermined value). If the magnitude of vibration is greater than or equal to the predetermined value, the system control unit 120 returns to step S401 and repeats detection of the magnitude of vibration, and if the magnitude of vibration is smaller than the predetermined value, proceeds to step S403. .

  In step S <b> 403, the system control unit 120 detects the posture of the camera 100 again based on the acceleration data from the acceleration sensor 123. In step S404, it is determined whether the posture of the camera 100 detected in step S403 is a downward posture (“lens is downward”). The system control unit 120 proceeds to step S405 when the posture of the camera 100 is the downward posture, and proceeds to step S406 when it is not the downward posture.

  In step S405, the system control unit 120 continues energization of the VCM 122 so as to hold the focus lens at the first retracted position. On the other hand, in step S406, the system control unit 120 continues energizing the VCM 122 so as to hold the focus lens at the second retracted position. Thereafter, the system control unit 120 proceeds to step S407.

  In step S407, the system control unit 120 determines whether the posture of the camera 100 detected in step S403 is a horizontal posture. If the posture is a horizontal posture, the process proceeds to step S408. The process proceeds to step S409. In step S408, the system control unit 120 immediately stops energization of the VCM 122 as in step S209 of the first embodiment. On the other hand, in step S409, the system control unit 120 gradually decreases the energization amount (voltage) to the VCM 122 at a predetermined decrease rate, and finally stops energization, as in step S210 of the first embodiment. The meaning of the processing in steps S408 and S409 is the same as the processing in steps S209 and S210 in the first embodiment. Thus, the system control unit 120 ends the focus energization stop process.

  Thus, according to the present embodiment, as in the first embodiment, depending on the posture of the camera 100 when the lens barrel 101 is retracted, the position at which the focus lens is driven in the retracting direction by the VCM 122 or the position to the VCM 122 is determined. Change the method of stopping energization. Accordingly, by stopping energization to the VCM 122 that has driven the focus lens after the lens barrel 101 reaches the retracted state, the focus lens falls so as to collide with other members, and the collision sound or the lens barrel 101 can be prevented from occurring. In addition, in this embodiment, when the magnitude of the vibration of the camera 100 is equal to or greater than a predetermined value, the focus lens is held at the first or second retracted position without stopping energization to the VCM 122. Thereby, it is possible to prevent the focus lens from moving due to the vibration of the camera 100 and colliding with other members.

  Note that, when the lens barrel 101 is retracted in response to an operation of turning off the power switch, the power supply to the VCM 122 is continued while the camera 100 is vibrating, and thus the power of the camera 100 cannot be turned off. For this reason, in this embodiment, energization to the VCM 122 is continued except when the lens barrel 101 is retracted in response to an operation of turning off the power switch. However, when the lens barrel 101 is retracted in response to an operation of turning off the power switch, energization to the VCM 122 may be continued for a predetermined time.

In each of the above embodiments, the VCM has been described as an example of the actuator that drives the focus lens. However, the actuator is not limited to the VCM and may be any actuator that does not generate a stop holding force for holding the focus lens at a predetermined position in a non-energized state. In each of the above embodiments, the case where the lens driven by such an actuator is a focus lens has been described, but a lens other than the focus lens may be used.
(Other examples)
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.

  Each embodiment described above is only a representative example, and various modifications and changes can be made to each embodiment in carrying out the present invention.

100 Digital Camera 102 Zoom Lens 103 Focus Lens 120 System Controller 122 Voice Coil Motor (VCM)
123 Accelerometer

Claims (14)

A lens control device used in an imaging device that performs a retraction operation from a state in which a lens barrel including a lens and an actuator that drives the lens in the optical axis direction is extended with respect to the imaging device body,
Control means for energizing the actuator so that the lens is driven to a predetermined position in the retracting operation, and stopping energization to the actuator after the lens is driven to the predetermined position;
Posture detecting means for detecting the posture of the imaging device;
The lens control device, wherein the control means changes the predetermined position according to the posture.   The lens control device according to claim 1, wherein the actuator is an actuator that does not generate a stop holding force for holding the lens at the predetermined position in a non-energized state in which the power supply to the actuator is stopped.   The lens control device according to claim 2, wherein the actuator is a voice coil motor. The predetermined position when the posture is a downward posture in which the lens barrel faces downward from the horizontal direction is a first predetermined position, and the predetermined position when the posture is a posture different from the downward posture Is the second predetermined position,
4. The lens control device according to claim 1, wherein the first predetermined position is a position closer to the object side in the lens barrel than the second predetermined position. 5. The control means, after the lens is driven to the predetermined position,
When the posture is a horizontal posture in which the lens barrel faces the horizontal direction, the energization amount to the actuator is decreased at a first reduction rate,
5. The method according to claim 1, wherein when the posture is a posture different from the horizontal posture, the energization to the actuator is reduced at a second reduction rate smaller than the first reduction rate. The lens control device according to Item. Having vibration detection means for detecting vibration applied to the imaging device;
6. The control unit according to claim 1, wherein after the lens is driven to the predetermined position, the control unit continues energization of the actuator when the magnitude of the vibration is larger than a predetermined value. The lens control device according to Item. A lens control device used in an imaging device that performs a retraction operation from a state in which a lens barrel including a lens and an actuator that drives the lens in the optical axis direction is extended with respect to the imaging device body,
Control means for energizing the actuator so that the lens is driven to a predetermined position in the retracting operation, and stopping energization to the actuator after the lens is driven to the predetermined position;
Posture detecting means for detecting the posture of the imaging device;
The lens control apparatus according to claim 1, wherein the control unit changes a reduction rate of an energization amount when the energization to the actuator is stopped according to the posture. When the control means stops energization of the actuator,
When the posture is a horizontal posture in which the lens barrel faces the horizontal direction, the energization amount to the actuator is decreased at a first reduction rate,
The lens control device according to claim 7, wherein when the posture is a posture different from the horizontal posture, the energization to the actuator is decreased at a second reduction rate smaller than the first reduction rate. . An imaging apparatus that performs a collapsing operation from a state in which a lens barrel including a lens and an actuator that moves the lens in the optical axis direction is extended with respect to the imaging apparatus body,
An image pickup apparatus comprising the lens control device according to claim 1.   2. The lens barrel in a retracted state with respect to the imaging apparatus main body, wherein a space in which the lens can move in the optical axis direction is formed between the lens and another member. 9. The imaging device according to 9. A lens control method used in an imaging apparatus that performs a retraction operation from a state in which a lens barrel including a lens and an actuator that drives the lens in the optical axis direction is extended with respect to the imaging apparatus body,
A control step of energizing the actuator so that the lens is driven to a predetermined position in the retracting operation, and stopping energization of the actuator after the lens is driven to the predetermined position;
Detecting the attitude of the imaging device,
In the control step, the predetermined position is changed according to the posture. A lens control method used in an imaging apparatus that performs a retraction operation from a state in which a lens barrel including a lens and an actuator that drives the lens in the optical axis direction is extended with respect to the imaging apparatus body,
A control step of energizing the actuator so that the lens is driven to a predetermined position in the retracting operation, and stopping energization of the actuator after the lens is driven to the predetermined position;
Detecting the attitude of the imaging device,
The lens control method according to claim 1, wherein, in the control step, a reduction rate of an energization amount when the energization to the actuator is stopped is changed according to the posture. A computer program that causes a computer of an imaging apparatus that performs a retraction operation from a state in which a lens barrel including a lens and an actuator that drives the lens in the optical axis direction is extended with respect to the imaging apparatus body;
The retracting process is
A control process of energizing the actuator so that the lens is driven to a predetermined position in the retracting operation, and stopping energization of the actuator after the lens is driven to the predetermined position;
Processing to detect the orientation of the imaging device,
The control process is characterized in that the predetermined position is changed according to the posture. A computer program that causes a computer of an imaging apparatus that performs a retraction operation from a state in which a lens barrel including a lens and an actuator that drives the lens in the optical axis direction is extended with respect to the imaging apparatus body;
The retracting process is
A control process of energizing the actuator so that the lens is driven to a predetermined position in the retracting operation, and stopping energization of the actuator after the lens is driven to the predetermined position;
Processing to detect the orientation of the imaging device,
The lens control program characterized in that the control process changes a decrease rate of the energization amount when the energization to the actuator is stopped according to the posture.