JP2012042635A - Imaging device, control method for imaging devices and computer program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To estimate, in detecting an origin of a focus lens, a direction of an origin position and determine an initial driving direction for origin detection.SOLUTION: An imaging device comprises: position detecting means that detects a position of a focus lens; origin detecting means that detects an origin position of the focus lens, and control means that determines, in detecting the origin of the focus lens, whether or not the position of a zoom lens driven from a collapsed state in an extending direction (S604) has gone beyond a prescribed position where the origin position is contained in the movable stroke of the focus lens (S605), if it is determined that the position of the zoom lens has gone beyond the prescribed position, sets a driving direction of the focus lens on the extending side (S606) and, if it is determined that the initial position of the zoom lens at the time of origin detection is not in the collapsed state (S603), sets the driving direction of the focus lens in a retreating direction (S607).

Description

  The present invention relates to an imaging apparatus that detects an origin of a focus lens position, a control method for the imaging apparatus, and a computer program.

  In recent years, image pickup apparatuses such as digital still cameras and video cameras have been required to have high accuracy on the order of several μm in positioning control of a focus lens with the increase in the number of pixels and the downsizing of image pickup elements such as CCD and CMOS. . This is because as the number of pixels of the image sensor increases and the size of the image sensor decreases, the focus blur of the captured image due to the positioning error of the focus lens becomes more conspicuous, and higher-accuracy positioning control is required to ensure the performance of the image sensor. Because it becomes.

  One of the lens position detection sensors that can realize highly accurate positioning control is an optical encoder. Among the optical encoders, what is called an incremental type converts a multi-phase sinusoidal signal output as the scale moves into a pulsed signal via a signal processing circuit, and increases or decreases the number of pulses. The amount of movement is detected. On the other hand, since incremental type position detection can only detect the relative movement amount, a separate sensor for detecting the origin position is required to detect the absolute position, and space and cost are required for sensor installation. Up is necessary. In order to solve this problem, an optical encoder capable of detecting the absolute position of the main scale by providing a discontinuous portion on the main scale or its accompanying members has been proposed in Patent Document 1 and the like.

Here, FIG. 9A shows an optical scale having portions (patterns P _n , P _{n + 1} ) _where the reflectance changes (decreases), and a signal obtained when the sensor passes over the optical scale. The change is as shown in FIG. SG1 and SG2 in FIG. 9B are encoder output signals (analog two-phase signals) obtained from sensors. Since the signal amplitude of the encoder output signal is locally reduced due to the change in reflectance, the origin position can be detected by detecting this change. Thus, the absolute position can be detected without separately providing a sensor for detecting the origin position, and an increase in cost and sensor installation space can be avoided.

JP 2007-47041 A

  However, in the above-described origin detection method, there is no way to determine in which direction the origin position is relative to the current lens position. In particular, when a drive mechanism such as a DC linear motor is used in the drive system, the position of the movable portion is moved by an external force / inertia force unless a separate lock mechanism is provided. For this reason, it is impossible to determine in which direction the origin is located in the origin detection process such as when the power is turned on, and it is necessary to temporarily determine one as the initial drive direction. At this time, if the determined driving direction is opposite to the actual origin direction, it is necessary to drive at least one reciprocation between the both ends of the movable stroke, or to drive against the stroke end. There existed a subject that it led to increase in processing time and damage to a member.

(Object of invention)
An object of the present invention is to provide an imaging apparatus, an imaging apparatus control method, and a computer program capable of estimating the direction of the origin position and determining an initial drive direction for performing origin detection in the focus lens origin detection process. There is to do.

  In order to achieve the above object, an imaging apparatus of the present invention includes a zoom lens that is driven in a retracted direction from a retracted state and performs a zooming operation, and a focus lens that has a movable stroke limited according to the position of the zoom lens. A focus motor that drives the focus lens and allows the focus lens to move due to an external force or an inertial force, a position detection unit that detects the position of the focus lens, and an origin that detects the origin position of the focus lens When detecting the origin of the focus lens and the origin of the focus lens, the position of the zoom lens driven in the retracted direction from the retracted state exceeds a predetermined position where the origin position is included in the movable stroke of the focus lens. When it is determined that the predetermined position has been exceeded, the focus level is Control means for setting the driving direction of the focus lens to the retraction side when it is determined that the initial position of the zoom lens at the time of origin detection is not retracted. It is characterized by this.

  According to the present invention, in the origin detection processing of the focus lens, the direction of the origin position can be estimated and the initial drive direction for performing origin detection can be determined.

It is a block diagram which shows the structure of the digital camera which concerns on the Example of this invention. It is a schematic diagram which shows the structure of the focus lens which concerns on an Example. It is a schematic diagram which shows the structure of the optical scale and optical sensor which concern on an Example. It is a figure which shows the relationship between the focus lens structure at the time of the lens barrel retracting and zoom lens position concerning an Example. It is a flowchart of the basic operation at the time of imaging | photography of the digital camera which concerns on an Example. 3 is a flowchart of a lens barrel initialization process of the digital camera according to the first embodiment. FIG. 6 is a diagram illustrating a relationship between a posture of a digital camera according to a second embodiment and a focus lens position. 7 is a flowchart of a lens barrel initialization process of a digital camera according to a second embodiment. It is a figure which shows the optical scale which is an example of the origin detection means in a prior art, and its output signal.

  The mode for carrying out the present invention is as shown in Examples 1 and 2 below.

  FIG. 1 is a block diagram showing the configuration of a digital camera that is Embodiment 1 of the present invention.

  In the figure, reference numerals 1, 2 and 3 denote elements constituting a lens system, each of which is a first lens group (hereinafter referred to as a zoom lens) for performing a zooming operation, a second having both a competition function and a focusing function. A lens group (hereinafter referred to as a focus lens) and a stop.

  The zoom lens 1 and the focus lens 2 are lenses that are held by moving members (not shown) provided independently of each other and can move independently along the optical axis direction. Further, the zoom lens 1 or the moving member of the zoom lens 1 is configured as a retractable lens barrel 17 in which the moving range of the focus lens 2 is limited.

  The image light transmitted through this lens system is imaged on the image pickup surface of the image pickup device 4, subjected to photoelectric conversion, converted into an image pickup signal, and output. The imaging signal processing unit 5 sets a method for reading signal charges from the imaging element 4. Further, the imaging signal processing unit 5 performs setting of a shutter speed for determining the charge accumulation time and gain setting for amplifying the imaging signal output from the imaging element 4.

  The video signal processing unit 6 is a signal processing circuit that performs predetermined signal processing on the imaging signal output from the imaging signal processing unit 5 to convert it into a standardized video signal. The video signal processed here is displayed as a photographed image on an LCD (liquid crystal display) 7 as an electronic viewfinder.

  On the other hand, the imaging signal output from the imaging signal processing unit 5 is also sent to the system controller 11.

  The system controller 11 adjusts the amount of light by controlling the aperture of the aperture 3 via the aperture controller 10 in accordance with the video signal input level. Reference numerals 12 and 13 denote a zoom control unit and a focus control unit for outputting drive energy to the lens driving motor in accordance with the drive commands for the zoom lens 1 and the focus lens 2 output from the system controller 11, respectively. Reference numerals 8 and 9 denote a zoom motor and a focus motor for driving the zoom lens 1 and the focus lens 2, respectively.

  Hereinafter, it is assumed that the zoom motor 8 is a DC motor and the focus motor 9 is a voice coil linear motor.

  The zoom motor 8 is provided with a light-shielding propeller that is set to generate an output pulse that is 45 degrees out of phase with an electrical angle by two photo interrupters (not shown). The rotation of the zoom motor 8 is detected, Generate encoder pulses. The zoom control unit 12 counts the output encoder pulses, thereby recognizing the position of the zoom lens 1 and using it for driving control of the zoom lens 1.

  Reference numeral 16 denotes a position detection unit of the focus lens 2 using an optical scale and an optical sensor not shown in FIG. 1 (details will be described later). The system controller 11 determines the drive speeds of the zoom motor 8 and the focus motor 9 by program processing and sends them to the zoom control unit 12 and the focus control unit 13. The zoom motor 8 and the focus motor 9 drive / stop command and the drive direction command of each motor are also sent to the zoom control unit 12 and the focus control unit 13. The drive / stop signal and the drive direction signal are determined mainly by the zoom lever operation (not shown) of the user with respect to the zoom motor 8. The focus motor 9 responds to a drive command determined by processing in the system controller 11 during zoom operation or AF (autofocus) operation.

  A flash memory 14 is connected to the system controller 11, and position data of the zoom lens 1 is stored in the flash memory 14. The position data of the zoom lens 1 is stored as flag data indicating whether or not the end processing of the zoom lens 1 has been normally executed when the digital camera is turned off. An acceleration sensor 15 detects the attitude of the digital camera.

  Next, details of the configuration of the focus lens 2 in Embodiment 1 will be described with reference to FIG.

  In FIG. 2, the focus lens 2 is supported by a support mechanism (not shown) so as to be movable in a predetermined movable stroke (a range indicated by an arrow A in FIG. 2) with respect to the lens barrel 17 in the optical axis direction. The light beam from the imaging target passes through the focus lens 2 and is then subjected to photoelectric conversion by the imaging element 4 and is subjected to image processing via the imaging signal processing unit 5 and the video signal processing unit 6 shown in FIG. Necessary processing such as display and recording is performed.

  The focus lens 2 is driven in the optical axis direction by the focus motor 9. At this time, as the focus lens 2 moves, the optical scale 19 fixed integrally with the support mechanism for the focus lens 2 (not shown) also moves. The optical scale 19 is provided with an optical grating arranged at a constant cycle along the optical axis direction for position detection by an optical encoder. The optical scale 19 is provided with an optical discontinuous portion 20 for detecting the origin. The optical scale 19 and the discontinuous portion 20 will be described in detail later. The optical sensor 18 is fixed to the lens barrel 17 so as to face the optical scale 19. The optical sensor 18 is configured by integrating a light source that irradiates light to the optical scale 19 and a light receiving element array that receives reflected light from the optical scale 19, and is used as an optical encoder in combination with the optical scale 19. The

  A two-phase sinusoidal output signal from the optical sensor 19 is amplified by an amplifier circuit (not shown) and taken into the system controller 11 via an A / D converter built in the focus control unit 13. In the first embodiment, the output from the optical sensor 18 has two phases, but it may have three or more phases. In the case of a two-phase signal, after being taken into the system controller 11, each is generated as an inverted signal, and becomes a four-phase signal. As a result, as in the prior art, the position of the focus lens 2 can be detected by performing an interpolation operation using signals between the intersections of the phases. Note that position calculation by interpolation calculation is known in Japanese Patent Publication No. 6-56304, Japanese Patent Application Laid-Open No. 2003-161645, and the like, and detailed description thereof is omitted here.

  The focus control unit 13 performs servo control by driving the focus motor 9 so that the relative position of the focus lens 2 follows the target relative position instructed from the system controller 11. Specifically, a drive waveform is generated based on the deviation between the relative position p output from the position detector 16 and the target relative position instructed from the system controller 11, and is output to the focus motor 9.

  By configuring such a feedback system, position control based on position detection of the optical encoder can be performed. The target relative position to which the focus lens 2 is moved is determined, for example, by determining the degree of focus of the captured image from the output signal of the video signal processing unit 6 so that the captured image is brought into focus based on a known focus control algorithm. It is determined by calculating the position of the focus lens 2 as the target relative position.

  Here, the optical sensor 18 and the optical scale 19 will be described in detail with reference to FIG. The optical sensor 18 includes a light emitting unit 100 and a light receiving unit 101. In the first embodiment, the light emitting unit 100 and the light receiving unit 101 are integrally configured. In addition, the optical scale 19 is periodically provided with a reflecting portion 111 and a non-reflecting portion 112. The light emitting unit 100 uses, for example, a light emitting diode and irradiates light toward the optical scale 19. Of the irradiated light, the light hitting the reflecting portion 111 is reflected and reaches the light receiving portion 101. On the other hand, the light hitting the non-reflecting part 112 hardly reaches the light receiving part 101. Since the reflecting part 111 and the non-reflecting part 112 are periodically arranged, the light reaching the light receiving part 101 forms a pattern whose optical characteristics change periodically, that is, a light / dark pattern. The light receiving unit 101 uses, for example, a photodiode, converts the above-described periodic light / dark pattern into an electric signal, and further performs predetermined electric signal processing, whereby the relative movement between the optical scale 19 and the optical sensor 18 is performed. A sine wave-like periodic signal corresponding to the above is generated. Since these electric signal processes are widely recognized as the prior art, a detailed description thereof will be omitted here.

  Next, the operation of the optical discontinuous portion 20 provided on the optical scale 19 for detecting the origin will be described. As shown in FIG. 3B, the discontinuous portion 20 is configured such that the reflective portion 111 is missing by three lines. Therefore, the light emitted to the discontinuous portion 20 hardly reaches the light receiving unit 101, and the signal from the light receiving unit 101 decreases compared to the other, and the origin is detected by detecting this signal change. Can do. The origin detection based on these signal changes is well known in Japanese Patent Application Laid-Open No. 2005-291980 and the like, and will not be described in detail here.

  Here, in Example 1, when shooting is not performed, that is, when the lens barrel 17 is housed, the zoom lens member 21 that holds the zoom lens 1 and the focus lens 2 as shown in FIG. The interval is narrowed to make the lens barrel 17 compact. That is, a configuration as a retractable lens barrel is used. Therefore, the movable stroke of the focus lens 2 at this time is limited according to the position of the zoom lens member 21. Hereinafter, the position of the zoom lens member 21 is referred to as a zoom lens position.

  FIG. 4B shows the relationship between the zoom lens position and the movable stroke of the focus lens 2. In a state where the zoom lens 1 is housed (hereinafter referred to as a retracted state), the movable stroke of the focus lens 2 is limited by the zoom lens position. Therefore, the area becomes extremely small and can hardly be moved from the end position of the movable stroke on the retraction side. On the other hand, the movable stroke of the focus lens 2 in a state where the zoom lens position protrudes (hereinafter referred to as the extended state) is the end position of the extended movable stroke from the end position of the retracted movable stroke according to the zoom lens position. Will gradually spread.

  Further, in the first embodiment, the origin position of the focus lens 2 is arranged between the retraction side stroke end and the retraction side stroke end, and the position is very close to the retraction side stroke end. Accordingly, when the zoom lens position is in the retracted state, the focus lens 2 is located near the retraction side stroke end, so that the origin position can always be determined to be in the direction of the retraction side. On the other hand, when the zoom lens position is not in the retracted state, the focus lens 2 is positioned at any position within the movable stroke, but it is determined that the origin position is likely to be in the retraction side direction. I can do it.

  Next, the photographing operation of the digital camera in the first embodiment will be described. FIG. 5 is a flowchart of the basic operation at the time of shooting by the digital camera in the first embodiment.

  In step S501, the system controller 11 initializes control variables and the like in response to a power-on instruction from the user. In step S502, a lens barrel initialization process is performed. In this step (lens barrel initialization process), the positions of the zoom lens 1 and the focus lens 2 are initialized (including the origin detection of the focus lens 2). Details of the lens barrel initialization process performed in step S502 will be described later.

  In step S503, the zoom lens 1 and the focus lens 2 are driven and a photographing operation by the image sensor 4 is performed according to a user operation. In step S504, it is determined whether there is a power-off instruction from the user. If there is a power-off instruction, the process proceeds to step S505. On the other hand, if there is no instruction to turn off the power, step S503 is repeated and the photographing operation is continued. In step S505, the focus lens 2 is first driven to the retracted standby position set near the retraction side stroke end of the focus lens 2. Thereafter, similarly, the zoom lens 1 is driven to the retracted standby position set in the vicinity of the stroke end on the retracting side of the zoom lens 1 to shift the lens barrel 17 to the retracted state. At this time, the focus lens 2 is moved to the retracted standby position prior to the zoom lens 1 in order to avoid a collision between the focus lens 2 and the zoom lens 1. In step S506, the zoom lens retracting standby position flag is set and stored in the flash memory 14 as data.

  Next, the lens barrel initialization process (including the origin detection) in step S502 will be described. FIG. 6 is a flowchart of the lens barrel initialization process of the digital camera according to the first embodiment.

  In step S <b> 601, the system controller 11 sets the target position of the focus lens 2 to the current position via the focus control unit 13. That is, the servo control is started so as to remain at the current position. Thereby, after this step, the position of the focus lens 2 does not change greatly depending on the external force or the posture of the digital camera. In step S <b> 602, the system controller 11 reads the zoom lens retracting standby position flag stored in the flash memory 14. If the read zoom lens retracted standby position flag is set, that is, if the zoom lens position is the retracted standby position (completely retracted state), the process proceeds to step S604. On the other hand, if the read zoom lens position is other than the retractable standby position (a state where the zoom lens is extended even a little), the process proceeds to step S607.

  In step S604, the system controller 11 drives the zoom lens 2 in the extension direction via the zoom control unit 12. In step S605, whether the position of the zoom lens 1 driven in the extending direction has exceeded a predetermined position (in the first embodiment, the position of the zoom lens 1 at which the origin position is included in the movable stroke of the focus lens 2). Determine if. If the position of the zoom lens 1 exceeds the predetermined position, the process proceeds to step S606. If the position of the zoom lens 1 does not exceed the predetermined position, step S604 is repeated and the driving of the zoom lens 1 is continued.

  In step S606, since the origin position of the focus lens 2 is always on the feeding side, the system controller 11 sets the driving direction of the focus lens 2 to the feeding side with respect to the focus control unit 13.

  On the other hand, in step S607, since the origin position of the focus lens 2 is likely to be on the retraction side, the system controller 11 sets the drive direction of the focus lens 2 to the retraction side with respect to the focus control unit 13. In step S608, the focus control unit 13 starts driving the focus lens 2 based on the set drive direction.

  In step S <b> 609, the system controller 11 determines whether the origin is detected via the position detection unit 16. If it is determined that the origin has been detected, the process proceeds to step S612. If it is determined that the origin has not been detected, the process proceeds to step S610. In step S610, it is determined whether or not the focus lens 2 has reached the stroke end. If the stroke end has been reached, the process proceeds to step S611. If the stroke end has not been reached, the process returns to S608 to continue driving. In step S611, the driving direction of the focus lens 2 is reversed and set in the reverse direction, the process proceeds to step S608, and driving is started again.

  In step S612, the zoom control unit 12 drives the zoom lens 1 and performs zoom lens origin detection processing. In step S613, the zoom control unit 12 drives the zoom lens 1 and moves the zoom lens 1 to a fixed point (a wide position in the first embodiment). In step S614, the focus control unit 13 drives the focus lens 2 and moves the focus lens 2 to a fixed point.

  As described above, according to the first embodiment, the initial driving direction of the focus lens 2 is determined by determining whether or not the zoom lens 1 is in the retracted state in the origin detection process of the focus lens 2 when the power is turned on. I can do things. Thereby, the processing time at the time of origin detection processing can be shortened, and damage to the member due to pressing against the stroke end can be reduced.

  The configuration of the digital camera in the second embodiment is the same as that shown in FIG.

  Next, a method for detecting the attitude of the digital camera body in the second embodiment will be described with reference to FIG.

The posture detection is determined from the output of the acceleration sensor 15. As shown in FIG. 7A, the direction of the optical axis and the sensor so that the single-axis detection type acceleration sensor 15 can detect the angle θ (the angle formed by the Z plane and the detection axis) with respect to the digital camera body 200. Are arranged so that their detection axes coincide. When the angle θ changes from −90 degrees to +90 degrees, the output of the acceleration sensor 15 changes according to the influence of gravity acceleration. When the output sensitivity of the acceleration sensor 18 is x (g / V) and the output change amount from the 0 g output is Δα (V), the posture angle θ of the digital camera body 200 is given by the following equation. Is easily calculated.
θ = arcsin (Δα / x) · (180 / π) (deg)

  Next, the relationship between the posture of the digital camera body 200 and the position of the focus lens 2 will be described with reference to FIGS. 7B to 7E.

  Since the focus lens 2 according to the second embodiment uses a drive mechanism of a voice coil type linear motor in the drive system, the drive mechanism of the linear motor allows the focus lens 2 to move by an external force / inertial force. End up. Therefore, before starting the control of the focus lens 2 such as when the power is turned on, the position of the focus lens 2 can be estimated according to the attitude of the digital camera body 200.

  For example, as shown in FIGS. 7B and 7C, when the power of the digital camera body 200 is upward when the power is turned on, it can be determined that the focus lens 2 is positioned at the retraction side stroke end. . On the other hand, as shown in FIGS. 7D and 7E, when the digital camera body 200 is facing downward when the power is turned on, it can be determined that the focus lens 2 is located at the extended stroke end.

  Next, the operation of the digital camera in the second embodiment will be described.

  Since the operation at the time of shooting of the digital camera in the second embodiment is the same as the sequence shown in FIG. 5, the description thereof is omitted.

  FIG. 8 is a flowchart of the lens barrel initialization process of the digital camera according to the second embodiment. In step S <b> 801, the system controller 11 sets the target position of the focus lens 2 to the current position via the focus control unit 13. That is, the servo control is started so as to remain at the current position. Thereby, after this step, the position of the focus lens 2 does not change greatly depending on the external force or the posture of the digital camera.

  In step S <b> 802, the system controller 11 determines the posture information of the digital camera body 200 from the detection result (output) of the acceleration sensor 15. In step S <b> 803, the system controller 11 reads the zoom lens retracting standby position flag stored in the flash memory 14. If the read zoom lens retracted standby position flag is set, that is, if the zoom lens position is the retracted standby position (completely retracted state), the process proceeds to step S805. On the other hand, if the read zoom lens position is other than the retractable standby position (a state where the zoom lens is extended even a little), the process proceeds to step S808.

  In step S805, the system controller 11 drives the zoom lens 2 in the extension direction via the zoom control unit 12. In step S806, the position of the zoom lens 1 driven in the pay-out direction exceeds a predetermined position (in the second embodiment, the position of the zoom lens 1 where the origin position is included in the movable stroke of the focus lens 2). It is determined. If the position of the zoom lens 1 exceeds the predetermined position, the process proceeds to step S807. If the position of the zoom lens 1 does not exceed the predetermined position, step S805 is repeated and driving of the zoom lens 1 is continued.

  In step S808, the posture of the digital camera body 200 is determined from the posture information determined in step S802. If it is determined that the digital camera body 200 is in the upward state, the process advances to step S807. If it is determined that the camera body is in a state other than upward, the process proceeds to step S809. When it is determined that the posture of the digital camera body 200 is upward, the focus lens 2 before starting servo control when the power is turned on is positioned at the stroke end in the gravity direction in this case, that is, the retraction side stroke end. There is a high possibility. When the focus lens 2 is positioned at the retraction side stroke end, the drive direction in which the origin of the focus lens 2 can be detected is always the retraction direction. Therefore, in step S807, the system controller 11 sets the drive direction of the focus lens 2 to the payout side with respect to the focus control unit 13.

  On the other hand, when it is determined that the posture of the digital camera body 200 is other than upward, when the power is turned on, the focus lens 2 before starting servo control is the stroke end in the gravity direction in this case, that is, the stroke end on the feeding side. Is likely to be located in. When the focus lens 2 is positioned at the feeding side stroke end, the driving direction in which the origin of the focus lens 2 can be detected is always the feeding direction. Therefore, in step S809, the system controller 11 sets the drive direction of the focus lens to the retraction side with respect to the focus control unit 13.

  In step S810, the focus control unit 13 starts driving the focus lens 2 based on the set drive direction. In step S <b> 811, the system controller 11 determines whether the origin is detected via the position detection unit 16. If it is determined that the origin has been detected, the process proceeds to step S814. If it is determined that the origin has not been detected, the process proceeds to step S812. In step S812, it is determined whether or not the focus lens 2 has reached the stroke end. If the stroke end has been reached, the process proceeds to step S813. If the stroke end has not been reached, the process returns to S810 to continue driving. In step S813, the driving direction of the focus lens 2 is reversed and set in the reverse direction, the process proceeds to S810, and driving is started again.

  In step S814, the zoom control unit 12 drives the zoom lens 1 and performs zoom lens origin detection processing. In step S815, the zoom control unit 12 drives the zoom lens 1 and moves the zoom lens 1 to a fixed point (a wide position in the second embodiment). In step S816, the focus control unit 13 drives the focus lens 2 and moves the focus lens 2 to a fixed point.

  As described above, according to the second embodiment, the initial driving direction of the focus lens 2 is determined by determining whether or not the zoom lens 1 is in the retracted state in the origin detection process of the focus lens 2 when the power is turned on. I can do things. Further, when the zoom lens 1 is not retracted, the accuracy of the initial driving direction of the focus lens 2 is determined by determining the position of the focus lens 2 from the posture information of the digital camera body 200 based on the detection result (output) of the acceleration sensor 15. Can be improved. Thereby, the processing time at the time of origin detection processing can be shortened, and damage to the member due to pressing against the stroke end can be reduced.

  As mentioned above, although the preferable Example of this invention was described, this invention is not limited to these Examples, A various deformation | transformation and change are possible within the range of the summary.

(Other examples)
The present invention can also be realized by executing the following processing. That is, software (computer program) that realizes the functions of the above-described embodiments is supplied to a system or apparatus via a network or various storage media, and the computer of the system or apparatus (or CPU, MPU, etc.) reads the program. To be executed. In this case, the computer program and the storage medium storing the computer program constitute the present invention.

DESCRIPTION OF SYMBOLS 1 Zoom lens 2 Focus lens 8 Zoom motor 9 Focus motor 11 System controller 15 Acceleration sensor 16 Position detection part 18 Optical sensor 19 Optical scale 20 Discontinuous part

Claims (6)

A zoom lens that is driven in the retracted direction from the retracted state and performs zooming operation,
A focus lens whose movable stroke is limited according to the position of the zoom lens;
A focus motor that drives the focus lens and allows movement of the focus lens by an external force or an inertial force;
Position detecting means for detecting the position of the focus lens;
Origin detection means for detecting the origin position of the focus lens;
When detecting the origin of the focus lens, it is determined whether the position of the zoom lens driven in the retracted direction from the retracted state exceeds a predetermined position at which the origin position is included in the movable stroke of the focus lens. When it is determined that the predetermined position has been exceeded, the driving direction of the focus lens is set to the extended side, and when it is determined that the initial position of the zoom lens at the time of origin detection is not in the retracted state, An image pickup apparatus comprising: a control unit that sets a driving direction of the focus lens to a retraction side. It further has posture detection means for detecting the posture of the imaging device,
The control means sets the drive direction of the focus lens to the feeding side when the initial position of the zoom lens at the time of origin detection is not in the retracted state and the detection result by the attitude detection means is upward. The imaging apparatus according to claim 1, wherein the driving direction of the focus lens is set to the retraction side in cases other than upward.   The said position detection means is equipped with the optical scale which has a pattern in which an optical characteristic changes periodically, and the optical sensor which receives light through the said optical scale, The Claim 1 or 2 characterized by the above-mentioned. Imaging device.   4. The origin detection means detects the origin position based on a signal change when passing through a discontinuous portion of optical characteristics provided in the optical scale. The imaging device described in 1. A zoom lens that is driven in the retracted direction from the retracted state and performs zooming operation,
A focus lens whose movable stroke is limited according to the position of the zoom lens;
A focus motor that drives the focus lens and allows movement of the focus lens by an external force or an inertial force;
Position detecting means for detecting the position of the focus lens;
A control method of an imaging apparatus having an origin detection means for detecting an origin position of the focus lens,
When the origin of the focus lens is detected, it is determined whether the position of the zoom lens driven in the retracted direction from the retracted state exceeds a predetermined position where the origin position is included in the movable stroke of the focus lens. And steps to
When it is determined that the predetermined position has been exceeded, the driving direction of the focus lens is set to the extension side, and when it is determined that the initial position of the zoom lens at the time of origin detection is not in the retracted state, the focus lens And a step of setting the driving direction of the imaging device to the retraction side.   A computer program for causing a computer to execute the method for controlling an imaging apparatus according to claim 5.

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