JP2007333922A - Lens control system and lens control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lens control system capable of preventing a damage of a driving mechanism and the like, while performing the operation to escape from an abnormal condition after the occurrence of the abnormal condition. <P>SOLUTION: A digital camera 100 is equipped with a linear motor 16, a position detection sensor 11, a CPU 4 and a motor driver 12. A focusing lens stops when a control means determines that the stop position detected by the position detection sensor 11 is not an intrinsic stop position but is in the abnormal condition, the control means controls the linear motor 16 so as to cancel the abnormal condition when the number of the previous times of canceling the abnormal condition is below the prescribed number of times. When the number of the previous times of canceling the abnormal condition exceeds the prescribed number of times, the control means stops the linear motor 16 to end the error. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a lens control device in which drive means for driving a lens of a camera is controlled by a control means, a camera including the lens control device, and a lens control method using the lens control device.

  When driving the lens of the camera, an external force may be applied, or the lens may stop at an unintended position due to other causes. There is a patent document disclosing a lens driving control method in such a case.

Patent Document 1 discloses a camera that switches to a slower moving speed when the detecting means detects that the photographing lens is not moving, and further continues driving the photographing lens. As a result, the driving force in an abnormal state is reduced, so that it is possible to prevent damage to the driving mechanism and driving circuit. Further, since the movement of the photographing lens is continuously detected even after switching to a slower movement speed, the operation can be easily continued.
JP 7-49447 A

  However, in the conventional camera, the lens driving is continued even after an abnormal state occurs, and there is a possibility that the driving mechanism is damaged even if the driving force is low.

  Accordingly, the present invention has been made in view of the above problems, and a lens control device capable of preventing damage to a drive mechanism or the like while performing an operation for removing the abnormal state after the abnormal state has occurred. The purpose is to provide.

  In order to solve the above problems, a lens control device of the present invention includes a driving unit that drives a lens, a position detection sensor that detects the position of the lens, and a control unit that controls the driving unit. When the lens stops and the stop position detected by the position detection sensor is determined to be in an abnormal state instead of the original stop position, the abnormal state has been canceled or the number of times it was previously determined to be in the abnormal state When the number of times is less than or equal to the predetermined number of times, the driving means is controlled so as to release the abnormal state.On the other hand, if the number of times determined to be in the abnormal state before or the number of times the abnormal state was previously released exceeds the predetermined number Stop the means and end in error.

  As a result, the operation for canceling the abnormal state is performed, so that it is possible to return from the abnormal state to the normal state without requiring a troublesome operation. In addition, since the number of abnormal state canceling operations is limited, it is possible to prevent damage to the drive mechanism and the like due to continuing driving of the lens when an abnormal state that cannot be canceled occurs.

  The lens control device of the present invention can recover from an abnormal state by a canceling operation for an abnormal state that can be canceled, but does not continue the canceling operation of the abnormal state indefinitely for an abnormal state that is difficult to cancel. Since the error is stopped after a predetermined number of release operations, the problem of damaging the driving means and the like by continuing the release operation of the abnormal state can be solved.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In each figure, the same reference number is attached | subjected about the same component or the component which functions similarly.

(Basic concept)
First, the basic concept of the present invention regarding cancellation of an abnormal state will be described with reference to FIG. FIG. 1 is a longitudinal sectional view of a digital camera 100 which is an embodiment of a lens control device of the present invention.

  The focus lens frame 23 that holds the focus lens 20 engages with the guides 22a and 22b, and is movable in the optical axis direction (the arrow AB direction in the figure). The linear motor 16 drives the focus lens frame 23. The linear motor 16 includes a coil 16a, a magnet 16b, and a yoke 16c. The coil 16 a is provided on a part of the focus lens frame 23. The yoke 16c is attached to the digital camera 100. The magnet 16b is fixed in the yoke 16c so as to face the coil 16a. In such a configuration, when a current is passed through the coil 16a, the coil 16a generates a magnetic force, and the focus lens frame 23 is driven by the magnetic force between the coil 16a and the magnet 16b. A magnet 21 is attached to the focus lens frame 23. The position detection sensor 11 is attached at a position facing the magnet 21 of the digital camera 100 main body and detects magnetism emitted from the magnet 21.

  With such a configuration, the focus lens frame 23 is driven in the optical axis direction by the linear motor 16 along the guides 22a and 22b. Further, the CPU 4 can grasp the position of the focus lens frame 23.

  Usually, since the focus lens frame 23 and the guides 22a and 22b are designed to have a small sliding resistance, the focus lens frame 23 can be moved and stopped as intended by the CPU 4 of the digital camera 100. However, when a foreign object adheres to the guides 22a and 22b, etc., the sliding resistance between the focus lens frame 23 and the guides 22a and 22b increases, so that the focus lens frame 23 is moved as intended. May not be possible. In such a case, the focus lens frame 23 stops at a position different from the stop position originally intended by the CPU 4 of the digital camera 100. In this specification, the state of the digital camera 100 is abnormal in this specification. It is called a state.

  The cause of the abnormal state of the digital camera 100 may be due to various causes such as contact of other members on the focus lens frame 23 and failure of the linear motor 16 in addition to adhesion of foreign matter on the guides 22a and 22b. It is done.

  The lens control device according to the present invention performs an operation for canceling the above-described abnormal state, and performs an error stop when the abnormal state cannot be canceled despite the operation for canceling the abnormal state. As a result, the abnormal state that can be cleared is quickly cleared and returned to the normal state, while the abnormal state that cannot be cleared is quickly stopped by an error, thereby preventing an unnecessary load from being applied to the lens control device.

(Embodiment 1)
1. Configuration FIG. 2 shows a control configuration of the digital camera 100 according to the first embodiment of the present invention. The subject image condensed by the lens barrel 24 is formed on the CCD image sensor 1. The CCD image sensor 1 converts the imaged subject image (optical signal) into an electrical signal to generate image data. The A / D converter 2 digitally converts the image data generated by the CCD image sensor 1.

  The CPU 4 controls the entire digital camera 100. The CPU 4 performs image processing such as white balance adjustment, YC conversion processing, electronic zoom processing, and compression processing on the image data converted by the A / D converter 2. The CPU 4 reads image data stored in the memory card 7 and performs predetermined processing such as decompression. The CPU 4 uses the work memory 8 when performing processing.

  An LCD (Liquid Crystal Display) 5 displays image data processed by the CPU 4. The memory card 7 is detachably attached to the card slot 6, and data is written to the loaded memory card 7 and data is read from the loaded memory card 7. The work memory 8 may be any storage means, and for example, a DRAM, SRAM, flash memory, or the like can be employed. The power switch 10 is an operation means for turning on / off the power of the digital camera 100.

  The release button 9 is an operation unit that gives an instruction to the CPU 4 to start imaging. When the release button 9 is half-pressed, the CPU 4 starts automatic focus adjustment control and controls the motor driver 12 to focus the subject image. When the release button 9 is fully pressed, the CPU 4 controls the CCD driver 3 to start an exposure operation in the CCD image sensor 1.

  The lens barrel 24 has four groups of lenses: an objective lens 17, a zoom lens 18, a shake correction lens 19, and a focus lens 20. The objective lens 17 is a lens positioned closest to the subject and is driven by the DC motor 13. The zoom lens 18 is movable in the optical axis direction, and the size of the subject image can be changed by moving in the optical axis direction. The zoom lens 18 is driven by the DC motor 14. The blur correction lens 19 cancels the blur of the subject image by moving in a plane perpendicular to the optical axis. The blur correction lens 19 is driven by the OIS motor 15. The focus lens 20 is movable in the optical axis direction, and the subject image can be focused by moving in the optical axis direction. The focus lens 20 is driven by a linear motor 16. The DC motors 13 and 14, the OIS motor 15 and the linear motor 16 are controlled by the motor driver 12, respectively. The motor driver 12 converts the voltage instructed by the CPU 4 into a current and drives the motor.

  The position detection sensor 11 detects the position of the focus lens 20. The detected position information is transmitted to the CPU 4. Based on the received position information, the CPU 4 determines whether or not the actual position of the focus lens 20 (the position detected by the position detection sensor 11) matches the target position intended by the CPU 4. When these positions are separated by a predetermined distance or more, the CPU 4 determines that the focus lens 20 is in an abnormal state. When it is determined that the CPU 4 is in an abnormal state, the CPU 4 performs control for canceling the abnormal state or error stop control.

  The focus lens 20 is an example of the lens of the present invention. The linear motor 16 is an example of the driving means of the present invention. The CPU 4 is an example of the control means of the present invention. The release button 9 and the power switch 10 are examples of the operation means of the present invention.

2. Applied voltage to linear motor The voltage applied to the linear motor 16 is controlled by the CPU 4. This control will be described with reference to FIG. FIG. 3 is a schematic diagram illustrating an example of a voltage applied to the linear motor. The vertical axis represents the applied voltage, and the horizontal axis represents the elapsed time.

  The linear motor 16 is driven according to the differential voltage between the applied voltage and the reference voltage. The reference voltage is a voltage that does not flow current through the linear motor 16. For example, when a voltage larger than the reference voltage is applied to the linear motor 16, the focus lens 20 is driven in the direction of arrow A in FIG. 1, and when a voltage smaller than the reference voltage is applied to the linear motor 16, Driven in the direction of arrow B.

  In FIG. 3, as an example, the linear motor 16 is normally driven during the period from time t0 to t1, stopped during the period from time t1 to t2, and driven to cancel the abnormal state during the period from time t2 to t4. The case where it stops after time t4 is shown.

  During the normal driving period (t0 to t1), the CPU 4 performs control so that the applied voltage falls within the range of the normal driving minimum voltage to the normal driving maximum voltage. On the other hand, when the abnormal state is canceled (t2 to t3), the CPU 4 performs control so that the applied voltage falls within the range from the lowest voltage when the abnormal state is released to the highest voltage when the abnormal state is released. The lowest voltage when the abnormal state is released is lower than the lowest voltage during normal driving, and the highest voltage when the abnormal state is released is higher than the highest voltage during normal driving. That is, the CPU 4 controls to apply a driving power larger than the driving power during the normal driving of the linear motor 16 when canceling the abnormal state.

3. Operation of Digital Camera FIG. 4 is a flowchart showing a lens control flow according to the first embodiment of the present invention. When the user presses the power button 10, the CPU 4 starts lens control. The CPU 4 has an abnormality canceling counter that counts the number of times the lens drive is in an abnormal state. This is because, in order to prevent damage to the lens, the abnormal state is canceled within a predetermined number of times M, and when the predetermined number of times M is exceeded, even if an abnormal state is detected, the process ends with an error without performing the abnormal state canceling process. When starting the lens control, the CPU 4 sets the abnormality cancellation counter to zero (S41).

  When the user presses the release button 9 halfway, the motor driver 12 converts the instructed voltage into current under the control of the CPU 4 to drive the motor. At this time, the CPU 4 controls the motor driver 12 based on the output of the position detection sensor 11. That is, the CPU 4 performs feedback control including the focus lens 20, the position detection sensor 11, the CPU 4, the motor driver 12, and the linear motor 16 for driving the focus lens 20. The lens group is moved by driving the motor. When the CPU 4 detects that the focus lens 20 is in a stopped state for a predetermined period (S42), the position detection sensor 11 detects the position of the focus lens 20, and the detected position information is transmitted to the CPU 4. Based on the received position information, the CPU 4 determines whether or not the actual stop position (position detected by the position detection sensor 11) of the focus lens 20 matches the original stop position (target position intended by the CPU 4). Judgment is made (S43). When the CPU 4 determines that these positions are separated by a predetermined distance or more and the focus lens 20 is in an abnormal state (Y in S43), the number of times of the abnormal state is within the predetermined number M based on the value of the abnormality cancellation counter. It is determined whether or not there is (S44). If the number of abnormal states is within the predetermined number M (Y in S44), abnormal state release processing is performed so as to release the abnormal state of the focus lens 20. Further, in order to prevent the lens from being damaged, the first embodiment limits the number of times that the abnormal state canceling process is performed, that is, the abnormal state canceling process is performed only a predetermined number of times. Then, when attempting to perform the abnormal state canceling process, first, the abnormal state canceling process count i is given to 0 (S451). Then, the abnormal state canceling process is repeated until the abnormal state canceling process count i is within the predetermined number N (S452, S453, S454). Note that the CPU 4 controls the motor driver 12 by simply applying a predetermined voltage to the motor driver 12 for a predetermined time, not based on the output of the position detection sensor 11 during the abnormal state release processing. That is, the CPU 4 does not perform feedback control including the focus lens 20, the position detection sensor 11, the CPU 4, the motor driver 12, and the linear motor 16 for driving the focus lens 20 during the abnormal state canceling process. As a result, the power applied to the linear motor 16 during the abnormal state canceling process can be kept constant for a predetermined time regardless of the position of the focus lens 20, so that the abnormal state canceling operation can be performed stably. Can do.

  When the abnormal state cancellation processing count i exceeds the predetermined number N (Y in S452), the CPU 4 stops the cancellation of the abnormal state, counts up 1 in the abnormal cancellation counter (S455), and controls the motor driver 12. By doing so, the focus lens 20 is returned to the position before detecting the abnormal state (S456). After the focus lens 20 is returned to the position before detecting the abnormal state, the CPU 4 continues to control the focus lens 20 (jump to S42).

  Further, when the number of times the focus lens 20 has been in an abnormal state exceeds the predetermined number M (N in S44), the motor driver does not cancel the abnormal state of the focus lens 20 and stops driving the lens. 12 is controlled (S461). Then, the camera displays an error (S462) and ends the lens control.

4). Summary As described above, the digital camera 100 according to the first embodiment includes the linear motor 16, the position detection sensor 11, the CPU 4, and the motor driver 12. The linear motor 16 drives the focus lens 20. The position detection sensor 11 detects the position of the focus lens 20. A control unit including the CPU 4 and the motor driver 12 controls the linear motor 16. When the control unit determines that the focus lens is stopped and the stop position detected by the position detection sensor 11 is not the original stop position but is in an abnormal state, the number of times the abnormal state has been canceled is a predetermined number of times. When the following is true, the linear motor 16 is controlled to cancel the abnormal state. On the other hand, if the number of times the abnormal state has been previously canceled exceeds a predetermined number, the linear motor 16 is stopped and the error is ended.

  As a result, an abnormal state that can be cleared can be recovered from the abnormal state by a canceling operation, while an abnormal state that is difficult to cancel is stopped after performing the canceling operation of the abnormal state within a predetermined number of times. Thus, it is possible to solve the problem that the driving means and the like are damaged due to the abnormal state canceling operation.

  Further, the control means 4 and 12 of the digital camera 100 according to the first embodiment controls to apply a driving power larger than the driving power during the normal driving of the linear motor 16 when canceling the abnormal state. Accordingly, since the driving force of the linear motor 16 can be increased during the abnormal state canceling operation, the abnormal state can be canceled more easily.

  Further, the control means 4 and 12 of the digital camera 100 according to the first embodiment controls the linear motor 16 based on the detection result of the position detection sensor 11 during normal driving, while releasing the abnormal state. The linear motor 16 is controlled without being based on the detection result of the position detection sensor 11. Thereby, the position of the focus lens 20 can be controlled more accurately during normal driving, while the power applied to the linear motor 16 can be applied for a predetermined time regardless of the position of the focus lens 20 during the abnormal state canceling process. Since it can be kept constant, the operation for canceling the abnormal state can be performed stably.

(Modification of Embodiment 1)
FIG. 5 is a flowchart illustrating a flow of lens control according to the modification of the first embodiment. This modified example has the same configuration as that of the first embodiment, but it is assumed that the abnormal state is released only once. In this modification, the abnormal state is canceled by driving the lens driving range with a sufficient force. Here, description of the same parts as those in Embodiment 1 is omitted, and only the operation part of the digital camera will be described.

  As in the first embodiment, when the user presses the power button 10, the CPU 4 starts lens control. When the lens control is started, the abnormality release counter is set to zero (S51). When the user presses the release button 9 halfway, the motor driver 12 converts the instructed voltage into current under the control of the CPU 4 to drive the motor. The lens group is moved by driving the motor. When the CPU 4 detects that the focus lens 20 is in a stopped state for a certain period (S52), the position detection sensor 11 detects the position of the focus lens 20, and the detected position information is transmitted to the CPU 4. Based on the received position information, the CPU 4 determines whether the actual stop position of the focus lens 20 matches the original stop position (S53). When the CPU 4 determines that these positions are separated by a predetermined distance or more and the focus lens 20 is in an abnormal state (Y in S53), the CPU 4 determines whether or not the abnormal state has been canceled before (S54). That is, if the value of the abnormality cancellation counter is zero, it is determined that the abnormal state has not been canceled (Y in S54). In that case, the abnormal state of the focus lens 20 is canceled. Then, the abnormal state cancellation processing is performed after setting the value of the abnormal cancellation counter to 1 (S551). First, 0 is set to the abnormal state cancel processing count i (S552). Then, the abnormal state canceling process is repeated until the abnormal state canceling process number i is within the predetermined number N (S553, S554, S555, S556).

  In this modification, the abnormal state is canceled by driving the lens driving range with a sufficient force. The CPU 4 controls the motor driver 12 so that a driving power larger than the driving power during normal driving is applied to the linear motor 16. The motor driver 12 converts the voltage larger than the normal drive instructed by the CPU 4 into a current to drive the linear motor 16. Then, the focus lens 20 is driven in one direction by the drive of the linear motor 16 (S554). Subsequently, the CPU 4 controls the motor driver 12 so that the focus lens 20 is driven in the other direction, and the linear motor 16 is driven by the same large driving current to drive the focus lens 20 in the other direction ( S555). After the focus lens 20 is driven in the other direction, 1 is incremented to the abnormal state cancel processing count i (S556). When the abnormal state cancel processing count i exceeds the predetermined number N (Y in S553), the CPU 4 stops canceling the abnormal state and controls the motor driver 12 to return the focus lens 20 to the position before the abnormal state detection. (S557). After the focus lens 20 is returned to the position before detecting the abnormal state, the CPU 4 continues to control the focus lens 20 (jump to S52).

  When the CPU 4 determines that the value of the abnormality cancellation counter is not zero, that is, the abnormal state has been canceled (N in S54), the abnormality of the focus lens 20 is the same as in the first embodiment. Without releasing the state, the motor driver 12 is controlled to stop driving the lens (S561). Then, the camera displays an error (S562) and ends the lens control.

  As described above, in this modification, the CPU 4 changes the value of the abnormality canceling counter to 1 when determining that it is in an abnormal state (Y in S53). In the first embodiment, the CPU 4 changes the value of the abnormality canceling counter after completing the abnormal state canceling process, but before performing the abnormal state canceling process after determining that it is in an abnormal state as in this modification. The present invention can be applied even if the value of the abnormality cancellation counter is changed.

  In the present modification, the control means controls the linear motor 16 so as to cancel the abnormal state by causing the linear motor 16 to reciprocate. Thereby, it is possible to easily realize the operation for canceling the abnormal state by a simple control.

(Embodiment 2)
In the second embodiment, an abnormal state canceling process is performed in accordance with a user operation. Accordingly, since it is possible to prevent the lens from being driven when the user does not intend, it is possible to provide a camera that does not feel uncomfortable for the user. Since other configurations and the like are the same as those of the first embodiment, description of the same parts is omitted here, and only different parts are described.

  FIG. 6 is a flowchart showing the flow of lens control according to the second embodiment. As in the first embodiment, when the user presses the power button 10, the CPU 4 starts lens control. When the lens control is started, the abnormality release counter is set to zero (S61). When the user presses the release button 9 halfway, the motor driver 12 converts the instructed voltage into current under the control of the CPU 4 to drive the motor. The lens group is moved by driving the motor. When the CPU 4 detects that the focus lens 20 is stopped for a certain period (S62), the position detection sensor 11 detects the position of the focus lens 20 and transmits it to the CPU 4. Based on the received position information, the CPU 4 determines whether or not the actual stop position of the focus lens 20 matches the original stop position (S63). When the CPU 4 determines that these positions are separated by a predetermined distance or more and the focus lens 20 is in an abnormal state (Y in S63), whether or not to operate the operation means so that the user manually performs lens control. Inquire about (S64). If the user selects to continue the lens control (Y in S64), the lens is controlled by canceling the abnormality as in the first embodiment (S661 to S666, S671, S672).

  When the user selects not to perform the lens control (N in S64), the abnormal state of the focus lens 20 is not canceled and the motor driver 12 is controlled to finish the lens control (S671, S672). ).

  As described above, in the second embodiment, the abnormal state canceling process is performed in accordance with the operation of the user pressing the release button 9. Accordingly, since it is possible to prevent the lens from being driven when the user does not intend, it is possible to provide a camera that does not feel uncomfortable for the user.

(Embodiment 3)
Another embodiment of the present invention will be collectively described below as a third embodiment.

  In Embodiments 1 and 2 of the present invention, the focus lens 20 is exemplified as the lens of the present invention, but the present invention is not limited to this. For example, the present invention may be applied when driving a zoom lens or an OIS lens.

  In the first and second embodiments of the present invention, the linear motor 16 is exemplified as the driving means of the present invention, but the present invention is not limited to this. For example, it can be applied to a DC motor or an ultrasonic motor. In short, the present invention can be applied to any lens that can drive the lens and has a mechanism that can cause an abnormal state.

  Moreover, in Embodiment 1 and 2 of this invention, although the position detection sensor 11 which detects magnetism was illustrated as a position detection sensor of this invention, it is not restricted to this. For example, a sensor that detects the position of the focus lens 20 by detecting light may be used, or a sensor that mechanically detects the position of the focus lens 20.

  In the first and second embodiments of the present invention, the position of the focus lens 20 is directly detected by the position detection sensor 11, but the present invention is not limited to this. For example, using a DC motor as a driving means, an encoder or the like is attached to the DC motor, and the rotation angle of the DC motor is input to the CPU 4 so that the CPU 4 indirectly grasps the position of the focus lens 20 based on the rotation angle of the DC motor. It is good also as a simple structure. In short, the position detection sensor of the present invention may be any sensor that can detect the position of the lens regardless of whether it is direct or indirect.

  In the first and second embodiments of the present invention, the configuration including the CPU 4 and the motor driver 12 is exemplified as the control means of the present invention. However, the present invention is not limited to this. For example, the motor driver 12 may not be used as the DC motor 13 or the DC motor 14 but may be a dedicated driver for the linear motor 16. Further, the CPU 4 and the motor driver 12 may be formed on the same semiconductor chip. The CPU 4 may be configured with a programmable microcomputer or may be configured with a hard wire.

  In the first and second embodiments of the present invention, the value of the abnormality canceling counter is set to 0 as part of the initial setting operation after the camera is turned on (S41, S51, S61). As a result, even after an abnormal stop, it is possible to initialize the abnormality canceling process again by turning on the power of the camera again. Therefore, the abnormal state canceling process can be performed as many times as the user desires by turning on the power of the camera again. However, the present invention is not limited to such examples. For example, the abnormality cancellation counter may be configured by a flash memory or the like, and the counter value once added may be stored without being reset. As a result, since the camera that has performed the abnormal state cancellation processing exceeding the predetermined number of times always stops with an error, the unnecessary abnormal state cancellation processing can be prevented, and thus the lens driving mechanism can be prevented from being damaged by the abnormal state cancellation processing.

  In the first and second embodiments of the present invention, the example in which the driving force of the linear motor 16 is increased during the abnormal state canceling operation is shown. However, the driving force of the linear motor 16 is increased in the normal state and the abnormal state. The present invention can also be applied to the same case. However, in the operation of canceling the abnormal state, increasing the driving force of the linear motor 16 makes it easier to remove the foreign matter that is the cause of the abnormal state, so that the abnormal state can be easily canceled.

  Although the embodiments of the present invention have been described in detail with reference to the drawings, the present invention is not limited to the details, and various modifications can be made by those skilled in the art.

  The present invention is applicable to a lens driving device that drives and controls a lens. Specifically, the present invention can be applied to an imaging apparatus having a lens barrel, such as a video camera, a digital still camera, a film camera, and an analog camera.

1 is a longitudinal sectional view of a digital camera which is an embodiment of a lens control device of the present invention. 1 is a block diagram showing an electrical configuration of a digital camera according to a first embodiment of the present invention. 1 is a schematic diagram illustrating an example of a voltage applied to a linear motor of a digital camera according to a first embodiment of the present invention. 6 is a flowchart showing a flow of lens control according to the first embodiment of the present invention. 10 is a flowchart showing a lens control flow according to a modification of the first embodiment of the present invention. 7 is a flowchart showing a flow of lens control according to the second embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 CCD image sensor 11 Position detection sensor 14 DC motor 16 Linear motor 16a Coil 16b Magnet 16c Yoke 17 Objective lens 18 Zoom lens 19 Shake correction lens 20 Focus lens 21 Magnet 22a, 22b Guide 23 Focus lens frame 100 Digital camera

Claims (6)

Driving means for driving the lens;
A position detection sensor for detecting the position of the lens;
Control means for controlling the drive means,
In the case where the control means determines that the lens is stopped and the stop position detected by the position detection sensor is not an original stop position but is in an abnormal state,
When the number of times determined to be in the abnormal state before or the number of times the abnormal state was previously canceled is less than or equal to a predetermined number of times, the drive means is controlled to cancel the abnormal state,
When the number of times determined to be in the abnormal state before or the number of times the abnormal state was previously released exceeds a predetermined number of times, the driving means is stopped and the error ends.
Lens control device. The lens control device according to claim 1, wherein the control unit controls the driving unit to release the abnormal state by reciprocating the driving unit. 3. The lens control device according to claim 1, wherein the control unit performs control so as to apply a driving power larger than a driving power during a normal driving of the driving unit when releasing the abnormal state. The control means includes
During normal driving, while controlling the driving means based on the detection result of the position detection sensor,
The lens control device according to claim 1, wherein when the abnormal state is canceled, the driving unit is controlled based on a detection result of the position detection sensor. It further comprises an operation means for receiving a user's operation,
The lens control device according to claim 1, wherein the control unit controls the driving unit to cancel the abnormal state in response to the operation unit receiving an operation by a user. Driving means for driving the lens;
Position detecting means for detecting the position of the lens;
In a camera comprising a lens control device having control means for controlling the drive means,
Driving the lens by the driving means under the control of the control means;
The lens stops, and the position detection sensor detects the position of the lens;
The control means determines whether the stop position of the lens detected by the position detection sensor is in an abnormal state instead of the original stop position;
In the case where the control unit determines that the stop position of the lens is in an abnormal state, the number of times that the position detection sensor has previously determined that the lens is in an abnormal state or the number of times that the abnormal state has been canceled is less than a predetermined number of times. The number of times that the position detection sensor has previously determined that the abnormal state has occurred or the number of times that the abnormal state has been previously released exceeds a predetermined number. And a step of stopping the driving means and terminating the error.

Images