JP2011164149A - Imaging apparatus and its control method - Google Patents

Abstract

A lens barrel is prevented from being damaged when an operation of escaping from a state in which the lens barrel cannot be extended is performed.
An imaging apparatus having a photographing mode for bringing a lens barrel into a photographing state and a non-photographing mode for bringing the lens barrel into a retracted state, wherein the lens barrel is driven into a photographing state or a retracted state. Means for determining whether or not the lens barrel has shifted to the operation from the housed state to the photographing state by driving by the driving means, and the lens barrel has been shifted to operation by the determining means. If it is determined that the lens barrel is not operating, the driving of the driving unit is controlled so as to operate from the non-operating state to the photographing state, and the determining unit determines that the lens barrel has shifted to operation. And when the operation of the lens barrel to the shooting state is restricted, the driving means is driven so as to stop the operation of the lens barrel to the shooting state. It has a Gosuru control means.
[Selection] Figure 5

Description

  The present invention relates to lens barrel control in an imaging apparatus.

  Conventionally, the lens barrel retracted into the main body of the device is extended when the power is turned on or when shooting, but it may not be fully extended due to being pressed by the photographer's hand or obstacle during the extension. . For example, Patent Document 1 describes a camera that retracts a lens barrel when it is determined that the feeding operation has stopped for a predetermined time.

Japanese Patent Laid-Open No. 10-260440

  However, as described in Patent Document 1, after the lens barrel is retracted by determining that it has been stopped for a predetermined time, the components of the camera body and the lens barrel are mechanically brought into close contact with each other or engaged with each other. An unsuccessful feeding failure may occur. The cause is considered to be caused by the engagement of the components of the lens barrel and the case where the force is applied from the outside by the photographer's hand or an obstacle. Here, if it is caused by the former, it is highly possible that it can escape if the driving torque of the motor is increased and the feeding operation is performed, but if it is caused by the latter, if the torque is increased more than usual, the lens barrel is damaged. There is a risk that.

  The present invention has been made in view of the above problems, and when performing an operation of escaping from a state where the lens barrel cannot be extended, the lens barrel control capable of returning to a normal state while preventing damage to the lens barrel Is to realize.

  In order to solve the above-described problem, an imaging apparatus according to the present invention is an imaging apparatus having a shooting mode in which a lens barrel is in a shooting state and a non-shooting mode in which the lens barrel is in a retracted state. Driving means for driving the camera to a shooting state or a storage state, a determination means for determining whether or not the lens barrel has shifted to an operation from the storage state to the shooting state by driving by the driving means, and the determination means If it is determined that the lens barrel has not shifted to operation, the driving of the driving unit is controlled so as to operate from the non-operating state to the shooting state, and the lens is controlled by the determining unit. When it is determined that the lens barrel has shifted to operation and the operation of the lens barrel to the shooting state is restricted, the operation of the lens barrel to the shooting state is stopped. And a control means for controlling driving of said driving means so as to.

  According to the present invention, when performing an operation of escaping from a state where the lens barrel cannot be extended, it is possible to return the lens barrel to a normal state while preventing damage to the lens barrel.

1 is a block diagram showing a configuration of an imaging apparatus according to an embodiment of the present invention. The block diagram which shows the detailed structure of the zoom drive control part of FIG. 1, and a focus drive control part. 2A and 2B are an external view (a) and a cross-sectional view (b) when the lens barrel is retracted in the imaging apparatus of the present embodiment. 2A and 2B are an external view (a) and a cross-sectional view (b) when the lens barrel is extended in the imaging apparatus of the present embodiment. The flowchart (a) which shows the operation | movement when extending a lens-barrel from the retractable side at the time of a power supply, and the timing chart (b) which shows the extending | stretching operation | movement and retracting operation | movement of a lens barrel.

  EMBODIMENT OF THE INVENTION Below, the form for implementing this invention with reference to an accompanying drawing is demonstrated in detail.

  The embodiment described below is an example as means for realizing the present invention, and should be appropriately modified or changed depending on the configuration and various conditions of the apparatus to which the present invention is applied. It is not limited to the embodiment.

  <Configuration of Imaging Device> First, the configuration of the imaging device of this embodiment will be described with reference to FIG. In FIG. 1, reference numeral 101 denotes a zoom lens that adjusts the focal length by changing the position in the optical axis direction, and reference numeral 109 denotes a zoom drive control unit that controls driving of the zoom lens 101. Reference numeral 102 denotes a shutter / aperture unit including a shutter and an aperture, and reference numeral 110 denotes a shutter / aperture drive control unit that controls driving of the shutter / aperture unit 102. Reference numeral 103 denotes a shift lens as a blur correction optical system whose position can be changed in a plane perpendicular to the optical axis, and 111 controls the drive of the shift lens 103 according to a blur amount detected by a blur detection system (not shown). This is a shift lens drive control unit. Reference numeral 104 denotes a focus lens that adjusts the in-focus state by changing the position in the optical axis direction. Reference numeral 112 denotes a focus drive control unit that controls the drive of the focus lens 104. Reference numeral 105 denotes an image sensor that photoelectrically converts a subject image incident through the photographing optical systems 101 to 104 and outputs an electrical signal.

  Reference numeral 106 denotes an image signal processing unit that converts an electric signal output from the image sensor 105 into a video signal. Reference numeral 107 denotes a video signal processing unit that processes the video signal output from the imaging signal processing unit 106 according to the application. Reference numeral 108 denotes a display unit that displays an image as necessary using the video signal output from the video signal processing unit 107. Reference numeral 113 denotes an imaging / display control unit that controls driving of the imaging element 105 and the display unit 108.

  Reference numeral 118 denotes a system control unit that controls the entire imaging apparatus. A power switch (SW) 120 is used by the user to turn on / off the power supply to the apparatus. Reference numeral 114 denotes a power supply unit such as an AC or a battery. When the power SW 120 is turned on, power is supplied to the entire apparatus according to the application. Reference numeral 115 denotes an external input / output terminal unit such as a USB, which inputs and outputs video signals and various signals related to communication with an external device such as a personal computer. Reference numeral 116 denotes a release SW for the user to release the shutter. Reference numeral 119 denotes a zoom lever for the user to set the zoom magnification. Reference numeral 117 denotes a storage unit such as a memory card, which stores various data such as video files.

  <Imaging Operation> Next, with reference to FIG. 1, a photographing operation by the imaging apparatus having the above-described configuration will be described. In the release SW 116, the first switch (hereinafter referred to as SW1) and the second switch (hereinafter referred to as SW2) are sequentially turned on in accordance with the pushing amount. SW1 is turned on when the release SW 116 is pushed in about half (half push), and SW2 is turned on (full push) when the release SW 116 is pushed to the end. When SW1 of the release SW 116 is turned on, the focus drive control unit 112 drives the focus lens 104 to adjust the in-focus state, and the shutter / diaphragm unit drive control unit 110 drives the shutter / diaphragm 102 to obtain an appropriate value. Set to exposure.

  Further, when SW2 is turned on, the image data obtained from the light image exposed to the image sensor 105 is stored in the storage unit 117. When the zoom lever 119 is operated, the zoom drive control unit 109 that receives an instruction to adjust the focal length via the system control unit 118 drives the zoom lens 101 and moves the zoom lens 101 to the instructed zoom position. . At the same time, the focus drive control unit 112 drives the focus lens 104 and adjusts the in-focus state using the video signal output from the image sensor 105 and processed by the signal processing units 106 and 107.

  <Operation of Lens Barrel> Next, the operation of the lens barrel of the image pickup apparatus will be described with reference to FIGS. 3 and 4, reference numeral 100 denotes an image pickup apparatus main body. A strobe 302 emits light when shooting a dark subject. FIG. 3 shows the state of the lens barrel when the power is off or in the non-photographing mode. When the power is off, the zoom lens 101 is retracted inside the apparatus main body 100 in order to protect the zoom lens 101. This does not need to be completely stored inside the apparatus main body 100, but is retracted compared to the shooting state, thereby improving portability and storage property as the storage state. FIG. 4 shows a state of the lens barrel when the power is turned on or in the photographing mode. When the power SW 120 is pressed from the power-off state, the system control unit 118 starts control so as to be in a photographing state, and the zoom lens 101 is extended from the apparatus main body 100 to a predetermined position where photographing is possible.

  In FIG. 3B, the zoom lens 101 is retracted with the power off. In FIG. 4B, the zoom lens 101 is extended to the photographing enabled position with the power on. Here, the state in which the zoom lens 101 is extended is a state in which the lens barrel constituting the zoom lens 101 protrudes outside the apparatus main body. The state in which the zoom lens 101 is retracted is a state in which the lens barrel constituting the zoom lens 101 is retracted and accommodated in the apparatus main body.

  Reference numeral 201 denotes a zoom motor that operates the lens barrel constituting the zoom lens 101 in the extended state (shooting state) or the retracted state (stored state). In the extended state, the focal length can be adjusted by changing the position of the zoom lens 101 with the zoom motor 201. A focus motor 207 can change the position of the focus lens 104. When retracting the zoom lens 101 in the apparatus main body, the focus lens 207 is retracted from the optical axis by the focus motor 207 and then the zoom lens 101 is moved to the retracted side.

  <Configurations of Zoom Drive Control Unit and Focus Drive Control Unit> Next, detailed configurations of the zoom drive control unit 109 and the focus drive control unit 112 shown in FIG. 1 will be described with reference to FIG. First, the zoom drive control unit 109 will be described. Reference numeral 201 denotes the zoom motor described above, and a DC motor, a stepping motor, or the like can be applied. Reference numeral 202 denotes a zoom motor drive circuit, which is an analog circuit for driving the zoom motor 201. Reference numeral 203 denotes a zoom reset position detection unit that detects a reset position of the zoom lens 101 and obtains a reference for the zoom lens position. A photo interrupter, a photo reflector, or the like can be applied as a reset sensor for detecting the reset position.

  A zoom position detection unit 204 detects the position of the zoom lens 101. An encoder, a potentiometer, or the like can be applied to detect the zoom lens position. It is also possible to calculate the zoom lens speed by measuring the movement time of the zoom lens position. For example, when position detection is performed using an encoder, the position can be detected from the number of rising and falling edges of the encoder pulse, and the speed can be detected from the time from the rising edge to the falling edge of the pulse. Further, when position detection is performed using a potentiometer, the position can be detected by converting a change in resistance value into a voltage and detected by an AD converter, and the speed can be calculated from the amount of movement during a predetermined time.

  A zoom control unit 205 calculates the movement amount of the zoom lens according to the detection result of the zoom position detection unit 204, and rotates the zoom motor 201 via the zoom motor drive circuit 202 using the calculated movement amount as a control amount. The zoom lens 101 is moved.

  Next, the focus drive control unit 112 will be described. Reference numeral 207 denotes the focus motor described above, and a stepping motor or the like can be applied. A focus motor driving circuit 208 is an analog circuit that drives the focus motor 207. Reference numeral 209 denotes a focus reset position detection unit that acquires a reference position of the focus lens. As the sensor for detecting the focus position, a photo interrupter, a photo reflector, or the like can be applied. Reference numeral 210 denotes a focus control unit that calculates the amount of movement of the focus lens 104 according to the detection result of a focus position detection unit 211 described later. Then, the focus control unit 210 drives the focus motor 207 by the focus motor drive circuit 208 based on the calculated movement amount, and moves the focus lens 104. Reference numeral 211 denotes an in-focus position detection unit that detects the in-focus position of the subject from the image signal captured by the image sensor 105 and outputs the detection result to the focus control unit 210. Other configurations are the same as those in FIG.

  <Defective feeding out of the zoom lens 101> Next, the feeding out failure of the zoom lens 101 related to the problem focused on by the present invention will be described. When the cylindrical member (lens barrel) holding the outer peripheral portion of the zoom lens 101 hits a component of the apparatus body with a mechanically strong force when the zoom lens 101 is retracted or extended, the structure of the apparatus body is rarely used. An unsuccessful feeding failure may occur when the element and the cylindrical member are brought into close contact with each other or engaged with each other. When a feeding failure occurs, the zoom lens 101 does not move even when the zoom motor 201 is driven, and the lens barrel cannot be operated. There are various methods for detecting this feeding failure. For example, when an encoder is used for the zoom position detection unit 204, it can be determined from the fact that the position does not change at all, the target position is not reached in a predetermined driving time, the predetermined speed is not reached, and the like. Further, when a current detection sensor is used, the determination can be made by detecting a current larger than a predetermined value during driving. Furthermore, when an acceleration sensor is used, if there is a mechanism that does not operate depending on the posture, determination can be made from the posture direction, and it can also be determined for a mechanism that does not operate when acceleration is applied during driving. The malfunction may be determined using at least one of the position, posture, speed and acceleration of the lens barrel, the driving time and driving current of the zoom motor 201.

  As a method of escaping from a feeding failure, there is a possibility that escaping can be achieved by increasing the torque of a motor that is normally set low for smooth movement. For example, in the case of a stepping motor, the motor torque can be increased by increasing the supply voltage of the motor or switching the driving waveform from a micro step to a rectangular wave.

  <Escape Operation> Next, with reference to FIG. 5, the escape operation by the imaging apparatus of this embodiment will be described. In the following description, as an example of the extension operation of the zoom lens 101 when the power is turned on, the extension operation up to the reset sensor switching position of the zoom reset position detection unit 203 will be described. Depending on the design specifications of the imaging apparatus, the image sensor may be extended to a predetermined position determined by the specification instead of the reset sensor switching position.

  First, the operation of the zoom lens 101 at the time of extension will be described with reference to FIG. FIG. 5B shows the relationship between the switching of the sensor output of the zoom reset position detection unit 203 and the feeding operation, and the horizontal axis shows the displacement of the zoom lens 101. Reference numeral 601 denotes a position where the reset sensor output is switched. Reference numeral 602 denotes a reset sensor output level. Reference numerals 603 and 604 denote the zoom-out operation of the zoom lens 101 when the power is turned on. Reference numeral 603 denotes an extension operation when the zoom lens 101 is on the retracted side from the reset position detection unit 203 when the power is turned on. Reference numeral 604 denotes an extension operation when the zoom lens 101 is on the extension side of the reset position detection unit 203 when the power is turned on.

  The reset sensor of the zoom reset position detection unit 203 is attached so that the signal level is switched when the zoom lens 101 is on the extension side from the sensor attachment position. For example, when a photo interrupter is used as the reset sensor, “Hi” is output when the zoom lens 101 is on the extension side from the photo interrupter, and “Low” is output when the zoom lens 101 is on the retracted side (602). ). Since the position of the zoom lens 101 is indefinite when the power is turned on, the position information of the zoom position detection unit 204 is initialized by switching the reset sensor output. At this time, even if the position of the zoom lens 101 is indefinite, the zoom lens 101 can be driven in the direction in which the reset sensor output is switched.

  In order for the zoom position detection unit 204 to perform highly accurate detection, the switching direction of the reset sensor output of the zoom reset position detection unit 203 may be made the same. That is, when the power is turned on, the zoom lens 101 normally starts operating from the retracted side (603). For this reason, the reset sensor output may be switched by changing the direction in which the reset sensor output is switched from the retracted side to the feeding side and then off. However, if the zoom lens 101 cannot be retracted when the power is turned off, the zoom lens 101 may stop on the extended side with respect to the reset sensor (604). When the zoom lens 101 is driven in the direction in which the reset sensor output is switched when the power is turned on next time from this state, the direction in which the reset sensor output is switched changes from the feeding side to the retracting side. This causes an error of mechanical play. Therefore, when the operation is started from the feeding side, the reset sensor output is once switched to the retracting side from the feeding side to the retracting side after being driven to the retracting side, and then the zoom lens 101 (zoom motor 201) is driven reversely to output the reset sensor output. Switch from retracted side to extended side.

  Here, with reference to FIG. 5A, an operation when the zoom lens 101 is extended from the retracted side when the power is turned on will be described. Note that the following operations are realized by the system control unit 118 expanding and executing a program stored in the ROM in the RAM unless otherwise noted.

  In FIG. 5A, when the power switch 120 is turned on by the user, the system control unit 118 determines whether the zoom lens 101 is on the extended side or the retracted side with respect to the reset sensor via the zoom control unit 205. Determine (S501). When the zoom lens 101 is on the retracted side from the reset sensor, the system control unit 118 outputs a command for driving the zoom lens 101 to the extension side to the zoom control unit 205 (S502). The zoom control unit 205 drives the zoom motor 201 in the extending direction by the zoom motor driving circuit 202. Here, since there is a case where the zoom lens 101 rarely causes a feeding failure due to close contact or engagement at the start of driving, it is determined in S503 whether or not an operation failure has occurred. The determination of the malfunction here can be made by the fact that the detection result of the zoom position detection unit 204 does not change even though the zoom motor 201 is driven. That is, it is determined that the operation of the lens is defective because the movement of the lens cannot be detected even if a predetermined time elapses after the driving of the lens is started, or the predetermined speed is not reached even if the predetermined time elapses after the driving starts. In addition, because of the configuration, even if it is in a malfunctioning state, it may operate by a mechanical fitting error (backlash), so a determination threshold value that allows for the error may be set.

  If it is determined that the operation is defective (YES in S503), an escape operation is performed (S510). In the escape operation here, as described above, the torque is increased to drive the motor by a predetermined amount of movement, and then the motor is stopped. Then, after the escape operation, the value of the counter for counting the number of times the escape operation has been executed is incremented (S511). If the counter is equal to or smaller than the predetermined value (YES in S512), the process returns to S501 and the feeding operation is continued. The reason for determining the number of escape operations is that, in rare cases, the escape operation may not be possible even if the escape operation is repeated. For this reason, when the counter exceeds a predetermined value (NO in S512), it is determined that the escape cannot be performed even if the escape operation is repeated, the escape operation is stopped (S521), an error is displayed (S508), and this process is performed. Exit.

  On the other hand, if it is determined in S503 that the movement has started (NO in S503), it is determined whether or not the operation speed is appropriate (S504). Since the zoom lens 101 is drawn out of the apparatus main body, the zoom lens 101 may not be moved because it is pressed by hand or a force is applied from the outside by an obstacle or the like, and the operation toward the feeding side is limited. If it is forcibly driven in such a state that an external force is applied, mechanical parts such as internal gears may be damaged. In this case, the motor speed is lower than the value set by the zoom control unit 205. Therefore, when the motor speed is lower than the predetermined value (YES in S504), the motor is stopped to prevent damage (S506). In addition, since the zoom lens 101 is in the extended position after the motor is stopped, the zoom control unit 205 drives the zoom lens 101 in the retracted direction (S507), and the zoom lens 101 that is extended at least carelessly becomes something. It is prevented from being damaged by being hit.

  The predetermined amount used for the determination in S504 may be, for example, an amount in which the speed is significantly reduced with respect to the motor wow and flutter (speed allowable range%). After the collapse in S507, an error is displayed (S508), and this process is terminated.

  If the speed of the zoom motor 201 is equal to or higher than the predetermined value (NO in S504), it is determined whether the reset sensor output has been switched (S505), and the process returns to step S504 until a switch is detected (NO in S505). Continue to drive the motor. That is, while the motor is being driven, it is always determined whether or not a force is applied from the outside based on fluctuations in the motor speed. If switching of the reset sensor output is detected (YES in S505), the zoom control unit 205 stops the zoom motor 201, initializes the position information of the zoom position detection unit 204 (S509), and ends this process. .

  Next, when it is determined in S501 that the zoom lens 101 is on the extension side from the reset sensor, the system control unit 118 outputs a command to retract the focus lens 104 to the focus control unit 210 (S513). This is because, as shown in FIG. 4B, the zoom lens 101 has a focus lens 104 on the retracted side, and the zoom lens 101 interferes unless the focus lens 104 is retracted to the retracted side. Needless to say, if the focus lens 104 is configured not to interfere with the zoom lens 101, the retreating operation in S513 is unnecessary.

  After retracting the focus lens 104 in S513, the system control unit 118 outputs a command for driving the zoom lens 101 to the retracted side to the zoom control unit 205 (S514). The zoom control unit 205 drives the zoom motor 201 to the retracted side by the zoom motor drive circuit 202. Here, since the zoom lens 101 rarely causes a feeding failure due to close contact or engagement at the start of driving, it is determined in S515 whether or not an operation failure has occurred. The determination of malfunction is the same as S503.

  If it is determined in S515 that the operation is defective (YES in S515), the process proceeds to S510, and the escape operation is executed as described above. On the other hand, if it is determined in S515 that the movement has started (NO in S515), it is determined whether or not the operation speed is appropriate (S516). This determination of the appropriate speed is for preventing damage as in S504. Therefore, when the motor speed is lower than the predetermined value (YES in S516), the motor is stopped (S518), an error is displayed (S508), and this process is terminated.

  If the speed of the zoom motor 201 is equal to or higher than the predetermined value (NO in S516), it is determined whether the reset sensor output has been switched (S517), and the process returns to Step S516 until a switch is detected (NO in S516). Continue to drive the motor. That is, while the motor is being driven, it is always determined whether or not a force is applied from the outside based on fluctuations in the motor speed. When switching of the reset sensor output is detected (YES in S517), the zoom control unit 205 stops the zoom motor 201 (S520) and returns to S501. At this time, since the zoom lens 101 is positioned on the retracted side from the reset sensor, in the re-determination after returning to S501, the process proceeds to S502 (the retracted side in S501), and the above-described feeding operation is executed.

  [Other Embodiments] The present invention is also realized by executing the following processing. That is, software (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 a computer (or CPU, MPU, etc.) of the system or apparatus reads and executes the program code. It is processing to do. In this case, the program and the storage medium storing the program constitute the present invention.

Claims (7)

An imaging apparatus having a shooting mode for setting the lens barrel in a shooting state and a non-shooting mode for setting the lens barrel in a retracted state,
Driving means for driving the lens barrel to a photographing state or a storage state;
Determining means for determining whether or not the lens barrel has shifted from the housed state to the shooting state by driving by the driving unit;
When it is determined by the determination means that the lens barrel has not shifted to operation, the drive of the drive means is controlled so as to operate from the non-operating state to the photographing state, and the determination means When it is determined that the lens barrel has shifted to operation and the operation of the lens barrel to the shooting state is restricted, the operation of the lens barrel to the shooting state is stopped. An image pickup apparatus comprising: control means for controlling the drive of the drive means.   The control means performs an escape operation to escape from the non-operating state when the determination means determines that the lens barrel is not operating, and counts the number of times the escape operation has been executed, The imaging apparatus according to claim 1, wherein when the lens barrel does not operate even if the counted value exceeds a predetermined value, control is performed so as to stop the escape operation.   3. The control unit according to claim 1, wherein the control unit controls the driving unit to generate a torque larger than a torque of the driving unit that is driven when the lens barrel is operated in the photographing mode. Imaging device.   The control unit drives the lens barrel when the determination unit determines that the lens barrel has shifted to an operation, and when the speed of the lens barrel to the shooting state is limited. The imaging apparatus according to claim 1, wherein the imaging apparatus is stopped.   The control unit controls the driving unit to operate the lens barrel to a shooting state when the lens barrel is close to a retracted state with respect to a predetermined reference position when the lens barrel is operated. 5. The image pickup apparatus according to claim 1, wherein when the camera is close to the shooting state, the driving unit that controls the lens barrel to the retracted state is controlled. 6.   The determination means determines whether or not the lens barrel has shifted to an operation using at least one of the position, speed, drive time, drive current, posture, and acceleration of the lens barrel. The imaging device according to any one of claims 1 to 5. A method for controlling an imaging apparatus having a shooting mode for setting a lens barrel in a shooting state and a non-shooting mode for setting a lens barrel in a retracted state,
A driving step of driving the lens barrel to a photographing state or a storage state;
A determination step of determining whether or not the lens barrel has shifted from the retracted state to the shooting state by driving in the driving step;
If it is determined in the determination step that the lens barrel has not shifted to operation, the driving in the driving step is controlled so that the lens barrel moves from the non-operating state to the photographing state, and the determination When it is determined that the lens barrel has shifted to an operation in step and the operation of the lens barrel to the shooting state is restricted, the operation of the lens barrel to the shooting state is performed. And a control step for controlling the drive in the drive step so as to stop.

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