JP2007025509A - Imaging apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an imaging apparatus equipped with a system capable of preventing thermal damage of a lens barrel caused by the elevated temperature of the lens barrel with light condensation, and also, which is easily usable for a photographer. <P>SOLUTION: In the imaging apparatus, an imaging optical system is moved by a drive control part, and the imaging optical system is moved by a first timer setting part from a first state to a second state after a lapse of a first setting time, and the imaging optical system is moved by a second timer setting part from the first state to the second state after a lapse of a second setting time shorter than the first setting time, the attitude of the imaging optical system is detected by an attitude detecting part, and when it is determined that the imaging optical system looks upward based on the detected attitude, the imaging optical system is moved by the drive control part to the second state after a lapse of the second setting time. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an imaging apparatus equipped with a retractable lens barrel, and more specifically to a configuration of an imaging apparatus that eliminates the influence of unnecessary light incident on the lens barrel.

  In recent years, image sensors such as charge coupled devices (CCDs) and complementary metal-oxide semiconductors (CMOS) have been improved in integration with signal processing and can be provided at low cost. Digital still cameras and digital video cameras (hereinafter, collectively referred to as “digital cameras”) are rapidly spreading as imaging devices that can convert and output a typical image signal.

  Today's digital cameras are capable of high magnification while achieving miniaturization. For this reason, the power of each lens group is strong, and the light may be condensed inside the lens barrel. In this case, particularly when sunlight enters, the temperature of the condensing part is extremely increased. Since the lens barrel is generally molded of plastic, the temperature of the light converging part exceeds the melting point of the plastic material due to sunlight, and the heat of the condensing part of the lens barrel and its surroundings. Deformation, fuming, and thermal damage may be caused by combustion.

For this reason, appropriate measures are required in the use of the digital camera. In order to solve this problem, it has been proposed to dispose a ceramic member having a low coefficient of thermal expansion at the position of the condensing part (Patent Document 1). In addition, a configuration has been proposed in which a mode is discriminated when using a digital camera, and a retractable lens barrel is automatically moved to a storage position except during shooting (Patent Document 2).
Japanese Patent Laid-Open No. 6-94959 JP 2004-110065 A

  However, the above-described conventional imaging device has the following problems. By using the configuration proposed in Patent Document 1, it is effective as a countermeasure against high heat to attach a plate having a low coefficient of thermal expansion, such as ceramic, to the plastic member that holds the lens group. However, since the number of parts increases, the cost increases and it is difficult to downsize the lens barrel.

  Further, if the configuration described in Patent Document 2 is used, for example, when a state in which the photographer does not operate the digital camera has elapsed for a predetermined time, the lens barrel of the sun rays is automatically moved to the storage position by automatically moving to the storage position. Condensation can be prevented. However, in a situation where the digital camera is left in an upward posture in a place where the sunlight is strong, and the sunlight is directly incident from the front of the lens, the condensing unit is moved, for example, in about 20 seconds before moving the lens barrel. The temperature easily exceeds the melting point of the plastic material, causing the above-mentioned problems.

In order to prevent such a situation, it is possible to construct a system in which the lens barrel is automatically moved to the storage position when the non-photographing state continues for 10 seconds by setting a timer, for example. However, if the timer setting time is as short as 10 seconds, the lens barrel will move to the storage position unless the photographer takes 10 seconds or more with the digital camera. As a result, even if the photographer tries to take a picture, a situation in which photography is not possible frequently occurs, so that it is very inconvenient, including missing a photo opportunity.
In view of the above-described problems, an object of the present invention is to provide an imaging apparatus having a system that is easy to use for a photographer while preventing a lens barrel from being heated and thermally damaged due to light collection.

The present invention is an imaging apparatus having an imaging optical system that forms an optical image of a subject,
Drive control means for moving the imaging optical system;
First timer setting means for moving the imaging optical system from the first state to the second state after elapse of a first setting time;
Second timer setting means for moving the imaging optical system from the first state to the second state after elapse of a second setting time shorter than the first setting time;
Posture detecting means for detecting the posture of the imaging optical system,
When it is determined that the posture of the imaging optical system is an upward posture based on the posture detected by the posture detection unit, the drive control unit is configured to perform the imaging optical system after the second set time has elapsed. Is moved to the second state.

  As described above, according to the imaging apparatus of the present invention, the plastic parts inside the lens barrel are not burned by sunlight incidence. Furthermore, in a normal use state, since the timer setting time becomes long, it does not immediately shift to the retracted state, so that the convenience of the photographer is not impaired.

(Embodiment 1)
With reference to FIG. 1, an imaging apparatus according to Embodiment 1 of the present invention will be described. In the present embodiment, a digital camera configured as an example of an imaging device will be described. The digital camera 1 includes an imaging optical system L, a microcomputer 3, a signal processing unit 3A, an imaging sensor 4, a CCD drive control unit 5, an analog signal processing unit 6, an A / D conversion unit 7, a digital signal processing unit 8, and a buffer memory. 9, an image compression unit 10, an image recording control unit 11, an image recording unit 12, an image display control unit 13, a motion correction unit 15A, a motion detection unit 18A, a first timer setting unit 20, a second timer setting unit 21, Power switch 35, shutter operation section 36, shooting / playback switching operation section 37, cross operation key 38, MENU setting operation section 39, SET operation section 40, shutter control section 41, shutter drive motor 42, and display section 45 such as an LCD. including.

  The imaging optical system L includes four lens groups, a first lens group L1, a second lens group L2, a third lens group L3, and a fourth lens group L4. The first lens unit L1 and the second lens unit L2 perform zooming by moving in the direction of the optical axis ZA. The fourth lens unit L4 (focus lens unit) performs focusing by moving in the optical axis direction. The third lens unit L3 is an image blur correction lens unit, and plays a role of correcting the movement of the image by moving the optical axis in a plane perpendicular to the optical axis AZ.

  When mechanical vibration or shaking by the photographer is applied to the digital camera 1, the optical axis of the light emitted from the subject toward the lens shifts from the optical axis of the lens. Therefore, the obtained image is an unclear image. A prevention mechanism for preventing this is called an image blur correction mechanism. In addition, vibration and shaking of the digital camera 1 are inevitably transmitted to the imaging optical system L built in the digital camera 1. Therefore, unless otherwise specified, the vibration or shaking of the digital camera 1 means the vibration or shaking of the imaging optical system L.

  The microcomputer 3 controls operations of various control units of the digital camera 1. Further, the microcomputer 3 can receive signals output from the power switch 35, the shutter operation unit 36, the photographing / playback switching operation unit 37, the cross operation key 38, the MENU setting operation unit 39, and the SET operation unit 40. is there.

  The shutter control unit 41 operates the shutter by driving the shutter drive motor 42 based on the control signal output from the microcomputer 3 in response to the timing signal generated by the operation of the shutter operation unit 36.

  The image sensor 4 is a CCD, and converts an optical image formed by the photographing optical system L into an electrical signal. The image sensor 4 is driven and controlled by the CCD drive control unit 5. The imaging sensor 4 may be a CMOS.

  The image signal output from the image sensor 4 is sequentially processed through the analog signal processing unit 6, the A / D conversion unit 7, the digital signal processing unit 8, the buffer memory 9, and the image compression unit 10. The analog signal processing unit 6 performs analog signal processing such as gamma processing on the image signal output from the imaging sensor 4. The A / D conversion unit 7 converts the analog signal output from the analog signal processing unit 6 into a digital signal. The digital signal processing unit 8 performs digital signal processing such as noise removal and edge enhancement on the image signal converted into a digital signal by the A / D conversion unit 7. The buffer memory 9 is a RAM (Random Access Memory) and temporarily stores an image signal processed by the digital signal processing unit 8.

  The image signal stored in the buffer memory 9 is further processed sequentially by the image compression unit 10 and the image recording unit 12. The image signal stored in the buffer memory 9 is transmitted to the image compression unit 10 in accordance with a command output from the image recording control unit 11. At this time, the image signal is compressed at a predetermined ratio to become data having a size smaller than the original size. For example, as such a compression method, a JPEG (Joint Photographic Experts Group) method is used. At the same time, the image compression unit 10 generates a reduced image signal corresponding to a captured image used for thumbnail display or the like. Thereafter, the compressed image signal is transmitted to the image recording unit 12.

  The image recording unit 12 includes an internal memory 48 (not shown) provided in the main body of the digital camera 1 and / or a detachable removable memory 49 (not shown). Based on a command output from the image recording control unit 11, an image file is generated by associating an image signal with predetermined information to be stored. The generated image file is stored in the image recording unit 12. The predetermined information to be recorded together with the image signal includes the date and time when the image was captured, focal length information, shutter speed information, aperture value information, shooting mode information, and attitude information of the digital camera 1 described later. It is. Since the attitude of the digital camera 1 and the attitude of the imaging optical system L are the same, the attitude of the digital camera 1 means the attitude of the imaging optical system L unless otherwise specified.

  The image display control unit 13 is controlled by a control signal output from the microcomputer 3. In response to a command from the image display control unit 13, the display unit 45 displays the captured image as a visible image based on the image signal stored in the image recording unit 12 or the buffer memory 9. There are a display form of the display unit 45 including a display form of only a photographed image based on the image signal and a form of displaying information at the time of photographing the image signal. The information at the time of shooting of the image signal includes focal length information, shutter speed information, aperture value information, shooting mode information, focus state information, and residual blur amount. These pieces of information are displayed when the MENU setting operation unit 39 is operated.

  The first timer setting unit 20 is a timer setting unit that sets a first time T1 for automatically retracting the lens barrel 2 from the photographing state to the retracted state. By setting the first time T1, for example, when a time T1 such as 5 minutes elapses, the lens barrel is moved from the wide (wide angle) state illustrated in FIG. 5 or the tele (telephoto) state illustrated in FIG. 4 is automatically retracted to the retracted state illustrated in FIG. The first time T1 may be set by default or may be arbitrarily set by the photographer.

  The second timer setting unit 21 is a timer setting unit that sets a second time T2 for automatically retracting the lens barrel 2 from the photographing state to the retracted state. By setting the second time T1, for example, when a time T2 such as 10 seconds shorter than the time T1 elapses, from the wide state shown in FIG. 5 or the tele state shown in FIG. 6 to the retracted state shown in FIG. The lens barrel 2 is automatically retracted.

  Next, the external configuration of the digital camera 1 will be described with reference to FIG. FIG. 2A shows the top surface of the digital camera 1, and FIG. 2B shows the back surface of the digital camera 1. The housing 1a includes an imaging optical system L including the lens barrel 2 on the front surface, and a power switch 35, a shooting / playback switching operation unit 37, a cross operation key 38, a MENU setting operation unit 39, and a SET on the back surface. An operation unit 40 and a display unit 45 including a liquid crystal monitor are provided. Furthermore, a shutter operation unit 36 and a zoom operation unit 47 are provided on the upper surface of the housing 1a.

  The zoom operation unit 47 is provided around the shutter operation unit 36 so as to be rotatable coaxially with the shutter operation unit 36. The power switch 35 is an operation member that turns on / off the power of the digital camera 1. The shooting / playback switching operation unit 37 is an operation member that switches between the shooting mode and the playback mode, and is switched by turning the lever. When the zoom operation unit 47 is rotated to the right in the state switched to the photographing mode, the imaging optical system L is controlled by the microcomputer 3 to the desired edge side and to the left side when the zoom operation unit 47 is rotated to the left. The

  The MENU setting operation unit 39 is an operation member for causing the display unit 45 to display various menus. The cross operation key 38 is selected by the microcomputer 3 by selecting various operation menus displayed on the display unit 45 by operating the MENU setting operation unit 39 by pressing the upper, lower, left and right parts. It is an operation member for outputting. When various operation menus are selected by the cross operation key 38, the microcomputer 3 outputs an execution command. The SET operation unit 40 is an operation member used by the user to return the display of various operation menus to the state before display.

  Next, a control system of the image blur correction mechanism 16 will be described with reference to FIG. In FIG. 3, the image blur correction mechanism 16 includes a motion correction unit 15A, a photographing posture detection unit 32A, a motion detection unit 18A, and a signal processing unit 3A. The motion correction unit 15A that controls the optical axis AZ of the imaging light includes a second lens group L2, a yawing control unit 14x, a pitching control unit 14y, and a position detection unit 15. The second lens unit L2 is a correction lens unit that decenters the optical axis by moving in a plane perpendicular to the optical axis AZ and corrects the movement of the image. The second lens group L2 is driven and controlled in two directions X and Y orthogonal to the optical axis AZ by the yawing drive control unit 14x and the pitching drive control unit 14y. Hereinafter, the X direction is called a yawing direction, and the Y direction is called a pitching direction. The position detection unit 15 is a detection unit that detects the position of the second lens unit L2, and forms a feedback control loop for controlling the second lens unit L2 together with the yawing drive control unit 14x and the pitching drive control unit 14y. .

  The photographing posture detection unit 32A includes a yawing current value detection unit 32x and a pitching current value detection unit 32y. The yawing current value detection unit 32x detects a current value flowing through the coil when a yawing actuator 29x described later operates. Similarly, the pitching current value detection unit 32y detects a current value flowing through the coil when a pitching actuator 29y described later operates.

  The motion detector 18A includes a yawing angular velocity sensor 18x and a pitching angular velocity sensor 18y. In order to avoid redundancy, the yawing angular velocity sensor 18x and the pitching angular velocity sensor 18y are appropriately abbreviated as angle sensors 18x and 18y. The angular velocity sensors 18x and 18y are sensors for detecting the movement of the imaging apparatus itself including the imaging optical system L due to camera shake and other vibrations, and detect movements in two directions, yawing and pitching, respectively. The angular velocity sensors 18x and 18y output an angular velocity signal having either a positive or negative value depending on the moving direction of the digital camera 1 with reference to the output when the digital camera 1 is stationary. The output signal is processed by the signal processing unit 3A.

  The signal processing unit 3A includes a microcomputer 3, A / D conversion units 19x and 19y, and D / A conversion units 19x and 19y. The signals output from the angular velocity sensors 18x and 18y are subjected to filter processing, amplification processing, and the like, and then converted into digital signals by the A / D conversion units 19x and 19y, and are given to the microcomputer 3.

  The microcomputer 3 performs processing such as filtering, integration processing, phase compensation, gain adjustment, and clipping processing on the output signals from the angular velocity sensors 18x and 18y taken in via the A / D conversion units 19x and 19y. Apply. By performing these processes, the microcomputer 3 calculates the drive control amount of the second lens unit L2 necessary for motion correction and generates a control signal.

  The generated control signal is output to the yawing drive control unit 14x and the pitching drive control unit 14y via the D / A conversion units 17x and 17y. Thereby, the yawing drive control unit 14x and the pitching drive control unit 14y drive the third lens unit L3 based on the control signal to correct the movement of the image.

  Next, the configuration of the retractable lens barrel 2 used in the digital camera 1 according to the present embodiment will be described with reference to FIGS. 4, 5, and 6. FIG. 4 shows a cross section of the lens barrel 2 in the retracted state during non-photographing, FIG. 5 shows a cross section of the lens barrel 2 in the wide state during photographing, and FIG. 6 shows the lens barrel 2 in the telephoto state during photographing. The cross section of is shown.

  As can be seen in FIG. 4, the first group holding frame 52 holds the first lens group L1, and the cylindrical outer frame 53 is arranged so that the central axis of the first lens group L1 is parallel to the optical axis AZ. On the other hand, it is fixed with screws. One end of two guide poles (guide members) 54 a and 54 b parallel to the optical axis AZ is fixed to the first group holding frame 52.

  The second group holding frame 55 holds the second lens group L2, and is configured to be slidable in the optical axis AZ direction by being supported by the above-described two guide poles 54a and 54b. The second group holding frame 55 meshes with a feed screw 56a of a second group lens driving actuator 56 such as a stepping motor and a screw portion of a rack 57 that is provided on the second group holding frame 55 so as to be rotatable about a predetermined axis. As a result, the zooming is performed by moving in the optical axis AZ direction by the driving force of the second group lens driving actuator 56.

  The third group holding frame 58 holds the third lens group L3 (image blur correction lens group) and constitutes an image blur correction mechanism 81 described later.

  The fourth group holding frame 59 is supported by two guide poles 61a and 61b which are sandwiched between the third group holding frame 58 and the master flange 60 and parallel to the optical axis AZ, and slides in the optical axis AZ direction. It is configured to be movable. Further, the fourth group holding frame 59 is engaged with a feed screw 62a of a fourth group lens drive actuator 62 such as a stepping motor and a thread portion of a rack 63 (not shown) provided on the fourth group holding frame 59. The driving force of the fourth lens group driving actuator 62 moves in the optical axis AZ direction to correct and focus the image plane variation accompanying zooming.

  The image sensor (CCD) 4 is attached to the master flange 60. The third group holding frame 58 is provided with support portions 58a (main shaft side) and 58b (rotation stop side). When the guide poles 54a and 54b penetrate the support portions 58a and 58b, the guide poles 54a and 54b are held parallel to the optical axis AZ.

  Next, a configuration for moving the first lens unit L1 in the optical axis AZ direction will be described. A gear 65a is formed on a part of the inner peripheral surface of the substantially hollow cylindrical drive frame 65 on the image plane side (negative direction of the Z axis). Further, on the inner peripheral surface on the subject side (positive direction of the Z axis), three protrusions 65b are formed at intervals of approximately 120 degrees. The protrusion 65 b engages with three circumferential grooves 53 a provided on the outer peripheral surface on the image surface side of the first group holding frame 52, so that the drive frame 65 has the optical axis AZ with respect to the first group holding frame 52. It is relatively rotatable as a center. The drive frame 65 moves integrally with the drive frame 65 and the first group holding frame 52 in the optical axis AZ direction. Further, three cam pins 66a, 66b, and 66c are press-fitted and fixed at an interval of approximately 120 degrees on the inner peripheral surface of the drive frame 65.

  Three cam grooves 68a, 68b and 68c are formed on the outer surface of the cylindrical cam frame 67 at intervals of approximately 120 degrees. The cam pins 66a, 66b and 66c of the drive frame 65 engage with the cam grooves 68a, 68b and 68c, respectively. A drive gear 69 (not shown) is rotatably held at a predetermined position on the outer peripheral surface of the cam frame 67. The drive gear 69 transmits the drive force of the drive unit 71 attached to the master flange 60 to the gear portion 65 a provided on the drive frame 65.

  Accordingly, when the drive gear 69 rotates, the drive frame 65 rotates about the optical axis AZ. The cam pins 66a, 66b and 66c provided on the drive frame 65 move in the cam grooves 68a, 68b and 68c of the cam frame 67, so that the drive frame 65 also moves in the optical axis AZ direction. At this time, the first group holding frame 52 is rotated around the optical axis AZ because the two guide poles 54a and 54b fixed to the first group holding frame 52 are inserted into the support portions 58a and 58b of the third group holding frame 58. Therefore, as the drive frame 65 moves in the optical axis AZ direction, the first group holding frame 52 moves straight in the optical axis AZ direction.

  The drive actuator 56 of the second group holding frame 5 is fixed to a predetermined mounting portion 67 b (not shown) of the cam frame 67. The fourth group lens driving actuator 62 of the fourth group holding frame 59 is fixed to a predetermined mounting portion 60 a (not shown) of the master flange 60. A drive unit 71 that transmits a driving force to the drive gear 69 includes a first group lens drive actuator 72 and a reduction gear unit 73 (not shown) including a plurality of gears, and is fixed to a predetermined mounting portion 60 b of the master flange 60. Is done.

  Next, a description will be given of combustion by sunlight incident on the plastic part of the lens barrel 2 in the tele position state shown in FIG. The sunlight 50 enters from the first lens group L1 and is collected on the front surface of the second group holding frame 55. Therefore, depending on conditions, the second group holding frame 55 may burn and emit smoke. As shown in FIG. 9A, this phenomenon is likely to occur when the digital camera 1 is left in an upward posture and sunlight 50 directly enters.

  Further, in the tele position state, the distance between the first lens group L1 and the second lens group L2 is increased, and the second group holding frame 55 is located at a position where the sunlight 50 incident from the first lens group L1 is condensed. The tendency becomes remarkable because of the arrangement. Therefore, particularly in fine weather, if the photographer is left in the tele position without using the digital camera 1 without using the digital camera 1, it burns and emits smoke in about 20 seconds.

  On the other hand, in the retracted state shown in FIG. 4, the lens barrel 2 does not burn because the sunlight 50 incident from the first lens unit L <b> 1 has no place to collect light inside the lens barrel 1. Absent. Therefore, when the digital camera 1 is in an upward posture as shown in FIG. 9A, the lens barrel 2 is retracted as shown in FIG. 9B before the time when the plastic parts start to burn. This problem can be avoided by moving into the state.

  Next, image blur correction using the third lens unit L3 will be described with reference to FIG. The third lens unit L3 used for correcting image blur that occurs during shooting is pitching that is movable in a pitching direction that is the first direction (Y direction) and a yawing direction that is the second direction (X direction). It is fixed to the holding frame 82. The pitching holding frame 82 has a bearing 82a on the −X direction side and a rotation stopper 82b on the + X direction side. A pitching shaft 83a parallel to the Y-axis direction is inserted into the bearing 82a, and a pitching shaft 83b parallel to the Y-axis direction to be described later is engaged with the rotation stopper 82b, so that the pitching holding frame 82 is in the first direction (Y) direction. It is configured to be slidable.

  On the image plane side with respect to the pitching holding frame 82, a yawing holding frame 84 for moving the third lens group L3 for image blur correction in the second direction (X direction) is attached. The yawing holding frame 84 is provided with fixing portions 84a and 84b for fixing both ends of the two pitching shafts 83a and 83b for sliding the pitching holding frame 82 described above in the pitching direction (Y direction). ing.

  The yawing holding frame 84 has a bearing 84c on the + Y direction side, and has a yawing shaft 85b and a fixing portion 84d on which both ends thereof are press-fitted and fixed on the −Y direction side. The yawing shaft 85a parallel to the X direction is inserted into the bearing 84c, and the yawing shaft 85b parallel to the X direction is engaged with the anti-rotation portion 58d of the third group holding frame 58, whereby the yawing holding frame 84 is moved in the second direction. It is configured to be slidable in the (X direction).

  The third group holding frame 58 provided on the image plane side with respect to the yawing holding frame 84 is fixed to fix both ends of the yawing shaft 85a for sliding the yawing holding frame 84 in the yawing direction (X direction). An anti-rotation portion 8d that engages the portion 58c and the yawing shaft 85b is provided.

  The substantially L-shaped electric substrate 86 is attached to the image side surface of the pitching holding frame 82. The electric board 86 is provided with a first coil 87y for driving the third lens unit L3 in the pitching direction and a second coil 87x for driving in the yawing direction. The electric board 86 is further provided with a hall element 88y for detecting the position in the pitching direction of the third lens unit L3 and a hall element 88x for detecting the position in the yawing direction. The coils 87y and 87x are integrally formed on the electric board 86 as a laminated coil.

  The magnets 89y and 89x are two-pole magnetized on one side. The magnets 89y and 89x are fixed to yokes 90y and 90x having a U-shaped cross section, respectively. The yoke 90y is press-fitted and fixed to the fitting portion 58y of the third group holding frame 58 from the Y direction. Similarly, the yoke 90x is press-fitted and fixed to the fitting portion 58x of the third group holding frame 58 from the X direction.

  The first electromagnetic actuator 91y includes a first coil 87y, a magnet 89y, and a first yoke 90y. Similarly, the second electromagnetic actuator 91x is composed of a second coil 87x, a magnet 89x, and a second yoke 90x. The first electromagnetic actuator 91y constitutes first driving means for driving the pitching holding frame 82 in the pitching direction (Y direction) which is the first direction, and the second electromagnetic actuator 91x sets the pitching holding frame 82 to the second direction. The second driving means is configured to drive in the yawing direction (X direction), which is the first direction.

  In the image blur correction mechanism 81 configured as described above, when a current is passed through the first coil 87y of the electric board 86, the first magnet 89y and the yoke 90y cause the pitching direction (Y direction) which is the first direction. ) Generates electromagnetic force. Similarly, when a current flows through the second coil 87x of the electric board 86, an electromagnetic force is generated along the yawing direction (X direction) which is the second direction by the second magnet 89x and the yoke 90x. In this way, the third lens unit L3 is driven in two directions X and Y substantially perpendicular to the optical axis AZ by the two electromagnetic actuators 91y and 91x.

  Next, the position detectors 92y and 92x that detect the position of the third lens unit L3 will be described. Hall elements 88y and 88x that convert magnetic flux into electric signals are positioned and fixed to the electric board 86. As the detection magnet, the magnets 89y and 89x of the electromagnetic actuators 91y and 91x described above are also used. Therefore, the position detectors 92y and 92x are constituted by the Hall elements 88y and 88x and the magnets 89y and 89x.

  The flexible printed cable 93 is attached to the electric board 86 and transmits signals between the coils 87x and 87y, the hall elements 88x and 88y, and a circuit (not shown) of the digital camera body. The image blur correction mechanism 81 is configured by the above components 82 to 93.

  The operation of the retractable lens barrel 2 configured as described above will be described below. When the power switch 35 is turned on in the non-shooting state shown in FIG. 4, the digital camera 1 is in a shooting preparation state. First, the first lens group driving actuator 72 that drives the first lens group L1 rotates, and the driving gear 69 is rotated via the reduction gear unit 73. As the drive gear 69 rotates, the drive frame 65 meshing with the drive gear 69 rotates about the optical axis AZ along the cam grooves 68a, 68b, and 68c. After the origin detection sensor is initialized, the drive frame 65 moves to the subject side, so that the first group holding frame 52 also moves to the subject side. When a rotation amount detection sensor (not shown) detects that the first group lens drive actuator 72 has rotated by a predetermined rotation amount, the first group lens drive actuator is moved to a predetermined position after the first group holding frame 52 has moved to a predetermined position. 72 stops rotating.

  Next, the second group lens driving actuator 56 rotates and drives the rack 57 via the feed screw 56a, whereby the second group holding frame 55 starts to move along the Z axis. After the origin detection sensor is initialized, the second group holding frame 55 moves to the subject side, stops at the wide position shown in FIG. 5, and the digital camera 1 becomes ready for photographing.

  During actual photographing, the second group lens driving actuator 56 and the fourth group lens driving actuator 62 perform a zooming operation, a correction of image plane variation accompanying the zooming, and a focusing operation, respectively. When zooming, photographing is performed in the state shown in FIG. 5 in the wide position state, and in the tele position, the second lens unit L2 is moved to the image plane side and photographing is performed in the state shown in FIG. I do. Therefore, it is possible to photograph at any position from the wide position to the tele position.

  Next, the operation of the internal mechanism of the lens barrel 2 when shifting from the shooting state shown in FIG. 5 to the non-shooting state shown in FIG. 4 will be described. When the power switch 35 of the digital camera 1 is turned off from the shooting state (wide position) shown in FIG. 5, the shooting ends. First, the second group holding frame 55 is moved to the image plane side by the second group lens driving actuator 56. Next, the first lens group driving actuator 72 is rotated, and the driving gear 69 is rotated in the direction opposite to the above-described direction via the reduction gear unit 73.

  As the drive gear 69 rotates, the drive frame 65 meshing with the drive gear 69 rotates about the optical axis AZ. At the same time, the drive frame 65 moves to the image plane side by the cam grooves 68a, 68b and 68c, so that the first group holding frame 52 also moves. When the rotation of the driving frame 65 is detected by the origin detection sensor, the first group lens driving actuator 72 stops rotating after the first group holding frame 52 has moved to a predetermined position.

  In this way, the internal mechanism of the lens barrel 2 shifts to the non-shooting state shown in FIG. 4, and a retracted state in which the optical total length is shortened compared to the shooting state. In the tele position state shown in FIG. 6, when the power is turned off, the operation of moving the second group holding frame 55 to the image plane side is omitted, and the first group holding frame 52 moves to the image plane side. .

  Next, a current value detection method by the yawing current value detection unit 32x and the pitching current detection unit 32y will be described with reference to FIG. 8, FIG. 9, and FIG. 8 and 9 show the posture of the digital camera 1. Specifically, FIG. 8A shows a landscape orientation, FIG. 8B shows a portrait orientation, FIG. 9A shows an upward orientation (non-collapsed state), and FIG. An upward posture (collapsed state) is shown.

  FIG. 10 shows the posture of the image blur correction mechanism 81 in each photographing posture of the digital camera 1. Specifically, FIG. 10A shows the posture of the image blur correction mechanism 81 in the shooting of the digital camera 1 in the pretending posture (FIG. 8A), and FIG. FIG. 10C shows the posture of the image blur correction mechanism 81 in photographing in the photographing posture (FIG. 8B), and FIG. 10C shows an upward posture in which the optical axis AZ of the photographing optical system L coincides with the self-weight direction of the digital camera 1 ( FIG. 9 (a)) is shown.

  In the landscape orientation of the digital camera 1 shown in FIG. 10A, the weight including the third lens unit L3, the pitching holding frame 82, the coils 87x and 87y, and the yawing holding frame 84 is in the direction of gravity. Acts in a certain Y direction. At this time, the third lens unit L3 needs to be held at the center of the optical axis in order to obtain an appropriate image. Therefore, it is necessary to generate an electromagnetic force for supporting the weight of the third lens unit L3. Therefore, the current Iy1 is supplied to the coil 87y in order to generate the necessary electromagnetic force. On the other hand, in the X direction, since it is not necessary to consider the own weight for holding the third lens unit L3 at the center of the optical axis AZ, the value of the current Ix2 supplied to the coil 87x is supplied to the coil 87y. It becomes smaller than the value of the current Iy1.

  In the vertical shooting posture rotated 90 degrees from the horizontal shooting posture described above around the optical axis AZ of the digital camera 1 shown in FIG. 10B, the third lens unit L3, the pitching holding frame 82, the coil The weight including 87x and 87y and the yawing holding frame 84 acts in the X direction, which is the direction of gravity. At this time, the third lens unit L3 needs to be held at the center of the optical axis AZ. Therefore, in the X direction, it is necessary to generate an electromagnetic force for supporting the weight of the yaw holding frame 84 in addition to the weight of the third lens unit L3. Therefore, the current Ix1 is supplied to the coil 87x in order to generate the necessary electromagnetic force.

  In consideration of the weight of the yawing holding frame 84, the value of the current Ix1 is larger than the value of the current value Iy1 supplied to the coil 87y in the landscape orientation. On the other hand, with respect to the Y direction, since it is not necessary to consider the own weight for holding the third lens unit L3 at the center of the optical axis AZ, the current value Iy2 supplied to the coil 87y is the current supplied to the coil 87x. The value is smaller than the value of Ix1.

  In the upward posture of the digital camera 1 shown in FIG. 10C, the optical axis AZ of the photographing optical system L and the direction of the weight of the digital camera 1 coincide. Therefore, since it is not necessary to consider the weight of the pitching holding frame 82 and the yawing holding frame 84, the current values supplied to the coils 87y and 87x are substantially the same as the currents Iy2 and Ix2, respectively.

  As described above, the value of the current flowing through the coils 87x and 87y is determined by the shooting posture of the digital camera 1. That is, the photographing posture of the image blur correction mechanism 81 and the digital camera 1 is determined by detecting the value of the current flowing through the coils 87x and 87y. Therefore, the image blur correction mechanism 81 can be used together as a posture detection unit of the digital camera 1 with a role of preventing image blur. FIG. 11 illustrates the relationship between the above-described currents Ix1, Ix2, Iy1, and Iy2.

  Next, with reference to a flowchart shown in FIG. 12, an operation of automatically retracting the lens barrel 2 in the retracted state according to the photographing posture in the above-described digital camera 1 will be described. The operation starts when the photographer leaves the digital camera 1 in an arbitrary posture with the digital camera 1 turned on.

  In step S1, the microcomputer 3 detects signals output from the angular velocity sensors 18x and 18y, and determines whether the digital camera 1 is stationary. In other words, the digital camera 1 is in the use state when the output fluctuations of the angular velocity sensors 18x and 18y are detected, and the digital camera 1 is in the non-use state when there is no output fluctuation. When the output fluctuations of the angular velocity sensors 18x and 18y are not detected, that is, when the digital camera 1 is in a stationary state, the control proceeds to the next step 2.

  In step S2, the shooting posture detection unit 32A detects the posture of the digital camera 1 by the yawing current value detection unit 32x and the pitching current value detection unit 32y. First, as shown in FIG. 10C, when the optical axis AZ of the imaging optical system L and the direction of the weight of the digital camera 1 coincide, that is, whether the digital camera 1 is in the upward posture or the other posture. Determine if. If the posture of the digital camera 1 is the upward posture, the control proceeds to step S4.

  In step S4, the microcomputer 3 counts the time by the timer, and the time T2 for determining whether or not the time T2 set by the second timer setting unit 21 has elapsed is the posture in which the digital camera 1 is in the upward posture. In this state, even if sunlight 50 is directly incident, it is a time during which the plastic part inside the lens barrel 2 does not burn, and is set to 10 seconds, for example. Therefore, when 10 seconds have elapsed, control proceeds to the next step S5.

  In step S5, the lens barrel 2 is retracted from the photographing state to the retracted state. That is, when the time T <b> 2 set by the second timer setting unit 21 elapses, the retracted state is entered, and the plastic parts inside the lens barrel 2 are prevented from burning. The timer function operating in the microcomputer 3 is configured to stop once when the digital camera 1 is in use, that is, when output fluctuations of the angular velocity sensors 18x and 18y are detected.

  On the other hand, when it is determined in step S3 described above that the digital camera 1 is not in the upward posture, the control proceeds to step S6. In step S <b> 6, the microcomputer 3 counts time with a timer and determines whether or not the time T <b> 1 set by the first timer setting unit 20 has elapsed. The time T1 is set for a state in which the posture of the digital camera 1 is other than the upward posture, and is, for example, about 5 minutes. Therefore, when 5 minutes have elapsed, control proceeds to the next step S7.

  In step S7, the lens barrel 2 is retracted from the photographing state to the retracted state. The timer function operating in the microcomputer 3 is configured to stop once when the digital camera 1 is in use, that is, when output fluctuations of the angular velocity sensors 18x and 18y are detected. It should be noted that after the transition to the retracted state, the photographer may automatically return to the photographing state by turning on the power button 35 again or pressing any button.

  As described above, in the present embodiment, when the digital camera is determined to be in the upward orientation, the second lens barrel is automatically retracted when the second set time shorter than the first set time elapses. By providing the timer setting unit, the plastic parts inside the lens barrel are not burned by the incident sunlight. Furthermore, in a normal use state, the timer setting time becomes long, so that it does not immediately shift to the retracted state, so that the convenience of the photographer is not impaired.

  In the present embodiment, the shooting posture is determined by detecting the current values of both the pitching and yawing current detectors. However, the shooting posture can be specified by detecting at least one of the current values. Is possible. In this case, even when an abnormality occurs in one of the current detection units of the pitching or yawing current detection unit, the photographing posture is accurately determined by detecting both current values.

  Note that the times T1 and T2 set by the first timer setting unit and the second timer setting unit are not limited to 10 seconds and 5 minutes, respectively. In addition, the configuration has been described in which the state automatically shifts to the retracted state after the time T2 set by the second timer setting unit has elapsed, but in order to reduce power after the time T2 has elapsed, The system may be a system in which the power is turned on and the power is automatically turned on when the photographer presses any button.

(Embodiment 2)
Hereinafter, an imaging apparatus according to Embodiment 2 of the present invention will be described. In this embodiment as well, a digital camera will be described as an example of an imaging device as in the first embodiment. The digital camera 1 ′ according to the present embodiment is configured in the same manner as the digital camera 1 according to the first embodiment described above, except for the posture determination unit (shooting posture detection unit 32A). Therefore, only features unique to the digital camera 1 ′ (not shown) according to the present embodiment will be described.

  With reference to FIGS. 13, 14, and 15, the photographing posture detection unit 32 </ b> A ′ that is a posture determination unit in the digital camera 1 ′ will be described. Specifically, FIG. 13A shows a state in which the linear actuator 103 that drives the image sensor 4 is viewed from the light incident side with respect to the fourth lens group L4. FIG. 13B shows a state in which the fourth lens unit L4 is viewed from the side opposite to FIG. 13A, that is, the side from which light is emitted. FIG. 14A shows a state in which the main yoke 106 attached to the master flange 60 is viewed from the X direction. FIG. 14B shows a state where the main yoke 106 attached to the master flange 60 is viewed from the Z direction.

  As shown in FIG. 13, the fourth group holding frame 59 holds the fourth group lens group L4, and the optical axis along the guide poles 62b and 62c arranged in parallel with the optical axis AZ of the fourth lens group L4. It is configured to be slidable in the AZ direction. Note that both ends of the guide poles 62b and 62c are fixed. The stator 104 of the linear actuator 103 that drives the fourth group holding frame 59 in the optical axis AZ direction includes a main magnet 105 magnetized perpendicularly to the drive direction (Z direction), and a main yoke 106 having a U-shaped cross section. And a plate-like side yoke 107.

  On the subject side of the main yoke 106, two fitting projections 106a are provided on the upper and lower sides, and can be fitted to a fitted portion 60c provided on the master flange 60 of the lens barrel 1, as shown in FIG. It is configured. The magnetic circuit 108 including the stator 104 is configured to be bilaterally symmetric (X direction) when viewed from the driving direction and substantially symmetric to the driving direction (Z direction).

  Returning to FIG. 13, the coil 110 constituting the mover 109 of the linear actuator 103 is fixed to the fourth group holding frame 59 so as to have a predetermined gap with respect to the main magnet 105. The fourth group holding frame 59 is configured to be driven in the optical axis AZ direction by passing a current through the coil 110 so as to be orthogonal to the magnetic flux generated by the main magnet 105. The position detection means includes a magnetic scale 112 integrally formed with the fourth group holding frame 59 and a magnetic sensor 111 that detects a signal output from the magnetic scale 112.

  Next, with reference to FIG. 15, the control system of the focus apparatus using the linear actuator 103 will be described. The fourth lens group L4 is driven and controlled by the focus drive controller 120 in the Z direction parallel to the optical axis AZ. The position detection unit 121 is a detection unit that detects the position of the fourth group lens unit L4, and forms a feedback control loop for controlling the fourth lens unit L4 together with the focus drive control unit 120.

  The photographing posture detection unit 32A ′ includes a focus current value detection unit 112. The focus current value detection unit 112 detects the value of the current flowing through the coil when the linear actuator 103 is operated.

  With reference to FIGS. 16 and 17, a current value detection method by the focus current value detection unit 112 will be described. FIG. 16 shows the attitude of the linear actuator 103. Specifically, FIG. 16A shows the attitude of the linear actuator 103 in the upward posture shooting, and FIG. 16B shows the linear actuator 103 in the downward posture shooting. Shows the attitude.

  In the upward posture shown in FIG. 16A, the weight including the fourth group lens unit L4, the fourth group holding frame 59, and the coil 110 acts in the −Z direction, which is the direction of gravity. At this time, the fourth lens unit L4 needs to be held in order to move to the predetermined focus position. Therefore, it is necessary to generate an electromagnetic force for supporting the weight of the fourth lens unit L4. Therefore, the current If1 is supplied to the coil 110 in order to generate the necessary electromagnetic force.

  On the other hand, in the downward posture shown in FIG. 16B, the weight including the fourth lens unit L4, the fourth group holding frame 59, and the coil 110 acts in the Z direction, which is the direction of gravity. At this time, the fourth lens unit L4 needs to be held in order to move to the predetermined focus position. Therefore, it is necessary to generate an electromagnetic force for supporting the weight of the fourth lens unit L4. Therefore, the current If2 is supplied to the coil 110 in order to generate the necessary electromagnetic force.

  As described above, the value of the current flowing through the coil 110 is determined by the shooting posture of the digital camera 1. That is, the photographing postures of the linear actuator 103 and the digital camera 1 can be determined by detecting the value of the current flowing through the coil 110. Accordingly, the linear actuator 103 can be used in combination with the role of driving the fourth group lens unit L4 and as posture detection means for the upward posture and the downward posture of the digital camera 1. FIG. 17 illustrates the relationship between the above-described currents If1 and If2.

  In the present embodiment, since the difference between the downward posture and the upward posture that could not be determined in the above-described first embodiment can be determined, the usability of the photographer can be further improved. In the present invention, since the posture of the digital camera is detected using the image blur correction device or the focus linear actuator, it is not necessary to provide a conventionally required posture detection sensor or the like. As a result, the number of parts can be reduced and the cost can be reduced.

  Furthermore, an image without blurring can be taken by installing an image blur correction device. In addition, by using a focus linear actuator, it is possible to realize a focus system that achieves low power consumption while increasing follow-up performance.

  The present invention is not limited to the configuration of the retractable lens barrel described in the first embodiment or the second embodiment described above, and shifts from the use state of the digital camera to the retracted (non-use) state. By doing so, it can be applied to a configuration in which combustion by sunlight in the lens barrel can be prevented. Instead of being in the retracted state, for example, a configuration in which a lens barrier disposed on the front surface of the lens barrel automatically closes may be employed. Further, the determination of the photographing posture is not limited to detecting the current value of the actuator. For example, the same effect can be obtained by measuring the voltage value instead of the current value.

  Note that the combination of the actuator of the image blur correction device used for posture detection and the focus linear actuator is not limited to the above-described configuration. For example, any one actuator of the image blur correction device and the focus The lens barrel may be configured such that the attitude can be detected by using the linear actuator for the actuator.

  INDUSTRIAL APPLICABILITY The present invention is preferably used for an imaging device that is required to have a comfortable operability at the time of shooting, particularly a high-magnification compatible digital still camera, a digital video camera, and a mobile phone terminal with a camera function. it can.

1 is a block diagram showing a control system for a digital camera that is an imaging apparatus according to Embodiment 1 of the present invention. The figure which shows the upper surface and back view of the digital camera of FIG. 1 is a block diagram showing a control system of an image blur correction mechanism in the digital camera of FIG. 1 is a cross-sectional view of a lens barrel in a retracted state when the digital camera of FIG. 1 is a cross-sectional view of a lens barrel in a wide state when the digital camera of FIG. Sectional view of the lens barrel in the tele state when the digital camera of FIG. Explanatory drawing of image blur correction using a 3rd lens group in the digital camera of FIG. Explanatory drawing of the horizontal shooting posture and the vertical shooting posture of the digital camera of FIG. Explanatory drawing of the non-collapsed state and retracted state of the lens barrel in the upward posture of the digital camera of FIG. Explanatory drawing of the attitude | position of the image blur correction mechanism in each attitude | position of the digital camera of FIG. The figure which shows the electric current amount supplied to the 1st coil and 2nd coil which were shown in FIG. 1 is a flowchart showing an operation of automatically retracting the lens barrel in the retracted state in accordance with the shooting posture in the digital camera of FIG. The perspective view which shows the linear actuator in the digital camera which is an imaging device which concerns on Embodiment 2 of this invention. The perspective view which shows the attaching part of the yoke of the linear actuator of FIG. The block diagram which shows the control system of the linear actuator of FIG. Explanatory drawing of the posture of the linear actuator of FIG. The figure which shows the coil supply electric current amount of the linear actuator according to imaging | photography attitude | position which concerns on Embodiment 2 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 1 'Digital camera 1a Case 2 Lens barrel 3 Microcomputer 3A Signal processing part 4 Image sensor 5 CCD drive control part 6 Analog signal processing part 7 A / D conversion part 8 Digital signal processing part 9 Buffer memory 10 Image compression Unit 11 image recording control unit 12 image recording unit 13 image display control unit 14x yawing drive control unit 14y pitching drive control unit 15 position detection unit 15A motion correction unit 17x, 17y D / A conversion unit 18A motion detection unit 18x yawing angular velocity sensor 18y Pitching angular velocity sensors 19x, 19y A / D conversion unit 20 First timer setting unit 21 Second timer setting unit 32A, 32A ′ Shooting posture detection unit 32x Yawing current value detection unit 32y Pitching current value detection unit 35 Power switch 36 Shutter Operation unit 37 Shooting / playback switching operation unit 38 Character operation key 39 MENU setting operation unit 40 SET operation unit 41 Shutter control unit 45 Display unit 47 Zoom operation unit 52 First group holding frame 53 Outer frame 55 Second group holding frame 56 Second group lens drive actuator 58 Third group holding frame 59 Fourth group Holding frame 60 Master flange 62 Fourth lens group driving actuator 62a Feed screw 62b Guide pole 62c Guide pole 65 Driving frame 67 Cam frame 69 Driving gear 71 Driving unit 72 Driving actuator 73 Reduction gear unit 81 Image blur correction mechanism 82 Pitching holding frame 84 Yawing Holding frame 86 Electric board 87x First coil 87y Second coil 89x, 89y Magnet 91y First electromagnetic actuator 91x Second electromagnetic actuator 103 Linear actuator 106 Main yoke 109 Movable element 110 Coil 1 2 focusing current detector L imaging optical system L1 first lens group L2 second lens unit L3 third lens unit L4 fourth lens group

Claims (6)

An imaging apparatus having an imaging optical system that forms an optical image of a subject,
Drive control means for moving the imaging optical system;
First timer setting means for moving the imaging optical system from the first state to the second state after elapse of a first setting time;
Second timer setting means for moving the imaging optical system from the first state to the second state after elapse of a second setting time shorter than the first setting time;
Posture detecting means for detecting the posture of the imaging optical system,
When it is determined that the posture of the imaging optical system is an upward posture based on the posture detected by the posture detection unit, the drive control unit is configured to perform the imaging optical system after the second set time has elapsed. An image pickup apparatus that moves the camera to the second state. A vibration detecting means for detecting vibration of the imaging optical system;
When it is determined that the posture of the imaging optical system is upward and vibration of the imaging optical system is not detected, the drive control unit moves the imaging optical system to the second state after the second set time has elapsed. The imaging apparatus according to claim 1, wherein the imaging apparatus is moved.   The imaging apparatus according to claim 1, wherein the first state is a shooting state and the second state is a non-shooting state. An image blur correction device that detects vibration applied to the imaging optical system and drives the correction lens of the imaging optical system in two directions orthogonal to the optical axis;
The imaging apparatus according to claim 1, wherein the posture detection unit determines a posture of the imaging optical system by detecting a signal for driving the correction lens. The image blur correction means includes first and second actuators for driving the correction lens in two directions orthogonal to the optical axis,
The imaging apparatus according to claim 4, wherein the attitude detection unit determines the attitude of the imaging optical system by detecting a drive current value of at least one of the first and second actuators. A linear actuator for driving the focus lens group;
The imaging apparatus according to claim 4, wherein the posture detection unit determines a posture of the imaging optical system by detecting a signal for driving the focus lens group.

Images