JP2010204341A - Camera - Google Patents

Abstract

Camera shake in a wide amplitude range and wide frequency range is corrected.
A lens barrel 2 that incorporates photographing lenses 3 and 5 and an image sensor 6, guides the light flux from a subject incident on the photographing lenses 3 and 5 in a horizontal direction, and guides the light to the image sensor 6, and a camera 1. A shake detection means for detecting a shake, an extraction means for extracting a horizontal direction component and a vertical direction component from a camera shake detected by the shake detection means, and provided in the lens barrel 2 and perpendicular to the horizontal direction component of the camera shake The first camera shake correction unit 7 that drives the camera shake correction lens 7a according to the direction component, and the lens barrel 2 is rotated around the optical axis L2 after the photographing lenses 3 and 5 are bent according to the vertical direction component of the camera shake. And a second blur correction unit 8 to be driven.
[Selection] Figure 1

Description

  The present invention relates to a camera.

  2. Description of the Related Art A camera that has a bending optical system and includes an imaging lens barrel that holds an optical axis after bending in a direction perpendicular to an object field and corrects camera shake in the vertical and horizontal directions is known ( For example, see Patent Document 1). In addition, the camera has an imaging lens barrel that holds the optical axis after bending in the horizontal direction of the object field, and is provided with actuators on the left and right sides of the imaging lens barrel to correct camera shake in the vertical and horizontal directions. Is known (see, for example, Patent Document 2).

JP 2006-166202 A JP 2007-148233 A

However, in the former camera disclosed in Patent Document 1, a large space for swinging the imaging lens barrel is required for camera shake with a large amplitude, which leads to an increase in size of the camera. Furthermore, it is difficult to absorb a blur component having a high frequency in order to swing the imaging lens barrel having a large inertia.
In the latter camera disclosed in Patent Document 2, the space for swinging the imaging lens barrel is smaller than that of the camera described above, but the two actuators are used separately to absorb vertical and horizontal blur components. In addition, the control becomes complicated, and it is difficult to absorb a blur component having a high frequency in order to swing the imaging lens barrel having a large inertia.

(1) The invention of claim 1 includes a photographic lens and an image pickup device, detects a camera barrel and a lens barrel that bends a light beam from a subject incident on the photographic lens in a horizontal direction and guides it to the image pickup device. A blur detection unit, an extraction unit that extracts a horizontal component and a vertical component from the camera shake detected by the blur detection unit, and a lens barrel, provided according to the horizontal component and the vertical component of the camera shake. First blur correction means for driving the blur correction lens, and second blur correction means for rotationally driving the lens barrel around the optical axis after the photographing lens is bent in accordance with the vertical direction component of the camera shake.
(2) According to a second aspect of the present invention, in the camera according to the first aspect, the second shake correcting means includes a rotary actuator that rotationally drives the lens barrel, and the output shaft of the rotary actuator is the photographic lens. A rotary actuator is connected to the lens barrel so as to be coaxial with the optical axis after bending.
(3) The invention of claim 3 is the camera according to claim 1 or 2, wherein the extraction means extracts a low-frequency component and a high-frequency component from a horizontal component and a vertical component of camera shake, respectively. The first blur correction unit drives the blur correction lens so as to cancel out the high frequency component of the horizontal direction component and the vertical direction component of the camera shake, and the second blur correction unit includes the vertical direction component of the camera shake. The lens barrel is rotationally driven so as to cancel out the low frequency component of the lens barrel.
(4) The invention of claim 4 is the camera according to any one of claims 1 to 3, wherein the lens barrel is formed in a substantially cylindrical shape.
(5) The invention of claim 5 is the camera according to any one of claims 1 to 4, wherein the photographing lens constitutes a zoom lens, and includes a focal length detection means for detecting a focal length of the zoom lens, The second blur correction unit limits the maximum rotation angle of the lens barrel in accordance with the focal length detected by the focal length detection unit.
(6) The invention of claim 6 is the camera according to any one of claims 1 to 5, further comprising rotation locking means for locking the rotation of the lens barrel, and the lens barrel by the rotation locking means. When the rotation is locked, the camera shake is not corrected by the second shake correcting means, but the camera shake is corrected only by the first shake correcting means.
(7) According to the invention of claim 7, in the camera according to any one of claims 1 to 6, an inclination detection means for detecting an inclination of the camera around the optical axis on the light incident side of the photographing lens, and an inclination detection And a third blur correction unit that rotationally drives the image sensor in accordance with the tilt of the camera detected by the unit.

  According to the present invention, camera shake in a wide amplitude range and a wide frequency range can be corrected.

The perspective view which shows the internal structure of the digital camera of one embodiment 1 is a block diagram showing an electrical configuration of a digital camera according to an embodiment; 1 is a longitudinal sectional view of a digital camera according to an embodiment

  FIG. 1 is a perspective view showing an internal structure of a digital camera according to an embodiment. In FIG. 1, in this specification, when the camera is held in a normal position, the horizontal direction of the object field is the x axis, the vertical direction of the object field is the y axis, and the center line of the light beam from the subject incident on the camera is z. It will be described as an axis. An imaging lens barrel 2 is built in the digital camera 1 of the embodiment. The imaging lens barrel 2 is provided with an objective lens 3 on the side where light from a subject is incident, and a prism 4 and a plurality of lens groups 5 are provided behind it. The objective lens 3 and the plurality of lens groups 5 constitute a photographing lens (zoom lens), and the prism 4 constitutes a bending optical system.

  The optical axis (optical axis on the light incident side of the photographing lens) L1 of the objective lens 3 is bent at right angles to the horizontal direction (x-axis direction) of the object field by the prism 4, and coincides with the optical axis L2 of the plurality of lens groups 5. Configured to do. An imaging element 6 is disposed at the end of the imaging lens barrel 2, and a lens shift image blur correction unit 7 is disposed between the imaging element 6 and the plurality of lens groups 5. Light from the subject incident through the objective lens 3 is bent at right angles to the horizontal direction (x-axis direction) by the prism 4 and transmitted through the plurality of lens groups 5 and the shake correction lens 7a of the image blur correction unit 7. Guided to the image sensor 6, a subject image is formed on the imaging surface of the image sensor 6.

  The imaging lens barrel 2 is configured such that when the digital camera 1 is held at the normal position, the optical axis L2 after being bent is in the horizontal direction (x-axis direction) of the object scene and can be rotated about the optical axis L2 as a rotation center. It is held in the digital camera 1. The lens barrel rotation motor 8 is connected to the imaging lens barrel 2 so that its output axis is coaxial with the optical axis L2 of the imaging lens barrel 2, and rotates the imaging lens barrel 2 around the optical axis L2. To drive. The rotational position sensor 9 detects the rotational position of the imaging lens barrel 2. By rotating the imaging lens barrel 2 around an optical axis L2 parallel to the horizontal direction of the object scene, the optical axis L1 on the light incident side of the imaging lens barrel 2 is set in the vertical direction (pitching direction) of the object scene. Therefore, camera shake with a large amplitude in the pitching direction due to camera shake or a shooting posture can be easily corrected.

  Further, the imaging lens barrel 2 is cylindrical, the bent optical axis L2 that is sufficiently longer than the optical axis L1 on the light incident side is held in the horizontal direction of the object field, and the imaging lens barrel 2 is set to the optical axis L2. By rotating around, it is possible to correct camera shake with a large amplitude without taking up a large space, and to reduce the size of the camera. In addition, even if the imaging lens barrel 2 is not completely cylindrical and has, for example, an elliptical cross section, the space for rotation can be minimized.

  The lens shift type image blur correction unit 7 drives the blur correction lens 7a in the x-axis direction and the y-axis direction by the x-axis actuator 7b and the y-axis actuator 7c, and the horizontal direction (x-axis direction) and the vertical direction of the object scene. Camera shake in the (y-axis direction) can be corrected.

  Here, camera shake caused by camera shake in the vertical direction (y-axis direction) of the object scene or camera posture is rotated by the lens barrel rotation motor 8 around the optical axis L2 after being bent. And the y-axis actuator 7c of the lens shift type image blur correction unit 7 can be driven for correction. Since the inertia in the y-axis direction of the lens shift type image blur correction unit 7 is smaller than the inertia around the optical axis L2 of the imaging lens barrel 2, the responsiveness to the high frequency component of camera shake is the lens shift type image blur correction unit 7 Is higher than the lens barrel rotation motor 8. On the other hand, camera shake correction by rotation of the imaging lens barrel 2 can correct camera shake with a larger amplitude than camera shake correction by the lens shift type image blur correction unit 7. Therefore, by using the blur correction by the rotation of the imaging lens barrel 2 around the optical axis L2 and the blur correction by the lens shift type image blur correction unit 7, the former corrects the camera shake having a large amplitude and a low frequency component. In addition, camera shake having a small amplitude and a high frequency component can be corrected by the latter, and camera shake in a wide amplitude range and a wide frequency range can be reliably corrected.

  The image pickup device rotation motor 10 rotates the image pickup device 6 around the optical axis L2 after being bent, and corrects camera shake around the optical axis L1 of the objective lens 3, that is, camera shake in the rolling direction. In this embodiment, an example in which the image pickup device 6 is rotationally driven by the image pickup device rotation motor 10 is shown, but a rotary actuator other than the motor may be used.

  FIG. 2 is a block diagram illustrating an electrical configuration of the digital camera 1 according to the embodiment. In FIG. 2, the same devices as those shown in FIG. The imaging lens barrel 2 includes a blur detection sensor 11, a signal filter 12, a tilt detection sensor 13, a zoom encoder 14 and the like in addition to the above-described imaging element 6, lens shift type image blur correction unit 7, and image sensor rotation motor 10. It has. On the other hand, the camera body 1a of the digital camera 1 includes an image processing circuit 15, a camera control circuit 16, a motor driver 17, a memory 18, an operation mode detection SW 19 and the like in addition to the lens barrel rotation motor 8 and the rotation position sensor 9 described above. It has.

  The image pickup device 6 picks up a subject image formed on the image pickup surface by the objective lens 3 of the image pickup lens barrel 2, the plurality of lens groups 5, and the shake correction lens 7a, and outputs an image signal to the image processing circuit 15 of the camera body 1a. Is output. The shake detection sensor 11 detects the angular velocity of rotational vibration (pitching) about the x-axis and the angular velocity of rotational vibration (yawing) about the y-axis, and shakes of the digital camera 1 due to camera shake or shooting posture shake. Is detected. The signal filter 12 filters the detection signal of the shake detection sensor 11 to extract an x-axis direction component and a y-axis direction component from the camera shake, and further, a low frequency component having a predetermined frequency or less from each axial direction component. A high frequency component higher than a predetermined frequency is extracted. The signal filter 12 may be provided on the camera body 1a side. The tilt detection sensor 13 detects an angular velocity of rotational vibration (rolling) about the z axis. The zoom encoder 14 detects a focal length (angle of view) of a zoom lens composed of the objective lens 3 and the plurality of lens groups 5.

  The image processing circuit 15 performs various processes such as clamp processing, gain processing, black level correction, pixel interpolation processing, color conversion processing, white balance processing, gamma correction, and image compression on the image signal input from the image sensor 6. . The camera control circuit 16 includes a microcomputer and a memory, executes various calculations and controls of the digital camera 1, and uses a motor based on the shake amount of the digital camera 1 detected by the shake detection sensor 11 and the tilt detection sensor 13. The driver 17 is controlled to drive the image blur correction unit 7, the lens barrel rotation motor 8, and the image sensor rotation motor 10, and to perform blur correction control of the digital camera 1.

  The camera control circuit 16 detects the camera shake of the high-frequency component in the x-axis direction and the high-frequency component in the y-axis direction detected by the shake detection sensor 11 and extracted by the signal filter 12. The x-axis actuator 7b and the y-axis actuator 7c of the image blur correction unit 7 are driven to correct high-frequency camera shake in the x-axis direction and the y-axis direction. Further, the camera control circuit 16 drives the lens barrel rotation motor 8 by the motor driver 17 so as to cancel the camera shake of the low frequency component in the y-axis direction detected by the shake detection sensor 11 and extracted by the signal filter 12. Thus, camera shake at a low frequency in the y-axis direction is corrected. Further, the camera control circuit 16 drives the image pickup device rotation motor 10 so as to cancel the camera shake around the incident optical axis L1 detected by the tilt detection sensor 13, thereby causing the camera shake around the incident optical axis L1. It is corrected.

  The memory 18 is a recording medium for recording a captured image, and is configured to be removable from the digital camera 1. The operation mode detection SW 19 detects the setting state of the operation mode for correcting the camera shake of the low frequency component having a large amplitude in the y-axis direction by rotating the imaging lens barrel 2 by the lens barrel rotation motor 8.

  FIG. 3 is a longitudinal sectional view of the digital camera 1 according to the embodiment. A transparent photographing window 1b is provided in front of the camera body 1a, and a light beam incident from the photographing window 1b is received by the objective lens 3 of the imaging lens barrel 2. In addition, a lock lever 20 is provided on the back surface of the camera body 1a, and the lock lever 20 locks or unlocks the rotation of the imaging lens barrel 2 around the optical axis L2 and is linked to the movement of the lock lever 20 as described above. The detected operation mode detection SW 19 is turned on / off. As shown in FIG. 3A, when the lock lever 20 is pushed down, the rotation of the imaging lens barrel 2 is locked, and the operation mode detection SW 19 is turned off, and the lens shift type image blur correction unit 7 and the imaging are taken. A shake correction mode by the element rotating motor 10 is set. In the state where the imaging lens barrel 2 is locked by the lock lever 20, as shown in FIG. 3A, the optical axis L1 and the z axis of the objective lens 3 (the center line of the light beam from the subject incident on the camera). Matches. On the other hand, when the lock lever 20 is pushed upward as shown in FIG. 3B, the rotation of the imaging lens barrel 2 is unlocked, and the operation mode detection SW 19 is turned on to turn on the lens shift type image blur correction unit. 7. A shake correction mode by the lens barrel rotation motor 8 and the image sensor rotation motor 10 is set.

  As described above, the lens shift type image blur correction unit 7 is suitable for correcting, for example, camera shake with a relatively small amplitude due to camera shake, while the lens barrel rotation motor 8 has, for example, a photographing posture. It is suitable for correcting low-frequency camera shake having a relatively large amplitude due to the shake. In general still image shooting, the shooting posture is less likely to occur, and it is not necessary to correct camera shake with a large amplitude and low frequency. Therefore, the imaging lens barrel is pressed by the lens barrel rotating motor 8 by pushing down the lock lever 20. Shake correction to rotate 2 is prohibited. Thereby, unnecessary power consumption by the lens barrel rotating motor 8 can be reduced. On the other hand, when taking a picture at the tele end of the taking lens, or when it is necessary to suppress camera shake as much as possible in the dark place, the lock lever 20 is pushed up and the imaging lens mirror is moved by the lens barrel rotating motor 8. The camera shake correction by rotating the body 2 is performed to effectively correct camera shake due to camera shake as well as camera shake.

  In FIG. 3A, the angle from the z-axis to the upper end of the photographing window 1b is θ1, and the vertical half field angle of the zoom lens composed of the objective lens 3 and the plurality of lens groups 5 (see FIG. 1) is shown. Assuming ω, θ2 obtained by subtracting ω from θ1 is the maximum rotatable angle of the imaging lens barrel 2 as shown in FIG. Since this maximum rotatable angle θ2 varies depending on the angle of view of the zoom lens composed of the objective lens 3 and the plurality of lens groups 5, that is, the focal length, the focal length is detected by the zoom encoder 14 (see FIG. 2). The maximum rotatable angle θ2 is obtained. Then, the rotation angle of the imaging lens barrel 2 detected by the rotational position detection sensor 9 is fed back, and the rotation angle is limited to the maximum angle θ2 or less in the rotational drive control of the imaging lens barrel 2 by the barrel rotation motor 8. Thereby, even when the camera shake in the y-axis direction is very large, it is possible to prevent a blank portion from being generated at the upper part or the lower part of the photographing screen of the photographing lens. The maximum rotatable angle θ2 of the imaging lens barrel 2 is limited according to the focal length, but the maximum angle θ2 becomes larger on the tele side where the angle of view is narrow and the camera shake is conspicuous, and a large shake correction is possible. On the contrary, the maximum angle θ2 becomes smaller on the wide side where the camera shake is less noticeable, but even with a small blur correction, a sufficient blur correction effect can be obtained on the image, and there is no practical problem.

  In the above-described embodiment, an example in which the prism 4 is disposed behind the objective lens 3 and the optical axis of the photographing lens is bent is shown. However, the position in the photographing lens where the prism is disposed is described in the above-described embodiment. It is not limited to. However, the closer the prism position is to the light incident side from the subject of the photographic lens, the easier it is to store the photographic lens in the cylindrical imaging lens barrel, and the imaging lens barrel should be made compact and cylindrical. Can do. Further, the bending optical system may be configured using a mirror instead of the prism.

  In the above-described embodiments and their modifications, all combinations of the embodiments and the modifications are possible.

  According to the above-described embodiment and its modifications, the following operational effects can be achieved. First, the imaging lenses 3 and 5 and the imaging device 6 are built in. The imaging lens barrel 2 that guides the light beam from the subject incident on the imaging lenses 3 and 5 in the horizontal direction and guides it to the imaging device 6; , A signal filter 12 that extracts a horizontal direction (x-axis direction) component and a vertical direction (y-axis direction) component from a camera shake detected by the shake detection sensor 11, and an imaging lens barrel 2 The lens control circuit 16 and the lens shift type image blur correction unit 7 which are provided in the camera and drive the blur correction lens 7a according to the horizontal component and the vertical component of the camera shake, and the photographing according to the vertical component of the camera shake. A camera control circuit 16, a motor driver 17 and a lens barrel rotation motor 8 are provided for rotating the imaging lens barrel 2 around the optical axis L2 after the lenses 3 and 5 are bent. Therefore, camera shake with a small amplitude and a high frequency component is corrected by the lens control circuit 16 and the lens shift type image blur correction unit 7, and camera shake with a large amplitude and a low frequency component is corrected by the camera control circuit 16 and the motor driver 17. Further, it can be corrected by the lens barrel rotation motor 8, and camera shake in a wide amplitude range and a wide frequency range can be reliably corrected.

  Next, according to one embodiment and its modification, it has a lens barrel rotating motor 8 that rotationally drives the imaging lens barrel 2, and the output shaft of the lens barrel rotating motor 8 is after the photographing lenses 3 and 5 are bent. Since the lens barrel rotation motor 8 is connected to the imaging lens barrel 2 so as to be coaxial with the optical axis L2, the imaging lens barrel 2 can be efficiently driven to rotate.

  Further, according to the embodiment and the modification thereof, the signal filter 12 extracts a low frequency component and a high frequency component from the horizontal direction component and the vertical direction component of the camera shake, respectively, so that it is perpendicular to the horizontal direction component of the camera shake. Since the shake correction lens 7a is driven so as to cancel out the high frequency component of the direction component, and the imaging lens barrel 2 is driven to rotate so as to cancel out the low frequency component of the vertical component of the camera shake. According to the frequency component of camera shake, two types of camera shake correction devices can be used properly, and camera shake can be corrected efficiently and reliably.

  According to the embodiment and its modification, the imaging lens barrel 2 is formed in a substantially cylindrical shape, so that the space for rotationally driving the imaging lens barrel 2 can be minimized, and the camera can be made compact. Can be

  According to one embodiment and its modification, the photographing lenses 3 and 5 constitute a zoom lens, and include a zoom encoder 14 that detects the focal length of the zoom lens, and according to the focal length detected by the zoom encoder 14. Since the maximum rotation angle of the imaging lens barrel 2 is limited, it is possible to prevent a blank portion from occurring at the top or bottom of the shooting screen when correcting a large camera shake.

  According to one embodiment and its modification, the lock lever 20 that locks the rotation of the imaging lens barrel 2 is provided, and when the rotation of the imaging lens barrel 2 is locked by the lock lever 20, the imaging lens Since the camera shake is corrected only by the lens shift type image blur correction unit 7 without correcting the camera shake due to the rotation of the lens barrel 2, it is possible to take a picture with a low possibility of camera shake due to the shake of the shooting posture. In the scene, correction of camera shake due to rotation of the imaging lens barrel 2 can be prohibited by the lock lever 20, and unnecessary power consumption of a battery mounted on the camera can be reduced.

  According to the embodiment and its modification, the tilt detection sensor 13 that detects the tilt of the camera around the optical axis L1 on the light incident side of the photographing lenses 3 and 5, and the tilt of the camera detected by the tilt detection sensor 13 Since the camera control circuit 16 and the image sensor rotating motor 10 that rotationally drive the image sensor 6 in accordance with the image sensor 6 are provided, the correction of the camera shake (x-axis direction blur) and vertical camera shake (y-axis direction blur) is performed. In addition, it is possible to effectively correct blurring around the optical axis on the light incident side of the camera.

DESCRIPTION OF SYMBOLS 1; Digital camera, 2; Imaging lens barrel, 3; Objective lens, 4; Prism, 5; Multiple lens group, 6: Image sensor, 7: Lens shift type image blur correction unit, 8: Lens barrel rotation motor, DESCRIPTION OF SYMBOLS 9; Rotation position sensor, 10; Image sensor rotation motor, 11; Shake detection sensor, 12; Signal filter, 13; Tilt detection sensor, 14: Zoom encoder, 16; Camera control circuit, 17: Motor driver, 19; Detection SW, 20; Lock lever

Claims (7)

A lens barrel that includes a photographic lens and an image sensor, and that guides the light beam from the subject incident on the photographic lens to the image sensor by bending the light beam in a horizontal direction;
Camera shake detecting means for detecting camera shake;
Extraction means for extracting a horizontal direction component and a vertical direction component from camera shake detected by the shake detection means;
A first blur correction unit provided in the lens barrel and driving a blur correction lens according to a horizontal component and a vertical component of the camera shake;
A camera comprising: a second blur correction unit that rotationally drives the lens barrel around the bent optical axis of the photographing lens in accordance with a vertical component of the camera blur. The camera of claim 1,
The second blur correction unit includes a rotary actuator that rotationally drives the lens barrel, and the rotary actuator is configured such that an output shaft of the rotary actuator is coaxial with an optical axis after bending of the photographing lens. And a lens barrel connected to the lens barrel. The camera according to claim 1 or 2,
The extraction means extracts a low frequency component and a high frequency component from a horizontal direction component and a vertical direction component of the camera shake, respectively.
The first blur correction unit drives the blur correction lens so as to cancel out a high frequency component of a horizontal component and a vertical component of the camera shake;
The camera is characterized in that the second shake correcting means rotationally drives the lens barrel so as to cancel out a low frequency component of vertical components of the camera shake. The camera according to any one of claims 1 to 3,
A camera characterized in that the lens barrel is formed in a substantially cylindrical shape. In the camera according to any one of claims 1 to 4,
The taking lens constitutes a zoom lens,
A focal length detecting means for detecting a focal length of the zoom lens;
The camera according to claim 2, wherein the second blur correction unit limits a maximum rotation angle of the lens barrel in accordance with a focal length detected by the focal length detection unit. In the camera according to any one of claims 1 to 5,
A rotation locking means for locking the rotation of the lens barrel;
When the rotation of the lens barrel is locked by the rotation locking unit, the camera shake is not corrected by the second blur correction unit, and the camera shake is corrected only by the first blur correction unit. A camera characterized by doing. In the camera according to any one of claims 1 to 6,
Tilt detecting means for detecting the tilt of the camera around the optical axis on the light incident side of the photographing lens;
A camera comprising: a third blur correction unit that rotationally drives the imaging device in accordance with the tilt of the camera detected by the tilt detection unit.

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