JPH07218950A - Image stabilization camera - Google Patents

Abstract

(57) [Abstract] [Purpose] While ensuring the accuracy of camera shake detection required on the telephoto side, shorten the release time lag on the wide-angle side. A variable magnification photographing optical system, a camera shake detection unit for detecting camera shake, a camera shake correction unit for correcting camera shake, and a control unit for controlling the camera shake correction unit according to a detection signal obtained from the camera shake detection unit. Then, the control means changes the sampling time for averaging the detection signals obtained from the camera shake detection means according to the focal length of the variable magnification photographing optical system.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a camera shake correction camera having a variable magnification photographing optical system.

[0002]

2. Description of the Related Art Japanese Unexamined Patent Publication (Kokai) No. 4-211230 discloses a camera shake having an average value detecting means for obtaining an average value of outputs of an angular velocity sensor within a predetermined time in order to remove a drift component of the angle sensor utilizing Coriolis force. A correction camera is disclosed. In this conventional camera shake correction camera, the detection time is constant with respect to the change in the focal length of the taking lens.

[0003]

Generally, when the focal length f of the taking lens changes, as shown in FIG.
The amount of camera shake d on the image plane becomes larger as the focal length f becomes longer (FIG. 6B), and conversely becomes smaller as the focal length f becomes shorter (FIG. 6A). Therefore, the detection accuracy of the amount of camera shake necessary for camera shake correction can be made higher as the focal length becomes longer and lowered as the focal length becomes shorter.

However, in the conventional camera-shake correction camera, the sensor output sampling time for obtaining the average value of the output of the angular velocity sensor is set to the focal length even when the taking lens is a variable magnification lens such as a zoom lens. It was constant regardless of. Therefore, there is a drawback that the release time lag becomes long because the sampling time for ensuring the accuracy required on the telephoto side becomes excessive on the wide angle side.

The present invention has been made in view of the above circumstances, and an object thereof is to ensure the accuracy of camera shake detection required on the telephoto side and to shorten the release time lag on the wide angle side.

[0006]

In order to achieve the above object, the present invention is provided by a variable magnification photographing optical system, a camera shake detecting means for detecting camera shake, a camera shake correcting means for correcting camera shake, and a camera shake detecting means. A control means for controlling the camera shake correction means in accordance with the detected detection signal, and the control means changes the sampling time for averaging the detection signals obtained from the camera shake detection means according to the focal length of the variable magnification photographing optical system. Is configured.

[0007]

In the camera-shake correcting camera having the above-mentioned structure, the sampling time for averaging the detection signals obtained from the camera-shake detecting means is changed according to the focal length of the variable magnification photographing optical system, so that it is necessary on the telephoto side. It is possible to secure the accuracy of camera shake detection and shorten the release time lag on the wide-angle side.

[0008]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block connection diagram showing an embodiment of an image stabilization camera according to the present invention.

In FIG. 1, the taking lens optical system is constituted by the taking lenses 1 to 4. Reference numeral 14 denotes a fixed lens barrel fixed to the camera body, and straight grooves 14a and 14b in the optical axis direction are formed on the peripheral surface of the fixed lens barrel 14.
A cam barrel 13 is rotatably fitted on the outer peripheral surface of the fixed lens barrel 14, and is prevented from coming off by a ring 15.
The rotation of the zooming motor M1 is transmitted to the gear portion 15a formed on the outer peripheral surface of the cam barrel 13 via the gears 23 and 22, and the cam barrel 13 is thereby rotated. 21a
Is a photo interrupter for detecting the amount of rotation of the gear 22 (depending on the zooming state).

On the peripheral surface of the cam barrel 13, cam grooves 13a, 1
3b and 13c are formed, and these cam grooves 13a are formed.
Square cam followers to be described later are engaged with .about.13c. The lens substrate 7 is inserted into the front end side of the inner peripheral surface of the fixed lens barrel 14, and the image stabilizing device is held by the lens substrate 7. The camera shake correction device includes a camera shake correction lens 3 held by a lens holder 9 and a drive mechanism for driving the camera shake correction lens 3, and the drive mechanism is as shown in FIG.
An X-direction drive mechanism 100x that drives the camera shake correction lens 3 in the X-direction, and a Y-direction drive mechanism 100y that drives the Y-direction.
It consists of and. Both the X direction and the Y direction are taken by the photographing lens 1.
Is a direction orthogonal to the optical axis of ~ 4.

The Y-direction drive mechanism 100y includes a Y-direction motor M3 and a gear 28 that rotates integrally with the output shaft of the motor M3.
A reduction gear train 27 for reducing the rotation of the gear 28, a Y-direction shift drive shaft 26 connected to the reduction gear train 27,
It has a Y-direction drive arm 24 that converts the rotation of the direction shift drive shaft 26 into a linear motion. Y direction shift drive shaft 26
Is rotatably supported on the lens substrate 7 by a pair of flanges 26c and 26d, and a gear 26 that meshes with the final gear of the reduction gear train 27 is provided above the Y-direction shift drive shaft 26.
A is connected, and a male screw portion 26b is formed on the lower portion. The Y-direction drive arm 24 is mounted in a space formed in the lens substrate 7 so as to be able to move up and down and non-rotatably.
The male screw portion 26b of the drive shaft 26 is screwed into a.

A holding portion 24b is provided below the Y-direction drive arm 24.
The upper connecting portion 9a of the lens holder 9 is held by the holding portion 24b via the four slider balls 25a to 25d. Therefore, when the drive arm 24 is moved up and down, the lens holder 9, that is, the image stabilizing lens 3
Are shifted in the Y direction in FIG. The shift amount is the motor M
3 depends on the amount of rotation. The X-direction drive mechanism 100x is also configured similarly to the Y-direction drive mechanism 100y, and is configured to shift the camera shake correction lens 3 in the X direction of FIG.

The camera shake correction lens 3 shifted by the Y direction drive mechanism 100y freely moves in the X direction, and the camera shake correction lens 3 shifted by the X direction drive mechanism 100x freely moves in the Y direction. . Therefore, the camera shake correction lens 3 can be shifted in all directions orthogonal to the optical axis by the operation of the drive mechanisms 100x and 100y.

A disk 29 having a plurality of holes formed concentrically is attached to the gear 28, which rotates integrally with the output shaft of the Y-direction motor M3, so as to be integrally rotatable. 30 is
The photo interrupter is a well-known photo interrupter having a light projecting portion and a light receiving portion that face each other across the hole forming portion of the disk 29, and a pulse signal is output every time the photo interrupter 30 detects the hole portion of the disk 29. Therefore, the rotation amount of the motor M3 (which depends on the shift amount of the image stabilizing lens 3) can be detected by counting the number of pulses. Also, X
A similar disk 29 and photo interrupter 30 are also provided on the direction motor M4 side, and the amount of rotation of the motor M4 is detected by this. The reference numerals 31 and 32 refer to the lens holder 9 for the Y-direction drive mechanism 100y or the X-direction drive mechanism 10.
These springs are biased toward the 0x side.

As shown in FIG. 1, a lens shutter mechanism is integrally attached to the camera shake correction device constructed as described above. The lens shutter mechanism is formed by integrating a shutter blade 12 (FIG. 1) that also serves as a diaphragm and a drive unit 6 that drives the shutter blade 12, and the drive unit 6 is screwed to the lens substrate 7 with screws 21. There is. Drive unit 6
The taking lens 2 is held by a lens holder 8. The cam followers 7c implanted in the lens substrate 7 are
It penetrates through the linear groove 14a and is engaged with the cam groove 13b. A lens holder 5 for holding the taking lens 1 is inserted into the front end side of the lens substrate 7, and a cam follower 5a planted on the outer peripheral surface of the lens holder 5 penetrates the rectilinear groove 14b and engages with the cam groove 13a. .

On the rear side of the fixed lens barrel 14, the lens substrate 10 having the helicoid 10b formed on its inner peripheral surface is inserted.
A cam follower 10 implanted on the outer peripheral surface of the lens substrate 10.
a penetrates the straight groove 14a and engages with the cam groove 13c. A lens holder 11 holds the focusing lens 4, and a helicoid 11b formed on the outer peripheral surface of the lens holder 11 is screwed into the helicoid 10a of the lens substrate 10. A gear portion 11a provided on the lens holder 11 meshes with a gear 18 that is integral with the output shaft of the focusing motor M2, and the lens holder 11 is rotated by the rotation of the motor M2. 20 is the rotation amount of the focusing motor M2, that is, the focusing lens 4
It is a photointerrupter for detecting the position of.

Next, the structure of the control system will be described.

The control system of this embodiment includes a CPU (hereinafter, referred to as a low-speed CPU) 41 having a relatively low arithmetic processing speed and a CPU (hereinafter, referred to as a high-speed CPU) 51 having an arithmetic processing speed faster than the low-speed CPU 41. It has two CPUs. Zooming motor M1 and focusing motor M2
Are respectively connected to the low-speed CPU 41 via the zoom motor driver 42 and the focusing motor driver 49. In addition, a Y-direction motor M3 and an X-direction motor M4 (both are shown in FIG. 2) that constitute the drive mechanism of the image stabilization apparatus.
Is connected to the high-speed CPU 51 via an FPC (flexible printed circuit board) 16 and a camera shake correction motor driver 44. The drive unit 6 of the lens shutter mechanism is an FPC.
16 through the lens shutter driver 43 and low speed C
It is connected to the PU 41.

The outputs of the X-direction and Y-direction photo interrupters 30 for camera shake correction are supplied to the high-speed CPU 51 via the FPC 16 and the lens shift amount detection circuit 45, and the photo interrupters 20 for detecting the focusing lens position and the zooming state. The output of the photo interrupter 21a for detection is supplied to the low-speed CPU 41 via the focusing lens position detection circuit 50 and the zoom state detection circuit 54a.

The low-speed CPU 41 includes a photometric circuit 46 for detecting the brightness of the object, a distance measuring circuit 47 for detecting the distance to the object, and a half-press switch SW1 which is turned on by half-pressing a release button (not shown). It is connected to a release switch SW2 which is turned on by fully pressing the release button.
Further, the high-speed CPU 51 includes a shake sensor 48 such as an angular velocity sensor that detects a shake amount in the X direction and the Y direction,
A film feeding driver 54 that drives the film feeding motor M5, a data imprinting device 52, and a film feeding amount detection circuit 53 are connected.

The data imprinting device 52 includes, for example, a plurality of imprinting light sources provided in the width direction of the film, and controls the lighting of the plurality of light sources as the film is wound to imprint the data on the film. It is complicated. The film feed amount detection circuit 53 is connected to a photoreflector or encoder for detecting film perforation, and supplies a pulse signal corresponding to the detected perforation to the high-speed CPU 51.

Next, the operation will be described.

When a zoom-up switch or a zoom-down switch (not shown) is turned on, the low speed CPU 41 causes the zoom motor M1 via the zoom motor driver 42.
A drive signal is output to the motor M1 to rotate the motor M1 in a predetermined direction. As a result, the rotational driving force of the motor M1 is transmitted via the gears 23, 22 and 15a, the cam barrel 13 rotates, and the cam grooves 13a, 13b and 13c move. With the movement of the cam grooves 13a to 13c, the cam followers 5a, 7c, and 10a move in the straight grooves 14a and 14c.
It is driven in the optical axis direction along b. As a result, the lens holder 5 that holds the taking lens 1, the lens substrate 7 that holds the taking lenses 2 and 3, and the lens substrate 10 that holds the taking lens 4 are driven in the optical axis direction, and zooming (zoom up or Zoom down) is performed. The photo interrupter 21a supplies a number of pulse signals corresponding to the rotation amount of the gear 22 to the low-speed CPU 41 via the zoom state detection circuit 54a, whereby the low-speed CPU 41 recognizes the zooming positions of the taking lenses 1 to 4. The zoom position f is recognized from the map of FIG. 5 according to the number of pulses. The map of FIG. 5 is stored in a memory (not shown) in the low speed CPU 41.

FIG. 3 is a flow chart for explaining the operation of the image stabilizing camera according to the present invention.

In FIG. 3, when the half-press switch SW1 (shutter release button) is turned on in step S101,
A battery check is performed in step S102. If the required voltage of the battery is secured, step S103
In step S10, the camera shake sensor 48 (camera shake detection means) is activated, and sampling of sensor data is started in order to calculate the reference signal level for detecting the camera shake amount (step S10).
4). In step S105, the timer is started at the same time when the sampling is started. In step S106, photometry and distance measurement are performed, and in step S107, the focal lengths of the taking lenses 1 to 4 are read. In step S108, exposure calculation is performed based on the photometry result, and in step S109, the focusing stop position is calculated from the distance measurement result.

In step S110, the release switch SW
It is determined whether or not 2 is fully pressed and on. If it is on, focusing is performed in step S112, and if it is not on, it is determined in step S111 whether the switch SW1 is on. If the switch SW1 is on, the process proceeds to step S110, and if not, the process returns to step S101.

In step S113 (FIG. 4), the time T (FIG. 5) corresponding to the current focal length zone is read. In step S116, the process waits until time T has elapsed from the timer start in step S105,
At 117, sampling of the sensor signal ends. As a result, the longer the focal length f of the taking lens is, the longer the sampling time of the sensor signal can be. Moreover, the shorter the focal length of the photographing lens, the shorter the sampling time of the sensor signal can be. Since it does not make sense to shorten the timer time from the time required for focusing after the release switch SW2 is turned on, the timer time is set to the release switch S
It was longer than the time from W2 on to the completion of focusing.

In step S118, camera shake correction is started,
In step S119, the shutter is released to perform the exposure operation. In step S120, the camera shake correction / detection ends,
In step S121, the film is wound up one frame and the process is completed.

With regard to focusing, since the shooting magnification increases as the shooting distance becomes shorter, the focusing mechanism is configured such that the focusing time on the wide-angle side is longer than the focusing time on the telephoto side, and the timer time for determining the sampling time is set. Is preferably the same as the farthest telephoto side focusing time. With this configuration, the release time lag can be minimized during the longest telephoto shooting, and the sampling time can be secured during the closest wide-angle shooting. Further, it is possible to obtain the effect that the time from pressing the release button to completion of shooting is substantially the same on the telephoto side and the wide-angle side.

In the above embodiment, the zoom state detection circuit (focal length detection means) 54 for detecting the focal length of the taking lens is provided, and the zoom state detection circuit 54a is activated after the release switch SW1 is turned on. The timer is started immediately after the sampling of the sensor signal is started, and when the release switch SW2 is turned on, the timer time T (FIG. 5) corresponding to the focal length of the photographing lens is read out,
The sampling of the sensor signal is ended when the time is up.

As a result, the sampling time on the wide-angle side can be shortened as compared with the telephoto side.
The release time lag when pressing 1 and SW2 at the same time can be shortened on the wide angle side. That is, in long-focal-length photography that requires camera-shake correction accuracy, hand-shake detection accuracy is improved, and in short-focal-length photography, the release time lag can be shortened, so that rapid shooting performance can be improved. On the other hand, on the telephoto side, there is a drawback that the release time lag becomes longer due to the longer sampling time, but conversely, the time the photographer holds the camera after operating the release button becomes longer, so the camera is stable and the camera shake is stable. There is an advantage that you can get few pictures.

[0033]

As described above, according to the present invention, the sampling time for averaging the detection signals obtained from the camera-shake detecting means is changed depending on the focal length of the variable magnification photographing optical system. It is possible to secure the accuracy of the shake detection which is considered to be, and to shorten the release time lag on the wide angle side.

[Brief description of drawings]

FIG. 1 is a block connection diagram showing an embodiment of an image stabilization camera according to the present invention.

FIG. 2 is a front view showing an embodiment of an image stabilization camera according to the present invention.

FIG. 3 is a flowchart illustrating an example of an image stabilization camera according to the present invention.

FIG. 4 is a flowchart illustrating an example of an image stabilization camera according to the present invention.

FIG. 5 is a memory map for explaining an embodiment of the image stabilization camera according to the present invention.

FIG. 6 is a front view illustrating an optical system of a camera shake correction camera according to the present invention and a conventional camera shake correction camera.

[Explanation of symbols]

 1 Photographic lens 2 Photographic lens 3 Correction lens 4 Focusing lens 20 Photointerrupter 21a Photointerrupter 30 Y direction photointerrupter 41 Low-speed CPU 42 Zoom motor driver 43 Lens shutter driver 44 Correction motor driver 45 Lens shift amount detection circuit 46 Photometry circuit 47 Distance measurement Circuit 48 Sensor 49 Focusing Motor Driver 50 Focusing Lens Position Detection Circuit 51 High Speed CPU 54a Zoom State Detection Circuit 100x X Direction Drive Mechanism 100y Y Direction Drive Mechanism

Claims (5)

[Claims] 1. A variable magnification photographing optical system, a camera shake detection means for detecting camera shake, a camera shake correction means for correcting camera shake, and a control for controlling the camera shake correction means according to a detection signal obtained from the camera shake detection means. A camera shake correction camera, characterized in that the control means changes the sampling time for averaging the detection signals obtained from the camera shake detection means according to the focal length of the variable magnification photographing optical system. 2. The image stabilizing camera according to claim 1, wherein the sampling time is shorter on the wide angle side than on the telephoto side of the variable magnification photographing optical system. 3. The focusing time according to claim 1 or 2, further comprising a focusing unit controlled by the control unit to perform focusing, wherein a sampling time on the telephoto side of the variable magnification photographing optical system is
An image stabilizing camera, which is terminated after the focusing is completed. 4. A camera shake correction camera according to claim 3, wherein the sampling time on the wide-angle side ends before the focusing is completed. 5. The image stabilizing camera according to claim 1, wherein the focusing time on the telephoto side is shorter than the focusing time on the wide angle side.