JPH02296230A - Moving detector camera - Google Patents

Abstract

PURPOSE:To always detect the correct blurring quantity of an image regardless of a position where shaking occurs by providing acceleration sensors in a virtual axis, and calculating the blurring quantity of the image on a film. CONSTITUTION:Two acceleration sensors 2a and 2b having sensitivity in the direction of an axis (x) of the camera main body 1 are provided in the direction of an axis (y), and two accelerating sensors 3a and 3b having the sensitivity in the direction of the axis (y) of the camera main body 1 are provided in the direction of an axis (z). The acceleration sensors 2a, 2b, 3a, and 3b generate output in proportion to the acceleration of vibration caused by hand-shaking, etc., carry out signal processing based on the output, and finally, calculate the overall moving quantity of an image on the surface of a film. Thus, the moving quantity of the camera in the axes (x) and (y) can be calculated, and a photograph free from blurring of image can be obtained by using this output.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a camera shake detection device that detects the amount of camera shake based on hand shake caused by a photographer of the camera.

[Prior Art] When photographing with a camera, camera shake is likely to occur, and image blur on the film surface is unavoidable. In particular, image blurring was noticeable during slow shutter speeds at low brightness or when using a long focal length lens. In order to avoid this image blur, it is necessary to issue a warning in advance when low-speed shutter speed is reached, to control the shutter speed at the camera shake limit, and to adjust the focal length to the short focal length side in the case of a variable focus lens. Changes were being made. However, in such conventional techniques, the control is not performed based on the detection of the actual amount of camera shake, but merely a prediction.

Therefore, it was proposed in Japanese Patent Application Laid-Open No. 63-12599 to detect the actual amount of camera shake using an acceleration sensor (hereinafter referred to as a sensor).
It is proposed in No. 3. In this conventional technology, the sensitivity axes of the two sensors are aligned with the incident optical axis, one of the sensors is placed near the release button, and the other sensor is spaced apart and facing the other sensor along the direction perpendicular to the incident optical axis. It was placed in the same position. This arrangement allows camera shake to be detected efficiently, taking into account that camera shake is likely to occur near the release button.

[Problem that the invention seeks to solve]

However, although what we originally want to detect is the amount of image blur on the film surface, the conventional technology described above uses an arrangement that is most effective for detecting the amount of camera shake around the release button. There was a drawback that the amount of image blur on the image cannot be detected accurately. Furthermore, the above-mentioned conventional technology has the disadvantage that accurate detection cannot be performed when the source of camera shake is located in a location other than the expected location, such as when the way the camera is held or the direction in which the release button is pressed changes.

The present invention has been made in view of the above-mentioned problems of the prior art, and provides a camera shake detection device that can accurately detect the amount of image blur on the film surface regardless of the position of the source of image blur. The purpose is to

[Means and effects for solving the problem] The present invention provides at least two first acceleration detection means provided on a virtual first axis of a camera body, and the first axis is At least two second acceleration detection means provided on different virtual second axes, and calculation of the amount of blur on the film surface based on the outputs of the first and second acceleration detection means. The invention is characterized in that it is provided with means.

〔Example〕

An embodiment of the present invention will be described below.

FIG. 1 is a perspective view of a camera to which the present invention is applied, in which a release button 4 is provided on the upper left surface of a camera body 1, and a lens barrel 5 is provided in the center of the front surface. The optical axis direction of the lens barrel 5 is defined as two axes, the longitudinal direction (film feeding direction) of the camera body 1 is defined as the y-axis, and the direction perpendicular to the y-axis and the two axes is defined as the y-axis. A sensor 2a having sensitivity in the X-axis direction is installed around the pentaprism section in the camera body 1, and a sensor 2b having sensitivity in the They are provided facing each other at a distance in the y-axis direction with respect to the center point 11 of .

Further, a sensor 3b having sensitivity in the y-axis direction is provided near the tip of the lens barrel 5, and a Z-axis including this sensor 3b is provided.
A sensor 3a having sensitivity in the y-axis direction is provided near the rear surface of the camera body 1 on a line parallel to the axis.

Next, we will explain how to calculate the rotation angle of the camera caused by camera shake, etc., and its custom-made translation amount, based on the output of the sensors arranged as described above.
).

Figure 2 (a) shows x passing through the center of the film surface of the camera body 1.
-A cross-sectional view on the y plane, showing the sensor 2a and the sensor 2.
The center point 11 of the film surface 12 is located on the straight line connecting the points b. Then, the distance from the center point 11 to the sensor 2a is rXo, and the distance from the center point 11 to the sensor 2b is rXo.
, Let the value obtained by integrating the output of the sensor 2a twice (ie, the displacement amount of arrow 15) be X11, and the value obtained by integrating the output of the sensor 2b twice (ie, the amount of displacement indicated by arrow 16) be Xl.

The rotation angle θX of the camera with respect to the y-axis is equal to the apex angle of the triangle formed by the difference in displacement at the two locations, and (
1) The amount of movement in the X-axis direction at the center point 11 (the amount of displacement of the arrow 17) dx is calculated from the above Xll+
It corresponds to the amount of internally dividing XI by the distance r Xo r XI and is obtained from equation (2).

The rotation angle θX of the camera with respect to the y-axis and the movement amount dx of the camera have been described above, but the y-axis can also be determined in the same manner. FIG. 2(b) is a cross-sectional view on the y-z plane passing through the center 11 of the film surface, and the straight line connecting the sensor 3a and the sensor 3b is parallel to the Z axis, but passes through the center 11 of the film surface. I haven't. Therefore, the intersection of the straight line connecting the sensors 3a and 3b with the y-axis passing through the center of the film surface 1 is set as the temporary center point 13 of the film surface, and this temporary center point 13
The distance from to sensor 3a is ry.

The distance from the temporary center point 13 to the sensor 3b is ry.

shall be. Then, the value obtained by dividing the output of the sensor 3a into two of the same type (that is, the displacement amount of the arrow 18) is yo, and the output of the sensor 3b is 2
When the homogeneous value (that is, the amount of displacement of the arrow 19) is yl, the rotation angle θy of the camera with respect to the two axes can be obtained from equation (3).

Next, the movement N in the y-axis direction at the center point 11 of the film surface
dy is the film surface center point 11 and the film surface temporary center point 1
If the interval between 3 and 3 is A, it is obtained from equation (4).

As is clear from the above equation (4), the amount of movement of the center point of the film surface can be calculated by correction even if the two sensors do not pass through the center point of the film surface. It goes without saying that this method can also be applied to the case of determining the amount of parallel movement dx with respect to the y-axis, and by performing such correction, a degree of freedom can be given to the arrangement of the sensors.

Next, a method of calculating the amount of movement of the image on the film surface using the camera shake, that is, the rotation angle and the amount of movement determined as described above, will be explained.

In Figure 3, the camera body l is at an angle θ. When it rotates high,
Film surface center 11, photographic lens 21, 22, and subject 2
3 is a diagram illustrating the positional relationship between the photographing lenses 21.3 and 21.3.
The focal length of 22 is f, the distance from the taking lens 21 to the center 11 of the film surface is f+f', and the distance from the taking lens 22 to the subject M[+! Indicated by From this stationary state, the camera body changes to an angle of θ due to camera shake, etc. When the photographing lens 2122 is rotated by 21', the photographing lens 2122 moves to positions 21' and 22', respectively, and the film plane rotates from the h-axis to the CD plane. As a result of this rotation, the image formed at the center point 11 of the filter plane moves to a point 25 on the C-0 plane.

At this time, the distance Ah between the center point 11 and the point 25 is obtained from equation (5).

Ah-(1+β)2 ・θ.・f ----------
-(5) (However, β-f/1. represents the photographic magnification) On the other hand of this equation (5), the focal length f can be obtained as lens information, and the distance l is the amount of lens extension. The above-mentioned camera rotation θ can be obtained from information or AF amount information. It can be seen that the amount of rotational movement Ah of the image due to rotation at the time of occurrence of blur can be calculated by calculating .

Next, calculation of the amount of movement of the fill 1 and the image on the surface caused by the amount of movement dh will be explained. FIG. 4 is a diagram illustrating the positional relationship between the film plane center point 11, the photographic lens 21, 22, and the subject 23 when the camera body 11 moves by a distance dh in the h-axis direction. Also at the position 21'22' is the center point 11 of the film surface.
moves to 11', and the image that was focused on center point 11 becomes 26
Move to. The amount of parallel movement Δh of the image at this time is determined by (6).

Δh−βd h −−−−−−−−−−−−−−−
−−−−−−−−−−−−−(6) (here β−f/
j2) Therefore, from the focal length information f, lens extension amount information or AF amount information ρ, and the above-mentioned parallel movement ldh of the camera, the amount of parallel movement △h of the image due to the parallel movement when blur occurs can be calculated. I understand.

In the above explanation, for generalization, the h-axis was explained, but the above-mentioned y-axis and y-axis can be calculated in the same way by replacing the symbols as appropriate, so a detailed explanation will be omitted.

The amount of image blur (movement amount) caused by camera shake is the camera rotation (θX) described above.

Usually, it is a combination of the one due to θy) and the one due to parallel movement (dx,,dy), and these are (7) (
8) It can be obtained using the formula.

X=Ax+Δx-(1+β)2・θx-f+β-dx
−−−−−(7) Y・＾y+△y・(1+ris2・su・
θy, r+βdy −−−−−−−−−−(8) Here, X is the amount of movement of the image in the X-axis direction caused by camera shake, and Y is the amount of movement in the y-axis direction.

Next, the configuration of the camera shake detection device incorporated in the camera shown in FIG. 1 will be explained based on the block diagram shown in FIG. 5. As shown in FIG. 1, two acceleration sensors 2a and 2b having sensitivity in the X-axis direction of the camera body 1 are provided in the y-axis direction, and two acceleration sensors 3a and 2b having sensitivity in the y-axis direction are provided. 3b are provided in two axial directions. These acceleration sensors 2a, 2b,
3. A and 3b generate an output in proportion to the acceleration of vibration caused by hand shake or the like. The outputs of the sensors 2a and 2b having sensitivity in the X-axis direction are each input to a differentiator 31a, while the outputs of the sensors 3a and 3b having sensitivity in the y-axis direction are each input to a differentiator 31b. The outputs of both the differentiators 3]a and 31b are respectively output from the signal processing circuit 3
2a, 32b, integrators 33a, 33b, and camera movement information calculation means 34a, 34b.
5a. This image blur information calculation means 35a
, 35b are input with focal length information 37 and subject distance information 38, respectively.

The output of the image blur information calculation means 35a is connected to the image blur information output means (y axis) 36a, and the output of the image blur information calculation means 35b
The output of is connected to image blur information output means (y axis) 3b,
Both image blur information output means 36a and 36b are connected to a blur correction mechanism control means 39.

The operation of the camera shake detection device configured as described above will be explained. Among the vibrations caused by camera shake, etc.
A signal proportional to the acceleration in the axial direction is generated at the sensor 2a and the sensor 2b, and the difference between the outputs of both sensors is calculated and output by the subtractor 31a. This differential output is output from the signal processing circuit 32.
After the signal is amplified by a and unnecessary high frequency components are removed, the integrator 33a performs an integral operation twice to obtain the signal X described above. -X, calculate the displacement amount corresponding to.

It is determined by this displacement amount (xo Xi) and the positions of the sensors 2a and 2b, and is stored in advance (rXo
+:, r X 1) Based on the value, the camera movement information calculation means 34a calculates the camera rotation angle θX and the camera translation amount dx according to equations (1) and (2). Next, the image blur information calculation means 35a calculates a fill value on the y-axis according to equations (5) and (6) based on the camera rotation angle θX, camera translation amount dx, focal point, distance information f, and subject distance information. The amount of movement of the image (Ax caused by the rotation angle and ΔX caused by parallel movement) on the image plane is calculated. Then, two outputs A of the image blur information calculation means 35a
Based on x and ΔX, image blur information output means (y axis) 3
6a calculates the overall moving amount X of the image on the film surface in the y-axis according to equation (7).

On the other hand, the image blur information output means 36b performs signal processing in the same way as in the case of the y-axis based on the outputs of the sensors 3a and 3b having sensitivity in the y-axis direction, and finally outputs an image on the film surface in the y-axis. The overall movement amount Y is calculated. Therefore, the image blur information output means 36a and 36b can calculate the amount of camera shake on the y-axis and the y-axis, and this output can be used to obtain a picture without image blur using the known blur correction mechanism control means 39. I can do it.

〔effect〕

According to the present invention, two acceleration sensors are provided on each of two virtual axes to calculate the amount of image blur on the film surface, so the position of the source of the blur is irrelevant. This has the effect that the amount of image blur can always be detected accurately.

[Brief explanation of the drawing]

Figure 1 is a perspective view of a camera to which the present invention is applied, and Figure 2 (a
) is a cross-sectional view of the camera in the x-y plane, Figure 2 (b) is a cross-sectional view of the camera in the V=Z plane, Figure 3 is a diagram showing the relationship between the camera rotation angle and the film plane, and Figure 4 is a diagram showing the relationship between the camera rotation angle and the film plane. FIG. 5, which is a diagram showing the relationship between the parallel movement of the camera and the film plane, is a block diagram showing an embodiment of the present invention.

Claims (3)

[Claims] (1) At least two first acceleration detection means provided on a virtual first axis of the camera body and a virtual second axis different from the first axis. It is characterized by comprising: at least two second acceleration detection means; and a calculation means for calculating the amount of image blur on the film surface based on the outputs of the first and second acceleration detection means. Camera shake detection device. (2) The camera shake detection device according to claim 1, wherein at least one of the first axis and the second axis passes through the center of the film surface. (3) When at least one of the first axis and the second axis passes through a location other than the center of the film surface, the calculation means performs a correction calculation to obtain the amount of blur at the center of the film surface. A camera shake detection device according to claim 1.