Image movement correction of camera

• US 5,649,237 A
• Filed: 12/14/1994
• Issued: 07/15/1997
• Est. Priority Date: 12/14/1993
• Status: Expired due to Term

• Current Assignee: Nikon Corporation
• Original Assignee: Nikon Corporation
• Inventors: Okazaki, Mitsuhiro
• Primary Examiner(s): Metjahic, Safet
• Assistant Examiner(s): Nelson, Eric
• Application Number:
  US08/355,475
• Time in Patent Office: 944 Days
• Field of Search: 354/430, 354/400, 354/475, 354/195.1, 348/208, 396/52-55
• US Class Current: 396/55
• CPC Class Codes: G02B 27/646 compensating for small deviations, e.g. due to vibration or shake movement of one or more optical elements for control of motion blur in cameras, projectors or printers G03B2205/0007; image stabilisation in cameras peculiar to the presence or use of an electronic image sensor H04N23/68
• CPC Class Codes: G03B 2205/0007 Movement of one or more optical elements for control of motion blur imaging systems in general using optical elements for stabilisation of the position of the image G02B27/64
• CPC Class Codes: G03B 2217/005 Blur detection
• CPC Class Codes: G03B 5/00 Adjustment of optical system relative to image or object surface other than for focusing
• CPC Class Codes: H04N 23/68 for stable pick-up of the scene, e.g. compensating for camera body vibrations
• CPC Class Codes: H04N 23/6812 based on additional sensors, e.g. acceleration sensors
• CPC Class Codes: H04N 23/687 by shifting the lens or sensor position

Abstract

In an image correcting camera capable of correcting movement of an image properly by detecting translational movements thereof, there are provided acceleration detectors for detecting respective accelerations in directions of three axes acting on the camera, angular rate detectors for detecting respective angular rates around the three axes acting on the camera, an attitude determining device for calculating a coordinate transformation matrix between a camera coordinate system and a static coordinate system from the accelerations in the three axial directions and the angular rates around the three axes, and a gravitation acceleration component calculating device for calculating gravitational acceleration components in the camera coordinate system by the use of the coordinate transformation matrix. Displacements of translational movements are calculated by eliminating the gravitational acceleration components from the outputs of the acceleration detectors and a correction drive amount calculating device calculates an amount of movement of the image based on the displacements.

Claims

1. An image correcting camera comprising:

an acceleration detecting device to detect accelerations in three directions of X-, Y- and Z-axes acting on said camera;

an angular rate detecting device to detect angular rates around said three axes acting on said camera;

an attitude determining device to calculate a coordinate transformation matrix between a camera coordinate system and a static coordinate system from an initial attitude of said camera with respect to said static coordinate system and said angular rates around said three axes;

a gravitational acceleration component calculating device to calculate gravitational acceleration components in said camera coordinate system by the use of said coordinate transformation matrix;

an object distance measuring device to measure the distance between said camera and an object;

a photographing magnification detector to detect a photographing magnification of said camera;

a correction drive amount calculating device to calculate an amount of movement of an image based on respective displacements in the X- and Y-axis directions or the three axial directions calculated by eliminating said gravitational acceleration components from said respective accelerations in the X- and Y-axis directions or the three axial directions, respective rotation angles around the X- and Y-axes or the three axes calculated from said respective angular rates around the X- and Y-axes or the three axes, the distance between said camera and said object, and said photographing magnification, and to calculate an amount of drive of a correcting lens and/or an image pick-up surface so as to cancel said amount of movement of said image; and

a correction drive device to drive said correcting lens and/or said image pick-up surface.

2. An image correcting camera according to claim 1, wherein the acceleration detecting device includes plural acceleration detecting devices to detect respective accelerations in three directions of X-, Y- and Z-axis acting on said camera;

and

the angular rate detecting device includes plural angular detecting devices to detect respective angular rates around said three axes acting on said camera.

3. An image correcting camera according to claim 2, wherein said attitude determining device calculates said initial attitude of said camera with respect to said static coordinate system from a gravitational acceleration direction in said camera coordinate system obtained from said accelerations in the three axial directions.

4. An image correcting camera comprising:

angular rate detecting devices to detect respective angular rates around X-, Y- and Z-axes acting on said camera;

acceleration detecting devices to detect respective accelerations in said X- and Y-axis directions acting on said camera;

an attitude detector to detect an initial attitude of said camera by detecting a gravitational acceleration direction;

an attitude determining device to calculate a coordinate transformation matrix between a camera coordinate system and a static coordinate system from said initial attitude of said camera and said angular rates around said three axes;

a gravitational acceleration component calculating device to calculate gravitational acceleration components in said camera coordinate system by the use of said coordinate transformation matrix;

an object distance measuring device to measure the distance between said camera and an object;

a photographing magnification detector to detect a photographing magnification of said camera;

a correction device amount calculating device to calculate an amount of movement of an image based on respective displacements in the X- and Y-axis directions calculated by eliminating said gravitational acceleration components from said respective accelerations in the X- and Y-axis directions, respective rotation angles around the X- and Y-axes calculated from said respective angular rates around the X- and Y-axes, the distance between said camera and said object, and said photographing magnification, and to calculate an amount of drive of a correcting lens and/or an image pick-up surface so as to cancel said amount of movement of said image; and

a correction drive device to drive said correcting lens and/or said image pick-up surface.

5. An image correcting camera comprising:

acceleration detecting devices to detect respective accelerations in three directions of X-, Y- and Z-axes acting on said camera;

angular rate detecting devices to detect respective angular rates around said three axes acting on said camera;

an attitude determining device to calculate a coordinate transformation matrix between a camera coordinate system and a static coordinate system from an initial attitude of said camera with respect to said static coordinate system and said angular rates around said three axes;

a gravitational acceleration component calculating device to calculate gravitational acceleration components in said camera coordinate system by the use of said coordinate transformation matrix;

an object distance measuring device to measure the distance between said camera and an object;

a photographing magnification detector to detect a photographing magnification of said camera;

a correction drive amount calculating device to calculate an amount of movement of an image and an amount of focal shift based on respective displacements in the three axial directions calculated by eliminating said gravitational acceleration components from said respective accelerations in the three axial directions, respective rotation angles around the three axes calculated from said respective angular rates around the three axes, the distance between said camera and said object, and said photographing magnification, to calculate an amount of drive of a correcting lens and/or an image pick-up surface so as to cancel said amount of movement of said image, and to calculate an amount of drive of a focusing lens and/or said image pick-up surface so as to cancel said amount of focal shift; and

a correction drive device to drive said correcting lens and/or said focusing lens and/or said image pick-up surface.

6. An image correcting camera according to claim 5, wherein said attitude determining device calculates said initial attitude of said camera with respect to said static coordinate system from a gravitational acceleration direction in said camera coordinate system obtained from said accelerations in the three axial directions.

7. An image correcting camera comprising:

an acceleration detecting device to detect at least one acceleration acting on said camera;

an angular rate detecting device to detect at least one angular rate acting on said camera;

an attitude determining device to calculate a coordinate transformation matrix between a camera coordinate system and a static coordinate system from said angular rate;

a gravitational acceleration component calculating device to calculate gravitational acceleration components in said camera coordinate system by the use of said coordinate transformation matrix;

a correction drive amount calculating device to calculate an acceleration component by eliminating said gravitational acceleration components from said acceleration, and to calculate an amount of movement of an image and an amount of correction for said movement of said image based on a displacement calculated from said acceleration component and a rotation angle calculated from said angular rate; and

an image movement correcting device to correct said movement of said image based on said amount of correction.

8. A method of correcting movement of an image in a camera, comprising:

the acceleration detecting step of detecting respective accelerations in three directions of X-, Y- and Z-axes acting on said camera;

the angular rate detecting step of detecting respective angular rates around said three axes acting on said camera;

the attitude determining step of calculating a coordinate transformation matrix between a camera coordinate system and a static coordinate system from an initial attitude of said camera with respect to said static coordinate system and said angular rates around said three axes;

the gravitational acceleration component calculating step of calculating gravitational acceleration components in said camera coordinate system by the use of said coordinate transformation matrix;

the correction drive amount calculating step of calculating an amount of movement of an image based on respective displacements in the X- and Y-axis directions or the three axial directions calculated by eliminating said gravitational acceleration components from said respective accelerations in the X- and Y-axis directions or the three axial directions, respective rotation angles around the X- and Y-axes or the three axes calculated from said respective angular rates around the X- and Y-axes or the three axes, the distance between said camera and an object, and a photographing magnification of said camera, and calculating an amount of drive of a correcting lens and/or an image pick-up surface so as to cancel said amount of movement of said image; and

the correction drive step of driving said correcting lens and/or said image pick-up surface.

9. An image correcting camera comprising:

an attitude determining device to calculate a coordinate transformation matrix between a camera coordinate system and a static coordinate system from an initial attitude of said camera with respect to said static coordinate system and angular rates in three directions;

a gravitational acceleration component calculating device to calculate gravitational acceleration components in said camera coordinate system by the use of said coordinate transformation matrix;

a correction drive device to drive a correcting lens and/or an image pick-up surface, and/or a focusing lens based on a drive amount calculated from said angular rates, an object distance, a photographing magnification, and displacements in said three directions by eliminating said gravitational acceleration components from accelerations in said three directions.

10. A method of correcting camera movement comprising the steps of:

calculating a coordinate transformation matrix between a camera coordinate system and a static coordinate system from an initial attitude of said camera with respect to said static coordinate system and angular rates in three directions;

calculating gravitational acceleration components in said camera coordinate system by the use of said coordinate transformation matrix;

driving a correcting lens and/or an image pick-up surface, and/or a focusing lens based on a correction amount calculated from said angular rates, an object distance, a photographing magnification, and displacements in said three directions by eliminating said gravitational acceleration components from accelerations in said three directions.