Shake-correction device and shake-correction method for photographing apparatus

Patent metadata

Field	Value
Publication number	US-10142546-B2
Application number	US-201715434461-A
Country	US
Kind code	B2
Filing date	Feb 16, 2017
Priority date	Mar 16, 2016
Publication date	Nov 27, 2018
Grant date	Nov 27, 2018

Abstract

A shake-correction device for a photographing apparatus, which photographs an object image projected onto an imaging surface, includes a mover provided with a movable member, the mover configured to rotate at least one of the object image and the imaging surface relative to a plane orthogonal to the optical axis, and to translate parallel to the plane that is orthogonal to the optical axis and translate in a translation direction parallel to the optical axis; a shake detector configured to detect an angular shake of the photographing apparatus in the rotational direction and detect a shift shake of the photographing apparatus in the translation directions; and a movement controller configured to control movement of the mover so that the object image does not relatively move with respect to the imaging surface when the shake detector detects at least one of the angular shake and the shift shake.

First claim

What is claimed is:

1. A shake-correction device for a photographing apparatus, said photographing apparatus configured to photograph an object image that is projected onto an imaging surface by a photographing optical system, said shake-correction device comprising:
a mover provided with a movable member, said mover configured to rotate at least one of the object image and the imaging surface in a rotational direction relative to a plane that is orthogonal to an optical axis of the photographing optical system, and configured to translate in a translation direction parallel to said plane that is orthogonal to the optical axis and translate in a translation direction parallel to the optical axis;
a shake detector configured to detect an angular shake of said photographing apparatus in said rotational direction and detect a shift shake of said photographing apparatus in said translation directions;
a movement controller configured to control movement of said mover so that the object image does not relatively move with respect to the imaging surface when said shake detector detects at least one of said angular shake and said shift shake; and
a calculator configured to calculate a rotational correction amount, in accordance with said angular shake, and a shift correction amount, in accordance with said shift shake, for moving said mover so that said object image that is projected onto said image surface does not relatively move with respect to the imaging surface, wherein:
when said shake detector detects shift shake in a direction orthogonal to the optical axis, said calculator calculates a shift amount in said direction orthogonal to the optical axis, caused by shift shake, and calculates an optical-axis direction movement amount and a rotational amount of said movable member in accordance with said shift shake, and
said movement controller controls said mover to translate said movable member in the optical axis direction based on said optical-axis direction movement amount, and to rotate said movable member about a direction that is orthogonal to said optical axis based on said rotational amount.

2. The shake-correction device for a photographing apparatus according to claim 1 , wherein said movable member comprises an image sensor configured to capture an image of said object image that is projected onto said imaging surface,
wherein said mover is configured to at least one of:
rotate said image sensor in a rotational direction relative to a plane that is orthogonal to an optical axis of the photographing optical system,
translate said image sensor in a translation direction parallel to said plane that is orthogonal to the optical axis, and
translate said image sensor in a translation direction parallel to the optical axis.

3. The shake-correction device for a photographing apparatus according to claim 1 , wherein said movable member comprises an optical element of said photographing optical system,
wherein said mover is configured to move said optical element so that said object image at least one of:
rotates in a rotational direction relative to a plane that is orthogonal to an optical axis of the photographing optical system,
translates in a translation direction parallel to said plane that is orthogonal to the optical axis, and
translates in a translation direction parallel to the optical axis.

4. The shake-correction device for a photographing apparatus according to claim 1 , wherein, when said shake detector detects angular shake, said calculator calculates a focusing shift amount, caused by said angular shake, and calculates a focusing correction amount in accordance with said focusing shift amount, and
wherein said movement controller controls said mover to translate said movable member in a focusing direction based on said focusing correction amount.

5. The shake-correction device for a photographing apparatus according to claim 1 , wherein, when said shake detector detects shift in the optical axis direction, said calculator calculates a shift amount in a focusing direction along the optical axis, and calculates a focusing correction amount in accordance with said shift amount, and
wherein said movement controller controls said mover to translate said movable member in said focusing direction based on said focusing correction amount.

6. The shake-correction device for a photographing apparatus according to claim 1 , wherein, when said shake detector detects an angular shake whereby the optical axis of said photographing optical system rotates relative to an initial position, said calculator calculates an image-surface tilt correction amount using the following formula:
Δθ× m , wherein

Δθ designates the amount of said angular shake,
m designates an optical magnification of said photographing optical system,
m=a/b,

“a” designates a distance between a principal plane of said photographing optical system and the imaging surface, and
“b” designates a distance between a principal plane of said photographing optical system and an object surface, and
said calculator calculates an optical-axis correction amount using the following formula:
α×tan Δθ, and

wherein said movement controller controls said mover to rotate said image sensor based on the calculated said image-surface tilt correction amount and controls said mover to translate said image sensor in a direction orthogonal to the optical axis based on the calculated said optical-axis correction amount, thereby correcting said angular shake.

7. The shake-correction device for a photographing apparatus according to claim 6 , wherein said calculator calculates an optical magnification of said photographing optical system based on the following formula:
m=a/b , wherein
m designates the optical magnification of said photographing optical system,
“a” designates a distance between a principal plane of said photographing optical system and the imaging surface, and
“b” designates a distance between a principal plane of said photographing optical system and an object surface, and
wherein said calculate calculates at least one of said rotational correction amount and said shift correction amount based on said optical magnification.

8. A shake-correction method for a shake-correction device of a photographing apparatus, said photographing apparatus configured to photograph an object image that is projected onto an imaging surface by said photographing optical system, and said shake-correction device including a mover provided with a movable member, said mover configured to rotate at least one of the object image and the imaging surface in a rotational direction relative to a plane that is orthogonal to an optical axis of the photographing optical system and configured to translate in a translation direction parallel to said plane that is orthogonal to the optical axis and translate in a translation direction parallel to the optical axis; a shake detector; and a movement controller configured to control movement of said mover, said shake-correction method comprising:
detecting, using said shake detector, an angular shake of said photographing apparatus in said rotational direction and detecting a shift shake of said photographing apparatus in said translation directions;
controlling movement of said mover so that the object image does not relatively move with respect to the imaging surface based on at least one of said angular shake and said shift shake that is detected by said shake detector; and
calculating a rotational correction amount, in accordance with said angular shake, and a shift correction amount, in accordance with said shift shake, for moving said mover so that said object image that is projected onto said image surface does not relatively mo

Assignees

• Ricoh Imaging Co Ltd

Inventors

• Ito Eiichi

Classifications

• H04N23/67

  Focus control based on electronic image sensor signals · CPC title

• G03B5/00 Primary

  Adjustment of optical system relative to image or object surface other than for focusing · CPC title

• H04N23/687 Primary

  by shifting the lens or sensor position · CPC title

• H04N23/6812

  based on additional sensors, e.g. acceleration sensors · CPC title

• H04N5/23287 Primary

  Electricity · mapped topic