Optical: systems and elements – Image stabilization – By movable refractive structure
Reexamination Certificate
1999-10-27
2001-06-26
Nguyen, Thong (Department: 2872)
Optical: systems and elements
Image stabilization
By movable refractive structure
C359S407000, C359S554000
Reexamination Certificate
active
06252713
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an optical device, for example, a pair of binoculars, which is provided with a correcting function for trembling of a focused image.
2. Description of the Related Art
Conventionally, there is known an optical device, such as a pair of binoculars, which is provided with a correcting function for trembling of a focused image. For example, an image tremble correcting mechanism is disclosed in U.S. Pat. No. 5,917,653. In the image tremble correcting mechanism, correcting optical. systems are driven two-dimensionally on a plane perpendicular to optical axes of the correcting optical systems.
Such an image tremble correcting mechanism is provided with a frame holding the correcting optical systems. A portion of this frame, at which a driving force is added, and a leading member which leads the frame in a predetermined direction on the plans, are spaced. Namely, a distance between the portion of the frame and the leading member is large. Accordingly, a moment of force, the rotational axis of which is the portion at which the driving force is added, is generated, when the frame is driven. Accordingly, the driving amount of the frame corresponding to the added driving force can not be determined. Namely, the driving of the correcting optical systems is unable to be accurately controlled.
Further, each time the frame is driven, unexpected forces are added to each member of the correcting mechanism, due to the aforementioned moment of force. Accordingly, the frame can not be driven smoothly, and portions of each member, which come into contact with other members due to the unexpected forces, are worn away.
SUMMARY OF THE INVENTION
Therefore, an object of the present invention is to provide an optical device which is provided with a correcting mechanism for trembling of a focused image, by which a correcting optical system is driven smoothly and accurately.
In accordance with an aspect of the present invention, there is provided an optical device with a correcting function for trembling of a focused image comprising: a holder that holds a correcting optical system for correcting a tremble of an optical axis of the optical device; a first driving mechanism that drives the holder along a first axis parallel to a direction of gravity, on a plane perpendicular to an optical axis of the correcting optical system; a second driving mechanism that drives the holder along a second axis perpendicular to the first axis, on the perpendicular plane; and a guide mechanism that leads the holder along the first axis when the holder is driven by the first driving mechanism. The first driving mechanism and the guide mechanism are positioned close to a center of gravity of the holder.
The first driving mechanism and the guide mechanism are disposed close to a position which is offset in a direction along the optical axis of the correcting optical system from a center point of the holder in a direction parallel to in the first axis.
The correcting optical system comprises a pair of correction lens elements. The holder comprises: a first driving frame that is supported by a fixed frame mounted on an inner wall of the optical device and has an opening portion; and a second driving frame that is slidably supported in the opening portion and holds the pair of correction lens elements. The first driving frame is driven by the first driving mechanism; and the second driving frame is driven by the second driving mechanism. The first driving mechanism and the guide mechanism are disposed on a line perpendicular to a plane which contains each center of the pair of correction lens elements and is perpendicular to optical axes of the pair of correction lens elements. The line is between the pair of correction lens elements.
The guide mechanism comprises: a first projecting member that is formed on a first edge portion of the first driving frame; a second projecting member that is formed on a second edge portion of the first driving frame; and a bar that is unitarily formed on the fixed frame and parallel to the first axis. The first edge portion is parallel to the second axis and positioned on an upper side of the optical device when the optical device is held in a standard position. The second edge portion is parallel to the second axis and positioned on a lower side of the optical device when the optical device is held in the standard position. The bar has a first guide hole and a second guide hole. The first projecting member pierces the first guide hole, being movable along the first axis, and the second projecting member pierces the second guide hole, being movable along the first axis.
The optical device further comprises: a first urging member that urges the first driving frame in a direction parallel to the second axis such that the first projecting member is held in contact with an inner wall, parallel to the first axis of the, first guide hole, at all times; and a second urging member that urges the first driving frame in the direction parallel to the second axis such that the second projecting member is held in contact with an inner wall, parallel to the first axis of the second guide hole, at all times.
The optical device further comprises a third urging member that urges the first driving frame along the first axis from the lower side to the upper side. The first driving mechanism can push the second projecting member against urging force of the third urging member, whereby the first driving frame is driven along the first axis from the upper side to the lower side.
The second projecting member includes a tip end that comprises a plane outer surface and a cylindrical outer surface. The second projecting member is situated such that the plane outer surface faces the upper side and the cylindrical outer surface faces the lower side.
The first driving mechanism:is a direct-drive-type actuator that comprises a motor and a shaft extending and retracting along the first axis in accordance with a rotational movement of the motor. A tip of the shaft abuts against the plane outer surface at all times.
The first driving frame is supported by the inner wall in such a manner that both side edge portions parallel to the first axis of the first driving frame are slidably supported by slots formed in the inner wall, enabling the first driving frame to move in a direction along the optical axis.
The first driving frame is rectangular, and the first axis is parallel to a longitudinal direction of the first driving frame.
The first axis is parallel to a vertical direction when this optical device is normally held.
In accordance with another aspect of the present invention, there is provided an optical device with a correcting function for trembling of a focused image comprising: a holder that holds a correcting optical system for correcting a tremble of an optical axis of the optical device; a first driving mechanism that drives the holder along a first axis perpendicular to a longitudinal direction of the holder; a second driving mechanism that drives the holder along a second axis perpendicular to the first axis, on a plane perpendicular to an optical axis of the correcting optical system; and a guide mechanism that leads the holder along the first axis when the holder is driven by the first driving mechanism. The first driving mechanism and the guide mechanism are positioned close to a center of gravity of the holder.
REFERENCES:
patent: 5153633 (1992-10-01), Otani
patent: 5541693 (1996-07-01), Enomoto
patent: 5583597 (1996-12-01), Enomoto
patent: 5721969 (1998-02-01), Arai
patent: 5768016 (1998-06-01), Kanbara
patent: 5883742 (1999-03-01), Kamata
patent: 5917653 (1999-06-01), Taniguchi
patent: 5959769 (1999-09-01), Yoneyama
patent: 6038072 (2000-03-01), Hirunuma et al.
Hirunuma Ken
Tsukamoto Shinji
Asahi Kogaku Kogyo Kabushiki Kaisha
Greenblum & Bernstein P.L.C.
Nguyen Thong
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