Image stabilizing system
AssigneeCanon Kabushiki Kaisha
InventorShingo Hayakawa
Life of this patent
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Abstract
An image stabilizing optical objective lens system comprising, in the order from the side of the system closest to an object, a first lens unit having a positive refractive power, a second lens unit having a negative refractive power, a third lens unit having a positive refractive power, a fourth lens unit having a negative refractive power, and a fifth lens unit having a positive refractive power. The objective lens system performs focusing by moving the second lens unit in the direction of the optical axis of the system for focusing and corrects image blur by moving the fourth lens unit in the direction perpendicular to the optical axis.
Claims17
An image stabilizing optical objective lens system comprising, in the order from the side of the system closest to an object, a first lens unit having a positive refractive power, a second lens unit having a negative refractive power, a third lens unit having a positive refractive power, a fourth lens unit having a negative refractive power, and a fifth lens unit having a positive refractive power, wherein said second lens unit is moved in the direction of the optical axis of the system for focusing and said fourth lens unit is moved in a direction perpendicular to the optical axis for correcting image blur, and wherein when the focal length of the entire system is normalized to 1, the following relationships hold true:
- −5.0<I4<−0.7
- 0.7<I5<5.0
- 0.5<|I4/I5|<2.0
- where I4 and I5 represent respectively the spherical aberration coefficients of said fourth and fifth lens units focused on an object at infinity.
An image stabilizing optical objective lens system comprising, in order from the side of the system closest to an object, a first lens unit having a positive refractive power, a second lens unit having a negative refractive power, a third lens unit having a positive refractive power, a fourth lens unit having a negative refractive power, and a fifth lens unit having a positive refractive power, wherein said second lens unit is movable in a direction of the optical axis of the system for focusing, and said fourth lens unit is movable in a direction perpendicular to the optical axis for correcting image blur, and wherein the following relationships hold true:
- 0.25<f123/f<0.75
- 0.07<|f4/f|<0.15
- 0.10<f5/f<0.30
- where f123 represents the total focal length of said first lens unit through said third lens unit, f represents the focal length of the entire system and fi represents a focal length of an i-th lens unit.
An image stabilizing optical objective lens system comprising, in order from the side of the system closest to an object, a first lens unit having a positive refractive power, a second lens unit having a negative refractive power, a third lens unit having a positive refractive power, a fourth lens unit having a negative refractive power, and a fifth lens unit having a positive refractive power, wherein said second lens unit is movable in a direction of the optical axis of the system for focusing, and said fourth lens unit is movable in a direction perpendicular to the optical axis for correcting image blur, and wherein the following relationships hold true:
- 0.35<f1/f<0.60
- 0.30<|f2/f|<0.70
- 0.25<f3/f<0.60,
- where fi represents a focal length of an i-th lens unit and f represents the focal length of the entire system.
An image stabilizing optical objective lens system comprising, in order from the side of the system closest to an object, a first lens unit having a positive refractive power, a second lens unit having a negative refractive power, a third lens unit having a positive refractive power, a fourth lens unit having a negative refractive power, and a fifth lens unit having a positive refractive power, wherein said second lens unit is movable in a direction of the optical axis of the system for focusing, and said fourth lens unit is movable in a direction perpendicular to the optical axis for correcting image blur, wherein said third lens unit comprises, in order from the side of the system closest to the object, one negative lens and two positive lenses, and wherein the following relationship holds true:
- −1.5<(R3s+R3e)/(R3s−R3e)<−0.2
- where R3s and R3e represent respectively the radii of curvature of the lens surface of the third lens unit closest to the object and the lens surface of the third lens unit closest to an image plane.
Dependencies are inferred from the claim text.