Zoom image pickup apparatus
AssigneeOlympus Corporation
InventorKeisuke TAKADA
Life of this patent
Estimating the term…
Abstract
A zoom image pickup apparatus includes a mount portion, a zoom lens which forms an image of light incident from the mount portion, and an image pickup element which is disposed at an image forming position, wherein the zoom lens includes in order from an object side, 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, and the fourth lens unit is a focusing lens unit, and at the time of zooming from a wide angle end to a telephoto end, only the second lens unit and the fourth lens unit move, and the following conditional expression (1) is satisfied: φL1<φ3GL1 (1).
Claims16
A zoom image pickup apparatus, comprising:
- a mount portion;
- a zoom lens which forms an image of light incident from the mount portion;
- and
- an image pickup element which is disposed at an image forming position, wherein
- the zoom lens includes in order from an object side,
- 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, and
- the fourth lens unit is a focusing lens unit, and
- at the time of zooming from a wide angle end to a telephoto end, at least the second lens unit and the fourth lens unit move, and
- at the wide angle end when focused to a first object, the following conditional expression (1) is satisfied:
- φL1<φ3GL1 (1)
- where,
- φL1 denotes an effective diameter of a lens surface positioned nearest to object of the zoom lens,
- φ3GL1 denotes an effective diameter of a lens surface positioned nearest to object of the third lens unit,
- the first object is an object when an object-point distance is 1000 mm, here
- the object-point distance is a distance from a lens surface positioned nearest to object of the zoom lens, up to the object, and
- the effective diameter is the maximum diameter of a range on a target lens surface, through which a light ray contributing to image formation passes.
A zoom image pickup apparatus, comprising:
- a mount portion;
- a zoom lens which forms an image of light incident from the mount portion;
- and
- an image pickup element which is disposed at an image forming position, wherein
- the zoom lens includes in order from an object side,
- 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, and
- the fourth lens unit is a focusing lens unit, and
- at the time of zooming from a wide angle end to a telephoto end, only the second lens unit and the fourth lens unit move, and the first lens unit, the third lens unit, and the fifth lens unit are fixed, and
- the following conditional expression (13) is satisfied:
- |(yw7d′−yw7d)/P|/(1/N)<250 (13)
- where,
- a side of the mount portion is let to be an object side and a side of the image pickup element is let to be an image side,
- each of yw7d and yw7d′ is a height of a predetermined light ray at a position at which the predetermined light ray intersects an image plane, and yw7d denotes a light-ray height when focused to the first object and yw7d′ denotes a light-ray height in a defocused state, here
- the defocused state is a state in which the focusing lens unit is moved by Δs2 when focused to the first object, and Δs2=10×P,
- 0.0008<P<0.005,0.05<1/N<1,
- where,
- N denotes the number of pixels (unit millions of pixels) of the image pickup element,
- P denotes a pixel pitch (unit mm) of the image pickup element,
- the predetermined light ray is a light ray with an angle of view of 7 degrees at the wide angle end, which passes through a center of a lens surface nearest to object of the zoom lens,
- the first object is an object when an object-point distance is 1000 mm, and
- the object-point distance is a distance from a lens surface positioned nearest to object of the zoom lens, up to the object.
Dependencies are inferred from the claim text.