Imaging optical system and image pickup apparatus having the same
AssigneeCanon Kabushiki Kaisha
InventorKoji Aoki
Life of this patent
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Abstract
An imaging optical system includes, in order from an object side to an image side, at least one concave lens, an aperture stop, a first transmissive reflective surface, a quarter waveplate, and a second transmissive reflective surface, arranged such that light from the object side transmits through the first transmissive reflective surface and the quarter waveplate in this order, is reflected by the second transmissive reflective surface toward the object side, transmits through the quarter waveplate, is reflected by the first transmissive reflective surface toward the image side, transmits through the quarter waveplate and the second transmissive reflective surface in this order, and travels toward the image side. A predetermined inequality is satisfied.
Claims20
An imaging optical system comprising, in order from an object side to an image side:
- at least one negative lens;
- an aperture stop;
- a first transmissive reflective surface;
- a quarter waveplate;
- and
- a second transmissive reflective surface,
- arranged such that light from the object side transmits through the first transmissive reflective surface and the quarter waveplate in this order, is reflected by the second transmissive reflective surface toward the object side, transmits through the quarter waveplate, is reflected by the first transmissive reflective surface toward the image side, transmits through the quarter waveplate and the second transmissive reflective surface in this order, and travels toward the image side,
- wherein the following inequality is satisfied:
- 0.55
- ≤
- zm
-
- 1
- /
- f
- ≤
- 4.8
- where zm1 is a distance on an optical axis from the first transmissive reflective surface to an image plane, and f is a focal length of the imaging optical system.
An imaging optical system comprising, in order from an object side to an image side:
- an aperture stop;
- a first transmissive reflective surface;
- a quarter waveplate;
- and
- a second transmissive reflective surface,
- arranged such that light from the object side transmits through the first transmissive reflective surface and the quarter waveplate in this order, is reflected by the second transmissive reflective surface toward the object side, transmits through the quarter waveplate, is reflected by the first transmissive reflective surface toward the image side, transmits through the quarter waveplate and the second transmissive reflective surface in this order, and travels toward the image side,
- wherein the following inequality is satisfied:
- 0.8
- ≤
- zm
-
- 1
- /
- f
- ≤
- 4.8
- where zm1 is a distance on an optical axis from the first transmissive reflective surface to the image plane, and f is a focal length of the imaging optical system.
An image pickup apparatus comprising:
- an imaging optical system;
- and
- an image sensor configured to receive an image formed by the imaging optical system,
- wherein the imaging optical system includes, in order from an object side to an image side:
- at least one negative lens;
- an aperture stop;
- a first transmissive reflective surface;
- a quarter waveplate;
- and
- a second transmissive reflective surface,
- arranged such that light from the object side transmits through the first transmissive reflective surface and the quarter waveplate in this order, is reflected by the second transmissive reflective surface toward the object side, transmits through the quarter waveplate, is reflected by the first transmissive reflective surface toward the image side, transmits through the quarter waveplate and the second transmissive reflective surface in this order, and travels toward the image side, and
- wherein the following inequality is satisfied:
- 0.55
- ≤
- zm
-
- 1
- /
- f
- ≤
- 4.8
- where zm1 is a distance on an optical axis from the first transmissive reflective surface to an image plane, and f is a focal length of the imaging optical system.
An image pickup apparatus comprising:
- an imaging optical system;
- and
- an image sensor configured to receive an image formed by the imaging optical system,
- wherein the imaging optical system includes, in order from an object side to an image side:
- an aperture stop;
- a first transmissive reflective surface;
- a quarter waveplate;
- and
- a second transmissive reflective surface,
- arranged such that light from the object side transmits through the first transmissive reflective surface and the quarter waveplate in this order, is reflected by the second transmissive reflective surface toward the object side, transmits through the quarter waveplate, is reflected by the first transmissive reflective surface toward the image side, transmits through the quarter waveplate and the second transmissive reflective surface in this order, and travels toward the image side, and
- wherein the following inequality is satisfied:
- 0.8
- ≤
- zm
-
- 1
- /
- f
- ≤
- 4.8
- where zm1 is a distance on an optical axis from the first transmissive reflective surface to the image plane, and f is a focal length of the imaging optical system.
Dependencies are inferred from the claim text.