Optical system and image capturing apparatus including the same
AssigneeCanon Kabushiki Kaisha
InventorTakahiro Komiyama
Life of this patent
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Abstract
An optical system includes a front lens unit, a first focusing unit having a negative refractive power, and a second focusing unit having a negative refractive power in this order from an object side to an image side. The optical system is a single focus optical system. When a focus is shifted from an object at infinity to an object at a short distance, the first focusing unit and the second focusing unit move to change a distance between the first focusing unit and the second focusing unit on an optical axis.
Claims18
An optical system comprising a front lens unit, a first focusing unit having a negative refractive power, and a second focusing unit having a negative refractive power in this order from an object side to an image side,
- wherein the optical system is a fixed local length optical system,
- wherein, when a focus is shifted from an object at infinity to an object at a short distance, the first focusing unit and the second focusing unit move to change a distance between the first focusing unit and the second focusing unit on an optical axis, and
- wherein the following inequalities are satisfied:
- 0.00<|fF1|/|f1|<0.77,
- −0.76<sk/fF1<0.00, and
- 0.10<fF1/fF2<1.90,
- where fF1 is a focal length of the first focusing unit, fF2 is a focal length of the second focusing unit, f1 is a focal length of the front lens unit, and sk is a back focus of the optical system.
An apparatus comprising an optical system and a sensor configured to receive an image formed by the optical system,
- wherein the optical system is a fixed focal length optical system comprising a front lens unit, a first focusing unit having a negative refractive power, and a second focusing unit having a negative refractive power in this order from an object side to an image side,
- wherein, when a focus is shifted from an object at infinity to an object at a short distance, the first focusing unit and the second focusing unit move to change a distance between the first focusing unit and the second focusing unit on an optical axis, and
- wherein the following inequalities are satisfied:
- 0.00<|fF1|/|f1|<0.77,
- −0.76<sk/fF1<0.00, and
- 0.10<fF1/fF2<1.90,
- where fF1 is a focal length of the first focusing unit, fF2 is a focal length of the second focusing unit, f1 is a focal length of the front lens unit, and sk is a back focus of the optical system.
Dependencies are inferred from the claim text.