Light-projecting system for automatic focus detection
AssigneeCanon Kabushiki Kaisha
InventorYusuke Ohmura
Life of this patent
Estimating the term…
Abstract
A light-projecting system for illuminating a central portion of a screen and a pair of peripheral portions on either side of the central portion in order to perform focus detection for each of the central portion and the pair of peripheral portions, comprises a first pattern for forming first illumination light for illuminating the central portion of the screen, and a second pattern common to the pair of peripheral portions, for forming second illumination light and third illumination light, different in light intensity distribution from the first illumination light, for illuminating the pair of peripheral portions separately, thereby providing the light-projecting system for automatic focus detection, permitting high-accuracy focus detection by expanding the illumination range.
Claims39
A light-projecting system for illuminating a central portion of a scene and a pair of peripheral portions on either side of said central portion in order to perform focus detection for each of said central portion and said pair of peripheral portions, said system comprising:
- a first pattern portion for forming, upon being illuminated, a first illumination light pattern for illuminating said central portion of the scene;
- and
- one second pattern portion, common to said pair of peripheral portions, for forming, upon being illuminated, a second illumination light pattern and a third illumination light pattern, different in light intensity distribution from said first illumination light pattern, for illuminating said pair of peripheral portions separately.
A light-projecting system for illuminating a central portion of a scene and a pair of peripheral portions on either side of said central portion in order to perform focus detection for each of said central portion and said pair of peripheral portions, said apparatus comprising:
- a first pattern for forming, upon being illuminated, a first illumination light pattern for illuminating said central portion of the scene;
- a first light-projecting lens for projecting the first illumination light pattern from said first pattern to said central portion of the scene;
- a second pattern, common to said pair of peripheral portions, for forming, upon being illuminated, a second illumination light pattern and a third illumination light pattern, different in light intensity distribution from said first illumination light pattern, for illuminating said pair of peripheral portions separately;
- and
- a second light-projecting lens for projecting the second illumination light pattern from said second pattern to said pair of peripheral portions.
An optical apparatus for illuminating a central portion of a scene and a pair of peripheral portions on either side of said central portion in order to perform focus detection for each of said central portion and said pair of peripheral portions, said apparatus comprising:
- a first pattern portion for forming, upon being illuminated, a first illumination light pattern for illuminating said central portion of the scene;
- and
- a second pattern portion, common to said pair of peripheral portions, for forming, upon being illuminated, a second illumination light pattern and a third illumination light pattern, different in light intensity distribution from said first illumination light pattern, for illuminating said pair of peripheral portions separately.
An optical apparatus for illuminating a central portion of a scene and a pair of peripheral portions on either side of said central portion in order to perform focus detection for each of said central portion and said pair of peripheral portions, said apparatus comprising:
- a first pattern for forming, upon being illuminated, a first illumination light pattern for illuminating said central portion of the scene;
- a first light-projecting lens for projecting the first illumination light pattern from said first pattern to said central portion of the scene;
- a second pattern, common to said pair of peripheral portions, for forming, upon being illuminated, a second illumination light pattern and a third illumination light pattern, different in light intensity distribution from said first illumination light pattern, for illuminating said pair of peripheral portions separately;
- and
- a second light-projecting lens for projecting the second illumination light pattern from said second pattern to said pair of peripheral portions.
A light-projecting system for illuminating a scene for focus detection, said system comprising:
- a pattern portion for forming illumination light for illuminating a scene;
- a light-projecting lens for light-projecting the pattern portion onto the scene;
- and
- a deflecting member having fine prism portions for splitting and deflecting a portion of the illumination light.
Dependencies are inferred from the claim text.