Light projection system for automatic focus detection
AssigneeCanon Kabushiki Kaisha
InventorsTakeshi Koyama, Keiji Ohtaka
Life of this patent
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Abstract
A focus detecting light projecting system for detecting the focus state of a photo taking optic by projecting a pattern with a light projecting lens onto a photographing object and by receiving a reflected image of the pattern reflected from the objects. The light projecting lens has a plurality of lens parts which have different optical axes and different forward focus-adjusting degrees.
Claims16
A pattern projecting device for focus detection, comprising:
- means for providing a pattern;
- and
- a projecting lens for projecting said pattern toward an object, said projecting lens being comprised of first and second lens parts which are integral in one unified body and have their optical axes deviating in parallel with each other, said first and second lens parts being disposed to cause a first image forming position in which said first lens part forms an image of said pattern and a second image forming position in which said second lens part forms an image of said pattern to differ from each other, said first and second lens parts each comprising a single lens.
A pattern projecting device removably attached to a camera body having a focus detecting system, comprising:
- means for providing a pattern;
- a projecting lens for projecting said pattern toward an object, said projecting lens comprising integral first and second lens parts arranged to form two images of said pattern in positions different from each other.
A camera system comprising:
- a photo taking system including a photo taking lens unit and an image receiver;
- and
- a pattern projector for projecting a pattern on an object, said projector including (1) a projecting lens comprising first and second lens parts which are integrally formed in one body with their optical axes arranged to deviate from each other, and (2) pattern providing means for providing a pattern having at least one stripe extending in the deviating direction of said optical axes, said first lens part having a portion extending beyond said second lens part.
A pattern projecting device for focus detection, comprising:
- means for providing a pattern;
- and
- a projection lens for projecting said pattern toward an object, said projection means having integral first and second lens parts having optical axes which deviate from each other, said first lens part having a portion extending beyond a surface of said second lens part.
Dependencies are inferred from the claim text.