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US 5,477,381 AGranted
Image sensing apparatus having an optical low-pass filter
AssigneeCanon Kabushiki Kaisha
InventorsTakashi Sasaki, Kan Takaiwa, Akihiko Shiraishi
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Abstract
An image sensing apparatus for converting an object image formed by a photographic lens into electrical signals includes a solid-state image sensor having an offset sampling structure for converting the image into electrical signals. An optical low-pass filter is positioned between the lens and the solid-state image sensor and includes at least two optical members each for splitting a light beam into plural light beams having two different propagation directions from each other.
Claims9
An image sensing apparatus for converting an object image formed by a photographic lens into electrical signals, comprising:
- solid-state image sensing means having an offset sampling structure for converting said image into electrical signals;
- and
- an optical low-pass filter positioned between the lens and said solid-stage image sensing means and including at least two optical members each for splitting a light ray into plural light rays having different propagation directions from each other,
- wherein said solid-state image sensing means includes a plurality of picture elements which are arrayed so that a pitch in a scanning direction is P.sub.H, the offset sampling structure is P.sub.H /2, and a pitch in a direction perpendicular to the scanning direction is P.sub.V, and wherein a low-pass filter characteristic in a spatial frequency plane (f.sub.X, f.sub.Y) of said optical low-pass filter is such that a frequency characteristic becomes zero or minimum on sides of a hexagon enclosed by four straight lines of .+-.45.degree. directions and two straight lines parallel to an f.sub.X axis;
- said optical low-pass filter having a structure wherein coordinates of vertices formed by the sides of said hexagon which are of the .+-.45.degree. directions lie on an f.sub.Y axis, coordinates which lie on a negative side of the f.sub.X axis being present in a zone from -(2/3)(1/P.sub.H) to -((1/3)(1/P.sub.H)+(1/2)(1/P.sub.V)), and coordinates which lie in a positive side of the f.sub.X axis being present in a zone from ((1/3)(1/P.sub.H)+(1/2)(1/P.sub.V)) to (2/3)(1/P.sub.H).
2 more elements
An image sensing apparatus for converting an object image formed by a photographic lens into electrical signals, comprising:
- a solid-state image sensing means including a plurality of picture elements arrayed so that a pitch in a scanning direction is P.sub.H, a pitch in a direction perpendicular to the scanning direction is P.sub.V, and a picture element offset amount is P.sub.H /2, for converting said image into electrical signals;
- and
- an optical low-pass filter arranged between the lens and said solid-state image sensing means and including at least a first optical member for splitting incident light into two beams and a second optical member for further splitting into two beams each light beam emitted by the first optical member, the light beam split width of said first optical member and the light beam split width of said second optical member each lying in a range of 3P.sub.H /2.sqroot.2 to 3.sqroot.2P.sub.H xP.sub.V /(3P.sub.H +2P.sub.V).
An image sensing apparatus for converting an object image formed by a photographic lens into electrical signals, comprising:
- solid-state image sensing means having an offset sampling structure for converting said image into electrical signals;
- and
- an optical low-pass filter positioned between the lens and said solid-stage image sensing means and including at least two optical members each for splitting a light ray into plural light rays having different propagation directions from each other,
- wherein said solid-state image sensing means includes a plurality of picture elements arrayed so that a pitch in a scanning direction is P.sub.H, a pitch in a direction perpendicular to the scanning direction is P.sub.V, a picture element offset amount of the scanning direction is P.sub.H /2, and the condition P.sub.V >(3/2)P.sub.H is satisfied, and wherein said optical low-pass filter includes at least a first optical member for splitting incident light into two beams in a direction inclined 45.degree. clockwise or counterclockwise with respect to the scanning direction or a direction to the scanning direction reverse, and a second optical member for splitting incident light into two beams in a direction inclined 90.degree. clockwise or counterclockwise with respect to the direction of the split beams of said first optical member, the light beam split width of said first optical member which produces the two split beams in said 45.degree. inclined direction, and the light beam split width of said second optical member which produces the two split beams in said 90.degree. inclined direction each lying in a range of 3P.sub.H /2.sqroot.2 to 3.sqroot.2P.sub.H xP.sub.V /(3P.sub.H +2P.sub.V).
1 more element
An image sensing apparatus for converting an object image formed by a photographic lens into electrical signals, comprising:
- solid-state image sensing means having an offset sampling structure for converting said image into electrical signals;
- and
- an optical low-pass filter positioned between the lens and said solid-stage image sensing means and including at least two optical members each for splitting a light ray into plural light rays having different propagation directions from each other,
- wherein said solid-state image sensing means includes a plurality of picture elements arrayed so that a pitch in a scanning direction is P.sub.H, a pitch in a direction perpendicular to the scanning direction is P.sub.V, an offset amount of the scanning direction is P.sub.H /2, and the condition P.sub.V .ltoreq.(3/2)P.sub.H is satisfied, and wherein said optical low-pass filter includes at least a first optical member for splitting incident light into two beams in a direction inclined 45.degree. clockwise or counterclockwise with respect to the scanning direction or the reverse direction to the scanning direction, and a second optical member for splitting incident light into two beams in a direction inclined 90.degree. clockwise or counterclockwise with respect to the direction of the split-off beam of said first optical member, the light beam split width of said first optical member which produces the two split beams in said 45.degree. inclined direction, and the light beam split width of said second optical member which produces the two split beams in said 90.degree. inclined direction each lying in a range of 3.sqroot.2P.sub.H xP.sub.V /(3P.sub.H +2P.sub.V) to 3P.sub.H /2.sqroot.2.
1 more element
Dependencies are inferred from the claim text.