Image pickup apparatus with color filter array and means for adding and subtracting signals

• US 6,757,016 B1
• Filed: 12/23/1998
• Issued: 06/29/2004
• Est. Priority Date: 12/26/1997
• Status: Expired due to Fees

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Kochi, Tetsunobu, Ueno, Isamu, Sakurai, Katsuhito, Hiyama, Hiroki, Sugawa, Shigetoshi, Koizumi, Toru, Ogawa, Katsuhisa
• Primary Examiner(s): Garber, Wendy R.
• Assistant Examiner(s): Rosendale, Matthew L
• Application Number:
  US09/219,754
• Time in Patent Office: 2,015 Days
• Field of Search: 348/279, 348/308, 348/281, 348/278, 348/277, 348/222.1
• US Class Current: 348/279
• CPC Class Codes: H04N 23/84 for processing colour signals
• CPC Class Codes: H04N 25/136 using complementary colours

Abstract

To provide an image pickup apparatus that generates an image signal having a high resolution both horizontally and vertically, the filter arrangement for a color filter array used in the apparatus is so designed that the colors of the filters in a cyclic patterned unit of N rows×N columns (4 lines×4 columns) differ from each other not only on the same line but also in the same column. Thus, from all the pixel blocks, pixel signals for each predetermined pixel block unit can be obtained that are required for the generation of a luminance signal and of color signals.

Claims

1. An image pickup apparatus comprising:

a plurality of pixels arranged horizontally and vertically; and

a color filter array of four colors arranged in said plurality of pixels,

wherein said color filter array has a cyclic pattern of adjacent units of four rows×

four columns,

wherein, in the cyclic pattern unit comprising four rows and four columns, colors of color filters on the same row differ from each other and colors of said color filters in the same column differ from each other, and

wherein when the cyclic pattern unit of four rows and four columns is divided into four subunits, each of which comprises two rows and two columns, colors of the four color filters included in each of said subunits are all different from each other.

2. An image pickup apparatus according to claim 1, further comprising:

a first addition unit arranged to add signals for pixels that are adjacent to each other horizontally and/or vertically.

3. An image pickup apparatus according to claim 2, further comprising:

a subtraction unit arranged to perform a subtraction between a plurality of signals that are added together by said first addition unit.

4. An image pickup apparatus according to claim 2, further comprising:

a second addition unit arranged to add together a plurality of signals that are added together by said first addition unit.

5. An image pickup apparatus according to claim 1, further comprising:

a first addition unit arranged to add signals for pixels that are adjacent to each other horizontally and/or vertically;

a subtraction unit arranged to perform a subtraction between a plurality of signals that are added together by said first addition unit; and

a second addition unit arranged to add together a plurality of signals that are added together by said first addition unit.

6. An image pickup apparatus according to one of claims 1 to 5, wherein said color filters are a filter for transmitting only green light within a visible radiation range, a filter for absorbing only a blue light within said visible radiation range, a filter for absorbing only green light within said visible radiation range, and a filter for absorbing only red light within said visible radiation range.