Solid-state color imaging apparatus having color filter array which eliminates vertical color error

• US 4,760,441 A
• Filed: 05/13/1987
• Issued: 07/26/1988
• Est. Priority Date: 11/10/1983
• Status: Expired due to Term

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Kohno, Akiyoshi
• Primary Examiner(s): NOT, DEFINED
• Assistant Examiner(s): Svihla, Randall S.
• Application Number:
  US07/049,025
• Time in Patent Office: 440 Days
• Field of Search: 358/41, 358/43, 358/44, 358/47, 358/48
• US Class Current: 348/278
• CPC Class Codes: H04N 25/134 based on three different wavelength filter elements
• CPC Class Codes: H04N 25/135 based on four or more different wavelength filter elements

Abstract

A solid-state color imaging apparatus includes an array of color filters. The first and third rows of the array are constructed entirely of same-color filters. The second row of the array comprises a first set of color filters for generating a first color difference signal component modulated with a predetermined number of picture elements forming one cycle in the horizontal direction, and the fourth row comprises a second set of color filters which generates a second color difference signal component modulated with a predetermined number of picture elements forming one cycle in the horizontal direction. In one embodiment, the same-color filters of the first and third rows are transparent to red, green and blue light. In another embodiment, the same-color filters transmit green light and attenuate the intensity of blue and red light so that intensity of the transmitted blue and red light is half the intensity of the incident blue and red light, respectively, thereby to approximate the spectral characteristics of a luminance signal of an NTSC color television signal. A color difference signal component is not included in the odd-numbered horizontal rows but only in the even-numbered horizontal rows whereby vertical color error is not generated in the color difference signal in the output signal even when the horizontal picture elements in the adjacent rows have no vertical correlation. Thus, the color difference signal included in the output signal from the color imaging apparatus is formed from a single horizontal picture element row to provide a color television signal without generating vertical color error.

Claims

1. A solid-state color imaging apparatus having color filters arrayed at a recurrence cycle of four picture elements in a vertical direction, and constructed so that in first and third rows, same-color filters for generating a same-signal component from each picture element are arrayed;

in a second row, a first set of color filters for generating a first modulated color difference signal component are arrayed with a predetermined number of picture elements forming one cycle in a horizontal direction; and

in a fourth row, a second set of color filters for generating a second modulated color difference signal component are arrayed with a predetermined number of picture elements forming one cycle in the horizontal direction;

wherein said same-color filters of said first and third rows transmit blue, green and red light, the predetermined number of picture elements in said second row is two, and the first set of color filters comprises alternately arranged green and magenta filters.

2. The apparatus of claim 1, wherein the predetermined number of picture elements in said fourth row is two, and said second set of filters comprises alternately arranged first and second color filters, said first color filter transmitting red light and transmitting and attenuating incident green light so that the intensity of the transmitted green light is half the intensity of the incident green light, and said second filter transmitting blue light and transmitting and attenuating incident green light so that the intensity of the transmitted green light is half the intensity of the incident green light.

5. The apparatus of claim 1, wherein the predetermined number of picture elements in said fourth row is two, and said second set of filters comprises alternately arranged first and second color filters, said first color filter transmitting red light and transmitting and attenuating incident green light so that the intensity of the transmitted green light is half the intensity of the incident green light, and said second filter transmitting blue light and transmitting and attenuating incident green light so that the intensity of the transmitted green light is half the intensity of the incident green light.

3. A solid-state color imaging apparatus having color filters arrayed at a recurrence cycle of four picture elements in a vertical direction, and constructed so that in first and third rows, same-color filters for generating a same-signal component from each picture element are arrayed;

in a second row, a first set of color filters for generating a first color modulated color difference signal component are arrayed with a predetermined number of picture elements forming one cycle in a horizontal direction; and

in a fourth row, a second set of color filters for generating a second modulated color difference signal component are arrayed with a predetermined number of picture elements forming one cycle in the horizontal direction;

wherein said same-color filters of said first and third rows transmit green light and transmit and attenuate incident red and blue light so that the transmitted red and blue light is half the intensity of the incident red and blue light, respectively, thereby to approximate the spectral characteristics of the luminance signal of an NTSC color television signal.

4. The apparatus of claim 3, wherein the predetermined number of picture elements in said second row is two, and the first set of color filters comprises alternately arranged green and magenta filters.