Color image sensor with improved resolution having time delays in a plurality of output lines

• US 4,580,160 A
• Filed: 03/22/1984
• Issued: 04/01/1986
• Est. Priority Date: 03/22/1984
• Status: Expired due to Term

• Current Assignee: Fuji Photo Film Company
• Original Assignee: Fuji Photo Film Co Limited (Fujifilm Holdings Corporation)
• Inventors: Ochi, Shigeharu, Inada, Jun
• Primary Examiner(s): Masinick, Michael A.
• Assistant Examiner(s): Svihla, Randall S.
• Application Number:
  US06/592,204
• Time in Patent Office: 740 Days
• Field of Search: 358/41, 358/43, 358/44, 358/48
• US Class Current: 348/276
• CPC Class Codes: H04N 23/84 for processing colour signals
• CPC Class Codes: H04N 25/702 SSIS architectures characterised by non-identical, non-equidistant or non-planar pixel layout

Abstract

A solid-state color image sensor and a method for operating such an image sensor in which high resolution is provided by delaying outputs from the various pixels in the sensor array by delay times determined in accordance with the actual positions of the pixels in the row direction of the array. Pixels are read out simultaneously in groups of three, one for each of white, cyan and yellow. The delays are imposed upon two of these. The delayed and undelayed outputs are combined with sum/difference circuits to produce chrominance and luminance signals. Preferably, the pixels have hexagonally shaped light sensitive areas to maximize the light sensitivity of each pixel and hence the resolution of the device.

Claims

1. A solid-state color image sensor comprising:

a plurality of pixels arranged in an array of rows and columns, said pixels being arranged in said array in groups each containing at least three pixels, each pixel in each group being sensitive to light of a different color;

a plurality of signal collecting output lines, one of said output lines being provided for each of said colors;

means for reading out color image signals from said groups in a predetermined sequence of groups with signals from all pixels within each group being read out simultaneously and being applied to respective ones of said output lines provided for the same color as that to which the respective pixels are sensitive;

means for delaying signals read out onto at least two of said output lines by time periods corresponding to scanning times in a direction of said rows from a one of said pixels in each of said groups, the output signal from which is not delayed, to respective ones of said pixels, the outputs from which are read out onto said at least two of said output lines; and

means for combining delayed and undelayed ones of said output signals in predetermined combinations to provide a luminance signal and at least two chrominance signals.

2. The solid-state color image sensor of claim 1, wherein each said group comprises three pixels, one pixel sensitive to white light, one pixel sensitive to cyan light and one pixel sensitive to yellow light.

3. The solid-state color image sensor of claim 2, wherein said delaying means comprises first and second delay elements, said first delay element having a delay time corresponding to one-third of a group-pitch scan time and said second delay element having a delay time corresponding to two-thirds of said group-pitch scan time.

4. The solid-state color image sensor of claim 1, wherein each of said pixels comprises a hexagonally shaped light-sensitive portion.

5. The solid-state color image sensor of claim 4, wherein each of said groups comprises a triad of said pixels.

6. The solid-state color image sensor of claim 1, wherein said delaying means comprises a frame memory for storing outputs of each of said pixels in said array and signal processing means for reading said outputs of said pixels stored in said frame memory from said frame memory.

7. The solid-state color image sensor of claim 1, wherein said combining means comprises a plurality of sum/difference circuits for combining said delay and undelayed ones of said output signals.

8. A solid-state color image sensor comprising:

a plurality of pixels arranged in an array of rows and columns, each of said pixels having a hexagonally shaped light-sensitive area, pixels in each of said rows being arranged in a repeating pattern of pixels sensitive to yellow, white and cyan light, pixels in alternate rows having centers falling along lines passing through points halfway between centers of the most closely adjacent pixels in contiguous rows, pixels in each column being sensitive to the same color of light, and pixels in contiguous rows forming triads of pixels, one triad comprising pixels sensitive to each of white, cyan and yellow light;

a plurality of horizontally-scanned vertical lines, one of said horizontally-scanned lines being provided for each column of pixels in said array sensitive to the same color of light;

a plurality of first switching devices for selectively coupling outputs of said pixels to respective ones of said horizontally-scanned lines;

means for actuating said switching devices for effecting interlaced scanning of said array such that outputs from two contiguous rows of said pixels are simultaneously read out onto respective ones of said horizontally-scanned lines;

first, second and third output lines corresponding to colors of yellow, cyan and white, respectively;

a plurality of groups of second switching devices, each of said groups of said second switching devices comprising three said second switching devices, said second switching devices being provided in a number equal to the sum of the number of pixels in any two adjacent rows of said array, each of said secod switching devices having an input terminal coupled to a respective one of said horizontally-scanned lines and an output terminal coupled to the one of said output lines corresponding to the same color of light to which are sensitive pixels in a column to which the respective horizontally-scanned line is coupled;

means for actuating said groups of second switching devices in sequence;

first and second delay elements coupled in series with said second and third output lines, respectively, said first delay element having a delay time equal to one-third of a triad-pitch scan time and said second delay element having a delay time equal to two-thirds a triad-pitch scan time;

first through third sum/difference circuits;

said first sum/difference circuit having noninverting inputs coupled to each of said first output line, an output of said first delay element, and an output of said second delay element;

said second sum/difference circuit having a noninverting input coupled to said output of said second delay element and an inverting input coupled to said output of said first delay element; and

said third sum/difference circuit having a noninverting input coupled to said output of said second delay element and a noninverting input coupled to said first output line; and

first through third low-pass filters connected in series with outputs of said first through third sum/difference circuits, respectively.

9. A method for extracting output signals from a solid-state color image sensor composed of a plurality of pixels arranged in an array of rows and columns with the pixels being arranged in groups containing at least three pixels, each pixel in said groups being sensitive to a different color of light, comprising the steps of:

reading out onto a set of output lines, equal in number to the number of pixels in each said group, output signals from each of said groups in sequence, signals from pixels within each said group being read out simultaneously, and signals from pixels sensitive to the same color of light being read out onto corresponding same ones of said output lines;

delaying all but one of the output signals on said output lines by predetermined time delays; and

combining delayed and undelayed ones of said output signals in predetermined combinations.

10. The method of claim 9, wherein said delay times correspond to scanning times in a row direction from one of said pixels in each of said groups, the output signal of which is not delayed, to the other said pixels in each of said groups, the output signals of which are delayed.