CONCENTRIC EXPOSURE SEQUENCE FOR IMAGE SENSOR

• US 20090268055A1
• Filed: 04/29/2008
• Published: 10/29/2009
• Est. Priority Date: 04/29/2008
• Status: Active Grant

• Current Assignee: Omnivision Technologies Incorporated (Will Semiconductor Co., Ltd. Shanghai)
• Original Assignee: Omnivision Technologies Incorporated (Will Semiconductor Co., Ltd. Shanghai)
• Inventors: Pillman, Bruce H., Compton, John T., Hamilton, John F. JR.
• Granted Patent: US 8,164,651 B2
• Time in Patent Office: Days
• US Class Current: 348/230.100
• CPC Class Codes: H04N 23/631 Graphical user interfaces [GUI] specially adapted for controlling image capture or setting capture parameters
• CPC Class Codes: H04N 23/70 Circuitry for compensating brightness variation in the scene
• CPC Class Codes: H04N 25/133 including elements passing panchromatic light, e.g. filters passing white light
• CPC Class Codes: H04N 25/135 based on four or more different wavelength filter elements
• CPC Class Codes: H04N 25/46 by combining or binning pixels
• CPC Class Codes: H04N 25/531 by controlling rolling shutters in CMOS SSIS
• CPC Class Codes: H04N 25/534 depending on the spectral component

Abstract

A method for image capture includes providing an image sensor having at least one segmented row of pixels, wherein the at least one segmented row comprises at least first and second disjoint row subsets of pixels, wherein the reset and readout operations for each row subset are controllably independent of each other; timing the exposure interval of the first subset to be photographically centered with the exposure interval of the second subset; and combining the image data obtained from the first and second row subset exposures to form a row of pixel values.

Claims

1. A method for image capture comprising:

(a) providing an image sensor having at least one segmented row of pixels, wherein the at least one segmented row comprises at least first and second disjoint row subsets of pixels, wherein the reset and readout operations for each row subset are controllably independent of each other;

(b) timing the exposure interval of the first subset to be photographically centered with the exposure interval of the second subset; and

(c) combining the image data obtained from the first and second row subset exposures to form a row of pixel values.

2. The method of claim 1 wherein both the first and the second row subsets have color pixels.

3. The method of claim 1 wherein the first row subset has color pixels and the second row subset has panchromatic pixels.

4. The method of claim 1 wherein combining the image data further comprises combining image data obtained from pixels in different rows.

5. The method of claim 1 wherein the at least one segmented row further comprises a third row subset, also disjoint with respect to the first and second row subsets and wherein the exposure interval of the third subset is photographically centered with the exposure intervals of the first and second subsets.

6. A method for image capture comprising:

(a) providing an image sensor having at least one segmented row of pixels, wherein the at least one segmented row comprises at least first and second disjoint row subsets of pixels, wherein each row subset can be separately read and reset;

(b) exposing pixels within the at least one row of pixels by;

(i) resetting the first row subset to begin a first exposure and, after a first interval, resetting the second row subset to begin a second exposure;

(ii) reading the second row subset to end the second exposure and obtain a second exposure signal value and, after a second interval, reading the first row subset to end the first exposure and obtain a first exposure signal value,

wherein the durations of the first interval and second interval are equal, to within 20% of the duration of the first exposure; and

c) combining the image data obtained from the first and second exposure signal values to form a row of pixel values.

7. The method of claim 6 wherein both the first and the second row subsets have color pixels.

8. The method of claim 6 wherein the first row subset has color pixels and the second row subset has panchromatic pixels.

9. The method of claim 6 wherein combining the image data further comprises combining image data obtained from pixels in different rows.

10. A method for image capture comprising:

(a) providing an image sensor having

(i) a first independently addressable row subset of pixels in a first row;

(ii) a second independently addressable row subset of pixels in a second row that is adjacent to the first row;

(b) exposing pixels within said first and second rows by;

(i) resetting the first row subset to begin a first exposure and, after a first interval, resetting the second row subset to begin a second exposure;

(ii) reading the second row subset to end the second exposure and obtain the second exposure value and, after a second interval, reading the first row subset to end the first exposure and obtain the first exposure value,

 

wherein the durations of the first interval and second interval are equal to within 20% of the duration of the first exposure; and

(c) combining the image data obtained from the first and second row subset exposures to form a row of pixel values.

11. A method for image capture comprising:

(a) providing an image sensor having

(i) a first row of pixels having at least first and second disjoint, independently addressable row subsets of pixels;

(ii) a second row of pixels adjacent to the first row and having a third independently addressable row subset of pixels,

wherein at least the first row subset and the third row subset share the same floating diffusion and are read simultaneously as a binned group of pixels;

(b) timing the exposure of the binned first and third row subsets of pixels to be photographically centered with the exposure of the second row subset of pixels; and

(c) combining the image data obtained from the exposures of the first, second, and third row subsets of pixels.

12. The method of claim 11 wherein the second row further comprises a fourth independently addressable row subset of pixels that is disjoint with the third row subset and wherein the second and fourth row subsets are binned and read simultaneously.