MULTIPLE COMPONENT READOUT OF IMAGE SENSOR

• US 20090021612A1
• Filed: 07/20/2007
• Published: 01/22/2009
• Est. Priority Date: 07/20/2007
• Status: Active Grant

• Current Assignee: Omnivision Technologies Incorporated (Will Semiconductor Co., Ltd. Shanghai)
• Original Assignee: Omnivision Technologies Incorporated (Will Semiconductor Co., Ltd. Shanghai)
• Inventors: Compton, John T., Hamilton, John F. JR.
• Granted Patent: US 7,855,740 B2
• Time in Patent Office: Days
• US Class Current: 348/249
• 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 25/447 by preserving the colour pattern with or without loss of information
• CPC Class Codes: H04N 25/531 by controlling rolling shutters in CMOS SSIS
• CPC Class Codes: H04N 25/533 by using differing integration times for different sensor regions
• CPC Class Codes: H04N 25/534 depending on the spectral component
• CPC Class Codes: H04N 25/583 with different integration times
• CPC Class Codes: H04N 25/585 with pixels having different sensitivities within the sensor, e.g. fast or slow pixels or pixels having different sizes

Abstract

A method for obtaining image data from an image sensor array including the steps of: providing an image sensor array having a first component subset of panchromatic pixels for integrating charge and a second component subset of color pixels for integrating charge; reading pixel charge to produce pixel signals from the first component subset of the panchromatic pixels while exposing the second component subset of color pixels and digitizing and storing the first component subset signals; and reading pixel charge to produce pixel signals from the second component subset of color pixels that were exposed for at least a portion of time during the reading of pixel signals from the first component subset of the panchromatic pixels and digitizing and storing the second component subset signals.

Claims

1. A method for obtaining image data from an image sensor array comprising the steps of:

a) providing an image sensor array having a first component subset of panchromatic pixels for integrating charge and a second component subset of color pixels for integrating charge;

b) reading pixel charge to produce pixel signals from the first component subset of the panchromatic pixels while exposing the second component subset of color pixels and digitizing and storing the first component subset signals; and

c) reading pixel charge to produce pixel signals from the second component subset of color pixels that were exposed for at least a portion of time during the reading of pixel signals from the first component subset of the panchromatic pixels and digitizing and storing the second component subset signals.

2. The method of claim 1 wherein the first component subset is completely read out prior to reading out the second component subset.

3. The method of claim 1 wherein there is at least one additional component subset of either panchromatic pixels or color pixels.

4. The method of claim 1 wherein a plurality of images of a scene is captured by the image sensor and, while a component subset of pixels is read out, the remaining component subsets of pixels are integrating charge.

5. The method of claim 1 wherein the image sensor array has panchromatic P, a first color R, a second color G, and a third color B pixels, and wherein the pixels are arranged with the following minimal repeating unit:

6. The method of claim 1 wherein the reading of pixel charge in both steps b) and c) includes simultaneously delivering and storing charge in separate floating diffusions for each pixel from a given component subset of pixels and serially reading out the corresponding pixel signals from the floating diffusions to produce the first and second component subset signals, respectively.

7. The method of claim 1 wherein the reading of pixel charge in both steps b) and c) includes simultaneously delivering and storing charge in separate charge-coupled devices for each pixel from a given component subset of pixels and serially reading out the corresponding pixel signals from the charge-coupled devices to produce the first and second component subset signals, respectively.

8. The method of claim 1 wherein reading out pixel charge in steps b) and c) is accomplished using an electronic rolling shutter sequence.

9. The method of claim 1 wherein the first component subset of pixels is exposed to light from the scene for a different length of time than the second component subset of pixels.

10. The method of claim 1 wherein the first component subset of pixels is exposed to light from the scene for a different length of time than the second component subset of pixels such that the first component subset of pixels is read out more frequently than the second component subset.

11. A method for obtaining image data from an image sensor array comprising the steps of:

a) providing an image sensor array and selectively organizing the image pixels into a first organization of a first component subset of panchromatic pixels for integrating charge and a second component subset of color pixels for integrating charge and a second organization with a different first component subset of panchromatic pixels and a different second component subset of color pixels;

b) reading pixel charge to produce pixel signals from the first component subset of the panchromatic pixels while exposing the second component subset of color pixels and digitizing and storing the first component subset signals;

c) reading pixel charge to produce pixel signals from the second component subset of color pixels that were exposed for at least a portion of time during the reading of pixel signals from the first component subset of the panchromatic pixels and digitizing and storing the second component subset signals; and

d) changing the organization of the image pixels in response to photographic conditions.

12. The method of claim 11 wherein photographic conditions include one or more of the following:

light level, degree of motion, and focus setting.

13. The method of claim 11 wherein the relative timing of steps b) and c) is changed in accordance with photographic conditions.