METHODS OF MANUFACTURING A CAMERA SYSTEM HAVING MULTIPLE IMAGE SENSORS
A method of manufacturing an image sensor from two defective image sensor arrays having identical structural design, each having substantially the same field of view and aligned to view substantially the same scene. The method includes providing a first defective image sensor array, having known defective pixels, providing a second defective image sensor array, having known defective pixels, and fusing the first image sensor array and the second image sensor array into a single output image array.
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The present application claims the benefit of U.S. provisional application 61/167,226 filed on Apr. 7, 2009, the disclosure of which is incorporated herein by reference.
FIELD OF THE INVENTIONThe present invention relates to imaging systems, and more particularly, the present invention relates to a method of manufacturing an imaging system from two or more image sensors having defective pixels.
BACKGROUND OF THE INVENTION AND PRIOR ARTIn the production of image sensors, often, one or more pixels of the produced image sensor are defective. The image sensor arrays are scanned and all detected defective pixels are sorted out, mapped and marked. In some types of image sensors such a defective image sensor is rejected. In other types of image sensors such a defective image sensor is computed from the adjacently surrounding pixels, for example, from the 4 or 8 adjacently surrounding pixels.
For Example, the yield of infra red (IR) image sensors is very low—about 0.1-5%, due to defective pixels. Therefore, there is a need for and it would be advantageous to have a method to substantially raise the production yield of image sensors, such as infra red image sensors.
SUMMARY OF THE INVENTIONAccording to teachings of the present invention, there is provided a method of manufacturing an image sensor from two defective image sensor arrays having identical structural design, each having substantially the same field of view (FOV) and aligned to view substantially the same scene. The method includes providing a first defective image sensor array, having known defective pixels, providing a second defective image sensor array, having known defective pixels, and fusing the first image sensor array and the second image sensor array into a single output image array.
For each of the defective pixels of the first image sensor array the respective pixel from the second image sensor array is selected to be an output pixel of the output image array. For each of the defective pixels of the second image sensor array the respective pixel from the first image sensor array is selected to be an output pixel of the output image array. For each valid pixel in the first image sensor array, having a respective valid pixel in the second image sensor array, either of the respective valid pixels is selected to be an output pixel of the output image array.
Preferably, the first defective image sensor array and the second defective image sensor array have no overlapping defective pixels.
In variations of the present invention, if the first defective image sensor array and the second defective image sensor array have overlapping defective pixels, then for each of the overlapping defective pixels, setting the value of a corresponding final output pixel in the output image array to be the average of the K immediately adjacent neighboring pixels of the overlapping defective pixel, in the output image array. In some variations of the present invention, K=4. In other variations of the present invention, K=8.
According to further teachings of the present invention, there is provided a computerized image acquisition system. The system includes a first image sensor array having defective pixels, a second image sensor array having defective pixels, and an image fusion module. The first image sensor array and the second image sensor array have substantially the same FOV and are aligned to view substantially the same scene. For each of the defective pixels of the first image sensor array, the image fusion module selects the respective pixel from the second image sensor array to be an output pixel of an output image array. For each of the defective pixels of the second image sensor array, the image fusion module selects the respective pixel from the first image sensor array to be an output pixel of the output image array. For each valid pixel in the first image sensor array having a respective valid pixel in the second image sensor array, the image fusion module selects either of the respective valid pixels to be an output pixel of the output image array.
Preferably, the first defective image sensor array and the second defective image sensor array have no overlapping defective pixels.
In variations of the present invention, if the first defective image sensor array and the second defective image sensor array have overlapping defective pixels, then for each of the overlapping defective pixels, the image fusion module sets the value of a corresponding final output pixel in the output image array to be the average of the K immediately adjacent neighboring pixels of the overlapping defective pixel, in the output image array. In some variations of the present invention, K=4. In other variations of the present invention, K=8.
In variations of the present invention, if the first defective image sensor array and the second defective image sensor array have overlapping defective pixels that have partial light energy sensitivity, a weighted average of the partially defective pixels is computed. The weights are directly proportional to the partial light energy sensitivity of each of the partially defective pixels. The computed weighted average is then assigned to the corresponding output pixel.
The present invention will become fully understood from the detailed description given herein below and the accompanying drawings, which are given by way of illustration and example only and thus not limitative of the present invention, and wherein:
The present invention now will be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided, so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.
Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The methods and examples provided herein are only illustrative and not intended to be limiting.
By way of introduction, a principal intention of the present invention includes providing a method for producing an imaging system having two or more defective image sensors, yielding a single logical valid image sensor.
Reference is made to
It should be noted that the manufacturing method of the present invention, substantially increases the image sensors production, for example, the yield of IR image sensors may increase to over 90%.
Preferably, image sensor arrays 130a and 130b are selected such that there are no respective pairs of pixels, where both pixels are defective.
The methodology of image fusion module 140 may be embodied in various methods. In a first embodiment, the methodology of image fusion module 140 includes the following steps:
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- a) selecting image sensor 130a as the primary image sensor and image sensor 130b as the secondary image sensor; and
- b) for each pair of respective pixels, performs the following steps:
- i. if the pixel of the primary image sensor is valid, setting the value of the corresponding output pixel in image frame 150 to be the value of the pixel of the primary image sensor; else
- ii. setting the value of the corresponding output pixel in image frame 150 to be the value of the pixel of the secondary image sensor.
In a second embodiment, the methodology of image fusion module 140 includes the following steps:
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- a) selecting image sensor 130b as the primary image sensor and image sensor 130a as the secondary image sensor; and
- b) for each pair of respective pixels, performs the following steps:
- i. if the pixel of the primary image sensor is valid, setting the value of the corresponding output pixel in image frame 150 to be the value of the pixel of the primary image sensor; else
- ii. setting the value of the corresponding output pixel in image frame 150 to be the value of the pixel of the secondary image sensor.
Reference is made to
In a third embodiment, the methodology of image fusion modules 140a, 140b and averaging module 240 includes the following steps:
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- a) performing the fusion method as in the first embodiment, thereby creating an output image frame 150a;
- b) performing the fusion method as in the second embodiment, thereby creating an output image frame 150b; and
- c) averaging each pair of pixels from image frames 150a and 150b whereby setting the value of a corresponding final output pixel in image frame 250.
In variations of the present invention, image sensor arrays 130a and 130b are selected such that there are a limited number of respective pairs of pixels, where both pixels are defective. Reference is also made to
In other variations of the present invention, image sensor arrays 130a and 130b are selected such that there are a limited number of respective pairs of pixels, where both pixels are partially defective. The output pixel is proportionally average from the partially defective pixels. For example, pixel Pia senses 60% of the arriving energy and pixel Pib senses 75% of the arriving energy. In such a case the output pixel Piout is averaged as follow:
Piout=(Pia*60+Pib*75)/130.
Reference is also made to
The invention being thus described in terms of embodiments and examples, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the claims.
Claims
1. A method of manufacturing an image sensor from two defective image sensor arrays having identical structural design, each having substantially the same field of view (FOV) and aligned to view substantially the same scene, the method comprising the steps of: wherein for each of said defective pixels of said first image sensor array the respective pixel from said second image sensor array is selected to be an output pixel of said output image array; wherein for each of said defective pixels of said second image sensor array the respective pixel from said first image sensor array is selected to be an output pixel of said output image array; and wherein for each valid pixel in said first image sensor array having a respective valid pixel in said second image sensor array, either of said respective valid pixels is selected to be an output pixel of said output image array.
- a) providing a first defective image sensor array, having known defective pixels;
- b) providing a second defective image sensor array, having known defective pixels; and
- c) fusing said first image sensor array and said second image sensor array into a single output image array,
2. The method as in claim 1, wherein said first defective image sensor array and said second defective image sensor array have no overlapping defective pixels.
3. The method as in claim 1, wherein said first defective image sensor array and said second defective image sensor array have overlapping defective pixels, and wherein the method further comprises the step of:
- d) for each of said overlapping defective pixels, setting the value of a corresponding final output pixel in said output image array to be the average of the K immediately adjacent neighboring pixels of said overlapping defective pixel, in said output image array.
4. The method as in claim 3, wherein K=4.
5. The method as in claim 3, wherein K=8.
6. A computerized image acquisition system comprising: wherein said first image sensor array and said second image sensor array have substantially the same FOV and are aligned to view substantially the same scene; wherein for each of said defective pixels of said first image sensor array, said image fusion module selects the respective pixel from said second image sensor array to be a corresponding output pixel of an output image array; wherein for each of said defective pixels of said second image sensor array, said image fusion module selects the respective pixel from said first image sensor array to be a corresponding output pixel of said output image array; and wherein for each valid pixel in said first image sensor array having a respective valid pixel in said second image sensor array, said image fusion module averages said valid pixel in said first image and said valid pixel in said second image and assigns said average to a corresponding output pixel of said output image array.
- a) a first image sensor array having defective pixels;
- b) a second image sensor array having defective pixels; and
- c) an image fusion module,
7. The system as in claim 6, wherein said first defective image sensor array and said second defective image sensor array have no overlapping defective pixels.
8. The system as in claim 6, wherein said first defective image sensor array and said second defective image sensor array have overlapping defective pixels, and wherein said image fusion module, for each of said overlapping defective pixels, sets the value of a corresponding final output pixel in said output image array to be the average of the K immediately adjacent neighboring pixels of said overlapping defective pixel, in said output image array.
9. The system as in claim 8, wherein K=4.
10. The system as in claim 8, wherein K=8.
11. The system as in claim 8, wherein said defective pixels are partially defective pixels, having partial light energy sensitivity, and wherein said image fusion module computes a weighted average of said partially defective pixels, wherein said weight is directly proportional to said partial light energy sensitivity of each of said partially defective pixels; and assigns said weighted average to said output pixel.
Type: Application
Filed: Apr 6, 2010
Publication Date: May 10, 2012
Applicant: NEXTVISION STABILIZED SYSTEMS LTD (Raanana)
Inventors: Chen Golan (Ein Vered), Boris Kipnis (Tel-Aviv)
Application Number: 13/263,024
International Classification: H04N 7/18 (20060101); B23P 11/00 (20060101);