Method and apparatus for distributing light onto electronic image sensors

• US 7,176,446 B1
• Filed: 10/24/2002
• Issued: 02/13/2007
• Est. Priority Date: 09/15/1999
• Status: Expired due to Term

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Zoran Corporation (Qualcomm, Inc.)
• Inventors: Wiedemann, Rudolf A.
• Primary Examiner(s): Luu; Thanh X.
• Application Number:
  US10/281,388
• Time in Patent Office: 1,573 Days
• Field of Search: 250/226, 250/208.1, 250/208.2, 250/216, 356/402, 348/259, 348/272, 348/273, 348/280, 348/281, 348289-291, 348336-339
• US Class Current: 250/226
• CPC Class Codes: G01J 3/02 Details
• CPC Class Codes: G01J 3/0205 Optical elements not provided otherwise, e.g. optical manifolds, diffusers, windows
• CPC Class Codes: G01J 3/0256 Compact construction
• CPC Class Codes: G01J 3/14 using refracting elements, e.g. prisms G01J3/18, G01J3/26 take precedence prisms per se G02B5/04
• CPC Class Codes: G01J 3/50 using electric radiation detectors
• CPC Class Codes: G01J 3/502 using a dispersive element, e.g. grating, prism
• CPC Class Codes: G01J 3/51 using colour filters
• CPC Class Codes: H04N 2209/042 having a single pick-up sensor
• CPC Class Codes: H04N 25/134 based on three different wavelength filter elements

Abstract

An apparatus that directs light onto individual photodetectors in an electronic image sensor array is disclosed. In one embodiment, refractive elements are used to appropriately refract different colors of light onto matching photodetector elements for different colors. In this manner, the image sensing apparatus most efficiently directs the proper colors of light on to the proper photodetector elements.

Claims

1. A method of constructing an electronic image sensor device, said method comprising:

forming an electronic image sensor array sensitive to at least three distinct wavelengths, comprising a plurality of individual image sensors, each made sensitive to substantially only one of the three distinct wavelengths, the plurality of individual image sensors arranged in a plurality of parallel lines defining an imaging plane; and

mounting a pattern of refractive elements in front of said electronic image sensor array, the pattern of refractive elements configured such that light of each one of the three distinct wavelengths is refracted in a direction oblique in the imaging plane relative to the parallel lines and is concentrated onto the individual image sensors sensitive to the one of the three distinct wavelengths;

wherein said act of mounting the pattern of refractive elements in front of said electronic image sensor array further comprises configuring the pattern of refractive elements to refract light at a first wavelength in a first direction oblique in the imaging plane relative to the parallel lines and to refract light at a second wavelength in a second direction oblique in the imaging plane relative to the parallel lines onto the individual image sensors sensitive to the second wavelength; and

wherein said act of refracting light in the first direction and in the second direction comprises refracting the light in the first direction substantially 180 degrees from said second direction.

2. The method as claimed in claim 1 wherein said act of mounting the pattern of refractive elements in front of said electronic image sensor array further comprises configuring the pattern of refractive elements to refract light in a third direction and a fourth direction oblique in the imaging plane relative to the parallel lines.

3. The method as claimed in claim 2 wherein said first, second, third and fourth directions are substantially 90 degrees apart.

4. A method of constructing an electronic image sensor device, said method comprising:

forming an electronic image sensor array sensitive to at least three distinct wavelengths, comprising a plurality of individual image sensors, each made sensitive to substantially only one of the three distinct wavelengths, the plurality of individual image sensors arranged in a plurality of parallel lines defining an imaging plane; and

mounting a pattern of refractive elements in front of said electronic image sensor array, the pattern of refractive elements configured such that light of each one of the three distinct wavelengths is refracted in a direction oblique in the imaging plane relative to the parallel lines and is concentrated onto the individual image sensors sensitive to the one of the three distinct wavelengths;

wherein the plurality of individual image sensors is arranged in a Bayer pattern.

5. An electronic image sensor apparatus, said apparatus comprising:

an electronic image sensor array sensitive to at least three distinct wavelengths, comprising a plurality of individual image sensors, each made sensitive to substantially only one of the three distinct wavelengths, the plurality of individual image sensors arranged in a plurality of parallel lines defining an imaging plane; and

a pattern of refractive elements mounted in front of said electronic image sensor array the pattern of refractive elements configured such that light of each one of the three distinct wavelengths is refracted in a direction oblique in the imaging plane relative to the parallel lines and is concentrated onto the individual image sensors sensitive to the one of the three distinct wavelengths;

wherein said pattern of refractive elements in front of said electronic image sensor array is further configured to refract light at different ones of the three distinct wavelengths in different directions oblique in the image plane relative to the parallel lines; and

wherein said first direction is substantially 180 degrees from said second direction.

6. The electronic image sensor apparatus as claimed in claim 5 wherein said pattern of refractive elements in front of said electronic image sensor array is further configured to refract light in a third direction and a fourth diagonal direction oblique in the image plane relative to the parallel lines.

7. The electronic image sensor apparatus as claimed in claim 6, wherein said first, second, third and fourth directions are substantially 90 degrees apart.

8. An electronic image sensor apparatus, said apparatus comprising:

an electronic image sensor array sensitive to at least three distinct wavelengths, comprising a plurality of individual image sensors, each made sensitive to substantially only one of the three distinct wavelengths, the plurality of individual image sensors arranged in a plurality of parallel lines defining an imaging plane; and

a pattern of refractive elements mounted in front of said electronic image sensor array the pattern of refractive elements configured such that light of each one of the three distinct wavelengths is refracted in a direction oblique in the imaging plane relative to the parallel lines and is concentrated onto the individual image sensors sensitive to the one of the three distinct wavelengths;

wherein the plurality of electronic image sensors is arranged in a Bayer pattern.

9. An image sensor apparatus comprising:

an array of image sensor elements arranged in a plurality of parallel lines forming a Bayer pattern of image sensor elements including at least three image sensor elements, each sensitive and corresponding to one of three different wavelengths, the array defining an imaging plane; and

a refractive element mounted in front of the array of image sensor elements, the refractive element configured to refract an image-forming beam such that light of each one of the three different wavelengths is refracted in a direction in the imaging plane that is oblique relative to the parallel lines of the Bayer pattern and is concentrated onto the image sensor elements sensitive to each one of the three different wavelengths.

10. The image sensor apparatus as claimed in claim 9, further comprising:

a protective cover transparent to the image forming beam for the array of image sensors; and

wherein the refractive element is formed on the protective cover.

11. The image sensor apparatus as claimed in claim 10, wherein the protective cover further comprises an infrared blocking coating.

12. The image sensor apparatus as claimed in claim 9, wherein the array of image sensor elements comprises a charged coupled device (CCD).

13. The image sensor apparatus as claimed in claim 9, wherein the array of image sensor elements comprises a CMOS image sensor array.

14. The image sensor apparatus as claimed in claim 9, wherein the refractive element is further configured to refract light at different ones of the three different wavelengths in different directions oblique in the imaging plane relative to the parallel lines.

15. The image sensor apparatus as claimed in claim 14, wherein the different directions include two directions substantially 180 degrees apart.

16. The image sensor apparatus as claimed in claim 14, wherein the different directions include four directions.

17. The image sensor apparatus as claimed in claim 16, wherein said four directions are substantially 90 degrees apart.

18. A method of constructing an electronic image sensor device, said method comprising:

forming an electronic image sensor array comprising at least three individual image sensors, each sensitive to one of three different wavelengths and arranged in a Bayer pattern on an imaging plane; and

mounting a pattern of refractive elements in front of said electronic image sensor array of individual image sensors arranged in a Bayer pattern, the pattern of refractive elements configured such that each of the three different wavelengths of light is refracted in a diagonal direction in the imaging plane relative to the Bayer pattern array of individual image sensors in a pattern concentrating the each of the three different wavelengths of light on correspondingly sensitive ones of the at least three individual image sensors.

19. The method as claimed in claim 18 wherein the act of mounting a pattern of refractive elements in front of said electronic image sensor array comprises:

forming said pattern of refractive elements on a cover transparent at the three different wavelengths; and

mounting said cover in front of said electronic image sensor array.

20. The method as claimed in claim 19 wherein the act of mounting the cover further comprises providing an infrared blocking coating.

21. The method as claimed in claim 18 wherein the act of mounting said electronic image sensor array comprises providing a charge coupled device (CCD).

22. The method as claimed in claim 18 wherein the act of mounting said electronic image sensor array comprises providing a CMOS image sensor.

23. The method as claimed in claim 18 wherein said act of mounting the pattern of refractive elements in front of said electronic image sensor array further comprises configuring the pattern of refractive elements to refract light at two of the three different wavelengths in different directions in the imaging plane relative to the Bayer pattern array of individual image sensors, onto correspondingly sensitive individual image sensors.

24. The method as claimed in claim 23 wherein said act of refracting light in different directions comprises refracting the light in directions substantially 180 degrees apart.

25. The method as claimed in claim 23 wherein said act of mounting the pattern of refractive elements in front of said electronic image sensor array further comprises configuring the pattern of refractive elements to refract light in four different directions in the imaging plane.

26. The method as claimed in claim 25 wherein said four different directions are substantially 90 degrees apart.