Color filter pattern

• US 6,714,243 B1
• Filed: 03/22/1999
• Issued: 03/30/2004
• Est. Priority Date: 03/22/1999
• Status: Expired due to Term

• Current Assignee: Biomorphic Vlsi, Inc.
• Original Assignee: Biomorphic Vlsi, Inc.
• Inventors: Mathur, Bimal P., Wang, H. Taichi
• Primary Examiner(s): Garber, Wendy R.
• Assistant Examiner(s): Tillery, Rashawn N
• Application Number:
  US09/274,413
• Time in Patent Office: 1,835 Days
• Field of Search: 348/272, 348/273, 348/274, 348/276, 348/277, 348/279, 348/280, 348/281, 348/282, 348/283, 348/308, 757/440
• US Class Current: 348/273
• CPC Class Codes: H01L 27/14645 Colour imagers
• 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

Abstract

A semiconductor imaging sensor utilizes a color filter pattern. The imaging sensor includes light sensitive-elements, each of which is sensitive to photon energy in a spectral region or color band associated with the light-sensitive elements. Select light-sensitive elements in the array are sensitive to energy in a wide band spectral region or “white” color band. This permits the capture of color information which can be lost with the use of typical semiconductor imaging sensors in digital photography. This capture of the additional color information in digital photography allows for better quality of reproduction of an image on a selected medium such as color prints.

Claims

1. An imaging array comprising:

a first set of light-sensitive elements, each of the first set of light-sensitive elements having a sensitivity to energy in one of a plurality of spectral regions which are substantially distinct from one another;

a second set of light-sensitive elements having a sensitivity to energy in a spectral region which includes substantially all of the spectral regions of the first set of light-sensitive elements, wherein the second set of light-sensitive elements are distributed among the first set of light-sensitive elements substantially uniformly throughout the array;

at least one signal generating unit for generating signals representative of a quantity of energy collected over a exposure period at each of the light-sensitive elements; and

at least one gain adjusting unit for scaling the signals representative of the quantity of the energy collected at the second set of light-sensitive elements based upon a photo absorbtance profile associated with the second set of light-sensitive elements in comparison with a photo absorbtance profile associated with a light-sensitive element of at least one of the spectral regions corresponding to one of the first set of light-sensitive elements.

2. The imaging array of claim 1, wherein the second set of light-sensitive elements have a sensitivity to energy in a substantially white spectral region and each of the first set of light-sensitive elements are sensitive to energy in one of red, blue and green spectral regions.

3. The imaging array of claim 1, wherein the second set of light-sensitive elements have a sensitivity to energy in a substantially white spectral region and each of the first set of light-sensitive elements are sensitive to energy in one of cyan, magenta and yellow spectral regions.

4. The imaging array of claim 1, wherein the first and second sets of light-sensitive elements include photodiodes which are formed in a semiconductor substrate as part of a CMOS device.

5. The imaging array of claim 4, wherein the photodiodes of the light-sensitive elements are formed at exposure regions corresponding to light-sensitive elements, wherein the first set of light-sensitive elements includes transmissive filters deposited over the exposure regions corresponding to the first set of light-sensitive elements, and wherein there is an absence of any transmissive filter deposited over the exposure regions corresponding to the second set of light-sensitive elements.

6. A method of manufacturing an imaging array, the method comprising:

forming a plurality of photodiodes in a semiconductor substrate, each photodiode corresponding to an exposure region on the semiconductor substrate;

depositing a transmissive filter over each of a first set of exposure regions corresponding to a first set of light-sensitive elements;

maintaining an absence of a transmissive filter over each of a second set of exposure regions corresponding to a second set of light-sensitive elements;

forming at least one signal generating unit for generating signals representative of a quantity of energy collected over a exposure period at each of the light-sensitive elements; and

forming at least one gain adjusting unit for scaling the signals representative of the quantity of the energy collected at the second set of light-sensitive elements based upon a photo absorbtance profile associated with the second set of light-sensitive elements in comparison with a photo absorbtance profile associated with a light-sensitive element of at least one of the spectral regions corresponding to one of the first set of light-sensitive elements.

7. The method of claim 6, the method further including distributing the second set of light-sensitive elements substantially uniformly among the first set of light-sensitive elements.

8. The method of claim 6, wherein the step of depositing a transmissive filter over each of a the first set of exposure regions further includes depositing the transmissive filters to form light-sensitive elements responsive to photon energy in a plurality of spectral regions selected from cyan, magenta and yellow spectral regions,

wherein the absence of a transmissive filter over the second set of exposure regions forms light sensitive elements responsive to photon energy in a wideband spectral region.

9. The method of claim 6, wherein the step of depositing a transmissive filter over each of a the first set of exposure regions further includes depositing the transmissive filters to form light-sensitive elements responsive to photon energy in a plurality of spectral regions selected from red, blue and green spectral regions,

wherein the absence of a transmissive filter over the second set of exposure regions forms light sensitive elements responsive to photon energy in a wideband spectral region.

10. An imaging array comprising:

a substrate including a plurality of light-sensitive elements, each of the light sensitive elements including energy collection circuitry formed in the substrate for collecting photon energy incident on an exposure surface of the substrate, the exposure surface having an absorptance to photon energy in a wideband spectral region;

a plurality of transmissive light filters formed over the exposure surface on areas corresponding to a first group of the light-sensitive elements, each of the selected ones of the light-sensitive elements in a first group having a corresponding transmissive light filter formed thereon for substantially blocking photon energy of wavelengths which are not in a spectral region defined by the corresponding transmissive light filter and permitting the energy collection circuitry to collect photon energy having a wavelength within the spectral region defined by the corresponding transmissive light filter, wherein there is an absence of any transmissive light filters formed over the exposure surface on areas corresponding to a remaining second group of the light-sensitive elements to enable the energy collection circuitry of each of the remaining second group of light-sensitive elements to collect photon energy incident on the exposure surface of the substrate having a wavelength in the wideband spectral region;

at least one signal generating unit for generating signals representative of a quantity of photon energy collected over a exposure period at each of the light-sensitive elements; and

at least one gain adjusting unit for scaling the signals representative of the quantity of the photon energy collected at the second set of light-sensitive elements based upon a photo absorbtance profile associated with the second set of light-sensitive elements in comparison with a photo absorbtance profile associated with a light-sensitive element of at least one of the spectral regions corresponding to one of the first set of light-sensitive elements.

11. The imaging array of claim 10, wherein each of the transmissive light filters permit the collection of energy having a wavelength within a spectral region corresponding to one of red light, blue light and green light.

12. The imaging array of claim 10, wherein each of the transmissive light filters permit the collection of energy having a wavelength within a spectral region corresponding to one of cyan light, magenta light and yellow light.

13. The imaging array of claim 10, wherein the energy collection circuitry for each of the light-sensitive elements in the first group collects photon energy having a wavelength within a spectral region corresponding to one of red light, green light and blue light, and the energy collection circuitry of the remaining light-sensitive elements in the second group collects photon energy having a wavelength within a spectral region including at least a union of the spectral regions corresponding to red light, green light and blue light.

14. The imaging array of claim 10, wherein the energy collection circuitry for each of the light-sensitive elements in the first group collects photon energy having a wavelength within a spectral region corresponding to one of cyan light, magenta light and yellow light, and the energy collection circuitry of the remaining light-sensitive elements in the second group collects photon energy having a wavelength within a spectral region including at least a union of the spectral regions corresponding to cyan light, magenta light and yellow light.

15. The imaging array of claim 10, wherein the energy collection circuitry for each of the light-sensitive elements includes a photodiode formed on the substrate.

16. A method of capturing a photographic image of an object formed onto an imaging array, the object reflecting photon energy, the method comprising:

exposing the imaging array to the photon energy reflected from the object for an exposure period;

collecting the photon energy over the exposure period at a first set of light-sensitive elements formed onto the imaging array, each of the first set of light sensitive elements collecting photon energy having wavelengths within a spectral region corresponding to a selected one of red light, blue light and green light; and

collecting the photon energy over the exposure period at a second set of light-sensitive elements formed onto the imaging array, each of the second set of light-sensitive elements collecting photon energy having wavelengths within a wideband spectral region including at least a union of the spectral regions corresponding to red light, blue light and green light;

generating signals representative of a quantity of the photon energy collected over the exposure period at each of the light-sensitive elements; and

scaling the signals representative of the quantity of the photon energy collected at the second set of light-sensitive elements based upon a photo absorbtance profile associated with the second set of light-sensitive elements in comparison with a photo absorbtance profile associated with a light-sensitive element of at least one of the spectral regions corresponding to red light, blue light and green light.

17. The method of claim 16, the method further comprising:

forming data representative of three sub-images based upon the signal representative of the quantity of the photon energy collected over the exposure period at each of the first set of light sensitive elements, the data representative of each of the three sub-images having values representative of an intensity of exposure at a location in the sub-image; and

forming data representative of a fourth sub-image based upon the scaled signals representative of the quantity of the photon energy collected at the second set of light-sensitive elements, the data representative of the fourth sub-image having values representative of an intensity of exposure at a location in the fourth sub-image.

18. A method of capturing a photographic image of an object formed onto an imaging array, the object reflecting photon energy, the method comprising:

exposing the imaging array to the photon energy reflected from the object for an exposure period;

collecting the photon energy over the exposure period at a first set of light-sensitive elements formed onto the imaging array, each of the first set of light sensitive elements collecting photon energy having wavelengths within a spectral region corresponding to a selected one of cyan light, magenta light and yellow light;

collecting the photon energy over the exposure period at a second set of light-sensitive elements formed onto the imaging array, each of the second set of light-sensitive elements collecting photon energy having wavelengths within a wideband spectral region including at least a union of the spectral regions corresponding to cyan light, magenta light and yellows light; and

generating signals representative of a quantity of the photon energy collected over the exposure period at each of the light-sensitive elements; and

scaling the signals representative of the quantity of the photon energy collected at the second set of light-sensitive elements based upon a photo absorbtance profile associated with the second set of light-sensitive elements in comparison with a photo absorbtance profile associated with a light-sensitive element of at least one of the spectral regions corresponding to cyan light, magenta light and yellow light.

19. The method of claim 18, the method further comprising:

forming data representative of three sub-images based upon the signal representative of the quantity of the photon energy collected over the exposure period at each of the first set of light sensitive elements, the data representative of each of the three sub-images having values representative of an intensity of exposure at a location in the sub-image; and

forming data representative of a fourth sub-image based upon the scaled signals representative of the quantity of the photon energy collected at the second set of light-sensitive elements, the data representative of the fourth sub-image having values representative of an intensity of exposure at a location in the fourth sub-image.

20. A method of capturing a photographic image of an object formed onto an imaging array, the object reflecting photon energy, the method comprising:

exposing the imaging array to the photon energy reflected from the object for an exposure period;

collecting the photon energy over the exposure period at a first set of light-sensitive elements formed onto the imaging array, each of the first set of light sensitive elements collecting photon energy having wavelengths within a spectral region corresponding to a selected one of red light, blue light and green light;

collecting the photon energy over the exposure period at a second set of light-sensitive elements formed onto the imaging array, each of the second set of light-sensitive elements collecting photon energy having wavelengths within a wideband spectral region including at least a union of the spectral regions corresponding to red light, blue light and green light, wherein a plurality of 2×

2 basic units is formed from three light-sensitive elements from the first set of light-sensitive elements and one light-sensitive element from the second set of light-sensitive elements;

generating signals representative of a quantity of the photon energy collected over the exposure period at each of the light-sensitive elements; and

scaling the signals representative of the quantity of the photon energy collected at the second set of light-sensitive elements based upon a photo absorbtance profie associated with the second set of light-sensitive elements in comparison with a photo absorbtance profile associated with a light-sensitive element of at least one of the spectral regions corresponding to red light, blue light and green light.

21. A method of capturing a photographic image of an object formed onto an imaging array, the object reflecting photon energy, the method comprising:

exposing the imaging array to the photon energy reflected from the object for an exposure period;

collecting the photon energy over the exposure period at a first set of light-sensitive elements formed onto the imaging array, each of the first set of light sensitive elements collecting photon energy having wavelengths within a spectral region corresponding to a selected one of red light, blue light and green light;

collecting the photon energy over the exposure period at a second set of light-sensitive elements formed onto the imaging array, each of the second set of light-sensitive elements collecting photon energy having wavelengths within a wideband spectral region including at least a union of the spectral regions corresponding to red light, blue light and green light, wherein a plurality of 2×

2 basic units is formed from three light-sensitive elements from the first set of light-sensitive elements and one light-sensitive element from the second set of light-sensitive elements;

forming data representative of three sub-images based upon the signal representative of the quantity of the photon energy collected over the exposure period at each of the first set of light sensitive elements, the data representative of each of the three sub-images having values representative of an intensity of exposure at a location in the sub-image; and

forming data representative of a fourth sub-image based upon the scaled signals representative of the quantity of the photon energy collected at the second set of light-sensitive elements, the data representative of the fourth sub-image having values representative of an intensity of exposure at a location in the fourth sub-image.

22. A method of capturing a photographic image of an object formed onto an imaging array, the object reflecting photon energy, the method comprising:

exposing the imaging array to the photon energy reflected from the object for an exposure period;

collecting the photon energy over the exposure period at a first set of light-sensitive elements formed onto the imaging array, each of the first set of light sensitive elements collecting photon energy having wavelengths within a spectral region corresponding to a selected one of cyan light, magenta light and yellow light;

collecting the photon energy over the exposure period at a second set of light-sensitive elements formed onto the imaging array, each of the second set of light-sensitive elements collecting photon energy having wavelengths within a wideband spectral region including at least a union of the spectral regions corresponding to cyan light, magenta light and yellows light, wherein a plurality of 2×

2 basic units is formed from three light-sensitive elements from the first set of light-sensitive elements and one light-sensitive element from the second set of light-sensitive elements;

generating signals representative of a quantity of the photon energy collected over the exposure period at each of the light-sensitive elements; and

scaling the signals representative of the quantity of the photon energy collected at the second set of light-sensitive elements based upon a photo absorbtance profie associated with the second set of light-sensitive elements in comparison with a photo absorbtance profile associated with a light-sensitive element of at least one of the spectral regions corresponding to cyan light, magenta light and yellow light.

23. The method of claim 22, the method further comprising:

forming data representative of three sub-images based upon the signal representative of the quantity of the photon energy collected over the exposure period at each of the first set of light sensitive elements, the data representative of each of the three sub-images having values representative of an intensity of exposure at a location in the sub-image; and

forming data representative of a fourth sub-image based upon the scaled signals representative of the quantity of the photon energy collected at the second set of light-sensitive elements, the data representative of the fourth sub-image having values representative of an intensity of exposure at a location in the fourth sub-image.