Method for determining color using CMOS image sensor

• US 8,383,444 B2
• Filed: 11/23/2010
• Issued: 02/26/2013
• Est. Priority Date: 12/13/2007
• Status: Active Grant

• Current Assignee: Semiconductor Manufacturing International Corporation
• Original Assignee: Semiconductor Manufacturing International Corporation
• Inventors: Zhu, Hong, Yang, Jim
• Primary Examiner(s): Smith, Zandra
• Assistant Examiner(s): DUONG, KHANH B
• Application Number:
  US12/953,410
• Publication Number:
  US 20110149085A1
• Time in Patent Office: 826 Days
• Field of Search: None
• US Class Current: 438/59
• CPC Class Codes: H01L 27/14647 Multicolour imagers having a stacked pixel-element structure, e.g. npn, npnpn or MQW elements
• CPC Class Codes: H01L 27/14689 MOS based technologies

Abstract

A method is provided for determining a color using a CMOS image sensor. The CMOS image sensor includes an n-type substrate and a p-type epitaxy layer overlying the n-type substrate. The method includes applying a first voltage on the n-type substrate and obtaining a first output, which is associated with the first voltage. The method further includes applying a second voltage on the n-type substrate and obtaining a second output, which is associated with the second voltage. The method additionally includes applying a third voltage on the n-type substrate and obtaining a third output, which is associated with the third voltage. The method also includes providing a plurality of weighting factors and determining the color based on the plurality of weighting factors, the first output, the second output, and the third output.

Claims

1. A method for determining a color using a CMOS image sensor, wherein the CMOS image sensor includes an n-type silicon substrate and a p-type epitaxy layer, the p-type epitaxy layer overlaying the n-type substrate, the method comprising:

applying a first voltage on the n-type substrate;

obtaining a first output, the first output being associated with the first voltage;

applying a second voltage on the n-type substrate;

obtaining a second output, the second output being associated with the second voltage;

applying a third voltage on the n-type substrate;

obtaining a third output, the third output being associated with the third voltage;

providing a plurality of weighting factors; and

determining the color based on the plurality of weighting factors, the first output, the second output, and the third output.

2. The method of claim 1, wherein the first output is associated with a first color.

3. The method of claim 2 wherein the first color is a blue color.

4. The method of claim 1, wherein the plurality of weighting factors includes:

a first weighting factor, the first weighting factor being associated with a blue color;

a second weighting factor, the second weighting factor being associated with a green color; and

a third weighting factor, the third weighting factor being associated with a red color.

5. The method of claim 1, wherein the color comprises:

a first component;

a second component; and

a third component.

6. The method of claim 5, wherein the determining the color comprises:

determining the first component based on the first output;

determining the second component based on the second output and the first component; and

determining the third component based on the third output, the first component, and the second component.

7. The method of claim 5, wherein:

the first component is a blue color component;

the second component is a green color component; and

the third component is a red color component.

8. The method of claim 1, wherein:

the first voltage is higher than the second voltage;

the second voltage is higher than the third voltage.

9. The method of claim 8, wherein the third voltage is zero volt.

10. The method of claim 1, wherein:

the first output is associated with a blue color;

the second output is associated with the blue color and a green color; and

the third output is associated with the blue color, the green color, and a red color.