Imaging system having extended useful latitude

• US 20040119104A1
• Filed: 12/20/2002
• Published: 06/24/2004
• Est. Priority Date: 12/20/2002
• Status: Active Grant

• Current Assignee: Omnivision Technologies Incorporated (Will Semiconductor Co., Ltd. Shanghai)
• Original Assignee: Eastman Kodak Company
• Inventors: Szajewski, Richard P., Irving, Lyn M.
• Granted Patent: US 7,423,679 B2
• Time in Patent Office: Days
• US Class Current: 257/291
• CPC Class Codes: H01L 27/14627 Microlenses
• CPC Class Codes: H04N 23/70 Circuitry for compensating brightness variation in the scene
• CPC Class Codes: H04N 25/00 Circuitry of solid-state image sensors [SSIS]; Control thereof
• 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
• CPC Class Codes: H04N 3/155 Control of the image-sensor operation, e.g. image processing within the image-sensor

Abstract

The invention provides an image sensor that has an array of photosensors and an array of micro-lenses with each micro-lens confronting more than one of the photosensors and concentrating light striking each micro-lens onto less than all of the confronted photosensors so that selected photosensors receive a greater exposure than other photosensors.

Claims

1. An image sensor comprising an array of photosensors and an array of micro-lenses with each micro-lens confronting more than one of the photosensors and concentrating light striking each micro-lens onto less than all of the confronted photosensors, so that selected photosensors receive a greater exposure than other photosensors.

2. The image sensing system of claim 1, wherein each micro-lens confronts at least two photosensors.

3. The image sensor of claim 1, wherein the concentration of light by the micro-lenses enables an exposure increase of at least 0.15 log E.

4. The image sensor of claim 1, wherein the concentration of light by the micro-lenses enables an exposure increase of less than 2.0 log E at the selected photosensors.

5. The image sensor of claim 1, wherein the micro-lenses enable a latitude increase of at least 0.15 log E.

6. The image sensor of claim 1, wherein the micro-lenses enable a latitude increase of less than 3.0 log E.

7. The image sensor of claim 1, wherein the micro-lenses confront at least 50 percent of the photosensors.

8. An image capture system comprising:

an image sensor comprising an array of photosensors and an array of micro-lenses with each micro-lens confronting more than one of the photosensors and concentrating light striking each micro-lens onto less than all of the confronted photosensors, so that selected photosensors receive a greater exposure than other photosensors;

a taking lens unit for focusing light from a scene onto the image sensing system;

an exposure control system controllably permitting the photosensors to receive light for a period of time; and

a processor extracting image information from the photosensors and forming an image based upon the extracted image information.

9. The image capture system of claim 8 wherein the period of time is sufficient for the other photosensors to form an image.

10. The image capture system of claim 8, wherein the processor is adapted to assemble an image using image information from the selected photosensors.

11. The image capture system of claim 8, further comprising an image processor adapted to extract image information from the image sensor and store the image information in a memory.

12. The image capture system of claim 8, wherein the processor extract image information from the selected photosensors and forms an image based upon the image information from the selected photosensors.

13. The image capture system of claim 8, wherein the processor is adapted to extract image information from other photosensors and forms an image based upon the image information from the other photosensors.

14. A method for using an array of photosensors to capture an image of a scene comprising the steps of:

focusing light from the scene at the array of photosensors;

concentrating light focused at groups of more than one of the photosensors onto less than all of the photosensors of each group, so that selected photosensors in each group receive a greater exposure than other photosensors in the group;

extracting image information from the photosensors; and

forming an image using the extracted image information.

15. The method of claim 14, wherein image information extracted from the photosensors in each group receiving concentrated light is used to form the image.

16. The method of claim 14, wherein image information is extracted from the other photosensors is used to form the image.

17. The method of claim 14, wherein image information is extracted from the photosensors receiving concentrated light and the other photosensors is used to form an image.