Image capture apparatus

• US 9,479,688 B2
• Filed: 12/13/2012
• Issued: 10/25/2016
• Est. Priority Date: 12/19/2011
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Ishii, Hirokazu
• Primary Examiner(s): Velez, Roberto
• Assistant Examiner(s): COLEMAN, STEPHEN P
• Application Number:
  US13/713,857
• Publication Number:
  US 20130155271A1
• Time in Patent Office: 1,412 Days
• Field of Search: 348/222.1, 348/246, 382/274
• US Class Current: 1/1
• CPC Class Codes: H04N 25/68 applied to defects

Abstract

The present invention relates to an image capture apparatus comprising an image sensor that includes a plurality of first pixel portions and a plurality of second pixel portions whose output signals can be used to perform a correlation operation. In a case of a first photographing condition, the apparatus performs correction processing on output signals from the first pixel portions using output signals from the second pixel portions, and in a case of a second photographing condition, does not perform correction processing on output signals from the first pixel portions using output signals from the second pixel portions. The apparatus also performs image processing on a signal resulting from the correction processing or a signal that was not subjected to the correction processing, and records a signal resulting from the image processing.

Claims

1. An image capture apparatus comprising:

an image sensor that includes a plurality of first pixel portions and a plurality of second pixel portions wherein each of the first pixel portions and the second pixel portions has a photoelectric conversion portion and an opening through which light is incident on the photoelectric conversion portion, and wherein the opening of the first pixel portion is larger than the opening of the second pixel portion; and

a CPU comprising a first signal processing unit that;

if a second pixel portion is determined as a first type defective pixel portion under a photographing condition, corrects an output signal from the second pixel portion and performs a correction processing on output signals from first pixel portions that are adjacent or neighboring to the second pixel portion, using the corrected output signal from the second pixel portion; and

if the second pixel portion is determined as a second type defective pixel portion under the photographing condition, does not perform the correction processing on output signals from the first pixel portions that are adjacent or neighboring to the second pixel portion.

2. The image capture apparatus according to claim 1, wherein the second type defective pixel is a blinking defective pixel.

3. The image capture apparatus according to claim 1, wherein the first type defective pixel is a stable defective pixel.

4. The image capture apparatus according to claim 1, wherein the photographing condition includes one of a charge accumulation time of the image sensor and a temperature of the image sensor or the vicinity thereof.

5. The image capture apparatus according to claim 1, wherein the second pixel portions are arranged regularly.

6. The image capture apparatus according to claim 1, wherein the correction processing performed by the first signal processing unit is a correction processing for reducing a difference that occurs due to a structural difference between the first pixel portions and the second pixel portions.

7. The image capture apparatus according to claim 1, further comprising aluminum wiring that shields the second pixel portions from light.

8. The image capture apparatus according to claim 1, wherein the correction processing performed by the first signal processing unit is a processing for correcting a crosstalk amount difference between the first pixel portions and the second pixel portions.

9. The image capture apparatus according to claim 1, the CPU further comprising a second signal processing unit that performs image processing on a signal on which the correction processing was applied by the first signal processing unit or a signal on which the correction processing was not applied by the first signal processing unit, and records a signal resulting from the image processing.

10. The image capture apparatus according to claim 1, wherein the first signal processing unit corrects an output signal from a first pixel portions that is adjacent or neighboring to a second pixel portion and was not subjected to the correction processing, using output signals from other first pixel portions.

11. The image capture apparatus according to claim 1, wherein output signals of a plurality of the second pixel portions are used to perform a correlation processing.

12. The image capture apparatus according to claim 1, the CPU further comprising a determination unit that determines whether or not each of the second pixel portions is a defective pixel based on its output signal, determines a defective pixel type with respect to each of second pixel portions that is determined as the defective pixel, and records information indicating determination results in a memory.

13. The image capture apparatus according to claim 12, wherein each of the second pixel portions is determined whether the first type defective pixel or the second type defective pixel based on the photographic condition the information recorded in the memory.

14. The image capture apparatus according to claim 13, wherein the determination unit further determines a defect level with respect to each of the second pixel portions that was determined as a defective pixel, and wherein the second pixel portions having the defective level within a range based on the photographic condition are determined as the first type defective pixel or the second type defective pixel included in is determined as whether or not.

15. The image capture apparatus according to claim 14,

wherein different ranges of the defect levels are used for determining the first type defective pixels and the second type defective pixel, and

wherein the range of the defect levels used for determining the first type defective pixel portion is more sensitive in a charge accumulation time of the image sensor than that used for determining the second type defective pixel portion.

16. The image capture apparatus according to claim 14,

wherein different ranges of the defect levels are used for determining the first type defective pixels and the second type defective pixel, and

wherein the range of the defect levels used for determining the first type defective pixel portion is more sensitive in a temperature of the image sensor or the vicinity thereof than that used for determining the second type defective pixel portion.