Image photographing apparatus, method and medium with stack-type image sensor, complementary color filter, and white filter

• US 8,339,489 B2
• Filed: 06/22/2007
• Issued: 12/25/2012
• Est. Priority Date: 09/19/2006
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Choe, Won-Hee, Kim, Chang-Yeong, Lee, Seong-Deok, Song, Hyun-Chul
• Primary Examiner(s): Tran, Sinh
• Assistant Examiner(s): BERARDESCA, PAUL M
• Application Number:
  US11/812,951
• Publication Number:
  US 20080068475A1
• Time in Patent Office: 2,013 Days
• Field of Search: 348/276, 348/216.1, 348/236, 348/238, 348/277, 348/294, 257/440, 250/339.05
• US Class Current: 348/276
• CPC Class Codes: G06T 3/4015 Image demosaicing, e.g. colour filter arrays [CFA] or Bayer patterns
• CPC Class Codes: H01L 27/14647 Multicolour imagers having a stacked pixel-element structure, e.g. npn, npnpn or MQW elements
• CPC Class Codes: H04N 2209/045 using mosaic colour filter
• CPC Class Codes: H04N 2209/047 using multispectral pick-up elements
• CPC Class Codes: H04N 25/131 including elements passing infrared wavelengths
• 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

An image photographing apparatus, method and medium that can enhance color reproducibility and sensitivity. The image photographing apparatus includes a filter unit having a first filter region to pass at least one band of an incident light signal corresponding to a complementary color of a first color, and a second filter region to pass all bands of the incident light signal, wherein the first filter region and the second filter region are each formed in one of two adjacent pixels, and an image sensor unit to sense an image from the incident light signal that passes through the filter unit, the image sensor unit including a plurality of photoelectric conversion layers each having a different spectral sensitivity.

Claims

1. An image photographing apparatus comprising:

a filter unit comprising;

a first filter region comprising;

a first sub-filter region which passes a first wavelength band of an incident light signal corresponding to a complementary color of a first color; and

a second sub-filter region which passes a second wavelength band of the incident light signal corresponding to a complementary color of a second color;

a second filter region which passes all wavelength bands of the incident light signal; and

a third filter region including a white filter which blocks an infrared wavelength band of the incident light signal; and

an image sensor unit to sense an image from the light signal that passes through the filter unit,

wherein each of the first sub-filter region and the second sub-filter region is formed of any one of a cyan filter, a magenta filter, and a yellow filter with a filter of the first sub-filter region being different than a filter of the second sub-filter region, and

wherein the first sub-filter region and the second sub-filter region are formed adjacent to each other in a first row and the second filter region and the third filter region are formed adjacent to each other in a second row that is consecutive to the first row.

2. The apparatus of claim 1, wherein the second filter region is formed of a white filter.

3. The apparatus of claim 1, wherein the image sensor comprises photoelectric conversion layers each having a different spectral sensitivity and the photoelectric conversion layers are formed at a location corresponding to the first filter region.

4. The apparatus of claim 3, wherein the photoelectric conversion layers comprise:

a first photoelectric conversion layer passing a first color component of a light signal that passes through the first filter region; and

a second photoelectric conversion layer longitudinally overlapping the first photoelectric conversion layer and passing a second color component of the light signal that passes through the first filter region,

wherein the first photoelectric conversion layer is located closer to a surface of a substrate than the second photoelectric conversion layer.

5. The apparatus of claim 4, wherein the first photoelectric conversion layer generates electric charges according to the first color component, and the second photoelectric conversion layer generates electric charges according to the second color component.

6. The apparatus of claim 4, wherein the first photoelectric conversion layer has a p-n junction located at a first depth from the surface of the substrate, and the second photoelectric conversion layer has a p-n junction located at a second depth from the surface of the substrate.

7. The apparatus of claim 4, wherein the image sensor unit calculates a color difference signal based on a luminance signal sensed from a light signal that passes through the third filter region, a signal sensed from the first photoelectric conversion layer, and a signal sensed from the second photoelectric conversion layer.

8. A method of operating an image photographing apparatus, the method comprising:

filtering an incident light signal using a first filter region comprising a first sub-filter region which passes a first wavelength band of the incident light signal corresponding to a complementary color of a first color, a second sub-filter region which passes a second wavelength band of the incident light signal corresponding to a complementary color of a second color, a second filter region which passes all wavelength bands of the incident light signal, and a third filter region including a white filter which blocks an infrared wavelength band of the incident light signal;

receiving the filtered light signal through a plurality of photoelectric conversion layers having different spectral sensitivity; and

sensing an image from the received light signal,

wherein each of the first sub-filter region and the second sub-filter region is formed of any one of a cyan filter, a magenta filter, and a yellow filter, and

wherein the first sub-filter region and the second sub-filter region are formed adjacent to each other in a first row and the second filter region and the third filter region are formed adjacent to each other in a second row that is consecutive to the first row.

9. The method of claim 8, wherein the second filter region is formed of a white filter.

10. The method of claim 8, wherein the photoelectric conversion layers are formed at a location corresponding to the first filter region.

11. The method of claim 8, wherein the photoelectric conversion layers comprise:

a first photoelectric conversion layer passing a first color component of a light signal that passes through the first filter region; and

a second photoelectric conversion layer longitudinally overlapping the first photoelectric conversion layer and passing a second color component of the light signal that passes through the first filter region,

wherein the first photoelectric conversion layer is located closer to a surface of a substrate than the second photoelectric conversion layer.

12. The method of claim 11, wherein the first photoelectric conversion layer generates electric charges according to the first color component, and the second photoelectric conversion layer generates electric charges according to the second color component.

13. The method of claim 11, wherein the first photoelectric conversion layer has a p-n junction located at a first depth from the surface of the substrate, and the second photoelectric conversion layer has a p-n junction located at a second depth from the surface of the substrate.

14. The method of claim 11, wherein the sensing of the image comprises calculating a color difference signal based on a luminance signal sensed from a light signal that passes through the third filter region, a signal sensed from the first photoelectric conversion layer, and a signal sensed from the second photoelectric conversion layer.

15. At least one non-transitory medium comprising computer readable code to control at least one processing element to implement the method of claim 8.

16. An image photographing apparatus comprising:

a filter unit including,

a first filter region including,

a first sub-filter region to pass a first wavelength band of an incident light signal corresponding to a complementary color of a first color,

a second sub-filter region to pass a second wavelength band of the incident light signal corresponding to a complementary color of a second color,

a second filter region to pass all bands of the incident light signal, and

a third filter region including a white filter which blocks an infrared wavelength band of the incident light signal,

wherein the first sub-filter region and the second sub-filter region are arranged parallel to each other as adjacent pixels and are each formed of any one of a cyan filter, a magenta filter, and a yellow filter, and the second filter region and the third filter region are arranged parallel to each other as adjacent pixels; and

an image sensor unit to sense an image from the incident light signal that passes through the filter unit, the image sensor unit including a plurality of photoelectric conversion layers each having a different spectral sensitivity.

17. The apparatus of claim 16, wherein the photoelectric conversion layers are formed at a location corresponding to the first filter region.

18. The apparatus of claim 16, wherein the photoelectric conversion layers comprise:

a first photoelectric conversion layer passing a first color component of a light signal that passes through the first filter region; and

a second photoelectric conversion layer longitudinally overlapping the first photoelectric conversion layer and passing a second color component of the light signal that passes through the first filter region,

wherein the first photoelectric conversion layer is located closer to a surface of a substrate than the second photoelectric conversion layer.

19. A method of operating an image photographing apparatus, the method comprising:

filtering an incident light signal using a first filter region including a first sub-filter region to pass a first wavelength band of the incident light signal corresponding to a complementary color of a first color and a second sub-filter region to pass a second wavelength band of the incident light signal corresponding to a complementary color of a second color, using a second filter region to pass all wavelength bands of the incident light signal, and using a third filter region including a white filter which blocks an infrared wavelength band of the incident light signal, wherein the first sub-filter region and the second sub-filter region are arranged parallel to each other as adjacent pixels and are each formed of any one of a cyan filter, a magenta filter, and a yellow filter, and the second filter region and the third filter region are arranged parallel to each other as adjacent pixels;

receiving the filtered incident light signal through a plurality of photoelectric conversion layers each having a different spectral sensitivity; and

sensing an image from the received light signal.

20. The method of claim 19, wherein the receiving of the filtered incident light signal comprises:

receiving a first color component and a second color component from the incident light signal that passes through the first filter region,

wherein the first color component is obtained by a first photoelectric conversion layer and the second color component is obtained by a second photoelectric conversion layer, the first photoelectric conversion layer being located closer to the surface of a substrate than the second photoelectric conversion layer.

21. The method of claim 20, wherein the receiving of the filtered incident light signal further comprises obtaining a white light signal from the incident light signal that passes through the second filter region.

22. The method of claim 21, further comprising

performing white balancing on the first color component and the second color component using the obtained white light signal;

performing demosaicing on the white balanced first color component signal and on the white balanced second color component signal

generating an image in a predetermined signal format and gamma correcting the generated image; and

outputting the gamma-corrected image to a predetermined display module.

23. At least one non-transitory medium comprising computer readable code to control at least one processing element to implement the method of claim 19.