IMAGE PICKUP DEVICE AND CAMERA MODULE USING THE SAME

• US 20080303919A1
• Filed: 06/06/2008
• Published: 12/11/2008
• Est. Priority Date: 06/07/2007
• Status: Active Grant

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: EGAWA, Yoshitaka
• Granted Patent: US 8,013,928 B2
• Time in Patent Office: Days
• US Class Current: 348/223.1
• CPC Class Codes: G06T 1/0007 Image acquisition
• CPC Class Codes: H01L 27/14621 Colour filter arrangements
• CPC Class Codes: H01L 27/14623 Optical shielding
• CPC Class Codes: H01L 27/14627 Microlenses
• CPC Class Codes: H04N 2209/046 Colour interpolation to calculate the missing colour values
• CPC Class Codes: H04N 23/959 by adjusting depth of field during image capture, e.g. maximising or setting range based on scene characteristics
• CPC Class Codes: H04N 25/133 including elements passing panchromatic light, e.g. filters passing white light
• CPC Class Codes: H04N 25/134 based on three different wavelength filter elements
• CPC Class Codes: H04N 25/135 based on four or more different wavelength filter elements
• CPC Class Codes: H04N 25/61 the noise originating only from the lens unit, e.g. flare, shading, vignetting or "cos4"
• CPC Class Codes: H04N 25/611 Correction of chromatic aberration

Abstract

An image pickup device includes a signal processing unit which processes a signal generated by separating a luminous signal into wavelength components of two or more colors by use of a sensor unit including two-dimensionally arranged pixels to which a wavelength separating unit for separating light wavelengths is arranged at a front face of a photoelectric converting element which converts the luminous signal condensed by an optical lens unit into electric signals, wherein the optical lens unit includes at least one optical lens having different focusing positions in accordance with the wavelengths of the luminous signal, and the signal processing unit includes an outline signal generating unit which extracts an outline signal from an output signal of the sensor unit.

Claims

1. An image pickup device comprising:

a signal processing unit for processing a signal generated by separating a luminous signal into wavelength components of two or more colors by use of a wavelength separating unit and a sensor unit comprising two-dimensionally arranged pixels to which the wavelength separating unit is arranged at a front face of a photoelectric converting element which converts the luminous signal condensed by an optical lens unit into an electric signal, wherein

the optical lens unit includes at least one optical lens having different focusing positions in accordance with the wavelengths of the luminous signal, and

the signal processing unit includes an outline signal generating unit for extracting an outline signal from the electric signal generated in the sensor unit.

2. The image pickup device according to claim 1, wherein the optical lens unit comprises lens assembly constituted of a plurality of lenses, at least two lenses of which are made of the same material.

3. The image pickup device according to claim 1, wherein the optical lens is made of a lens material with a dispersion ratio so that the lens has enlarged different focusing positions in accordance with the light wavelengths and further has spherical aberration.

4. The image pickup device according to claim 1, wherein a filter which does not separate light wavelengths is arranged to the wavelength separating unit at a front face of the photoelectric converting unit.

5. The image pickup device according to claim 4, wherein the wavelength separating unit is constituted of micro-lenses each of which condenses light for each pixel and a filter layer which separates the light wavelengths, and the micro-lenses include a micro-lens with the filter layer which does not separate light wavelengths, the micro-lens being formed to be smaller in size than the micro-lenses to which color filter layers are arranged.

6. The image pickup device according to claim 5, wherein the color filter layers are formed to be the same size as the corresponding micro-lenses.

7. The image pickup device according to claim 5, wherein the micro-lens having a large area is formed to have a large curvature, and the micro-lens having a small area is formed to have a small curvature.

8. The image pickup device according to claim 7, wherein the micro-lens having the large area is formed through at least two process steps.

9. The image pickup device according to claim 1, wherein the outline signal generating unit comprises outline signal generating means for generating and combining an outline signal from at least a signal in R wavelength range, a signal in G wavelength range and a signal in B wavelength range which are output from the sensor unit.

10. The image pickup device according to claim 1, wherein the outline signal generating unit comprises outline signal generating means for generating an outline signal from an addition signal obtained by adding a color signal of one center pixel and a color signal of a plurality of peripheral pixels in accordance with a predetermined weighting in a predetermined pixel array which includes the one center pixel at a position in the sensor unit and the plurality of peripheral pixels thereof.

11. The image pickup device according to claim 10, wherein the signal processing means comprises defocus correcting means for correcting image defocus by correcting a signal changing part of the addition signal.

12. The image pickup device according to claim 11, wherein the defocus correcting means comprises:

signal inclination determining means for detecting the signal change of the addition signal by a predetermined criterion; and

signal replacing means for replacing the addition signal with a peripheral signal having a smaller signal change than that of the addition signal based on a detection result of the signal inclination determining means.

13. A camera module comprising:

a signal processing unit for processing a signal generated by separating a luminous signal into wavelength components of two or more colors by used of a sensor unit including two-dimensionally arranged pixels to which a wavelength separating unit for separating light wavelengths is arranged at a front face of a photoelectric converting element which converts the luminous signal condensed by an optical lens unit into electric signals, wherein

the optical lens unit includes at least one optical lens having different focusing positions in accordance with the wavelengths of the luminous signal, and

the signal processing unit includes outline signal generating unit for extracting an outline signal from an output signal of the sensor unit.

14. An image pickup device comprising:

signal processing means for processing a W signal which is generated without performing wavelength separation and a signal generated by separating a luminous signal into wavelength components of two or more colors by use of a sensor unit comprising two-dimensionally arranged pixels to which a wavelength separating unit for separating light wavelength is arranged at a front face of a photoelectric converting element which converts the luminous signal condensed by an optical lens into electric signals, wherein

the wavelength separating unit is constituted of micro-lenses each of which condenses light for each pixel and color filter layers which separate light wavelengths, and a micro-lens corresponding to the W signal to which a filter layer which does not separate light wavelengths is arranged is formed to be smaller in size than the micro-lenses to which color filter layers are arranged.

15. The image pickup device according to claim 14, wherein the color filter layers each is formed to be the same size as the each micro-lens.

16. The image pickup device according to claim 14, wherein the micro-lens having a large area is formed to have a large curvature, and the micro-lens having a small area is formed to have a small curvature.

17. The image pickup device according to claim 16, wherein the micro-lens having a large area is formed through at least two process steps.

18. The image pickup device according to claim 14, wherein the signal processing means comprises outline signal generating means for generating an outline signal from an addition signal obtained by adding a color signal of one center pixel and color signals of a plurality of peripheral pixels in accordance with a predetermined weighting in a predetermined pixel array which includes the one center pixel at a position in the sensor unit and the plurality of peripheral pixels thereof.

19. The image pickup device according to claim 18, wherein the signal processing means comprises defocus correcting means for correcting image defocus by correcting a signal changing part of the addition signal.

20. The image pickup device according to claim 19, wherein the defocus correcting means comprises:

signal inclination determining means for detecting the signal change of the addition signal by a predetermined criterion; and

signal replacing means for replacing the addition signal with a peripheral signal having a smaller signal change than that of the addition signal based on a detection result of the signal inclination determining means.

21. An image pickup device which processes color signals including a signal generated by separating a luminous signal into wavelength components of two or more colors by use of a sensor unit comprising two-dimensionally arranged pixels to which wavelength separating means for separating light wavelengths is arranged at a front face of a photoelectric converting element which converts the luminous signal condensed by an optical lens into electric signals, comprising:

adding means for generating an addition signal by adding a color signal of one center pixel and color signals of a plurality of peripheral pixels in accordance with a predetermined weighting in a predetermined pixel array which includes the one center pixel at a position in the sensor unit and the plurality of peripheral pixels thereof;

defocus correcting means for correcting image defocus by correcting a signal changing part of the addition signal;

outline signal generating means for generating an outline signal by extracting signal change from a signal before addition which is input to the adding means;

combining means for generating a combined signal by combining the outline signal and the addition signal corrected by the defocus correcting means;

ratio coefficient calculating means for respectively calculating a ratio coefficient of each mean value of each color signal which is output from each pixel in the predetermined pixel array and a mean value of the combined signal; and

RGB signal generating means for newly generating an R signal, a G signal and a B signal by use of the ratio coefficient calculated by the ratio coefficient calculating means and the combined signal.

22. The image pickup device according to claim 21, wherein the defocus correcting means comprises:

signal inclination determining means for detecting the signal change of the addition signal by a predetermined criterion; and

signal replacing means for replacing the addition signal with a peripheral signal having a smaller signal change than that of the addition signal based on the detection result of the signal inclination determining means.

23. A camera module which processes color signals including a signal generated by separating a luminous signal into wavelength components of two or more colors by use of a sensor unit including two-dimensionally arranged pixels to which wavelength separating means for separating light wavelengths is arranged at a front face of a photoelectric converting element which converts the luminous signal condensed by an optical lens into electric signals, comprising:

adding means for generating an addition signal by adding a color signal of one center pixel and color signals of a plurality of peripheral pixels in accordance with a predetermined weighting in a predetermined pixel array which includes the one center pixel at a position in the sensor unit and the plurality of peripheral pixels thereof;

defocus correcting means for correcting image defocus by correcting a signal changing part of the addition signal;

outline signal generating means for generating an outline signal by extracting signal change from a signal before addition which is input to the adding means;

combining means for generating a combined signal by combining the outline signal and the addition signal corrected by the defocus correcting means;

ratio coefficient calculating means for respectively calculating a ratio coefficient of each mean value of color signal which is output from each pixel in the predetermined pixel array and a mean value of the combined signal; and

RGB signals generating means for newly generating an R signal, a G signal and a B signal by use of the ratio coefficient calculated by the ratio coefficient calculating means and the combined signal.

24. The camera module according to claim 23, wherein the defocus correcting means comprises:

signal inclination determining means for detecting the signal change of the addition signal by a predetermined criterion; and

signal replacing means for replacing the addition signal with a peripheral signal having a smaller signal change than that of the addition signal based on a detection result of the signal inclination determining means.

25. The camera module according to claim 23, wherein the wavelength separating means has wavelength signal generating means for generating a W signal without performing wavelength separation, and

the wavelength signal generating means is constituted of a micro-lens which condenses a light for each pixel and a filter layer which separates light wavelengths, and a micro-lens corresponding to the W signal to which the filter layer which does not separate light wavelengths is arranged is formed to be smaller in size than the micro-lenses to which color filter layers are arranged.