SOLID-STATE IMAGE CAPTURING DEVICE AND ELECTRONIC DEVICE

• US 20140024164A1
• Filed: 09/24/2013
• Published: 01/23/2014
• Est. Priority Date: 03/31/2010
• Status: Active Grant

• Current Assignee: Sony Semiconductor Solutions Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Izuha, Kyoko, Harada, Kouichi
• Granted Patent: US 9,219,090 B2
• Time in Patent Office: Days
• US Class Current: 438/69
• CPC Class Codes: H01L 27/14621 Colour filter arrangements
• CPC Class Codes: H01L 27/14625 Optical elements or arrangements associated with the device
• CPC Class Codes: H01L 27/14685 Process for coatings or optical elements

Abstract

A solid-state image capturing device including: a semiconductor substrate having a photosensitive surface including a matrix of pixels as respective photoelectric converters; and a photochromic film disposed in a light path through which light is applied to each of the photoelectric converters, the photochromic film being made of a photochromic material having a light transmittance variable depending on the intensity of applied light in a predetermined wavelength range; wherein the light transmittance has a half-value period shorter than one frame during which pixel signals generated by the pixels are read from all the pixels.

Claims

1. A method comprising:

forming a semiconductor substrate having a photosensitive surface including a matrix of pixels as respective photoelectric converters; and

forming a photochromic film disposed in a light path through which light is applied to each of said photoelectric converters, said photochromic film being made of a photochromic material having a light transmittance variable depending on the intensity of applied light in a predetermined wavelength range,

wherein,

said light transmittance has a half-value period shorter than one frame during which pixel signals generated by said pixels are read from all said pixels.

2. The method of claim 1, further comprising providing a light amount measuring unit for measuring an amount of light absorbed by said photochromic film.

3. The method of claim 2, further comprising providing a signal processor for combining a light signal representative of the amount of light measured by said light amount measuring unit and light signals generated by the photoelectric converters into pixel signals from said pixels.

4. The method of claim 2, further comprising providing a resetting unit for resetting a light signal which is generated by said photochromic film when said photochromic film absorbs the applied light.

5. The method of claim 1, wherein said pixels are divided into red pixels, green pixels, and blue pixels, further including:

color filters for passing light in wavelength ranges of red, green, and blue, said color filters being disposed on said semiconductor substrate in respective light paths leading to the photoelectric converters of the red pixels, the green pixels, and the blue pixels.

6. The method of claim 5, wherein said photochromic film is made of different materials disposed in alignment with said color filters, respectively, depending on said wavelength ranges.

7. The method of claim 5, wherein said photochromic film is made of one material irrespective of said wavelength ranges.

8. The method of claim 5, wherein said photochromic film doubles as said color filters.

9. The method of claim 1, wherein the light transmittance of said photochromic film varies depending on the intensity of applied light in a visible range.

10. The method of claim 1, wherein the light transmittance of said photochromic film is higher as the intensity of applied light in a visible range is lower and is lower as the intensity of applied light in a visible range is higher.

11. The method of claim 1, wherein the light transmittance of said photochromic film is continuously variable depending on the intensity of applied light in a visible range.

12. The method of claim 1, wherein said photochromic material includes a hexarylbisimidazole derivative.

13. The method of claim 1, further comprising disposing said pixels as an alternate array of sets of pixels each including a pixel or a plurality of pixels incorporating said photochromic film and sets of pixels each including a pixel or a plurality of pixels free of said photochromic film.

14. The method of claim 13, wherein each of said sets of pixels includes one red pixel, two green pixels, and one blue pixel, said photochromic film being shared by the pixels in each of the sets.

15. The method of claim 13, wherein each of said sets of pixels includes one column of pixels, said photochromic film being shared by the pixels in each of the sets.

16. The method of claim 13, wherein each of said sets of pixels includes a plurality of columns of pixels, said photochromic film being shared by the pixels in each of the sets.

17. The method of claim 1, wherein said photochromic film is shared by all the pixels of said photosensitive surface.

18. The method of claim 1, further comprising disposing said photochromic film over a region in which said pixels are disposed.

19. A method comprising:

forming a solid-state image capturing device including an image capturing unit by (a) forming a semiconductor substrate having a photosensitive surface including a matrix of pixels as respective photoelectric converters, and (b) forming a photochromic film disposed in a light path through which light is applied to each of said photoelectric converters, said photochromic film being made of a photochromic material having a light transmittance variable depending on the intensity of applied light in a predetermined wavelength range;

providing an optical system for guiding incident light to the image capturing unit of said solid-state image capturing device;

providing a signal processing circuit for processing an output signal from said solid-state image capturing device; and

assembling the solid-state image capturing device, the optical system and the signal processing circuit in an electronic device,

wherein,

said light transmittance has a half-value period shorter than one frame during which pixel signals generated by said pixels are read from all said pixels.