Image sensing apparatus and imaging system

Abstract

An image sensing apparatus includes a pixel array, a first color filter, a second color filter, and a light shielding portion. The amount of electric charges generated in a first pixel after light of a first wavelength enters the first pixel is larger than that of electric charges generated in a second pixel after light of a second wavelength enters the second pixel. The light shielding portion defines the aperture regions of the first and second pixels so as to set the aperture area of the first pixel larger than that of the second pixel.

1 . An image sensing apparatus comprising:
 a pixel array in which a plurality of pixels including a first pixel and a second pixel are arrayed two-dimensionally;   a first color filter which selectively transmits light of a first wavelength so as to make light of the first wavelength enter the first pixel;   a second color filter which selectively transmits light of a second wavelength so as to make light of the second wavelength enter the second pixel; and   a light shielding portion which is interposed between the first color filter, the second color filter, and the pixel array, and defines an aperture region of each of the plurality of pixels,   wherein an amount of electric charges generated in the first pixel in accordance with light of the first wavelength entering the first pixel when white light having a continuous spectrum equivalent in light energy per unit wavelength width between all wavelengths in a visible region is partially transmitted by the first color filter is larger than an amount of electric charges generated in the second pixel in accordance with light of the second wavelength entering the second pixel when the white light is partially transmitted by the second color filter, and   the light shielding portion defines aperture regions of the first pixel and the second pixel so as to set an aperture area of the first pixel larger than an aperture area of the second pixel.   
     
     
         2 . The apparatus according to  claim 1 , wherein
 the first wavelength is shorter than the second wavelength.   
     
     
         3 . The apparatus according to  claim 1 , wherein
 the first pixel and the second pixel are arranged adjacent to each other.   
     
     
         4 . The apparatus according to  claim 1 , wherein
 the light shielding portion includes a plurality of wiring layers, and   the aperture area of each of the plurality of pixels is defined by a lowermost wiring layer of the light shielding portion.   
     
     
         5 . An image sensing apparatus comprising:
 a pixel array in which a plurality of pixels including a first pixel and a second pixel are arrayed two-dimensionally;   a first color filter which selectively transmits light of a first wavelength so as to make light of the first wavelength enter the first pixel;   a second color filter which selectively transmits light of a second wavelength so as to make light of the second wavelength enter the second pixel; and   a light shielding portion which is interposed between the first color filter, the second color filter, and the pixel array, and defines an aperture region of each of the plurality of pixels,   wherein the first wavelength is shorter than the second wavelength, and   the light shielding portion defines aperture regions of the first pixel and the second pixel so as to set an aperture area of the first pixel larger than an aperture area of the second pixel.   
     
     
         6 . The apparatus according to  claim 5 , wherein
 the first pixel and the second pixel are arranged adjacent to each other.   
     
     
         7 . The apparatus according to  claim 5 , wherein
 the light shielding portion includes a plurality of wiring layers, and   the aperture area of each of the plurality of pixels is defined by a lowermost wiring layer of the light shielding portion.   
     
     
         8 . An imaging system comprising:
 an image sensing apparatus defined in  claim 1 ;   an optical system which forms an image on an image sensing surface of the image sensing apparatus; and   a signal processing unit which processes a signal output from the image sensing apparatus to generate image data,   wherein the image sensing apparatus senses a reference white object before sensing an object, and   the signal processing unit determines a gain for a signal output from the first pixel to have a value smaller than a value of a gain for a signal output from the second pixel so as to obtain a proper white level for the reference white object in a display or recording image.   
     
     
         9 . An imaging system comprising:
 an image sensing apparatus defined in  claim 5 ;   an optical system which forms an image on an image sensing surface of the image sensing apparatus; and   a signal processing unit which processes a signal output from the image sensing apparatus to generate image data,   wherein the image sensing apparatus senses a reference white object before sensing an object, and   the signal processing unit determines a gain for a signal output from the first pixel to have a value smaller than a value of a gain for a signal output from the second pixel so as to obtain a proper white level for the reference white object in a display or recording image.