Solid-state image sensor and image capturing apparatus

Abstract

A solid-state image sensor which comprises a pixel group in which unit pixels each including a microlens and a plurality of photo-electric converters are arrayed two-dimensionally, wherein a shielding unit that shields part of all of a plurality of photo-electric converters corresponding to a single microlens is provided in a portion of the unit pixels.

What is claimed is: 
     
         1 . A solid-state image sensor comprising:
 a plurality of unit pixels, each unit includes a microlens and a plurality of photo-electric converters arranged adjacent to each other in an array below the microlens, wherein light passing through the microlens is incident on the plurality of photo-electric converters; and   a shielding layer that shields part of the photo-electric converters from incident light entering into the photo-electric converters, wherein the shielding layer in the unit pixel spans part of the photo-electric converters.   
     
     
         2 . The sensor according to  claim 1 ,
 wherein one of first to fourth shielding layers is provided with each unit pixel,   the first to fourth shielding layers include first to fourth openings which has different opening region, respectively,   the first opening of the first shielding layer is formed to be axis symmetrical with respect to an axis and the second opening of the second shielding layer is formed to be axis symmetrical with respect to the axis, and the third opening of the third shielding layer is formed to be axis symmetrical with respect to another axis and the fourth opening of the fourth shielding layers is formed to be axis symmetrical with respect to the other axis, the axes being perpendicular to each other intersecting at a pixel center.   
     
     
         3 . The sensor according to  claim 2 , wherein the first to fourth openings of first to fourth shielding layers shield different portion of first to fourth photo-electric converters in each unit pixel by the opening having different opening region in each unit pixel, respectively. 
     
     
         4 . The sensor according to  claim 1 , wherein the shielding layer is formed by an electrode arranged for each unit pixel. 
     
     
         5 . An image capturing apparatus, comprising:
 the solid-state image sensor according to  claim 1 ;   a focus detection unit configured to perform focus detection using signals from the unit pixels; and   a control unit configured to control an optical system to achieve an in-focus state according to a result of the detection by the focus detection unit.   
     
     
         6 . The apparatus according to  claim 5 , wherein the focus detection unit performs focus detection in a phase-difference detection method using a pair of the unit pixels. 
     
     
         7 . The apparatus according to  claim 6 , wherein the focus detection unit performs focus detection using a signal obtained by adding signals from the plurality of photo-electric converters in the unit pixels. 
     
     
         8 . The apparatus according to  claim 7 , wherein the method of adding the signals from the plurality of photo-electric converters is changed. 
     
     
         9 . The apparatus according to  claim 5 , wherein an image sensing pixel is configured such that sensed images of an object image have parallax.