Imaging device and portable information terminal

Abstract

A solid-state imaging device according to an embodiment includes: an imaging element formed on a semiconductor substrate, and comprising an imaging region including a plurality of pixel blocks each including a plurality of pixels; a first optical system forming an image of an object on an imaging plane; and a second optical system comprising a microlens array including a plurality of microlenses each corresponding to one of the pixel blocks, and reducing and re-forming the image to be formed on the imaging plane on the pixel blocks corresponding to the respective microlenses. The imaging plane of the first optical system is located further away from the first optical system than the imaging element when the object is located at an infinite distance.

1 . An imaging device comprising:
 an imaging element including a plurality of pixels;   a lens; and   a plurality of microlenses,   an imaging plane of the lens being located further away from the lens than the imaging element when an object is located at an infinite distance.   
     
     
         2 . The device according to  claim 1 , wherein the microlenses are semi convex lenses having a convex shape toward the imaging element. 
     
     
         3 . The device according to  claim 1 , further comprising color filters that are provided for the respective pixels. 
     
     
         4 . The device according to  claim 1 , wherein the microlenses reduce and re-form an image to be formed on the imaging plane respectively. 
     
     
         5 . The device according to  claim 4 , wherein the reduction rate of the microlenses is 0.5 or lower when the object is located at the infinite distance. 
     
     
         6 . The device according to  claim 1 , wherein the microlenses are arranged in a hexagonal closed-packed array. 
     
     
         7 . The device according to  claim 1 , wherein the imaging element is provided on a semiconductor substrate, and the microlenses are provided on a substrate that absorbs or reflects infrared light while transmitting visible light. 
     
     
         8 . The device according to  claim 7 , further comprising a spacer provided between the semiconductor substrate and the substrate on which the imaging element is provided, the spacer located around the periphery of the imaging element. 
     
     
         9 . The device according to  claim 1 , further comprising an image signal processor that calculates a shift length of the same object from microlens images and determines a distance from the lens to the object based on the shift length. 
     
     
         10 . The device according to  claim 9 , wherein the shift length is calculated by performing an image matching operation. 
     
     
         11 . The device according to  claim 9 , wherein the image signal processor determines an image reduction rate based on the shift length and determines the distance from the lens to the object based on the image reduction rate. 
     
     
         12 . A portable information terminal comprising an imaging device, the imaging device comprising:
 an imaging element including a plurality of pixels;   a lens; and   a plurality of microlenses,   an imaging plane of the lens being located further away from the lens than the imaging element when an object is located at an infinite distance.   
     
     
         13 . The terminal according to  claim 12 , wherein the microlenses are semi convex lenses having a convex shape toward the imaging element. 
     
     
         14 . The terminal according to  claim 12 , further comprising color filters that are provided for the respective pixels. 
     
     
         15 . The terminal according to  claim 12 , wherein the microlenses reduce and re-form an image to be formed on the imaging plane respectively. 
     
     
         16 . The terminal according to  claim 15 , wherein the reduction rate of the microlenses is 0.5 or lower when the object is located at the infinite distance. 
     
     
         17 . The terminal according to  claim 12 , wherein the microlenses are arranged in a hexagonal closed-packed array. 
     
     
         18 . The terminal according to  claim 12 , wherein the imaging element is provided on a semiconductor substrate, and the microlenses are provided on a substrate that absorbs or reflects infrared light while transmitting visible light. 
     
     
         19 . The terminal according to  claim 18 , further comprising a spacer provided between the semiconductor substrate and the substrate on which the imaging element is provided, the spacer located around the periphery of the imaging element. 
     
     
         20 . The terminal according to  claim 12 , further comprising an image signal processor that calculates a shift length of the same object from microlens images and determines a distance from the lens to the object based on the shift length. 
     
     
         21 . The terminal according to  claim 20 , wherein the shift length is calculated by performing an image matching operation. 
     
     
         22 . The terminal according to  claim 20 , wherein the image signal processor determines an image reduction rate based on the shift length and determines the distance from the lens to the object based on the image reduction rate.