Imaging device

Abstract

An image capture device according to the present disclosure includes: a lens optical system L; an image sensor N on which light that has passed through the lens optical system L is incident and which includes at least a plurality of first pixels and a plurality of second pixels; and an array of optical elements K which is arranged between the lens optical system and the image sensor. The lens optical system has a first optical region D 1 which transmits mostly light vibrating in the direction of a first polarization axis and a second optical region D 2 which transmits mostly light vibrating in the direction of a second polarization axis that is different from the direction of the first polarization axis. The array of optical elements makes the light that has passed through the first optical region D 1 incident on the plurality of first pixels and also makes the light that has passed through the second optical region D 2 incident on the plurality of second pixels.

1 . An image capture device comprising:
 a lens optical system;   an image sensor on which light that has passed through the lens optical system is incident and which includes at least a plurality of first pixels and a plurality of second pixels; and   an array of optical elements which is arranged between the lens optical system and the image sensor and which includes a plurality of optical elements, each having a lens surface,   wherein the lens optical system has a first optical region which transmits mostly light vibrating in the direction of a first polarization axis and a second optical region which transmits mostly light vibrating in the direction of a second polarization axis that is different from the direction of the first polarization axis, and   each of the optical elements that form the array of optical elements makes the light that has passed through the first optical region incident on the plurality of first pixels and also makes the light that has passed through the second optical region incident on the plurality of second pixels.   
     
     
         2 . The image capture device of  claim 1 , wherein the image sensor is a monochrome image sensor. 
     
     
         3 . The image capture device of  claim 1 , wherein the lens optical system is an image-space telecentric optical system. 
     
     
         4 . The image capture device of  claim 1 , wherein the lens optical system includes a split polarizer having first and second polarizing portions which are located in the first and second regions, respectively. 
     
     
         5 . The image capture device of  claim 1 , wherein the optical elements that form the array of optical elements are a lenticular lens. 
     
     
         6 . The image capture device of  claim 5 , wherein in the image sensor, a number of the first pixels and a number of the second pixels are arranged in a first direction and the first pixels arranged in the first direction and the second pixels arranged in the first direction alternate with each other in a second direction that intersects with the first direction at right angles, thus forming an image capturing plane. 
     
     
         7 . The image capture device of  claim 4 , wherein the lens optical system further has a third optical region which transmits mostly light vibrating in the direction of a third polarization axis and a fourth optical region which transmits mostly light vibrating in the direction of a fourth polarization axis, and
 the split polarizer further has third and fourth polarizing portions which are located in the third and fourth regions, respectively.   
     
     
         8 . The image capture device of  claim 7 , wherein the optical elements that form the array of optical elements are a micro lens array. 
     
     
         9 . The image capture device of  claim 1 , further comprising a polarization direction changing section which changes the direction of at least one of the first and second polarization axes of the first and second optical regions. 
     
     
         10 . The image capture device of  claim 1 , wherein the lens optical system includes a split polarizer with at least three polarizing portions, two adjacent ones of which have polarization axes in mutually different directions, and
 the image capture device further includes a drive mechanism which drives the split polarizer so that any two adjacent ones of the at least three polarizing portions of the split polarizer are located in the first and second regions.   
     
     
         11 . The image capture device of  claim 10 , wherein the split polarizer includes a common transparent electrode, two divided transparent electrodes which are located in the first and second optical regions, respectively, a liquid crystal layer which is interposed between the common transparent electrode and the two divided transparent electrodes, and a control section which applies mutually different voltages to the two divided transparent electrodes. 
     
     
         12 . (canceled) 
     
     
         13 . The image capture device of  claim 1 , wherein the plurality of first pixels includes a number of 1A pixels with filters having a first spectral transmittance characteristic, a number of 2A pixels with filters having a second spectral transmittance characteristic, a number of 3A pixels with filters having a third spectral transmittance characteristic, and a number of 4A pixels with filters having a fourth spectral transmittance characteristic,
 the plurality of second pixels includes a number of 1B pixels with filters having the first spectral transmittance characteristic, a number of 2B pixels with filters having the second spectral transmittance characteristic, a number of 3B pixels with filters having the third spectral transmittance characteristic, and a number of 4B pixels with filters having the fourth spectral transmittance characteristic, and   the array of optical elements includes:   a plurality of first optical elements which makes light that has passed through the first optical region incident on the 1A and 3A pixels and which also makes light that has passed through the second region incident on the 2B and 4B pixels; and   a plurality of second optical elements which makes light that has passed through the first region incident on the 2A and 4A pixels and which also makes light that has passed through the second region incident on the 1B and 3B pixels.   
     
     
         14 . The image capture device of  claim 13 , wherein on the image capturing plane of the image sensor, the 1A, 2B, 3A and 4B pixels that form a single set are adjacent to each other and are arranged at the four vertices of a quadrangle,
 wherein the filters having the first spectral transmittance characteristic and the filters having the second spectral transmittance characteristic transmit light falling within the wavelength range of the color green,   the filters having the third spectral transmittance characteristic transmit light falling within the wavelength range of the color red,   the filters having the fourth spectral transmittance characteristic transmit light falling within the wavelength range of the color blue, and   the 1A, 2B, 3A and 4B pixels that form a single set are arranged in a Bayer arrangement pattern.   
     
     
         15 . (canceled) 
     
     
         16 . The image capture device of  claim 13 , wherein the plurality of first optical elements and the plurality of second optical elements form a lenticular lens. 
     
     
         17 . The image capture device of  claim 1 , wherein the lens optical system further includes a stop, and the first and second optical regions are located in the vicinity of the stop. 
     
     
         18 . An image capture device comprising:
 a lens optical system;   an image sensor which includes a plurality of first pixels with filters having a first spectral transmittance characteristic, a plurality of second pixels with filters having a second spectral transmittance characteristic, a plurality of third pixels with filters having a third spectral transmittance characteristic, and a plurality of fourth pixels with filters having a fourth spectral transmittance characteristic and in which a first row where the first and second pixels are arranged alternately in a first direction and a second row where the third and fourth pixels are arranged alternately in the first direction alternate in a second direction, thereby forming an image capturing plane, wherein light that has passed through the lens optical system is incident on the first, second, third and fourth pixels; and   an array of optical elements which is arranged between the lens optical system and the image sensor,   wherein the lens optical system has a first optical region which transmits mostly light vibrating in the direction of a first polarization axis and a second optical region which transmits mostly light vibrating in the direction of a second polarization axis that is different from the direction of the first polarization axis, the first and second optical regions being arranged in the second direction,   on the image capturing plane, the array of optical elements includes a plurality of optical elements, each of which makes the light that has been transmitted through the lens optical system incident on every four pixels, which are the first, second, third and fourth pixels that are arranged adjacent to each other in the first and second directions, and   the plurality of optical elements forms a number of columns, each of which is arranged linearly in the second direction, wherein on two columns that are adjacent to each other in the first direction, each optical element on one of the two columns is shifted from an associated optical element on the other column in the second direction by a length corresponding to a half of one arrangement period of the optical elements.   
     
     
         19 . A biometric image capturing system comprising:
 the image capture device of  claim 7 ; and   a light source which irradiates an object with polarized light.   
     
     
         20 . The biometric image capturing system of  claim 19 , wherein the lens optical system of the image capture device includes split color filters to be arranged in the first to fourth optical regions,
 the split color filters transmit light falling within the same wavelength range in two of those first through fourth optical regions, and   in the two optical regions, the polarization axes of the split polarizer are in mutually different directions.   
     
     
         21 . (canceled) 
     
     
         22 . The biometric image capturing system of  claim 19 , further comprising a control section which controls the light source and the image capture device,
 wherein the control section controls the image capture device so that the image capture device captures multiple images synchronously with flickering of the light source, and   the image capture device performs arithmetic processing between the multiple images to generate another image.   
     
     
         23 . The biometric image capturing system of  claim 19 , further comprising a display section which displays an image that has been shot by the image capture device,
 wherein the image capture device further includes a signal processing section, and   the signal processing section generates an image signal by inverting horizontally the image shot and outputs the image signal to the display section.