Imaging sensor capable of phase difference focus detection

Abstract

An imaging device capable of phase difference focus detection is described. The imaging device includes a plurality of pixels that are 2-dimensionally arranged and which receive image light. At least one pixel of the plurality of pixels comprises: a micro lens; a plurality of photoelectric conversion units, which are biased around an optical axis of the micro lens; and a control unit, which limits generation of electrons photoelectrically converted at at least one photoelectric conversion unit of the plurality of photoelectric conversion units.

What is claimed is: 
     
       1. An imaging device comprising:
 a plurality of pixels that are 2-dimensionally arranged and which receive image light, 
 wherein at least one pixel of the plurality of pixels comprises: 
 a micro lens; 
 a plurality of photoelectric conversion units, which are biased around an optical axis of the micro lens; and 
 a control unit, which limits generation of electrons photoelectrically converted at at least one photoelectric conversion unit of the plurality of photoelectric conversion units. 
 
     
     
       2. The imaging device of  claim 1 , wherein the plurality of photoelectric conversion units comprise a plurality of photo diodes; and
 the control unit limits generation of photoelectrically converted electrons by changing an electric potential of at least one photo diode of the plurality of photo diodes. 
 
     
     
       3. The imaging device of  claim 1 , wherein the plurality of photoelectric conversion units comprise a plurality of photo transistors; and
 the control unit limits generation of photoelectrically converted electrons by changing a gate electric potential of an electron generating unit of at least one photo transistor of the plurality of photo transistors. 
 
     
     
       4. The imaging device of  claim 1 , wherein the plurality of photoelectric conversion units comprise a plurality of photo diodes; and
 the control unit comprises a reset unit for discharging electrons generated by the plurality of photo diodes and limits generation of photoelectrically converted electrons by discharging electrons generated by at least one photo diode of the plurality of photo diodes. 
 
     
     
       5. The imaging device of  claim 4 , wherein the reset unit includes a reset circuit for discharging electrons; and
 the reset unit is independent from an output unit. 
 
     
     
       6. The imaging device of  claim 1 , wherein at least one pixel, of the plurality pixels, that includes the plurality of photoelectric conversion units is arranged only at a particular region of the imaging device. 
     
     
       7. The imaging device of  claim 6 , wherein, from the pixels arranged only at the particular region, pixels of which the photoelectric conversion units are biased in a same direction are arranged in the same direction as the direction in which the corresponding photoelectric conversion units are biased. 
     
     
       8. The imaging device of  claim 7 , wherein pixels of the plurality of pixels that include photoelectric conversion units biased in a horizontal direction are arranged at the imaging device in the horizontal direction. 
     
     
       9. The imaging device of  claim 7 , wherein pixels of the plurality of pixels that include photoelectric conversion units biased in a vertical direction are arranged at the imaging device in the vertical direction. 
     
     
       10. The imaging device of  claim 1 , wherein each pixel of the plurality of pixels included in the imaging device comprises a respective plurality of the photoelectric conversion units. 
     
     
       11. The imaging device of  claim 10 , wherein the plurality of pixels, each of which includes the respective plurality of photoelectric conversion units, comprise the plurality of photoelectric conversion units biased in a horizontal direction and a vertical direction. 
     
     
       12. An imaging device comprising:
 a plurality of pixels that are 2-dimensionally arranged and which receive image light, 
 wherein at least one pixel of the plurality of pixels comprises: 
 a micro lens; 
 a plurality of photoelectric conversion units, which are biased around an optical axis of the micro lens; and 
 a control unit, which selects a first output mode for outputting electrons photoelectrically converted at the plurality of photoelectric conversion units or a second output mode for outputting only electrons photoelectrically converted at one of the plurality of photoelectric conversion units; 
 wherein generation of electrons photoelectrically converted at at least one photoelectric conversion unit is limited in the second output mode. 
 
     
     
       13. The imaging device of  claim 12 , wherein the control units selects the first output mode for an imaging operation; and
 the control unit selects the second output mode for a phase difference focusing operation. 
 
     
     
       14. The imaging device of  claim 12 , wherein electrons photoelectrically converted at the plurality of photoelectric conversion units are combined and output in the first output mode. 
     
     
       15. The imaging device of  claim 12 , wherein the at least one pixel further comprises a read-out unit which outputs electrons photoelectrically converted at the plurality of photoelectric conversion units. 
     
     
       16. The imaging device of  claim 15 , wherein the read-out unit comprises a plurality of read-out transistors for selectively outputting the photoelectrically converted electrons from the plurality of photoelectric conversion units. 
     
     
       17. The imaging device of  claim 16 , wherein only electrons photoelectrically converted at one photoelectric conversion unit of the plurality of photoelectric conversion units are output by selectively operating the plurality of read-out transistors in the second output mode. 
     
     
       18. The imaging device of  claim 12 , wherein the at least one pixel that comprises the plurality of photoelectric conversion units is arranged only at a particular region of the imaging device. 
     
     
       19. The imaging device of  claim 18 , wherein, from the at least one pixel arranged only at the particular region, pixels of which the plurality of photoelectric conversion units are biased in a same direction are arranged in the same direction as the direction in which the corresponding plurality of photoelectric conversion units are biased. 
     
     
       20. The imaging device of  claim 19 , wherein the at least one pixel that comprises the plurality of photoelectric conversion units is arranged at the imaging device in a horizontal direction and a vertical direction;
 wherein the control unit selects the second output mode for the pixels arranged in the horizontal direction when the pixels arranged in the vertical direction correspond to the first output mode; and 
 wherein the control unit selects the second output mode for the pixels arranged in the vertical direction when the pixels arranged in the horizontal direction correspond to the first output mode. 
 
     
     
       21. The imaging device of  claim 20 , wherein pixels at points where the pixels arranged in the horizontal direction and the pixels arranged in the vertical direction intersect comprise a plurality of photoelectric conversion units biased in the horizontal direction and the vertical direction. 
     
     
       22. The imaging device of  claim 12 , wherein each pixel of the plurality of pixels included in the imaging device comprises the plurality of photoelectric conversion units; and
 the plurality of pixels, each of which includes a respective plurality of photoelectric conversion units, comprise the plurality of photoelectric conversion units biased in a horizontal direction and a vertical direction.