Solid state image pickup device

• US 6,552,747 B1
• Filed: 05/14/1999
• Issued: 04/22/2003
• Est. Priority Date: 05/18/1998
• Status: Expired due to Fees

• Current Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Original Assignee: Fuji Photo Film Co Limited (Fujifilm Holdings Corporation)
• Inventors: Hasegawa, Jun
• Primary Examiner(s): HO, TUAN V
• Application Number:
  US09/311,291
• Time in Patent Office: 1,439 Days
• Field of Search: 348/294, 348/300, 348/301, 348/302, 348/307, 348/308, 348/309, 348/311, 348/299, 348/241, 348/272, 348/273, 348/280, 348/281, 348/314, 348/315, 348/316, 358/513, 358/514, 358/515, 358/517, 358/506, 358/533, 358/75, 358/44, 250/578, 250/208.1
• US Class Current: 348/314
• CPC Class Codes: H01L 27/14806 Structural or functional details thereof
• CPC Class Codes: H01L 27/14825 Linear CCD imagers
• CPC Class Codes: H01L 27/14868 CCD or CID colour imagers
• CPC Class Codes: H04N 25/701 Line sensors
• CPC Class Codes: H04N 25/713 Transfer or readout registers; Split readout registers or multiple readout registers

Abstract

A solid state image pickup device includes: a photoelectric conversion element line having a plurality of first and second photoelectric conversion elements disposed alternately, the first and second photoelectric conversion elements being sensitive to light of different colors; first and second charge storage area lines for storing electric charges photoelectrically converted by the first and second photoelectric conversion elements; first and second charge read units for reading the electric charges stored in the first and second charge storage area lines; first and second transfer members for sequentially transferring the read electric charges to an external circuit; and first and second charge drain members for draining electric charges in the first and second charge storage members.

Claims

1. A solid state image pickup device comprising:

a photoelectric conversion element line having a plurality of first and second conversion elements disposed alternately, the first and second photoelectric conversion elements converting light having different colors into electric charges;

first transfer means for transferring electric charges generated by the plurality of first photoelectric conversion elements to an external circuit;

a first transfer gate for transferring the electric charges generated by the plurality of first photoelectric conversion elements to said first transfer means;

a first drain for draining unnecessary electric charges generated by the plurality of first photoelectric conversion elements;

a first drain gate for transferring the unnecessary electric charges generated by the plurality of first photoelectric conversion elements to said first drain;

second transfer means for transferring electric charges generated by the plurality of second photoelectric conversion elements to an external circuit;

a second transfer gate for transferring the electric charges generated by the plurality of second photoelectric conversion elements to said second transfer means;

a second drain for draining unnecessary electric charges generated by the plurality of second photoelectric conversion elements;

a second drain gate for transferring the unnecessary electric charges generated by the plurality of second photoelectric conversion elements to said second drain; and

a controller for independently controlling a charge transfer by said first and second transfer gates or by said first and second drain gates.

2. A solid state image pickup device according to claim 1, wherein said controller independently controls a charge transfer by said first and second drain gates.

3. A solid state image pickup device according to claim 1, wherein the first photoelectric conversion element converts light of red color into electric charges, and the second photoelectric conversion element converts light of blue color into electric charges.

4. A solid state image pickup device according to claim 1, wherein said first and second transfer means have a positional relation substantially symmetrical to a center axis of said photoelectric conversion element line.

5. A solid state image pickup device according to claim 1, wherein said controller closes said first drain gate to start accumulating electric charges to be generated by the plurality of first photoelectric conversion elements and closes said first transfer gate to end accumulating electric charges to be generated by the plurality of first photoelectric conversion elements, and closes said second drain gate to start accumulating electric charges to be generated by the plurality of second photoelectric conversion elements and closes said second transfer gate to end accumulating electric charges to be generated by the plurality of second photoelectric conversion elements.

6. A solid state image pickup device according to claim 5, wherein said controller sets a storage time of electric charges to be generated by the first photoelectric conversion element differently from a storage time of electric charges to be generated by the second photoelectric conversion element.

7. A solid state image pickup device according to claim 5, wherein said controller sets a storage start time of electric charges to be generated by the first photoelectric conversion element differently from a storage start time of electric charges to be generated by the second photoelectric conversion element.

8. A solid state image pickup device according to claim 1, wherein said controller sets a storage end time of electric charges to be generated by the first photoelectric conversion element same as a storage end time of electric charges to be generated by the second photoelectric conversion element.

9. A solid state image pickup device according to claim 1, further comprising:

a first amplifier for amplifying a signal corresponding to an amount of electric charges transferred by said first transfer means; and

a second amplifier for amplifying a signal corresponding to an amount of electric charges transferred by said second transfer means.

10. A solid state image pickup device according to claim 1, further comprising:

a plurality of first charge storage areas for storing electric charges generated by the plurality of first photoelectric conversion elements; and

a plurality of second charge storage areas for storing electric charges generated by the plurality of second photoelectric conversion elements, wherein;

said first transfer gate is provided between said first charge storage area and said first transfer means and transfers electric charges stored in said first charge storage area to said first transfer means;

said first drain gate is provided between said first charge storage area and said first drain and transfers electric charges stored in said first charge storage area to said first drain;

said second transfer gate is provided between said second charge storage area and said second transfer means and transfers electric charges stored in said second charge storage area to said second transfer means; and

said second drain gate is provided between said second charge storage area and said second drain and transfers electric charges stored in said second charge storage area to said second drain.

11. A solid state image pickup device according to claim 10, further comprising:

a first barrier gate for transferring electric charges generated by the first photoelectric conversion element to said first charge storage area; and

a second barrier gate for transferring electric charges generated by the second photoelectric conversion element to said second charge storage area.

12. A solid state image pickup device according to claim 10, wherein said first and second charge storage areas have a positional relation substantially symmetrical to a center axis of said photoelectric conversion element line.

13. A solid state image pickup device according to claim 10, wherein said first and second transfer means have a positional relation substantially symmetrical to a center axis of said photoelectric conversion element line.

14. A solid state image pickup device according to claim 10, wherein said first charge storage area, said first drain and said first drain gate are provided between said photoelectric conversion element line and said first transfer means, and said second charge storage area, said second drain and said second drain gate are provided between said photoelectric conversion element line and said second transfer means.

15. A solid state image pickup device according to claim 14, wherein said first transfer means is provided on a side opposite to said second transfer means, relative to said photoelectric conversion element line.

16. A solid state image pickup device according to claim 15, wherein said controller closes said first drain gate to start accumulating electric charges to be generated by the plurality of first photoelectric conversion elements and closes said first transfer gate to end accumulating electric charges to be generated by the plurality of first photoelectric conversion elements, and closes said second drain gate to start accumulating electric charges to be generated by the plurality of second photoelectric conversion elements and closes said second transfer gate to end accumulating electric charges to be generated by the plurality of second photoelectric conversion elements.

17. A solid state image pickup device according to claim 16, wherein said controller sets a storage time of electric charges to be generated by the first photoelectric conversion element differently from a storage time of electric charges to be generated by the second photoelectric conversion element.

18. A solid state image pickup device according to claim 16, wherein said controller sets a storage start time of electric charges to be generated by the first photoelectric conversion element differently from a storage start time of electric charges to be generated by the second photoelectric conversion element.

19. A solid state image pickup device according to claim 18, wherein said controller sets a storage end time of electric charges to be generated by the first photoelectric conversion element same as a storage end time of electric charges to be generated by the second photoelectric conversion element.

20. A solid state image pickup device according to claim 1, further comprising:

a plurality of first charge storage areas for storing electric charges generated by the plurality of first photoelectric conversion elements; and

a plurality of second charge storage areas for storing electric charges generated by the plurality of second photoelectric conversion elements, wherein;

said first transfer gate is provided between said first charge storage area and said first transfer means and transfers electric charges stored in said first charge storage area to said first transfer means;

said first drain gate is provided between the first photoelectric conversion element and said first drain and transfers electric charges generated by the first photoelectric conversion element to said first drain;

said second transfer gate is provided between said second charge storage area and said second transfer means and transfers electric charges stored in said second charge storage area to said second transfer means; and

said second drain gate is provided between the second photoelectric conversion element and said second drain and transfers electric charges generated by the second photoelectric conversion element to said second drain.

21. A solid state image pickup device according to claim 20, wherein said first charge storage area is provided between the first photoelectric conversion element and said first transfer means, and said second charge storage area is provided between the second photoelectric conversion element and said second transfer means.

22. A solid state image pickup device according to claim 21, wherein said first drain and said first drain gate are provided between the first photoelectric conversion elements and said second transfer means, and said second drain and said second drain gate are provided between the second photoelectric conversion element and said first transfer means.

23. A solid state image pickup device according to claim 22, wherein said first transfer means is provided on a side opposite to said second transfer means, relative to said photoelectric conversion element line.

24. A solid state image pickup device according to claim 23, wherein said controller closes said first drain gate to start accumulating electric charges to be generated by the plurality of first photoelectric conversion elements and closes said first transfer gate to end accumulating electric charges to be generated by the plurality of first photoelectric conversion elements, and closes said second drain gate to start accumulating electric charges to be generated by the plurality of second photoelectric conversion elements and closes said second transfer gate to end accumulating electric charges to be generated by the plurality of second photoelectric conversion elements.

25. A solid state image pickup device according to claim 24, wherein said controller sets a storage time of electric charges to be generated by the first photoelectric conversion element differently from a storage time of electric charges to be generated by the second photoelectric conversion element.

26. A solid state image pickup device according to claim 24, wherein said controller sets a storage start time of electric charges to be generated by the first photoelectric conversion element differently from a storage start time of electric charges to be generated by the second photoelectric conversion element.

27. A solid state image pickup device according to claim 26, wherein said controller sets a storage end time of electric charges to be generated by the first photoelectric conversion element same as a storage end time of electric charges to be generated by the second photoelectric conversion element.

28. A solid state image pickup device according to claim 15, wherein:

said first and second charge storage areas each have a lamination structure of a first conductive layer, an insulating film, and a charge storage semiconductor region;

said first and second drain gates each have a lamination structure of a second conductive layer, an insulating film, and a semiconductor region;

the second conductive layer forming the first drain gate is formed on the insulating film formed on the first conductive layer forming the second charge storage area; and

the second conductive layer forming the second drain gate is formed on the insulating film formed on the first conductive layer forming the first charge storage area.

29. An image sensor having a first line sensor for generating image signals of red and blue colors and a second line sensor for generating image signals of green color, wherein the first line sensor comprising:

a photoelectric conversion element line having a plurality of first and second conversion elements disposed alternately, the first and second photoelectric conversion elements converting light of red and blue colors into electric charges;

first transfer means for transferring electric charges generated by the plurality of first photoelectric conversion elements to an external circuit;

a first transfer gate for transferring the electric charges generated by the plurality of first photoelectric conversion elements to said first transfer means;

a first drain for draining unnecessary electric charges generated by the plurality of first photoelectric conversion elements;

a first drain gate for transferring the unnecessary electric charges generated by the plurality of first photoelectric conversion elements to said first drain;

second transfer means for transferring electric charges generated by the plurality of second photoelectric conversion elements to an external circuit;

a second transfer gate for transferring the electric charges generated by the plurality of second photoelectric conversion elements to said second transfer means;

a second drain for draining unnecessary electric charges generated by the plurality of second photoelectric conversion elements;

a second drain gate for transferring the unnecessary electric charges generated by the plurality of second photoelectric conversion elements to said second drain; and

a controller for independently controlling a charge transfer by said first and second transfer gates or by said first and second drain gates.