Imaging device

• US 9,894,303 B2
• Filed: 01/13/2017
• Issued: 02/13/2018
• Est. Priority Date: 01/22/2016
• Status: Active Grant

• Current Assignee: Panasonic Intellectual Property Management Co., Ltd. (Panasonic Holdings Corporation)
• Original Assignee: Panasonic Intellectual Property Management Co., Ltd. (Panasonic Holdings Corporation)
• Inventors: Miyake, Yasuo
• Primary Examiner(s): PRABHAKHER, PRITHAM DAVID
• Application Number:
  US15/405,408
• Publication Number:
  US 20170214875A1
• Time in Patent Office: 396 Days
• Field of Search: 348308
• CPC Class Codes: H01L 27/14636 Interconnect structures
• CPC Class Codes: H04N 25/626 Reduction of noise due to residual charges remaining after image readout, e.g. to remove ghost images or afterimages
• CPC Class Codes: H04N 25/75 Circuitry for providing, modifying or processing image signals from the pixel array
• CPC Class Codes: H04N 25/76 Addressed sensors, e.g. MOS or CMOS sensors
• CPC Class Codes: H04N 25/78 Readout circuits for addressed sensors, e.g. output amplifiers or A/D converters
• CPC Class Codes: H10K 39/32 Organic image sensors
• CPC Class Codes: Y02E 10/549 Organic PV cells

Abstract

An imaging device includes: a first unit pixel cell including a first electrode, a second electrode facing the first electrode, a first photoelectric conversion layer between the first electrode and the second electrode, the first photoelectric conversion layer generating first signal charge, and a first signal detection circuit connected to the first electrode, the first signal detection circuit detecting the first signal charge; and a voltage supply circuit. The voltage supply circuit supplies a first voltage to the second electrode during a first period when the first unit pixel cell accumulates the first signal charge. The voltage supply circuit supplies a second voltage to at least one of the first electrode and the second electrode during a second period other than the first period, the second period including a first moment at which a difference in potential between the first electrode and the second electrode is zero.

Claims

1. An imaging device comprising:

one or more unit pixel cells including a first unit pixel cell, the first unit pixel cell including

a first electrode,

a second electrode facing the first electrode,

a first photoelectric conversion layer between the first electrode and the second electrode, the first photoelectric conversion layer generating first signal charge, and

a first signal detection circuit connected to the first electrode, the first signal detection circuit detecting the first signal charge; and

a voltage supply circuit, wherein

the voltage supply circuit supplies a first voltage to the second electrode during a first period when the first unit pixel cell accumulates the first signal charge, and

the voltage supply circuit supplies a second voltage to at least one of the first electrode and the second electrode during a second period other than the first period, the second period including a first moment at which a difference in potential between the first electrode and the second electrode is zero.

2. The imaging device according to claim 1, comprising a first controller that causes the voltage supply circuit to supply the first voltage and the second voltage.

3. The imaging device according to claim 2, wherein the second voltage changes in the second period.

4. The imaging device according to claim 2, wherein

the one or more unit pixel cells includes a second unit pixel cell, the second unit pixel cell including

a third electrode,

a fourth electrode facing the third electrode,

a second photoelectric conversion layer between the third electrode and the fourth electrode, the second photoelectric conversion layer generating second signal charge, and

a second signal detection circuit connected to the third electrode, the second signal detection circuit detecting the second signal charge,

the voltage supply circuit supplies the first voltage to the fourth electrode during a third period when the second unit pixel cell accumulates the second signal charge,

the voltage supply circuit supplies the second voltage to at least one of the third electrode and the fourth electrode during the second period, the second period including a second moment at which a difference in potential between the third electrode and the fourth electrode is zero, and

timing of the first moment in a frame period is different from timing of the second moment in the frame period.

5. The imaging device according to claim 4, wherein the second photoelectric conversion layer includes an organic semiconductor material.

6. The imaging device according to claim 2, wherein

the first period and the second period are included in a frame period, and

the second period divides the first period into two separate periods.

7. The imaging device according to claim 2, wherein

the one or more unit pixel cells are arranged in a two-dimensional array having rows and columns,

the one or more unit pixel cells include a second unit pixel cell, the second unit pixel cell including

a third electrode,

a fourth electrode facing the third electrode,

a second photoelectric conversion layer between the third electrode and the fourth electrode, the second photoelectric conversion layer generating second signal charge, and

a second signal detection circuit connected to the third electrode, the second signal detection circuit detecting the second signal charge,

a row in which the first unit pixel cell is located is different from a row in which the second unit pixel cell is located, and

the first signal detection circuit outputs a signal of the first unit pixel cell at first timing in a frame period, the second signal detection circuit outputting a signal of the second unit pixel cell at second timing different from the first timing in the frame period.

8. The imaging device according to claim 7, comprising a second controller that causes the first signal detection circuit to output the signal of the first unit pixel cell, and causes the second signal detection circuit to output the signal of the second unit pixel cell.

9. The imaging device according to claim 1, wherein the first photoelectric conversion layer includes an organic semiconductor material.