Imaging device and imaging system

Patent metadata

Field	Value
Publication number	US-12058458-B2
Application number	US-202318322185-A
Country	US
Kind code	B2
Filing date	May 23, 2023
Priority date	Jan 15, 2019
Publication date	Aug 6, 2024
Grant date	Aug 6, 2024

Abstract

An imaging device according to an embodiment of the present disclosure includes: a plurality of current sources including first group current sources and second group current sources; and a control unit that controls driving of the first group current sources to generate a first-phase ramp voltage and controls driving of the first group current sources and at least one current source of the second group current sources to generate a second-phase ramp voltage.

First claim

The invention claimed is:

1. An imaging device comprising:
a ramp signal generator configured to generate a ramp signal;
a comparator configured to compare a voltage based on the ramp signal with a fixed voltage and output a result of the comparison;
malfunction detection circuitry configured to perform a malfunction detection of the ramp signal generator based on the result of the comparison and output a result of the malfunction detection, wherein
the ramp signal generator comprises a plurality of current sources, and
the malfunction detection circuitry is configured to detect a malfunction of at least one of the plurality of current sources.

2. The imaging device according to claim 1 , further comprising:
a controller, wherein
the ramp signal comprises a first-phase ramp voltage and a second-phase ramp voltage,
the plurality of current sources comprises first group current sources and second group current sources,
the controller is configured to control the first group current sources to generate the first-phase ramp voltage and to control the first group current sources and at least one current source of the second group current sources to generate the second-phase ramp voltage, and
the comparator is configured to compare the first-phase ramp voltage with the fixed voltage and to compare the second-phase ramp voltage with the fixed voltage.

3. The imaging device according to claim 2 , wherein
the malfunction detection circuitry is configured to detect a malfunction of the at least one current source of the second group current sources based on results of the comparisons.

4. The imaging device according to claim 1 , further comprising:
a communication interface configured to communicate with a vehicular electronic control unit (ECU).

5. The imaging device according to claim 1 , wherein
the ramp signal includes a first ramp voltage and a second ramp voltage;
the comparator compares voltages based on the first ramp voltage and the second ramp voltage with the fixed voltage to produce the output; and
the malfunction detection circuitry performs the malfunction detection based on the output of the comparator.

6. An imaging device comprising:
a pixel array having a plurality of pixels;
a ramp signal generator configured to generate a ramp signal;
a comparator configured to compare a pixel signal output from at least one of the plurality of pixels with the ramp signal;
malfunction detection circuitry configured to perform a malfunction detection of the ramp signal generator and output a result of the malfunction detection, wherein
the ramp signal generator comprises a plurality of current sources, and
the malfunction detection circuitry is configured to detect a malfunction of at least one of the plurality of current sources.

7. The imaging device according to claim 6 , further comprising:
a controller,
wherein
the ramp signal comprises a first-phase ramp voltage and a second-phase ramp voltage,
the plurality of current sources comprises first group current sources and second group current sources,
the controller is configured to control the first group current sources to generate the first-phase ramp voltage and to control the first group current sources and at least one current source of the second group current sources to generate the second-phase ramp voltage, and
the comparator is configured to compare the first-phase ramp voltage with the fixed voltage and to compare the second-phase ramp voltage with the fixed voltage.

8. The imaging device according to claim 7 , wherein
the malfunction detection circuitry is configured to detect a malfunction of the at least one current source of the second group current sources based on results of the comparisons.

9. The imaging device according to claim 6 , wherein
in an imaging mode, the comparator is configured to compare the pixel signal with the ramp signal, and
in a malfunction detection mode, the comparator is configured to compare the ramp signal with the fixed voltage.

10. The imaging device according to claim 9 , further comprising:
switching circuitry configured to provide the pixel signal to the comparator in the imaging mode and to provide the fixed voltage to the comparator in the malfunction detection mode.

11. The imaging device according to claim 6 , further comprising:
a communication interface configured to communicate with a vehicular electronic control unit (ECU).

12. The imaging device according to claim 6 , wherein
the ramp signal includes a first ramp voltage and a second ramp voltage;
the comparator compares voltages based on the first ramp voltage and the second ramp voltage with the fixed voltage to produce the output; and
the malfunction detection circuitry performs the malfunction detection based on the output of the comparator.

Assignees

• Sony Semiconductor Solutions Corp

Inventors

• Watanabe Tomoki
• Takenaka Kyoichi

Classifications

• H04N25/767

  Horizontal readout lines, multiplexers or registers · CPC title

• H04N17/002 Primary

  for television cameras · CPC title

• H04N25/78

  Readout circuits for addressed sensors, e.g. output amplifiers or A/D converters · CPC title

• H04N25/68

  applied to defects · CPC title

• H03M1/56

  Input signal compared with linear ramp · CPC title