Current/voltage conversion circuit and imaging apparatus

• US 10,009,565 B2
• Filed: 08/08/2013
• Issued: 06/26/2018
• Est. Priority Date: 08/23/2012
• Status: Expired due to Fees

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Sonoda, Takahiro, Suzuki, Atsushi
• Primary Examiner(s): PYO, KEVIN K
• Application Number:
  US14/421,043
• Publication Number:
  US 20150244962A1
• Time in Patent Office: 1,783 Days
• Field of Search: 250214 R, 250214 A, 250214 SW, 250214 LS, 2502081
• CPC Class Codes: G01T 1/17 Circuit arrangements not adapted to a particular type of detector pulse-selection circuits H03K, G01R
• CPC Class Codes: G01T 1/20184 Detector read-out circuitry, e.g. for clearing of traps, compensating for traps or compensating for direct hits
• CPC Class Codes: H01L 27/14612 involving a transistor
• CPC Class Codes: H01L 27/14661 of the hybrid type
• CPC Class Codes: H04N 25/30 for transforming X-rays into image signals
• CPC Class Codes: H04N 25/709 Circuitry for control of the power supply
• CPC Class Codes: H04N 25/75 Circuitry for providing, modifying or processing image signals from the pixel array
• CPC Class Codes: H04N 25/77 Pixel circuitry, e.g. memories, A/D converters, pixel amplifiers, shared circuits or shared components
• CPC Class Codes: H04N 25/772 comprising A/D, V/T, V/F, I/T or I/F converters
• CPC Class Codes: H04N 25/78 Readout circuits for addressed sensors, e.g. output amplifiers or A/D converters
• CPC Class Codes: H04N 5/32 Transforming X-rays cameras or camera modules for generating image signals from X-rays H04N23/30; circuitry of SSIS for transforming X-rays into image signals H04N25/30

Abstract

An imaging apparatus 10 includes an imaging panel 11 formed by arranging imaging element units 20 included in one pixel or a plurality of pixels, in a two-dimensional matrix form. Each of the imaging element units 20 includes an imaging element 30 which converts an incident electromagnetic wave to a current, and a current/voltage conversion circuit 40A which converts the current from the imaging element to a voltage.

Claims

1. An imaging apparatus comprising:

a plurality of imaging element units arranged in rows and columns,

each of the imaging element units including an imaging element configured to convert an incident electromagnetic wave to a current, and

each of the imaging element units further including a current/voltage conversion circuit configured to convert the current from the imaging element to a voltage, wherein

the current/voltage conversion circuit includes an operational amplifier and a capacitor section,

the operational amplifier includes an output section connected to an output section of the current/voltage conversion circuit, and includes a first input section and a second input section, and

a first end of the capacitor section is connected to the output section of the operational amplifier, and a second end of the capacitor section is connected to the second input section of the operational amplifier and an output section of the imaging element.

2. The imaging apparatus according to claim 1, wherein charge is stored in the capacitor section by the current from the imaging element.

3. The imaging apparatus according to claim 1, wherein

the current/voltage conversion circuit includes a plurality of capacitor sections and a changeover switch circuit, and

each of the plurality of capacitor sections is connected to the output section of the operational amplifier and the second input section of the operational amplifier via the changeover switch circuit.

4. An imaging apparatus comprising:

a plurality of imaging element units arranged in rows and columns,

at least one of the imaging element units including

an imaging element configured to convert an incident electromagnetic wave to a current, and

a current/voltage conversion circuit configured to convert the current from the imaging element to a voltage, wherein

the current/voltage conversion circuit includes an operational amplifier and a capacitor section,

the operational amplifier includes an output section connected to an output section of the current/voltage conversion circuit, and includes a first input section and a second input section,

a first end of the capacitor section is connected to the output section of the operational amplifier, and a second end of the capacitor section is connected to the second input section of the operational amplifier and an output section of the imaging element,

the current/voltage conversion circuit further includes a first switch circuit and a second switch circuit,

the first input section of the operational amplifier is connected to a first power supply,

the output section of the imaging element is connected to the second end of the capacitor section via the first switch circuit and connected to a second power supply via the second switch circuit, and

the first switch circuit and the second switch circuit operate complementarily.

5. The imaging apparatus according to claim 4, wherein

the current/voltage conversion circuit further includes a second capacitor section and a third switch circuit which conducts same operation as the first switch circuit, and

a first end of the second capacitor section is connected to the output section of the operational amplifier via the third switch circuit.

6. The imaging apparatus according to claim 4, wherein

the current/voltage conversion circuit further includes a second capacitor section, a third switch circuit, a fourth switch circuit, a fifth switch circuit, and a sixth switch circuit,

a first end of the second capacitor section is connected to the output section of the operational amplifier via the third switch circuit,

a second end of the second capacitor section is connected to the second input section of the operational amplifier via the fourth switch circuit and connected to the first power supply via the fifth switch circuit, and

the sixth switch circuit is connected between the second end of the capacitor section, and

the first switch circuit and the second input section of the operational amplifier.

7. The imaging apparatus according to claim 4, wherein the current/voltage conversion circuit further includes a buffer circuit connected to the output section of the operational amplifier and the output section of the current/voltage conversion circuit.

8. The imaging apparatus according to claim 4, wherein the imaging element unit is shaped integrally.

9. A current/voltage conversion circuit connected to an imaging element configured to convert an incident electromagnetic wave to a current, and configured to convert the current from the imaging element to a voltage, the current/voltage conversion circuit comprising:

an operational amplifier including an output section connected to an output section of the current/voltage conversion circuit, and a first input section and a second input section;

a capacitor section connected at a first end of the operational amplifier to the output section of the operational amplifier and at a second end thereof to the second input section of the operational amplifier; and

a first switch circuit and a second switch circuit configured to operate complementarily,

the first input section of the operational amplifier being connected to a first power supply, and

an output section of the imaging element being connected to the second end of the capacitor section via the first switch circuit and connected to a second power supply via the second switch circuit.

10. The current/voltage conversion circuit according to claim 9, wherein charge is stored in the capacitor section by the current from the imaging element.

11. The current/voltage conversion circuit according to claim 9, wherein the current/voltage conversion circuit is shaped integrally with the imaging element.