Method and apparatus for triggering image acquisition in radiography

• US 20080179531A1
• Filed: 01/31/2007
• Published: 07/31/2008
• Est. Priority Date: 01/31/2007
• Status: Active Grant

• Current Assignee: Semiconductor Components Industries LLC (ON Semiconductor Corporation)
• Original Assignee: Cypress Semiconductor Corporation (Infineon Technologies AG)
• Inventors: Scheffer, Danny
• Granted Patent: US 7,659,517 B2
• Time in Patent Office: Days
• US Class Current: 250/370.11
• CPC Class Codes: A61B 6/032 Transmission computed tomography [CT]
• CPC Class Codes: A61B 6/51 for dentistry

Abstract

An apparatus for triggering image acquisition in radiography includes an interconnect, a detector to detect radiation and a switch coupled between the interconnect and the detector to charge the interconnect in response to the radiation while the switch is in an open-circuit state. The apparatus also includes control circuitry coupled to the interconnect to detect the charge on the interconnect and to generate a signal indicating presence of the radiation in response to the charge. A method for triggering image acquisition in radiography includes coupling a switch between an interconnect and a detector, then charging an interconnect with that switch in response to radiation incident upon the switch while the switch is in an open-circuit state. Next, the charge on the interconnect is monitored and a signal is generated indicating the presence of the radiation in response to that charge.

Claims

1. A method comprising:

charging an interconnect with a switch in response to radiation incident upon the switch while the switch is in an open-circuit state, wherein the switch is coupled between the interconnect and a detector;

monitoring charge on the interconnect; and

generating a signal indicating presence of the radiation in response to the charge on the interconnect.

2. The method of claim 1, further comprising enabling the detector in response to the signal.

3. The method of claim 2, wherein enabling the detector comprises changing the switch from the open-circuit state to a closed-circuit state, the method further comprising reading an output from the detector via the interconnect in response to the signal.

4. The method of claim 3, further comprising resetting the charge on the interconnect prior to reading the output from the detector.

5. The method of claim 1, wherein monitoring the charge of the interconnect comprises monitoring for a voltage change on the interconnect.

6. The method of claim 5, further comprising resetting the voltage on the interconnect prior to monitoring for the voltage change on the interconnect.

7. The method of claim 1, wherein the interconnect is one of a plurality of interconnects, the switch is one of a plurality of switches, and the detector is one of a plurality of detectors, the method further comprising:

connecting the plurality of interconnects to one another;

charging the plurality of interconnects with the plurality of switches in response to radiation incident upon the plurality of switches while in the open-circuit state; and

monitoring the charge on the plurality of interconnects; and

generating the signal indicating presence of the radiation in response to the charge on the plurality of interconnects.

8. An apparatus comprising:

an interconnect;

a detector to detect radiation;

a switch coupled between the interconnect and the detector to charge the interconnect in response to the radiation while the switch is in an open-circuit state; and

control circuitry coupled to the interconnect to detect the charge on the interconnect and to generate a signal indicating presence of the radiation in response to the charge.

9. The apparatus of claim 8, wherein the control circuitry is further coupled to enable the detector in response to the signal by changing the switch from the open-circuit state to a closed-circuit state.

10. The apparatus of claim 8, wherein the control circuitry further comprises an edge detector coupled to detect a voltage change on the interconnect.

11. The apparatus of claim 8, wherein the control circuitry further comprises a reset circuit coupled to discharge the interconnect.

12. The apparatus of claim 8, wherein the switch comprises an n-type metal oxide semiconductor field effect transistor (“

nMOSFET”

) coupled between the interconnect and the detector to charge the interconnect in response to the radiation incident upon a p-n junction of the nMOSFET.

13. The apparatus of claim 8, further comprising:

a plurality of interconnects;

a plurality of detectors to detect radiation; and

a plurality of switches coupled between the plurality of interconnects and the plurality of detectors to charge the plurality of interconnects in response to the radiation while the plurality of switches are in an open-circuit state,

wherein the control circuitry is coupled to connect the plurality of interconnects to one another, and to generate a signal indicating presence of the radiation in response to the charge on the plurality of interconnects.

14. The apparatus of claim 8, wherein the detector comprises:

a photodiode to accumulate charge in response to the radiation;

a reset coupled to remove the accumulated charge from the photodiode; and

a buffer coupled between the photodiode and the switch to output an electrical characteristic representative of the accumulated charge on the photodiode via the interconnect.

15. The apparatus of claim 8, further comprising a scintillator disposed proximate to the detector to translate the radiation from a first wavelength to a second wavelength.

16. A system comprising:

a radiation source to emit radiation;

a plurality of interconnects;

a plurality of detectors to detect the radiation;

a plurality of switches coupled between the plurality of interconnects and the plurality of detectors to charge the plurality of interconnects in response to the radiation while the plurality of switches are in an open-circuit state; and

control circuitry coupled to the plurality of interconnects to detect the charge and to generate a signal indicating presence of the radiation in response to the charge.

17. The system of claim 16, wherein the control circuitry is further coupled to connect the plurality of interconnects to one another.

18. The system of claim 17, wherein the control circuitry is further coupled to discharge the plurality of interconnects.

19. The system of claim 18, wherein the control circuitry further comprises an edge detector coupled to detect a voltage change on the plurality of interconnects and to generate the signal in response to the voltage change.

20. The system of claim 19, wherein the control circuitry is further coupled to change the plurality of switches from the open-circuit state to a closed-circuit state in response to the signal, and to read an output from each of the plurality of detectors via the plurality of interconnects.