1. A circuit arrangement for counting X-ray radiation X-ray quanta in detector elements in a detector in an emitter-detector system of an X-ray CT system, the X-ray radiation including a multiplicity of X-ray quanta that can have a maximum energy and wherein the X-ray quanta registered in each detector element generate a signal profile with X-ray-quanta-energy-dependent voltage pulses with different heights, which may be superposed on one another, the circuit arrangement, in each detector element, comprising:
at least one first comparator with a first energy threshold less than or equal to the maximum X-ray-quantum energy; and
at least one second comparator with a second energy threshold greater than the maximum X-ray-quantum energy, the at least one first comparator and at least one second comparator being connected to the detector element, wherein the at least one first comparator and at least one second comparator each respectively generate a comparator output signal if their respective energy threshold is exceeded, the at least one first comparator and at least one second comparator including a logical interconnection, wherein at least a first comparator and a second comparator of the at least one first comparator and at least one second comparator are connected to the inputs of an XOR gate, and each XOR gate connected to the first comparator is connected to precisely one counter.
2. The circuit arrangement as claimed in claim 1, wherein at least two first comparators with different first energy thresholds are connected to the detector element and there is an XOR gate for each first comparator.
3. The circuit arrangement as claimed in claim 2, wherein there is a time-delay circuit between a first comparator and the XOR gate thereof.
4. The circuit arrangement as claimed in claim 2, wherein there is a dead-time circuit between a first comparator and the XOR gate thereof.
5. The circuit arrangement as claimed in claim 2, wherein at least one output of an XOR gate connected to a first comparator for a lower energy threshold includes a veto circuit, which, when triggered by the output from another first comparator with a higher first energy threshold, blocks the input of the counter of the first comparator with the lower energy threshold.
6. The circuit arrangement as claimed in claim 1, wherein at least two second comparators with different second energy thresholds are connected to the detector element, wherein the second comparator with the lowest energy threshold and the at least one first comparator are connected to a respective XOR gate, and there is an OR gate for each further second comparator.
7. The circuit arrangement as claimed in claim 1, wherein the at least one counter is connected to a rate correction circuit in order to correct the measured count rates of the X-ray quanta to an actual flux rate of X-ray quanta.
8. The circuit arrangement as claimed in claim 7, wherein the rate correction circuit includes a lookup table, which converts the measured count rates of the X-ray quanta to an actual flux rate of X-ray quanta.
9. The circuit arrangement as claimed in claim 7, wherein the rate correction circuit emulates a polynomial, which converts the measured count rates of the X-ray quanta to an actual flux rate of X-ray quanta.
10. The circuit arrangement as claimed in claim 1, wherein the circuit arrangement is part of an application-specific integrated circuit on a detector.
11. An application-specific integrated circuit (ASIC) for use in a detector in an emitter-detector system of a CT system with a multiplicity of detector elements, the ASIC including at least one circuit arrangement as claimed in claim 1 for each detector element.
12. The application-specific integrated circuit (ASIC) as claimed in claim 11, wherein the ASIC is connected to a plurality of detector elements.
13. An emitter-detector system of an X-ray CT system, comprising at least one circuit arrangement as claimed in claim 1.
14. The circuit arrangement as claimed in claim 3, wherein there is a dead-time circuit between a first comparator and the XOR gate thereof.
15. The circuit arrangement as claimed in claim 3, wherein at least one output of an XOR gate connected to a first comparator for a lower energy threshold includes a veto circuit, which, when triggered by the output from another first comparator with a higher first energy threshold, blocks the input of the counter of the first comparator with the lower energy threshold.
16. The circuit arrangement as claimed in claim 4, wherein at least one output of an XOR gate connected to a first comparator for a lower energy threshold includes a veto circuit, which, when triggered by the output from another first comparator with a higher first energy threshold, blocks the input of the counter of the first comparator with the lower energy threshold.
17. An application-specific integrated circuit (ASIC) for use in a detector in an emitter-detector system of a CT system with a multiplicity of detector elements, the ASIC including at least one circuit arrangement as claimed in claim 2 for each detector element.
18. The application-specific integrated circuit (ASIC) as claimed in claim 17, wherein the ASIC is connected to a plurality of detector elements.
19. An emitter-detector system of an X-ray CT system, comprising at least one circuit arrangement as claimed in claim 2.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A keyless entry system comprising a transmitter and a receiver, for operating equipment as a keyless entry target using radio communication between the transmitter and the receiver,
wherein the transmitter includes:
a control switch configured to specify an operation of the equipment;
a transmission controller configured to generate operation information corresponding to the operation specified by the control switch, the operation information including a function code corresponding the control switch and a count value indicating a number of switching operations of the control switch; and
a transmission section configured to transmit the operation information using a plurality of radio signals in different frequency bands, the transmission section being controlled by the transmission controller;
and wherein the receiver includes:
a receiving section configured to receive the plurality of radio signals and detect the operation information from the plurality of received radio signals; and
a determination section configured to determine the specified operation of the equipment based on the function code and the count value included in the detected operation information.
2. The keyless entry system according to claim 1,
wherein the transmission section simultaneously transmits the plurality of radio signals each containing the same operation information, and
the receiving section receives the plurality of radio signals simultaneously.
3. The keyless entry system according to claim 1, wherein
the plurality of radio signals includes a first radio signal in a first frequency band and a second radio signal in a second frequency band substantially different from the first frequency band,
the transmitter includes a first transmission section for the first frequency band and a second transmission section for the second frequency band, and
the receiver includes a first receiving section for the first frequency band and a second receiving section for the second frequency band.
4. The keyless entry system according to claim 1,
wherein the plurality of radio signals have frequencies in a UHF band, the frequencies being separated from each other by 300 MHz or more.
5. The keyless entry system according to claim 1, wherein
the transmitter is a portable device carried by a user,
the receiver is an in-vehicle receiver mounted in a vehicle, and
the equipment is an in-vehicle equipment mounted in the vehicle.
6. The keyless entry system according to claim 1, wherein the determination section further determines if at least part of the operation information is missing from one of the plurality of received radio signals, and determines the specified operation of the equipment by recovering the missing operation information from the operation information detected in another of the plurality of received signals.
7. The keyless entry system according to claim 1, wherein the control switch includes:
a first switch corresponding to a first function; and
a second switch corresponding to a second function.