OPERATING AN X-RAY TUBE

Abstract

An X-ray tube has at least one grid electrode arranged between an anode electrode and a cathode electrode. Via a focusing unit, an electron flow from the cathode electrode to the anode electrode is focused in that the focusing unit supplies the grid electrode with a first electric grid potential. The focusing unit is supplied with electrical energy in an electrically isolated manner via an energy converter. The first electric grid potential is provided via an adjustable voltage divider, and the adjustable voltage divider is adjusted via a control circuit of the focusing unit in that the control circuit is supplied with an electrically isolated control signal of a control unit. The control signal depends on a value for the first electric grid potential.

Claims

1. A method for operating an X-ray tube having at least one grid electrode arranged between an anode electrode and a cathode electrode, wherein an electron flow from the cathode electrode to the anode electrode is focused via a focusing unit, and wherein the focusing unit is configured to supply the at least one grid electrode, at least in a focusing mode, with a first electric grid potential to focus the electron flow, the method comprising: supplying the focusing unit with electrical energy in an electrically isolated manner via an energy converter; providing the first electric grid potential via an adjustable voltage divider of the focusing unit; adjusting the adjustable voltage divider via a control circuit of the focusing unit, the adjusting including supplying the control circuit with at least one electrically isolated control signal of a control unit that is electrically isolated from the X-ray tube, wherein the at least one electrically isolated control signal depends on a value for the first electric grid potential; and adjusting an electric power of the energy converter based on the value for the first electric grid potential.

2. The method as claimed in claim 1, further comprising: selecting the electric power of the energy converter based on at least one of electric power, an electrical voltage or an electrical current of the focusing unit, the at least one of the electric power, the electrical voltage or the electrical current being required by the focusing unit to provide the first electric grid potential.

3. The method as claimed in claim 1, further comprising: ascertaining the electric power of the energy converter based on a characteristic diagram.

4. The method as claimed in claim 1, wherein the energy converter is operated in an operating mode in which the energy converter provides an adjustably constant electrical current at a side of the focusing unit.

5. The method as claimed in claim 1, further comprising: ascertaining the electric power of the energy converter based on an adjustment reserve for the adjustable voltage divider.

6. The method as claimed in claim 1, wherein the energy converter includes a voltage transformer coupled to an electrical energy source and an electrically isolating resonant converter, the electrically isolating resonant converter is electrically coupled to the voltage transformer at an input side, and at least to the focusing unit at an output side, and an input current of the electrically isolating resonant converter is adjusted based on the value for the first electric grid potential.

7. The method as claimed in claim 6, wherein a minimum current value and a maximum current value are defined for the input current, and the method includes detecting the input current, comparing the input current with at least the minimum current value or the maximum current value, and adjusting an electrical voltage provided by the voltage transformer for the electrically isolating resonant converter based on the comparing.

8. The method as claimed in claim 1, wherein a frequency of the electrically isolating control signal depends on the value for the first electric grid potential, and the method includes ascertaining, by the control circuit, the value for the first electric grid potential from the frequency of the electrically isolating control signal.

9. The method as claimed in claim 8, further comprising: deactivating the focusing unit in the case of a defined frequency.

10. The method as claimed in claim 8, further comprising: adjusting an output current of a voltage transformer based on the value for the first electric grid potential.

11. The method as claimed in claim 6, wherein the electrically isolating resonant converter is always operated in a resonance mode at least during a focusing operation.

12. The method as claimed in claim 6, wherein the electrically isolating resonant converter includes a full bridge circuit having two half-bridge circuits, and the method includes activating, during a focusing operation, one of the two half-bridge circuits and at least temporarily deactivating others of the two half-bridge circuits.

13. A circuit arrangement for operating an X-ray tube having at least one grid electrode arranged between an anode electrode and a cathode electrode, the circuit arrangement comprising: a focusing unit configured to focus an electron flow from the cathode electrode to the anode electrode, and to supply the at least one grid electrode, at least in a focusing mode, with a first electric grid potential to focus the electron flow; an energy converter configured to supply the focusing unit with electrical energy in an electrically isolated manner; and a control unit configured to adjust an electric power of the energy converter, the control unit being electrically isolated from the X-ray tube; wherein the focusing unit has an adjustable voltage divider and a control circuit configured to control the adjustable voltage divider; wherein the control unit is configured to provide at least one electrically isolated control signal for the control circuit, the at least one electrically isolated control signal being based on a value for the first electric grid potential; wherein the control circuit is configured to adjust the adjustable voltage divider based on the at least one electrically isolated control signal; and the control unit is configured to adjust the electric power of the energy converter based on the value for the first electric grid potential.

14. The circuit arrangement as claimed in claim 13, further comprising: a switching unit configured to supply, in a first switching state, the at least one grid electrode with the first electric grid potential focusing the electron flow, and supply, in a second switching state, the at least one grid electrode with a second electric grid potential for pinching-off the electron flow between the anode electrode and the cathode electrode.

15. An X-ray device comprising: an X-ray tube having at least one grid electrode arranged between an anode electrode and a cathode electrode; and a circuit arrangement as claimed in claim 13, the circuit arrangement connected, via a connecting cable, to the X-ray tube to operate the X-ray tube.

16. The method of claim 9, wherein the defined frequency is a maximum or a minimum frequency.

17. The method as claimed in claim 2, further comprising: ascertaining the electric power of the energy converter based on a characteristic diagram.

18. The method as claimed in claim 2, wherein the energy converter is operated in an operating mode in which the energy converter provides an adjustably constant electrical current at a side of the focusing unit.

19. The method as claimed in claim 2, wherein the energy converter includes a voltage transformer coupled to an electrical energy source and an electrically isolating resonant converter, the electrically isolating resonant converter is electrically coupled to the voltage transformer at an input side, and at least to the focusing unit at an output side, and an input current of the electrically isolating resonant converter is adjusted based on the value for the first electric grid potential.

20. The method as claimed in claim 19, wherein a minimum current value and a maximum current value are defined for the input current, and the method includes detecting the input current, comparing the input current with at least the minimum current value or the maximum current value, and adjusting an electrical voltage provided by the voltage transformer for the electrically isolating resonant converter based on the comparing.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0060] In the drawings:

[0061] FIG. 1 shows a schematic circuit diagram representation of an X-ray device with an X-ray tube connected to a circuit arrangement, with a detail of a grid actuation of the X-ray tube of the circuit arrangement being illustrated;

[0062] FIG. 2 shows a schematic block diagram representation of the circuit arrangement, including the detail in FIG. 1;

[0063] FIG. 3 shows a schematic block diagram representation of the circuit arrangement in FIG. 2 in a first operating state;

[0064] FIG. 4 shows a schematic block diagram representation of the circuit arrangement in FIG. 2 in a first operating state;

[0065] FIG. 5 shows a schematic graph representation of electrical voltages of the circuit arrangement in the first operating state;

[0066] FIG. 6 shows a schematic graph representation of a supply current in the first operating state provided by an energy converter of the circuit arrangement in FIG. 2;

[0067] FIG. 7 shows a schematic graph representation of the electrical voltages in FIG. 5 in the first operating state;

[0068] FIG. 8 shows a schematic graph representation of the supply current in FIG. 6 in the first operating state;

[0069] FIG. 9 shows a schematic graph representation of the electrical voltages in FIG. 4 in the first operating state; and

[0070] FIG. 10 shows a schematic graph representation of the supply current in FIG. 6 in the first operating state.

DETAILED DESCRIPTION

[0071] FIG. 1 shows in a schematic circuit diagram representation a detail of an X-ray device 10 with an X-ray tube 12, which has an anode electrode 14 and a cathode electrode 16, which are arranged in an evacuated vessel. Arranged between the anode electrode 14 and the cathode electrode 16 is a grid electrode 18. The anode electrode 14 is electrically connected to a terminal 52, the grid electrode to a terminal 50 and the cathode electrode 16 to two terminals 46, 48. For heating purposes the cathode electrode 16 has two terminals, namely the terminals 46 and 48, via which the cathode electrode 16 can be electrically supplied with energy in order to heat the cathode electrode 16 during normal operation to a predefinable temperature so the desired electron emission can be achieved. For this purpose the terminals 46, 48 are electrically connected to an electrical heat energy source 54.

[0072] The terminals 48, 52 are also electrically connected to a voltage source 56, which provides an anode-cathode voltage 72, which is substantially also applied between the cathode electrode 16 and the anode electrode 14. An anode potential of the anode electrode 14 is, as a rule, greater than a cathode potential of the cathode electrode 16.

[0073] Dependent on an electric grid potential at the grid electrode 18, electrons issuing from a cathode material of the cathode electrode 16, forming an electron flow 26, are accelerated to the anode electrode 14. When the electrons impinge on the anode electrode 14, which, as a rule, is designed as a rotating electrode, X-ray radiation is generated and emitted by the X-ray tube 12.

[0074] The function of the X-ray tube 12 can be influenced by the grid potential at the grid electrode 18. On the one hand it is therefore possible to supply the grid electrode 18 with a second electric grid potential with which a pinching-off of the electron flow 26 between the anode electrode 14 and the cathode electrode 16 can be achieved. The second electric grid potential is also referred to as a pinch-off potential. A grid-cathode voltage correspondingly results, which is accordingly referred to as a pinch-off voltage. With X-ray tubes, the pinch-off voltage can lie, for example, in a range from approximately zero to approximately 4 kV. In the present embodiment the pinch-off voltage lies at more than approximately 500 V, for example approximately 3.5 kV or even higher. A transition region between focusing and pinching-off is undesirable because it can result in an undefined focus and in an undefined electron flow in the X-ray tube 12.

[0075] As a rule, the grid potential, at least for the pinching-off of the electron flow 26, is negative with respect to the cathode potential of the cathode electrode 16.

[0076] The second electric grid potential is, as a rule, selected such that a safe, reliable pinching-off of the electron flow 26 can be achieved without damaging an electrical isolation in the X-ray device 10. In many cases the maximum admissible grid-cathode voltage is approximately 4 kV, for which reason the X-ray device 10 with its components is designed accordingly for this voltage.

[0077] Substantially no X-ray radiation is generated during pinching-off of the electron flow 26 because the electron flow 26 is substantially suppressed.

[0078] Furthermore, the grid electrode 18 can be supplied with a first electric grid potential, which allows a release, in particular focusing, of the electron flow 26. A corresponding grid-cathode voltage is also referred to as a focusing voltage. With the focusing voltage, it is possible to release not only the electron flow 26, preferably in a controlled manner, but, at the same time to also control focusing of the electron flow 26 in relation to impinging on the anode electrode 14. A focus 58 on the anode electrode 14 can be achieved, for example in a predefinable manner as a result. The generation of X-ray radiation can be influenced over a wide range as a result.

[0079] A first terminal is connected to a connecting cable 20 at the electrical terminals 46, 48, 50. An opposing terminal of the connecting cable 20 is connected to electrical terminals 60, 62, 64. The connecting cable 20 comprises in particular the high-voltage cable of the cable capacitance 66 influencing the grid voltage. In the present case, the electrical terminals 46, 48, 50, 52 are the tube-side terminals. The electrical terminals 60, 62, 64 are the generator-side terminals.

[0080] The heat energy source 54 is connected to the electrical terminals 60, 62. Connected to the electrical terminals 62, 64 is a circuit arrangement 22 by which the electric grid potential for the grid electrode 18 can be provided in a predefinable manner. FIG. 1 illustrates only a detail of the circuit arrangement 22. A schematic block diagram representation of the circuit arrangement 22 can be found in FIGS. 2 to 4 still illustrated below.

[0081] Furthermore, it can be seen from FIG. 1 that the connecting cable 20 has a cable capacitance, which is symbolically represented in FIG. 1 by a capacitor 66. The capacitor 66 also comprises a grid-cathode capacitance of the X-ray tube 12, although this is not represented further in FIG. 1. The capacitor 66 depends, inter alia, on a length of the cable and can have for example a capacitance value of approximately 4 nF. This is relevant for controlling the X-ray tube in relation to the pinching-off of the electron flow 26 and focusing of the electron flow 26 only by way of the grid electrode 18, as will be illustrated below.

[0082] In the present case, a grid-cathode voltage of approximately zero to approximately 500 V is required for focusing. Depending on the construction of the X-ray tube 12, this voltage can also be different, just like the pinch-off voltage.

[0083] For providing the grid potential the circuit arrangement 22 has an energy supply, which will be illustrated in more detail below and is designated in FIG. 1 only schematically by 38. The energy supply 38 has an internal resistance 68, via which elements and assemblies of the circuit arrangement 22 are supplied with electrical energy for normal operation.

[0084] The circuit arrangement 22 also has a focusing unit 24, which is wired in series with a switching unit 28. This series circuit comprising the focusing unit 24 and the switching unit 28 is connected by the internal resistance 68 to the energy supply 38 and is supplied by it with an operating voltage.

[0085] In the present case, the switching unit 28 provides two switching states, namely a switched-on switching state as a first switching state and a switched-off switching state as a second switching state. The switched-on switching state corresponds to the focusing function and corresponds to the first operating state of the above description. In the switched-on switching state the operating voltage is substantially applied to the focusing unit 24. The focusing unit 24 provides, as will be illustrated below, a grid-cathode voltage, which allows the electron flow 26 to be focused in a predefinable manner.

[0086] In the second switching state of the switching unit 28, in which the switching unit 28 is in the switched-off switching state, the focusing unit 24 is substantially deactivated, so that approximately the operating voltage of the energy supply 38 is provided between the grid electrode 18 and the cathode electrode 16. It should be noted in this connection that substantially no electrical current flows in this operating state, at least in a steady state. If, therefore, the operating voltage is approximately 3.5 kV, this operating voltage, in the switched-off switching state of the switching unit 28, is also applied between the grid electrode 18 and the cathode electrode 16. In the present case, this voltage is negative in relation to the cathode electrode 16 so the grid potential is less than the cathode potential. In this switching state a pinching-off of the electron flow 26 is achieved therefore, so that substantially no electrons reach the anode electrode 14 anymore and therefore the generation of X-ray radiation is substantially interrupted.

[0087] In the first switching state of the switching unit 28, namely the switched-on switching state, the focusing unit 24 is supplied with the operating voltage. The focusing unit 24 then provides a corresponding first electric grid potential so not only is the electron flow 26 released, but a corresponding predefinable focusing of the electron flow 26 can also be achieved on striking the anode electrode 14.

[0088] For this purpose the focusing unit 24 comprises at least one series circuit comprising an electrical resistor 30, which can simultaneously serve as a series resistor in relation to connection of the energy supply 38, and a transistor 32, which in the present case is formed by a field effect transistor, and, more precisely, a self-locking re-channel MOSFET. An adjustable voltage divider is provided as a result. Depending on the embodiment, a different transistor can also be used here, however, in particular also a bipolar transistor.

[0089] In the present case, the transistor 32 has a gate terminal, which is not designated, and which is connected to a control circuit 40, schematically indicated in FIG. 1, which supplies the gate terminal with a predefinable electrical gate potential, so that at a central terminal 34 of this series circuit substantially the electric grid potential can be provided for a first electric grid potential in accordance with a predefinable value. For this purpose the transistor 32 is operated in a linear mode, so that the respective grid potential can be established at the central terminal 34 dependent on the respective adjustment of the gate potential at the transistor 32. As can be seen from the representation in FIG. 1, the focusing unit 24 is activated by the switching-on of the switching unit 28 and deactivated by the switching-off. In the deactivated operating state of the focusing unit 24 the pinch-off potential consequently corresponds to a predefinable value for a second electric grid potential.

[0090] FIG. 2 shows the circuit arrangement 22 now in a schematic block diagram representation. From FIG. 2 it can be seen that, apart from the elements and assemblies already illustrated on the basis of FIG. 1, the circuit arrangement 22 also comprises the energy converter 38, which serves as the energy supply in particular for the focusing unit 24. For this purpose the energy converter 38 is designed as an electrically isolated energy converter to be able to supply the focusing unit 24 and the switching unit 28 electrically coupled to the grid potential and the cathode potential of the X-ray tube 12 with energy. For this purpose the energy converter 38 is connected to a direct voltage source 80. The direct voltage source 80 can for its part be supplied with electrical energy from a public power grid.

[0091] The energy converter 38 is connected to a control unit 74, which provides corresponding control signals for normal operation of the energy converter 38. The control unit 74 is also coupled for communication to a higher-order controller 90, via which operating values, in particular a value for the first electric grid potential, can be predefined.

[0092] Furthermore, an auxiliary converter 82 is provided, which is likewise supplied with electrical energy by the direct voltage source 80. The auxiliary converter 82 is likewise connected to the control unit 74 and is also supplied by it with corresponding (non-designated) control signals for normal operation. The auxiliary converter 82 serves to provide two control signals 42, 44 in an electrically isolated manner, which signals serve to control the control circuit 40. One of the control signals 42 serves to supply the control circuit 40 with electrical energy, whereas a second one of the control signals, and, more precisely, the control signal 44, serves to control at least one operating value for the control circuit 40 and the units controlled by the control circuit 40, namely the focusing unit 24 and the switching unit 28. This will be illustrated in more detail below.

[0093] In the present case, the energy converter 38 has a voltage transformer 76, which is electrically connected at the input side to the direct voltage source 80. At the output side a resonant converter 78 is connected to the voltage transformer 76 and provides an electrical energy supply for the focusing unit 24 and the switching unit 28 in an electrically isolated manner. For this purpose the resonant converter 38 has an inverter 96, which is in the present case is formed from two half-bridge circuits, which operate a resonance circuit whose inductance is formed at least partially by a primary side of a transformer 98 designed as an isolating transformer. At the secondary side the transformer 98 is connected to a rectifier 100, which provides a corresponding direct voltage for the focusing unit 24 and the switching unit 28. A voltage detection unit 84 detects the converted voltage provided by the voltage transformer 76 and supplies a corresponding voltage signal to the control unit 74. The control unit 74 supplies corresponding control signals likewise for the inverter 96, so that the desired converter mode of the resonant converter 78 can be achieved.

[0094] The transformer 98 also comprises an auxiliary winding (not represented further), which is connected to a transformer detection unit 86, which supplies a corresponding transformer signal to the control unit 74.

[0095] In the present case, the auxiliary converter 82 comprises an auxiliary inverter 88 connected to the direct voltage source 80, and an auxiliary transformer 92 connected to the auxiliary inverter 88. The auxiliary transformer 92 is likewise designed as an isolating transformer and connected by its primary winding to the auxiliary inverter 88. A secondary winding of the auxiliary transformer 92 is connected to a rectifier 94, which provides the control signals 42, 44 for the control circuit 40. As already illustrated, the control signal 42 series to supply the control circuit 40 with energy, whereas the control signal 44 supplies corresponding control values, for example a predefined value for the first electric grid potential of the grid electrode 18. In the present case, it is provided that the predefined value for the first electric grid potential is dependent on the frequency of the control signal 44. As long as the frequency of the control signal 44 is greater than a predefined minimum frequency value, the switching unit 28 is switched by the control circuit 40 in the switched-on switching state. At the same time the transistor 32 is adjusted in respect of its electrical conductivity by the control circuit 40 dependent on the frequency, so that a grid-cathode voltage is supplied at the terminals 62, 64 in accordance with the value for the first electric grid potential. The auxiliary inverter 88 is therefore controlled by the control unit 74 accordingly, so that the corresponding control signals 42, 44 can be provided via the rectifier 94. The auxiliary converter 82 therefore serves not only as an energy converter for the control circuit 40, and therewith in particular for the focusing unit, which provides a free from potential energy supply, but the auxiliary converter 82 simultaneously also still serves as an electrically isolating signal transmitter. A signal functionality for transmission of data or signals can therefore simultaneously be achieved by way of the type of control of the auxiliary inverter 88 by the control unit 74, for example by applying a suitable modulation, whereby data or signals can be transmitted in accordance with the control signal 44. The control unit 74 is isolated in terms of electrical potential from the control circuit 40, in particular the focusing unit, as a result. At the same time a control signal can be transmitted to the control circuit 40 with potential isolation. The control signal 42 is consequently an energy signal here, which serves substantially to supply the control circuit 40 with energy.

[0096] FIG. 2 represents an electrical potential isolation 102, which is implemented by the transformers 92, 98. Inter alia, the control unit 74 is electrically isolated from the X-ray tube 12 as a result.

[0097] In the present case, the resonant converter 78 is designed as an LLCC resonant converter. In alternative embodiments a different type of resonant converter or an electrically isolating energy converter can of course also be provided here. The present invention is not limited hereto.

[0098] FIG. 2 shows the circuit arrangement 22, including the detail in FIG. 1. The control circuit 40 receives a desired value for the grid potential and a switching state for the switching unit 28 from the control unit 74. In the present case, the units are operated independently of each other. Both achieve a corresponding regulating functionality. The control unit 74 controls or regulates the energy converter 38, with the control unit 74 receiving corresponding control commands and data from a higher-order controller 90. In the present case, a communications link between the higher-order controller 90 and the control unit 74 is designed as a unidirectional communications link. However, the present invention does not need to be limited to this. Instead, the communications link can also be bidirectional.

[0099] The control circuit 40 assumes the functionality of adjusting the adjustable voltage divider 36, and actuates the transistor 32 accordingly. The corresponding desired values and switching states are transmitted from the control unit 74 to the control circuit 40 via the auxiliary converter 82. Basically, two operating states can be differentiated in this connection, and, more precisely, in the present case a first operating state in which the switching unit 28 is in the switched-on switching state, and therewith the circuit arrangement 22 in a focusing mode, in which by the focusing unit 24 the grid potential of the grid electrode 18 is adjusted in accordance with the predefined value for the first electric grid potential, which has been transmitted as the desired value from the control unit 74 to the control circuit 40. The control circuit 40 provides a regulating functionality in this regard and adjusts the grid potential of the grid electrode 18 accordingly. At the same time, in the present embodiment the grid potential also serves as an electric reference potential of the focusing unit. In alternative embodiments this can vary and for example the cathode potential can also be selected as an electric reference potential. The function of the present invention is independent of this, however.

[0100] In a second operating state, also referred to as grid blocking, the switching unit 28 is switched by the control circuit 40 into the switched-off switching state, so that the grid electrode 18 is supplied with the pinch-off potential. These operating states are adjusted by the control circuit 40 via the control signal 44.

[0101] In the second operating state, as is also represented on the basis of FIG. 3, the focusing unit 24 is deactivated and the switching unit 28 in the switched-off switching state. There is no influencing of the grid potential at the high-voltage side. In this operating state the grid-cathode voltage is dependent on the voltage provided by the energy converter 38, which is dependent on the output voltage of the voltage transformer 76. The voltage transformer 76 can be operated in an unregulated manner in this operating state. Regulation can take place, by contrast, by taking into account the voltage provided by the auxiliary winding of the transformer 98 via the transformer detection unit 86. This variable can provide an actual variable, which is compared with a manipulated variable, which is provided by the output voltage of the voltage transformer 76.

[0102] In this operating state, the resonant converter 78 is operated at a fixed frequency in the LLCC-operating point with a voltage-inflexible output. The actual value for regulating the electric grid potential in this operating state is acquired via the measurement of the voltage at a at the primary-side auxiliary winding of the transformer 98. The grid-cathode voltage can be mapped with the aid of an evaluation by the magnetic coupling between the secondary winding of the transformer 98 and the auxiliary winding. It is thus possible to regulate the grid-cathode voltage at the primary side without a direct electrical coupling to the high-voltage side.

[0103] The situation differs in the focusing mode or in the first operating state in that now the adjustable voltage divider 36 loads the transformer 98 at the secondary side. As already illustrated, the electric grid potential is regulated via the adjustable voltage divider 36 in that the current is changed through the adjustable voltage divider 36 by the transistor 32 by changing its electrical conductivity. With an increase in current, voltage drop increases at the electrical resistor 30 and at the internal resistor 68. The greater this voltage drop becomes, the lower the grid-cathode voltage becomes at the output of the adjustable voltage divider or at the central terminal 34. Since the auxiliary winding approximately maps the secondary-side voltage of the energy converter 38, the electrical voltage detected in the process consequently sinks. This is corrected using the control unit 74, where the voltage provided by the energy converter 38 increases again. The control circuit 40 will react by way of corresponding control of the transistor 32 in order to correct the increased voltage. This produces undesirable positive feedback, which can result not only in a high power loss, in particular in the adjustable voltage divider 36, but also in overloading through to failure of a component. The same can also occur with an inverse regulating situation.

[0104] This behavior is schematically shown by the schematic graphs in FIGS. 5 and 6. FIG. 5 shows a schematic graph representation of electrical voltages of the circuit arrangement 22 in this first operating state, whereas FIG. 6 shows a corresponding schematic graph representation of a supply section of the detail of the circuit arrangement 22 represented in FIG. 1 in the first operating state. In FIG. 5 the ordinate is assigned to the electrical voltage and the abscissa is assigned to the time. In FIG. 6 the ordinate is assigned to the electrical current and the abscissa to the time. The time axes of FIGS. 5 and 6 correspond to each other. FIG. 5 and FIG. 6 belong together.

[0105] FIG. 5 shows voltage characteristics, whereas FIG. 6 shows correspondingly associated current characteristics. An embodiment of the present invention is not applied here. The output voltage of the transformer 98 is regulated (graph 106), and, more precisely, at the element with reference character 68 in FIG. 1. In the present case, this is the leakage inductance with a wire resistance of the transformer 98 (FIG. 2). A desired value of the grid voltage is reduced. The regulating unit in FIG. 1 increases the current through transistor 32 in FIG. 1 as a result in order to increase the voltage drop at the element 68. From this it follows that the input current increases (FIG. 6). The input voltage of the transformer 98 increases (corresponds to transformed voltage or reference character 38 in FIG. 1) as a result, whereby positive feedback is produced.

[0106] As can be seen from FIGS. 5 and 6, in a period of approximately 3 ms to approximately 4 ms an operating state is adjusted in which the grid-cathode voltage is approximately 250 V, which is represented by a graph 108 in FIG. 5. The voltage of the energy converter 38 provided upstream of the internal resistor 68 is approximately 500 V here, and this is represented by a graph 104. The electrical voltage across the focusing unit 24 in series with the switching unit 28, which is in the switched-on switching state in the present case, is approximately 300 V, and this is represented by a graph 106. In the graph in FIG. 6 an electrical current of approximately 40 mA is provided for this period, and flows through the adjustable voltage divider 36. This is represented by a graph 110.

[0107] At instant t=4 ms the desired value for the grid-cathode voltage or the first electric grid potential is changed via the control signal 44, and, more precisely, to a grid-cathode voltage of approximately 150 V, as can be seen with reference to the graph 108 in FIG. 5. Owing to the previously described positive feedback, the control unit 74 will now control the energy converter 38 in such a way that the voltage provided by it compensates the higher load, so that, in accordance with the graph 106, a largely constant voltage is provided. For this the voltage provided by the energy converter 38 increases accordingly, and, more precisely, to a value of approximately 1,000 V. From an instant of approximately t=6.5 ms the value for the first electric grid potential is then reset again to the value indicated before the instant t=4 ms. Accordingly, the electrical voltages change in accordance with the graph 104, 108. From FIG. 6 it can be seen that in the range of t=4 ms to t=6.5 ms there is an electrical current of approximately 150 mA. In said period this results in a considerable power loss, which not only has to be provided by the energy converter 38, but at the same time also has to be dissipated at the high-voltage side, in particular by the adjustable voltage divider 36. This can also result in defects or disruptions. A scenario will be described below, which reduces or avoids this problem.

[0108] A third operating state can be provided, moreover, in which the switching unit 28 is in the switched-on switching state and the transistor 32 is operated in a switching mode in the switched-on switching state. The grid electrode can be short-circuited as a result.

[0109] FIGS. 7 and 8 refer to schematic graph representations like FIGS. 5 and 6, likewise for the first operating state, and, more precisely, with application of one or more example embodiments of the present invention, in which the voltage provided by the energy converter 38 is permanently adjusted by the voltage transformer 76. These two figures also belong together. The graphs again refer to the same variables as already illustrated in relation to FIGS. 5 and 6. As can be seen from FIGS. 7 and 8, the voltage provided by the energy converter 38 is now permanently adjusted here by the control unit 74 to a fixed value of approximately 500 V. At the instant t=4 ms the change state illustrated in relation to FIGS. 5 and 6 is brought about again. From the representations it can be seen that the grid-cathode voltage is accordingly adjusted. At the same time the supply voltage for the adjustable voltage divider 36 is also reduced hereby, by a small value. At the instant of approximately t=6.5 ms the change is reset again. From FIG. 8 it can be seen that the current likewise increases slightly. From FIGS. 7 and 8 it can be seen that with application of one or more example embodiments of the present invention stable operating behavior can be achieved in the first operating state without the large power loss with respect to the application represented in FIGS. 5 and 6.

[0110] The higher-order controller 90 predefines a value for the first electric grid potential. The control unit 74 accordingly provides an output voltage through the energy converter 38. Furthermore, the predefined value for the first electric grid potential is transmitted to the control circuit 40 via the auxiliary converter 82. On the basis of the frequency of the control signal 44, the control circuit 40 recognizes the switching state for the switching unit 28 and switches it into the switched-on switching state. The control circuit 40 recognizes that the frequency is greater than a predefined minimum frequency, below which the switching unit 28 should be switched in the switched-off switching state. Furthermore, it can be provided that a maximum frequency is predefined, on detection of which by the control circuit 40 via the switching unit 28 and the transistor 32 there is direct coupling to the electrical cathode potential, whereby a short-circuit can virtually be achieved between the grid electrode 18 and the cathode 16. Intermediate values in relation to the frequency can then be used to determine a respective value for the first electric grid potential in that a respective value is assigned to a respective frequency.

[0111] The function of this circuitry principle can also be seen by way of the schematic circuit diagram representation of the circuit arrangement 22 in FIG. 3, in which the voltage detection unit 84 is used for the first operating state with respect to the first operating state in FIG. 2. Unit 86 is used for the second operating state by contrast.

[0112] In an alternative embodiment to the second operating state, it can be provided that an output current of the voltage transformer 76 can be used to simplify a characteristic diagram for control or regulation. Control or regulation can take place on the basis of this output current here.

[0113] In a further alternative to the second operating state, a minimum value and a maximum value can be predefined for an input current of the resonant converter 78. A tolerance band regulation can then be achieved on the basis of this. For example if the voltage provided by the energy converter 38 is too small for adjusting a predefined value for the first electric grid potential by way of the adjustable voltage divider 36, owing to the regulating functionality of the control circuit 40, the current through the transistor 32 could become zero. The input current of the resonant converter 78 could also undershoot the minimum value thereby. In this case it is provided that the control unit 74 carries out regulating in such a way that the voltage provided by the voltage transformer 76 is increased. It is then no longer the voltage which is regulated, but the current instead. If said positive feedback would increase the voltage provided by the energy converter, and therewith also the current for the adjustable voltage divider 36, it would be possible to limit the maximum current in the same way. Overall, at least in the second operating state, with application of one or more example embodiments of the present invention, it is possible for the input voltage of the transformer 98 to remain substantially stable.

[0114] FIGS. 9 and 10 show in schematic graph representations, like FIGS. 5 and 6, the situation for the first operating state in accordance with a further embodiment of the present invention, as will be illustrated below. The reference characters of the graphs of FIGS. 9 and 10 correspond to the respective graphs in FIGS. 5 and 6. The graph axes correspond to those as have already been illustrated in relation to FIGS. 5 and 6. These two figures also belong together. In this embodiment of the present invention it is provided for the first operating state that, at least in the focusing mode, the voltage provided by the energy converter 38 is based on a current source characteristic. This can be achieved by suitable regulating via the control unit 74. Furthermore, there exists the possibility of increasing an operating frequency or clock rate of the resonant converter 78 in order to operate it in the actual resonance, in particular the LLCC resonance. At this frequency an output current of the resonant converter 78 is substantially independent of a load and determined only by an oscillating circuit inductance and an input voltage of the resonant converter 78. As a result, regulating by way of the controller 74 and the resonant converter itself can be operated in a controlled manner because, owing to the current source characteristic, a suitable, sufficiently high voltage can always be established at the output of the energy converter 38. A sufficient regulating reserve can be achieved for normal operation of the focusing unit 24, in particular of the adjustable voltage divider 36. This is shown by the schematic block diagram representation in FIG. 4 in which the transformer detection unit 86 does not need to be used for the focusing mode. The undesirable positive feedback can be avoided hereby.

[0115] As can be seen from FIGS. 9 and 10, in accordance with the graph 110, the current is—independently of carrying out the changes in relation to the value for the first electric grid potential, almost independently substantially at a value of approximately 10 mA. From FIG. 9 it can be seen that the corresponding voltages are varied. With respect to FIG. 5, it can be seen that the voltage provided by the energy converter 38 in the period of approximately 4 ms to approximately 6.5 ms in the third operating state is even smaller than in the period before t=4 milliseconds. Normal operation can be achieved with particularly low power as a result. This is advantageous for the construction of the circuit arrangement, in particular of the X-ray device 10, because, firstly, much less power is required compared to the first operating state and, secondly, owing to the much lower power during normal operation, the components can have a more cost-effective and more compact design.

[0116] To be able to achieve further advantages in respect of normal operation it can be provided that in particular the inverter 96 can be dynamically operated in respect of its operating mode. This can take into account the fact that the pinch-off voltage, as a rule, lies in a range of several kilovolts. As a rule, the focusing voltage in the focusing mode is, by contrast, only a few 100 V. It can therefore be advantageous in the focusing mode to deactivate one of the half-bridge circuits of the inverter 96. The voltage transmission ratio of the resonant converter 78 can thereby be reduced, substantially halved, accordingly.

[0117] In an alternative embodiment it can also be provided that two separate converters are provided. With a change between providing the pinch-off voltage and the focusing voltage, it is possible to switch over between outputs of the converter. For example short switchover times, in particular great rates of change, for example on a switchover from focusing to blocking or pinching-off of the electron flow, can be achieved thereby. A switchover time from blocking or pinching-off of the electron flow to focusing can be determined by the focusing unit. Each of the converters can be optimally designed for its output voltage range.

[0118] It will be understood that, although the terms first, second, etc. may be used herein to describe various elements, components, regions, layers, and/or sections, these elements, components, regions, layers, and/or sections, should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element, without departing from the scope of example embodiments. As used herein, the term “and/or,” includes any and all combinations of one or more of the associated listed items. The phrase “at least one of” has the same meaning as “and/or”.

[0119] Spatially relative terms, such as “beneath,” “below,” “lower,” “under,” “above,” “upper,” and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as “below,” “beneath,” or “under,” other elements or features would then be oriented “above” the other elements or features. Thus, the example terms “below” and “under” may encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly. In addition, when an element is referred to as being “between” two elements, the element may be the only element between the two elements, or one or more other intervening elements may be present.

[0120] Spatial and functional relationships between elements (for example, between modules) are described using various terms, including “on,” “connected,” “engaged,” “interfaced,” and “coupled.” Unless explicitly described as being “direct,” when a relationship between first and second elements is described in the disclosure, that relationship encompasses a direct relationship where no other intervening elements are present between the first and second elements, and also an indirect relationship where one or more intervening elements are present (either spatially or functionally) between the first and second elements. In contrast, when an element is referred to as being “directly” on, connected, engaged, interfaced, or coupled to another element, there are no intervening elements present. Other words used to describe the relationship between elements should be interpreted in a like fashion (e.g., “between,” versus “directly between,” “adjacent,” versus “directly adjacent,” etc.).

[0121] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments. As used herein, the singular forms “a,” “an,” and “the,” are intended to include the plural forms as well, unless the context clearly indicates otherwise. As used herein, the terms “and/or” and “at least one of” include any and all combinations of one or more of the associated listed items. It will be further understood that the terms “comprises,” “comprising,” “includes,” and/or “including,” when used herein, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. Expressions such as “at least one of,” when preceding a list of elements, modify the entire list of elements and do not modify the individual elements of the list. Also, the term “example” is intended to refer to an example or illustration.

[0122] It should also be noted that in some alternative implementations, the functions/acts noted may occur out of the order noted in the figures. For example, two figures shown in succession may in fact be executed substantially concurrently or may sometimes be executed in the reverse order, depending upon the functionality/acts involved.

[0123] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which example embodiments belong. It will be further understood that terms, e.g., those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[0124] It is noted that some example embodiments may be described with reference to acts and symbolic representations of operations (e.g., in the form of flow charts, flow diagrams, data flow diagrams, structure diagrams, block diagrams, etc.) that may be implemented in conjunction with units and/or devices discussed above. Although discussed in a particularly manner, a function or operation specified in a specific block may be performed differently from the flow specified in a flowchart, flow diagram, etc. For example, functions or operations illustrated as being performed serially in two consecutive blocks may actually be performed simultaneously, or in some cases be performed in reverse order. Although the flowcharts describe the operations as sequential processes, many of the operations may be performed in parallel, concurrently or simultaneously. In addition, the order of operations may be re-arranged. The processes may be terminated when their operations are completed, but may also have additional steps not included in the figure. The processes may correspond to methods, functions, procedures, subroutines, subprograms, etc.

[0125] Specific structural and functional details disclosed herein are merely representative for purposes of describing example embodiments. The present invention may, however, be embodied in many alternate forms and should not be construed as limited to only the embodiments set forth herein.

[0126] In addition, or alternative, to that discussed above, units and/or devices according to one or more example embodiments may be implemented using hardware, software, and/or a combination thereof. For example, hardware devices may be implemented using processing circuitry such as, but not limited to, a processor, Central Processing Unit (CPU), a controller, an arithmetic logic unit (ALU), a digital signal processor, a microcomputer, a field programmable gate array (FPGA), a System-on-Chip (SoC), a programmable logic unit, a microprocessor, or any other device capable of responding to and executing instructions in a defined manner. Portions of the example embodiments and corresponding detailed description may be presented in terms of software, or algorithms and symbolic representations of operation on data bits within a computer memory. These descriptions and representations are the ones by which those of ordinary skill in the art effectively convey the substance of their work to others of ordinary skill in the art. An algorithm, as the term is used here, and as it is used generally, is conceived to be a self-consistent sequence of steps leading to a desired result. The steps are those requiring physical manipulations of physical quantities. Usually, though not necessarily, these quantities take the form of optical, electrical, or magnetic signals capable of being stored, transferred, combined, compared, and otherwise manipulated. It has proven convenient at times, principally for reasons of common usage, to refer to these signals as bits, values, elements, symbols, characters, terms, numbers, or the like.

[0127] It should be borne in mind that all of these and similar terms are to be associated with the appropriate physical quantities and are merely convenient labels applied to these quantities. Unless specifically stated otherwise, or as is apparent from the discussion, terms such as “processing” or “computing” or “calculating” or “determining” of “displaying” or the like, refer to the action and processes of a computer system, or similar electronic computing device/hardware, that manipulates and transforms data represented as physical, electronic quantities within the computer system's registers and memories into other data similarly represented as physical quantities within the computer system memories or registers or other such information storage, transmission or display devices.

[0128] In this application, including the definitions below, the term ‘module’ or the term ‘controller’ may be replaced with the term ‘circuit.’ The term ‘module’ may refer to, be part of, or include processor hardware (shared, dedicated, or group) that executes code and memory hardware (shared, dedicated, or group) that stores code executed by the processor hardware.

[0129] The module may include one or more interface circuits. In some examples, the interface circuits may include wired or wireless interfaces that are connected to a local area network (LAN), the Internet, a wide area network (WAN), or combinations thereof. The functionality of any given module of the present disclosure may be distributed among multiple modules that are connected via interface circuits. For example, multiple modules may allow load balancing. In a further example, a server (also known as remote, or cloud) module may accomplish some functionality on behalf of a client module.

[0130] Software may include a computer program, program code, instructions, or some combination thereof, for independently or collectively instructing or configuring a hardware device to operate as desired. The computer program and/or program code may include program or computer-readable instructions, software components, software modules, data files, data structures, and/or the like, capable of being implemented by one or more hardware devices, such as one or more of the hardware devices mentioned above. Examples of program code include both machine code produced by a compiler and higher level program code that is executed using an interpreter.

[0131] For example, when a hardware device is a computer processing device (e.g., a processor, Central Processing Unit (CPU), a controller, an arithmetic logic unit (ALU), a digital signal processor, a microcomputer, a microprocessor, etc.), the computer processing device may be configured to carry out program code by performing arithmetical, logical, and input/output operations, according to the program code. Once the program code is loaded into a computer processing device, the computer processing device may be programmed to perform the program code, thereby transforming the computer processing device into a special purpose computer processing device. In a more specific example, when the program code is loaded into a processor, the processor becomes programmed to perform the program code and operations corresponding thereto, thereby transforming the processor into a special purpose processor.

[0132] Software and/or data may be embodied permanently or temporarily in any type of machine, component, physical or virtual equipment, or computer storage medium or device, capable of providing instructions or data to, or being interpreted by, a hardware device. The software also may be distributed over network coupled computer systems so that the software is stored and executed in a distributed fashion. In particular, for example, software and data may be stored by one or more computer readable recording mediums, including the tangible or non-transitory computer-readable storage media discussed herein.

[0133] Even further, any of the disclosed methods may be embodied in the form of a program or software. The program or software may be stored on a non-transitory computer readable medium and is adapted to perform any one of the aforementioned methods when run on a computer device (a device including a processor). Thus, the non-transitory, tangible computer readable medium, is adapted to store information and is adapted to interact with a data processing facility or computer device to execute the program of any of the above mentioned embodiments and/or to perform the method of any of the above mentioned embodiments.

[0134] Example embodiments may be described with reference to acts and symbolic representations of operations (e.g., in the form of flow charts, flow diagrams, data flow diagrams, structure diagrams, block diagrams, etc.) that may be implemented in conjunction with units and/or devices discussed in more detail below. Although discussed in a particularly manner, a function or operation specified in a specific block may be performed differently from the flow specified in a flowchart, flow diagram, etc. For example, functions or operations illustrated as being performed serially in two consecutive blocks may actually be performed simultaneously, or in some cases be performed in reverse order.

[0135] According to one or more example embodiments, computer processing devices may be described as including various functional units that perform various operations and/or functions to increase the clarity of the description. However, computer processing devices are not intended to be limited to these functional units. For example, in one or more example embodiments, the various operations and/or functions of the functional units may be performed by other ones of the functional units. Further, the computer processing devices may perform the operations and/or functions of the various functional units without sub-dividing the operations and/or functions of the computer processing units into these various functional units.

[0136] Units and/or devices according to one or more example embodiments may also include one or more storage devices. The one or more storage devices may be tangible or non-transitory computer-readable storage media, such as random access memory (RAM), read only memory (ROM), a permanent mass storage device (such as a disk drive), solid state (e.g., NAND flash) device, and/or any other like data storage mechanism capable of storing and recording data. The one or more storage devices may be configured to store computer programs, program code, instructions, or some combination thereof, for one or more operating systems and/or for implementing the example embodiments described herein. The computer programs, program code, instructions, or some combination thereof, may also be loaded from a separate computer readable storage medium into the one or more storage devices and/or one or more computer processing devices using a drive mechanism. Such separate computer readable storage medium may include a Universal Serial Bus (USB) flash drive, a memory stick, a Blu-ray/DVD/CD-ROM drive, a memory card, and/or other like computer readable storage media. The computer programs, program code, instructions, or some combination thereof, may be loaded into the one or more storage devices and/or the one or more computer processing devices from a remote data storage device via a network interface, rather than via a local computer readable storage medium. Additionally, the computer programs, program code, instructions, or some combination thereof, may be loaded into the one or more storage devices and/or the one or more processors from a remote computing system that is configured to transfer and/or distribute the computer programs, program code, instructions, or some combination thereof, over a network. The remote computing system may transfer and/or distribute the computer programs, program code, instructions, or some combination thereof, via a wired interface, an air interface, and/or any other like medium.

[0137] The one or more hardware devices, the one or more storage devices, and/or the computer programs, program code, instructions, or some combination thereof, may be specially designed and constructed for the purposes of the example embodiments, or they may be known devices that are altered and/or modified for the purposes of example embodiments.

[0138] A hardware device, such as a computer processing device, may run an operating system (OS) and one or more software applications that run on the OS. The computer processing device also may access, store, manipulate, process, and create data in response to execution of the software. For simplicity, one or more example embodiments may be exemplified as a computer processing device or processor; however, one skilled in the art will appreciate that a hardware device may include multiple processing elements or processors and multiple types of processing elements or processors. For example, a hardware device may include multiple processors or a processor and a controller. In addition, other processing configurations are possible, such as parallel processors.

[0139] The computer programs include processor-executable instructions that are stored on at least one non-transitory computer-readable medium (memory). The computer programs may also include or rely on stored data. The computer programs may encompass a basic input/output system (BIOS) that interacts with hardware of the special purpose computer, device drivers that interact with particular devices of the special purpose computer, one or more operating systems, user applications, background services, background applications, etc. As such, the one or more processors may be configured to execute the processor executable instructions.

[0140] The computer programs may include: (i) descriptive text to be parsed, such as HTML (hypertext markup language) or XML (extensible markup language), (ii) assembly code, (iii) object code generated from source code by a compiler, (iv) source code for execution by an interpreter, (v) source code for compilation and execution by a just-in-time compiler, etc. As examples only, source code may be written using syntax from languages including C, C++, C#, Objective-C, Haskell, Go, SQL, R, Lisp, Java®, Fortran, Perl, Pascal, Curl, OCaml, Javascript®, HTML5, Ada, ASP (active server pages), PHP, Scala, Eiffel, Smalltalk, Erlang, Ruby, Flash®, Visual Basic®, Lua, and Python®.

[0141] Further, at least one example embodiment relates to the non-transitory computer-readable storage medium including electronically readable control information (processor executable instructions) stored thereon, configured in such that when the storage medium is used in a controller of a device, at least one embodiment of the method may be carried out.

[0142] The computer readable medium or storage medium may be a built-in medium installed inside a computer device main body or a removable medium arranged so that it can be separated from the computer device main body. The term computer-readable medium, as used herein, does not encompass transitory electrical or electromagnetic signals propagating through a medium (such as on a carrier wave); the term computer-readable medium is therefore considered tangible and non-transitory. Non-limiting examples of the non-transitory computer-readable medium include, but are not limited to, rewriteable non-volatile memory devices (including, for example flash memory devices, erasable programmable read-only memory devices, or a mask read-only memory devices); volatile memory devices (including, for example static random access memory devices or a dynamic random access memory devices); magnetic storage media (including, for example an analog or digital magnetic tape or a hard disk drive); and optical storage media (including, for example a CD, a DVD, or a Blu-ray Disc). Examples of the media with a built-in rewriteable non-volatile memory, include but are not limited to memory cards; and media with a built-in ROM, including but not limited to ROM cassettes; etc. Furthermore, various information regarding stored images, for example, property information, may be stored in any other form, or it may be provided in other ways.

[0143] The term code, as used above, may include software, firmware, and/or microcode, and may refer to programs, routines, functions, classes, data structures, and/or objects. Shared processor hardware encompasses a single microprocessor that executes some or all code from multiple modules. Group processor hardware encompasses a microprocessor that, in combination with additional microprocessors, executes some or all code from one or more modules. References to multiple microprocessors encompass multiple microprocessors on discrete dies, multiple microprocessors on a single die, multiple cores of a single microprocessor, multiple threads of a single microprocessor, or a combination of the above.

[0144] Shared memory hardware encompasses a single memory device that stores some or all code from multiple modules. Group memory hardware encompasses a memory device that, in combination with other memory devices, stores some or all code from one or more modules.

[0145] The term memory hardware is a subset of the term computer-readable medium. The term computer-readable medium, as used herein, does not encompass transitory electrical or electromagnetic signals propagating through a medium (such as on a carrier wave); the term computer-readable medium is therefore considered tangible and non-transitory. Non-limiting examples of the non-transitory computer-readable medium include, but are not limited to, rewriteable non-volatile memory devices (including, for example flash memory devices, erasable programmable read-only memory devices, or a mask read-only memory devices); volatile memory devices (including, for example static random access memory devices or a dynamic random access memory devices); magnetic storage media (including, for example an analog or digital magnetic tape or a hard disk drive); and optical storage media (including, for example a CD, a DVD, or a Blu-ray Disc). Examples of the media with a built-in rewriteable non-volatile memory, include but are not limited to memory cards; and media with a built-in ROM, including but not limited to ROM cassettes; etc. Furthermore, various information regarding stored images, for example, property information, may be stored in any other form, or it may be provided in other ways.

[0146] The apparatuses and methods described in this application may be partially or fully implemented by a special purpose computer created by configuring a general purpose computer to execute one or more particular functions embodied in computer programs. The functional blocks and flowchart elements described above serve as software specifications, which can be translated into the computer programs by the routine work of a skilled technician or programmer.

[0147] Although described with reference to specific examples and drawings, modifications, additions and substitutions of example embodiments may be variously made according to the description by those of ordinary skill in the art. For example, the described techniques may be performed in an order different with that of the methods described, and/or components such as the described system, architecture, devices, circuit, and the like, may be connected or combined to be different from the above-described methods, or results may be appropriately achieved by other components or equivalents.

[0148] Although the present invention has been shown and described with respect to certain example embodiments, the example embodiments serve solely to illustrate the present invention and do not limit it. Equivalents and modifications will occur to others skilled in the art upon the reading and understanding of the specification. The present invention includes all such equivalents and modifications and is limited only by the scope of the appended claims.