CA1193751A - Method of operating an x-ray generator, and x-ray generator suitable for this method - Google Patents
Method of operating an x-ray generator, and x-ray generator suitable for this methodInfo
- Publication number
- CA1193751A CA1193751A CA000404426A CA404426A CA1193751A CA 1193751 A CA1193751 A CA 1193751A CA 000404426 A CA000404426 A CA 000404426A CA 404426 A CA404426 A CA 404426A CA 1193751 A CA1193751 A CA 1193751A
- Authority
- CA
- Canada
- Prior art keywords
- filament
- ray
- filament current
- stand
- tube
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05G—X-RAY TECHNIQUE
- H05G1/00—X-ray apparatus involving X-ray tubes; Circuits therefor
- H05G1/08—Electrical details
- H05G1/70—Circuit arrangements for X-ray tubes with more than one anode; Circuit arrangements for apparatus comprising more than one X ray tube or more than one cathode
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05G—X-RAY TECHNIQUE
- H05G1/00—X-ray apparatus involving X-ray tubes; Circuits therefor
- H05G1/08—Electrical details
- H05G1/26—Measuring, controlling or protecting
- H05G1/30—Controlling
- H05G1/34—Anode current, heater current or heater voltage of X-ray tube
Abstract
ABSTRACT:
The method of operating an X-ray generator in accordance with the invention involves the storage of a plurality of stand-by filament current values for differ-ent X-ray tube filaments. Before an exposure using the selected X-ray tube or the corresponding filament, by value stored is addressed and adjusted as a stand-by filament current. Consequently, by a suitable selection of the stand-by filament current values, the period of time required for the heating of its filament to the ultimate temperature can be reduced. The preparation time can thus be substantially reduced.
The method of operating an X-ray generator in accordance with the invention involves the storage of a plurality of stand-by filament current values for differ-ent X-ray tube filaments. Before an exposure using the selected X-ray tube or the corresponding filament, by value stored is addressed and adjusted as a stand-by filament current. Consequently, by a suitable selection of the stand-by filament current values, the period of time required for the heating of its filament to the ultimate temperature can be reduced. The preparation time can thus be substantially reduced.
Description
3 ~75 ~
PHD 81.065 1 07.05.1982 Methcd of operating an X-ray generator, and X-ray generator suitable for this method.
The invention relates to a rret`nod of operating an X-ray system comprising an X-ray generator for a plurality of X-ray tukes with a de-vice for adjusting a stand-by filament current for the filament of an X-ray tuke during the intervals between exFosures, and also relates to an X-ray generator intended for this method.
An exposure is usually preceded by a preparation phase during which inter alia the temperature of the cathode filament is raised to the value required for the exposure; however, during this phase tlle tuke voltage is not yet switched on, so that no radiation is yet produced.
The duration of this preparation phase can ke reduced by boosting the filament, but such a reduction cannot ke substantial when the risk of burning through of the filament is to be avoided. Therefore, in order to reduce the preparation period it is known to apply, during the stand-by periods, a stand-by filament current .o the filament of the X-ray tu~e to be used for a later exposure. The filament temperature, and hence also the ohmic resistance, of the filament is thus increased, so that the ul-timate tem~erat~lre of the filarrent can be reached sukstantially sooner during a subsequent preparation phase.
When one X-ray generator is used for several X-ray tukes with different filaments, the stand-ky filament current is generally chosen so that it has exactly the correct value for the filament having the highest resistance. Consequently, when X-ray tukes comprising low-ohmic filaments are connected, comparatively long preparation periods are rec~lired in order to reach the filament temperature required for the exposure.
It is an object of the present invention to provide a method of the kind set forth in which the ultimate temperature of the filament can be reached more quic]cly during the preparation phase, and also to provide an X-ray generator which is suitable for this method.
This ob~ect is achieved in accordance with the in~7ention in that there are stored a plurality of stand-by filar.~ent current values which are associated with different X-ray tuke filaments, the stand-by filament current value associated with an X-ray tube which is conne ~3~
PHD 31.065 2 07.05.1982 to the high-voltage generator being addressed ar.d adjusted for the rele vant filament. A~cordingly, the X-ray generator for performing this methcd which comprises a tuke selection device for selecting an X-ray tube, a focus selection device, and a filament current adjusting nem~er which is controlled by a filament current value s.ored, is characterized in that there is provided a non-volatile digital memory device comprising a plurality of cells for different stand-by filament current values, the tube selection device being coupled to a device for the addressing and accessing of the memory device so that for each tu~e fila~.ent selected by the tuke selection device and the focus selection device a given memory cell is addressed, whose content is used to control a fila-ment current adjusting memker.
The invention will be described in detail hereinafter with re-ference to the drawing; therein;
Figure 1 shows a block diagram of an X-ray generator in accor-dance with the invention, Figur.e 2 shows a block diagram of the control device and -the memory device of the X-ray generator shown in Figure 1, Figure 3 shows a further detail of the X-ray generator sh~n in Figure 1, and Figure 4 shows flowcharts of the operation of the X-ray genera-tor and its control system in accordance with the invention.
The X-ray generator in accordance with the invention comprises a high-voltage generator 1 whereto one of several (three in the present em~odiment) X-ray tubes 14, 15, 16 can be connected via a high-voltage switch 2. Each of the X-ray tubes comprises two filaments 4, 4', 5, 5', 6, 6'. The high-vol-tage generator thus comprises, in addition to a high-voltage transformer for generating the tube voltage, two filament curren-t transformers whose primary windings can ke connected i.n known 30 manner to the filaments 4, 4', 5, 5', 6, 6', by means of the focus selec-tion devices 17, 1~, 19 in order to supply the filament currents for the fiL~ments of an X-ray tube. The filament current transformers (not shown) may form part of a filament current control circuit 3 which con-sists of a comparison mer.~er 31 which compares the actual value of the 35 filament current with a reference value and a control amplifier 32 which .
amplifies the control deviation which i5 applied to -the connected filament current transformer, so that the actual value of the fil.ament current substantially corresponds to its reference value.
3~
PHD 81.065 3 07.05.1982 The reference value of the filament c~rrent is supplied by a digital-to-analog converter 7 which is connected to an intenrediate memory 8 which in its turn is coupled, via switching means 10, to a memory 9 which is cons~ructed as a programmab].e read-only memory. The read-only memory 9 comprises a first ~Em~ry section 91 in which filament current values are stored (as known from DE-OS 27 03 420) and a second memory section which comprises memory ce].ls 94~ 95 and 96 in which the stand by filament current values for the three X-ray tubes 14, 15 and 16 are s-tored (tw~ s-tand-by fila~.ent current values for each X-ray tube).
These stand-by filament current values are chosen for each X-ray tube and each of its filaments so that a given maximum emission value is maintained, for example, 20 /uA , during operation of the X ray tube with this rilament current when a high voltage is applied (for example, 40 kV) to the tu~e. This step is necessary to ensure that, even in the case where the filamient associated with the large focus is preselected for the exposure mocle whilst fluoroscopy takes place by means of the filaments 4, 5, 6 for the small focus, the image quality and tlle control properties of the fluoroscopy control circuit are not substantially influenced by the additionc~l emission of the filament whereto the stand-by current is applied.
The switching means 10 and the high-voltage switch 2 for the selection of the X-ray tube as well as the focus selection device (not shown) are coupled to one another v a control device 11 so that the memory cell 94 acts for the X-ray tube 14, the memory cell 95 for the X-ray tube 15 and the memory cell 96 for t~.e X-ray tube 16, the measured stand-b~ filament current values for each filament being stored in said cells in the described mc~nner. It is thus ensured that at the beginning of the preparation period the filament already has such a tempe-rature that only a comparatively short period of time is required in order to reach the u].timate temperature. When the preparation phase is initiated, signalled also to the control device 11 via th.e input 12, a switch over takes place to the memory section 91 in wich the filament current required for an exposure is stored for the relevant X-ray tuke.
The control device 11 is preferably realized by means of a microcomputer; the access to the read-only memory 9 then tc~kes place _ a bus which connects the microcomputer to the read-only memory 9 an~i the intermediate memory 8.
3~5~
PHD 81.065 4 07.05~1982 The control device 11 and the me~ory 9 are shown in greater detail in Figure 2. The control device 11 comprises a microprocessor 20 (Intel 8086), a clock generator 21 (8284), an interrup-t controller 22 (8259A), an octal latch-circuit 23 (8282), and scme further circuits which will ke described later on. The micro2rocessor 20 comprises an address/data h1s 24 which interconnects the latch-circuit 23, the memory 9' (2732, 2118) and the interrupt controller 22. An address generated by the ~icroprocessor 20 is latched into the circuit 23 on a stro~e signal which is applied to the stro~e input STB of the circuit 23 by the micro-processor 20 via a control line of the bus 25. The address can be placedon the address bus 26 by an output enable signal OE which is received by the circuit 23 via the control bus 25. The sianals on the control bus 25 or the address bus 26 are placed on a system hus 27 via bus driver circuits 28a and c (75LS244). The memory 9' is connected to the data bus 24 and to the address bus 26. Via a memory decoder 29 (N82S137), thie read-only memory 9 or the random access me~ory 9a is activated. For proper operation, the deccder circuit 29 receives (a part of) -the address from the latch-circuit 23 and also a further control signal which indicates whether an input is to be received or an output is to be despatched to the system bus via a bidirectional bus driver 28d (8286).
The stand-by mcde of the X-ray system is initiated by a signal on the interrupt input 12 which activates, via the interrupt controller 22, thie microprocessor 2O which could ke in a waiting routine (4~0) at that instant. The microprocessor 20 reads the selected X ray tube number i and thie selected filament thereof by applying thie corresponding address;
via the latch-circuit 23 and the bus driver 28a, to the system bus 27 and by taking in the data via the driver circuit 28d (step 4-1 of the flow-chart of Figure 4), As appears from Figure 3 the position of switch 2 is sensed via an input multiplex circuit 40 (HEF-4512), which receives via a bus 41, an address of an inpu-t to be sensed and supplies an output HIGH on output line 42 if said input is connected to ~V via switch 2'~
The ~switch 2' is mechanically linked to the switch 2 to ke sensed. The microprocessor 20 selects, on the basis of the tub~num~er l, the address (ADRti)) of the stand-by current table which is stored in the memory 9 (step 4-2, Figure 4). The processor 20 subsequently checks which filament has been selected ~large focus (LF) for large tube current, small focus for snk~ tube current, step 4-3, Figure 4). If the large focus is used, the address generated on the kasis oE the tube num~er 1 is incremented by a fixed ~3~5~
PHD 81.065 5 07.05.1982 value C (step 4-4, Figure 4). If the small focus is used, step 4~4 is skipped. The address thus generated is latched into the circuit 23 and the filament current value (If) can be read from the memory 9 (step 4 5, Figure 4). I-t will be clear -that the switching means 10 (fisure 1) are actually formed by the latch-circuit 23 and the decoder circuit 29.
Chlring the next step (4-6) the filament current value is fed, via the driver circuit 28d and the system bus 27, to the latching-circuits 8 (4516, see Figure 3), the input lines of which are connected to the system hus 27. The filament current value is latched into the circuit 8 whose outputs are connected to the digital-to-analog converter 7, an output of ~hich is connected to the filament current control circuit 3. The X-ray system then enters a preparation stage 4-7.
The stand-by filam~ent current values can be programmed in indi-vidual memory cells (94, ...... 96, Figure 2) which are each time associated with a tube, extensions being possible by the addition of storage units, or they can be program~ed in accumulator memories which are manufactured for all types of tu~e which can be connected to the generator, the addres-sing of the values stored and their assigmrent to the connected X-ray tubes being governed by the programming of the control device or the 20 microcomputer 2s
PHD 81.065 1 07.05.1982 Methcd of operating an X-ray generator, and X-ray generator suitable for this method.
The invention relates to a rret`nod of operating an X-ray system comprising an X-ray generator for a plurality of X-ray tukes with a de-vice for adjusting a stand-by filament current for the filament of an X-ray tuke during the intervals between exFosures, and also relates to an X-ray generator intended for this method.
An exposure is usually preceded by a preparation phase during which inter alia the temperature of the cathode filament is raised to the value required for the exposure; however, during this phase tlle tuke voltage is not yet switched on, so that no radiation is yet produced.
The duration of this preparation phase can ke reduced by boosting the filament, but such a reduction cannot ke substantial when the risk of burning through of the filament is to be avoided. Therefore, in order to reduce the preparation period it is known to apply, during the stand-by periods, a stand-by filament current .o the filament of the X-ray tu~e to be used for a later exposure. The filament temperature, and hence also the ohmic resistance, of the filament is thus increased, so that the ul-timate tem~erat~lre of the filarrent can be reached sukstantially sooner during a subsequent preparation phase.
When one X-ray generator is used for several X-ray tukes with different filaments, the stand-ky filament current is generally chosen so that it has exactly the correct value for the filament having the highest resistance. Consequently, when X-ray tukes comprising low-ohmic filaments are connected, comparatively long preparation periods are rec~lired in order to reach the filament temperature required for the exposure.
It is an object of the present invention to provide a method of the kind set forth in which the ultimate temperature of the filament can be reached more quic]cly during the preparation phase, and also to provide an X-ray generator which is suitable for this method.
This ob~ect is achieved in accordance with the in~7ention in that there are stored a plurality of stand-by filar.~ent current values which are associated with different X-ray tuke filaments, the stand-by filament current value associated with an X-ray tube which is conne ~3~
PHD 31.065 2 07.05.1982 to the high-voltage generator being addressed ar.d adjusted for the rele vant filament. A~cordingly, the X-ray generator for performing this methcd which comprises a tuke selection device for selecting an X-ray tube, a focus selection device, and a filament current adjusting nem~er which is controlled by a filament current value s.ored, is characterized in that there is provided a non-volatile digital memory device comprising a plurality of cells for different stand-by filament current values, the tube selection device being coupled to a device for the addressing and accessing of the memory device so that for each tu~e fila~.ent selected by the tuke selection device and the focus selection device a given memory cell is addressed, whose content is used to control a fila-ment current adjusting memker.
The invention will be described in detail hereinafter with re-ference to the drawing; therein;
Figure 1 shows a block diagram of an X-ray generator in accor-dance with the invention, Figur.e 2 shows a block diagram of the control device and -the memory device of the X-ray generator shown in Figure 1, Figure 3 shows a further detail of the X-ray generator sh~n in Figure 1, and Figure 4 shows flowcharts of the operation of the X-ray genera-tor and its control system in accordance with the invention.
The X-ray generator in accordance with the invention comprises a high-voltage generator 1 whereto one of several (three in the present em~odiment) X-ray tubes 14, 15, 16 can be connected via a high-voltage switch 2. Each of the X-ray tubes comprises two filaments 4, 4', 5, 5', 6, 6'. The high-vol-tage generator thus comprises, in addition to a high-voltage transformer for generating the tube voltage, two filament curren-t transformers whose primary windings can ke connected i.n known 30 manner to the filaments 4, 4', 5, 5', 6, 6', by means of the focus selec-tion devices 17, 1~, 19 in order to supply the filament currents for the fiL~ments of an X-ray tube. The filament current transformers (not shown) may form part of a filament current control circuit 3 which con-sists of a comparison mer.~er 31 which compares the actual value of the 35 filament current with a reference value and a control amplifier 32 which .
amplifies the control deviation which i5 applied to -the connected filament current transformer, so that the actual value of the fil.ament current substantially corresponds to its reference value.
3~
PHD 81.065 3 07.05.1982 The reference value of the filament c~rrent is supplied by a digital-to-analog converter 7 which is connected to an intenrediate memory 8 which in its turn is coupled, via switching means 10, to a memory 9 which is cons~ructed as a programmab].e read-only memory. The read-only memory 9 comprises a first ~Em~ry section 91 in which filament current values are stored (as known from DE-OS 27 03 420) and a second memory section which comprises memory ce].ls 94~ 95 and 96 in which the stand by filament current values for the three X-ray tubes 14, 15 and 16 are s-tored (tw~ s-tand-by fila~.ent current values for each X-ray tube).
These stand-by filament current values are chosen for each X-ray tube and each of its filaments so that a given maximum emission value is maintained, for example, 20 /uA , during operation of the X ray tube with this rilament current when a high voltage is applied (for example, 40 kV) to the tu~e. This step is necessary to ensure that, even in the case where the filamient associated with the large focus is preselected for the exposure mocle whilst fluoroscopy takes place by means of the filaments 4, 5, 6 for the small focus, the image quality and tlle control properties of the fluoroscopy control circuit are not substantially influenced by the additionc~l emission of the filament whereto the stand-by current is applied.
The switching means 10 and the high-voltage switch 2 for the selection of the X-ray tube as well as the focus selection device (not shown) are coupled to one another v a control device 11 so that the memory cell 94 acts for the X-ray tube 14, the memory cell 95 for the X-ray tube 15 and the memory cell 96 for t~.e X-ray tube 16, the measured stand-b~ filament current values for each filament being stored in said cells in the described mc~nner. It is thus ensured that at the beginning of the preparation period the filament already has such a tempe-rature that only a comparatively short period of time is required in order to reach the u].timate temperature. When the preparation phase is initiated, signalled also to the control device 11 via th.e input 12, a switch over takes place to the memory section 91 in wich the filament current required for an exposure is stored for the relevant X-ray tuke.
The control device 11 is preferably realized by means of a microcomputer; the access to the read-only memory 9 then tc~kes place _ a bus which connects the microcomputer to the read-only memory 9 an~i the intermediate memory 8.
3~5~
PHD 81.065 4 07.05~1982 The control device 11 and the me~ory 9 are shown in greater detail in Figure 2. The control device 11 comprises a microprocessor 20 (Intel 8086), a clock generator 21 (8284), an interrup-t controller 22 (8259A), an octal latch-circuit 23 (8282), and scme further circuits which will ke described later on. The micro2rocessor 20 comprises an address/data h1s 24 which interconnects the latch-circuit 23, the memory 9' (2732, 2118) and the interrupt controller 22. An address generated by the ~icroprocessor 20 is latched into the circuit 23 on a stro~e signal which is applied to the stro~e input STB of the circuit 23 by the micro-processor 20 via a control line of the bus 25. The address can be placedon the address bus 26 by an output enable signal OE which is received by the circuit 23 via the control bus 25. The sianals on the control bus 25 or the address bus 26 are placed on a system hus 27 via bus driver circuits 28a and c (75LS244). The memory 9' is connected to the data bus 24 and to the address bus 26. Via a memory decoder 29 (N82S137), thie read-only memory 9 or the random access me~ory 9a is activated. For proper operation, the deccder circuit 29 receives (a part of) -the address from the latch-circuit 23 and also a further control signal which indicates whether an input is to be received or an output is to be despatched to the system bus via a bidirectional bus driver 28d (8286).
The stand-by mcde of the X-ray system is initiated by a signal on the interrupt input 12 which activates, via the interrupt controller 22, thie microprocessor 2O which could ke in a waiting routine (4~0) at that instant. The microprocessor 20 reads the selected X ray tube number i and thie selected filament thereof by applying thie corresponding address;
via the latch-circuit 23 and the bus driver 28a, to the system bus 27 and by taking in the data via the driver circuit 28d (step 4-1 of the flow-chart of Figure 4), As appears from Figure 3 the position of switch 2 is sensed via an input multiplex circuit 40 (HEF-4512), which receives via a bus 41, an address of an inpu-t to be sensed and supplies an output HIGH on output line 42 if said input is connected to ~V via switch 2'~
The ~switch 2' is mechanically linked to the switch 2 to ke sensed. The microprocessor 20 selects, on the basis of the tub~num~er l, the address (ADRti)) of the stand-by current table which is stored in the memory 9 (step 4-2, Figure 4). The processor 20 subsequently checks which filament has been selected ~large focus (LF) for large tube current, small focus for snk~ tube current, step 4-3, Figure 4). If the large focus is used, the address generated on the kasis oE the tube num~er 1 is incremented by a fixed ~3~5~
PHD 81.065 5 07.05.1982 value C (step 4-4, Figure 4). If the small focus is used, step 4~4 is skipped. The address thus generated is latched into the circuit 23 and the filament current value (If) can be read from the memory 9 (step 4 5, Figure 4). I-t will be clear -that the switching means 10 (fisure 1) are actually formed by the latch-circuit 23 and the decoder circuit 29.
Chlring the next step (4-6) the filament current value is fed, via the driver circuit 28d and the system bus 27, to the latching-circuits 8 (4516, see Figure 3), the input lines of which are connected to the system hus 27. The filament current value is latched into the circuit 8 whose outputs are connected to the digital-to-analog converter 7, an output of ~hich is connected to the filament current control circuit 3. The X-ray system then enters a preparation stage 4-7.
The stand-by filam~ent current values can be programmed in indi-vidual memory cells (94, ...... 96, Figure 2) which are each time associated with a tube, extensions being possible by the addition of storage units, or they can be program~ed in accumulator memories which are manufactured for all types of tu~e which can be connected to the generator, the addres-sing of the values stored and their assigmrent to the connected X-ray tubes being governed by the programming of the control device or the 20 microcomputer 2s
Claims (2)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A method of operating an X-ray system compris-ing an X-ray generator for a plurality of X-ray tubes with a device for adjusting a stand-by filament current for the filament of an X-ray tube during the intervals between exposures, characterized in that there are stored a plurality of stand-by filament current values which are associated with different X-ray tube filaments, the stand-by filament current value associated with an X-ray tube which is connected to the high-voltage gener-ator being addressed and adjusted for the relevant fila-ment.
2. An X-ray generator for performing the method claimed in Claim 1, comprising a tube selection device for selecting an X-ray tube, a focus selection device, and a filament current adjusting member for adjusting the filament current, characterized in that there is provided a non-volatile digital memory device comprising a plurality of cells for different stand-by filament current values, the tube selection device being coupled to a device for the addressing and accessing of the memory device so that for each tube filament selected by the tube selection device and the focus selection device a given memory cell is addressed whose content is used to control a filament current adjusting member.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19813122185 DE3122185A1 (en) | 1981-06-04 | 1981-06-04 | METHOD FOR OPERATING AN X-RAY GENERATOR AND X-RAY GENERATOR FOR CARRYING OUT THIS METHOD |
| DEP3122185.8 | 1981-06-04 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1193751A true CA1193751A (en) | 1985-09-17 |
Family
ID=6133892
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000404426A Expired CA1193751A (en) | 1981-06-04 | 1982-06-03 | Method of operating an x-ray generator, and x-ray generator suitable for this method |
Country Status (4)
| Country | Link |
|---|---|
| EP (1) | EP0066928B1 (en) |
| JP (1) | JPS57210600A (en) |
| CA (1) | CA1193751A (en) |
| DE (2) | DE3122185A1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US10874372B2 (en) | 2016-02-22 | 2020-12-29 | Shanghai United Imaging Healthcare Co., Ltd. | Systems and methods for controlling an X-ray tube filament |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2598583A1 (en) * | 1986-05-06 | 1987-11-13 | Thomson Cgr | RADIOLOGY INSTALLATION WITH COMMUNICATION NETWORK |
| DE3741109A1 (en) * | 1987-12-04 | 1989-06-15 | Thomson Cgr | X-RAY DIAGNOSTIC APPARATUS |
| DE4416556A1 (en) * | 1994-05-11 | 1995-11-16 | Philips Patentverwaltung | X-ray generator |
Family Cites Families (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB829521A (en) * | 1958-04-11 | 1960-03-02 | Picker X Ray Corp Waite Mfg | Improvements relating to x-ray apparatus |
| JPS4310518Y1 (en) * | 1965-07-31 | 1968-05-08 | ||
| JPS4510429Y1 (en) * | 1967-02-20 | 1970-05-13 | ||
| JPS5621385Y2 (en) * | 1973-05-29 | 1981-05-20 | ||
| DE2539898C2 (en) * | 1975-09-08 | 1982-06-03 | Siemens AG, 1000 Berlin und 8000 München | X-ray diagnostic apparatus with an adjusting means for the control circuit containing the X-ray tube heating current for a recording parameter dependent on the X-ray tube current |
| DE2542016A1 (en) * | 1975-09-20 | 1977-03-24 | Philips Patentverwaltung | Control circuit for X-ray tube exposure current - has resistor switched between two HV generators with voltage drop proportional to actual value of exposure current |
| DE2703420C2 (en) * | 1977-01-28 | 1985-11-21 | Philips Patentverwaltung Gmbh, 2000 Hamburg | Method for setting the tube current flowing through an X-ray tube and circuit arrangement for carrying out the method |
| JPS5424587A (en) * | 1977-07-27 | 1979-02-23 | Toshiba Corp | X-ray unit |
| EP0025688A3 (en) * | 1979-09-13 | 1981-05-27 | Pfizer Inc. | Process for rapidly achieving stabilized X-ray emission from an X-ray tube |
| JPS6459720A (en) * | 1987-08-28 | 1989-03-07 | Mitsubishi Metal Corp | Manufacture of superconductive ceramic processing material |
-
1981
- 1981-06-04 DE DE19813122185 patent/DE3122185A1/en not_active Withdrawn
-
1982
- 1982-05-28 DE DE8282200653T patent/DE3266339D1/en not_active Expired
- 1982-05-28 EP EP82200653A patent/EP0066928B1/en not_active Expired
- 1982-06-01 JP JP57092277A patent/JPS57210600A/en active Granted
- 1982-06-03 CA CA000404426A patent/CA1193751A/en not_active Expired
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US10874372B2 (en) | 2016-02-22 | 2020-12-29 | Shanghai United Imaging Healthcare Co., Ltd. | Systems and methods for controlling an X-ray tube filament |
| US11751838B2 (en) | 2016-02-22 | 2023-09-12 | Shanghai United Imaging Healthcare Co., Ltd. | Systems and methods for controlling an X-ray tube filament |
Also Published As
| Publication number | Publication date |
|---|---|
| EP0066928A1 (en) | 1982-12-15 |
| JPH0159720B2 (en) | 1989-12-19 |
| DE3122185A1 (en) | 1982-12-30 |
| DE3266339D1 (en) | 1985-10-24 |
| JPS57210600A (en) | 1982-12-24 |
| EP0066928B1 (en) | 1985-09-18 |
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