Ionographic exposure method, apparatus

Claim 2

In a method for arranging for, and conducting, an ionographic imaging sequence for imaging a subject by directing a prescribed radiation flux upon the subject for a prescribed irradiation period and generating an electrostatic image of the differential flux transmission therethrough, across a prescribed ionographic arrangement including electrodes defining an imaging gap, the improvement therewith comprising: providing detection means adapted to detect and monitor current across this gap; with this detection means, monitoring the level of gap current before, and during, said irradiation period to derive values reflecting such; comparing these values to a prescribed standard and determining any variance therefrom; and providing for imaging controls for adjusting and limiting the imaging sequence according to varianCes so found.

Claim 3

In a method for arranging for, and conducting, an ionographic imaging sequence for imaging a subject by directing a prescribed radiation flux upon the subject for a prescribed irradiation period and generating an electrostatic image of the differential flux transmission therethrough, across a prescribed ionographic arrangement including electrodes defining an imaging gap, the improvement therewith comprising: providing detection means adapted to detect and monitor current across this gap; with this detection means, monitoring the level of gap current before, and during, said irradiation period to derive values reflecting such; comparing these values to a prescribed standard and determining any variance therefrom; and providing for imaging controls for adjusting and limiting the imaging sequence according to varianCes so found.

Claim 4

In a method for arranging for, and conducting, an ionographic imaging sequence for imaging a subject by directing a prescribed radiation flux upon the subject for a prescribed irradiation period and generating an electrostatic image of the differential flux transmission therethrough, across a prescribed ionographic arrangement including electrodes defining an imaging gap, the improvement therewith comprising: providing detection means adapted to detect and monitor current across this gap; with this detection means, monitoring the level of gap current before, and during, said irradiation period to derive values reflecting such; comparing these values to a prescribed standard and determining any variance therefrom; and providing for imaging controls for adjusting and limiting the imaging sequence according to varianCes so found.

Claim 5

The method as recited in claim 1 as adapted to check-out gap current before imaging to determine excess gap current and, accordingly, indicate the stability of the arrangement for prescribed proper imaging.

Claim 6

The method as recited in claim 2 as provided in conjunction with a programmed voltage control arrangement adapted to compensate for retarding voltage across the gap and wherein detected gap current is employed to control this voltage control arrangement, adjusting it to produce and maintain a prescribed programmed gap current level.

Claim 7

The method as recited in claim 2 wherein the ionographic imaging device, including said electrodes, is arranged to settle for a prescribed settling period, after which the test for excess gap current is repeated to verify that it is persistent and not merely transient.

Claim 8

The method as recited in claim 1 as applied to evaluate imaging with an ionographic cassette and to optimize and evaluate imaging current and thus control the imaging sequence within prescribed limits.

Claim 9

The combination as recited in claim 5 including specifically the steps of: energizing a power stage portion of the ionographic imaging arrangement and to thereby apply energizing voltage across the gap electrodes in the cassette; then, testing for leakagae current across the gap before imaging and responsively passing or rejecting the subject cassette as being suitable or unsuitable for imaging; and then carrying out the prescribed imaging sequence accordingly.

Claim 10

The method as recited in claim 6, wherein, during the course of testing for gap current, the cassette and associated elements are allowed to equilibrate, mechanically and otherwise, for a prescsribed settling period, lasting at least several seconds, after which gap current is rechecked to assure that the detected level is not merely transient.

Claim 11

The combination as recited in claim 7, wherein said settling period duration is adjustable and manually selected in accordance with the influential conditions then prevailing; and thereafter comparing gap current to a standard value and interrupting the imaging sequence if this value is exceeded.

Claim 12

The combination as recited in claim 8 wherein said current detecting and related responsive steps are performed automatically, rather than manually by an operator.

Claim 13

The combination as recited in claim 6 wherein said gap current is monitored during the imaging sequence as well as before, so as to evaluate whether the arrangement is suitable for proper imaging under the circumstances; and, where improper conditions are detected, appropriate corrective action is thereupon invoked.

Claim 14

The combination as recited in claim 6 including the final step of resetting the control and detection means to be placed in condition to start the next imaging and pre-imaging sequence.

Claim 15

The method as recited in claim 11 wherein said steps are provided automatically without need for manual intervention.

Claim 16

The method as recited in claim 1 wherein said gap current detected is compared with reference current to thereby evaluate imaging conditions as compared with a standard, and interrupt imaging when conditions vary from that standard.

Claim 17

The combination as recited in claim 13 wherein said gap current is monitored during the imaging sequence, and upon detection of a current level which varies from a prescribed reference level, corrective action is taken to restore the level to reference or to interrupt imaging.

Claim 18

The combination as recited in claim 14 also including the step of providing charge integrating means adapted to generate an output keying signal, which is, in turn, adapted to automatically interrupt and disable the imaging sequence.

Claim 19

The method, as recited in claim 15 is conducted in the course of imaging with an ionographic cassette, and wherein gap current is tested for abnormal conditions, before the imaging sequence begins, and upon detection thereof, the sequence interrupted; and wherein the system is also tested for such abnormal conditions during the imaging sequence, and is likewise responsively interrupted upon detection thereof; both said testing operation being conducted so as to include a settling period during which the system equilibrates to eliminate brief transient readings; and wherein, after the imaging sequence, the system is reset to be ready to begin the next imaging sequence.

Claim 20

The method as recited in claim 15 wherein said steps are provided automatically without the need for manual intervention.

Claim 21

A control system in an ionographic imaging arrangement for monitoring and controlling an imaging sequence, such as by controlling the flow of imaging current, this system comprising in combination: ionographic gap current detection means adapted to generate a prescribed detect signal reflecting the level of current detected; ionographic gap current evaluation means adapted to receive this detect signal; compare it with a standard reference, and, responsively, generate a pass or no pass signal according to whether the detected gap current is within prescribed limits or not; and system interrupt means adapted and arrangaed to receive the signal output from said evaluation means, and to responsively interrupt the imaging system upon receipt of a no pass signal.

Claim 22

A control system in an ionographic imaging arrangement for monitoring and controlling an imaging sequence, such as by controlling the flow of imaging current, this system comprising in combination: ionographic gap current detection means adapted to generate a prescribed detect signal reflecting the level of current detected; ionographic gap current evaluation means adapted to receive this detect signal; compare it with a standard reference, and, responsively, generate a pass or no pass signal according to whether the detected gap current is within prescribed limits or not; and system interrupt means adapted and arrangaed to receive the signal output from said evaluation means, and to responsively interrupt the imaging system upon receipt of a no pass signal.

Claim 23

The system as recited in claim 18 wherein said evaluation means is adapted to provide ionographic gap current evaluation before, as well as during, an imaging sequence, and provide evaluation output signals indicating when prescribed current variation indicate a deviation from prescribed standard conditions.

Claim 24

The system as recited in claim 18 wherein are also included current stabilizing means adapted to maintain gap current at a prescribed working level and comprising: a programmable power supply; means for generating a feedback signal which varies in accordance with the current across said gap; level detector means for detecting a predetermined level of said current and generating a keying signal when said level has been detected; and control means for controlling the voltage output of said programmable power supply, the control action of said control means being initiated in response to said keying signal, said control means receiving said feedback signal and generating a control signal for controlling said programmable power supply as a function of said feedback signal to thereby control the output voltage of the power supply and thus maintain the gap current at the prescribed level.

Claim 25

The combinataion as recited in claim 18 wherein is also included current stabilizing means operated in combination therewith, and adapted to maintain gap current at about a prescribed level, said stabilizing means comprising in combination: a programmable power supply adapted to be energized for supplying current to said gap load; means for generating a feedback signal which varies in accordance with the current across said gap; means for detecting the predetermined level of said feedback signal following energization of said power supply and providing a keying signal when said feedback signal is substantially at said predetermined level; control means for controlling the voltage output of said programmable power supply, the control action of said control means being initiated in response to said keying signal, said control means receiving said feedback signal and generating a control signal for said programmable power supply as a function of said feedback signal thereby to control the output voltage of said programmable power supply so as to maintain the gap current at the said prescribed level; integrator means for integrating the current supplied to said gap as a function of time and for generating a control signal in accordance with a predetermined integration of the current supplied at said prescribed level to said gap, the integration action of said integrator means being initiated by said keying signal; and switChing circuit means responsive to said control signal from said integrator means for cutting off the output of said programmable power supply and thus the current to said gap when said predetermined integration has occurred.

Claim 26

The system as recited in claim 18 wherein are also included: ''''exposure control'''' means adapted to accept input power, and condition it, for application as DC energizing voltage, to the gap electrodes of said imaging arrangement; ''''exposure indicator'''' means associated with said exposure control means to indicate energization thereof; ''''power control'''' means adapted to control the application of line power to said exposure control means; ''''power indicator'''' means associated with said power control means to indicate the enrgization thereof; ''''reset'''' means adapted to energize and initialize the state of said detection and other system means, selectively; ''''reset indicator'''' means adapted to indicate the bistable state of said reset means; and ''''excess gap current indicator'''' means adapted to indicate the presence of excess gap current at said detection means.