US4101774A — X-ray system having a driving mechanism for an x-…

Claim 1

Independent Claim 262 words

An X-ray system for making a shadow image of a layer of an object, which X-ray system comprises an X-ray source and an X-ray detector, as well as driving means which are designed to move the X-ray source and the X-ray detector with respect to each other in at least substantially parallel planes and with a constant velocity ratio in which the driving means comprise, in combination: at least one electric motor driving the X-ray source; at least one electric motor driving the X-ray detector, each electric motor being connected to an electronic control circuit to control the number of revolutions of said motor, an electric coupling existing between the electric motors; wherein the electric coupling comprises: signal generators which are connected to the electric motor and/or to the X-ray radiator and detector driven by electric motors so as to obtain signals which are a measure of the instantaneous position of the X-ray source and detector; at least one comparison circuit which is connected to the signal generators and functions to derive from the signals generated by the signal generators a correction signal for a control circuit of one of the said electric motors, whereby the movements of the X-ray source and detector are coordinated with each other; and a controllable inverter circuit connected between the comparison circuit and the control circuit and selectably functioning in a first or in a second operating condition, as the need may be, a correction signal from the comparison circuit being inverted in the first operating condition and being not inverted in the second operating condition.

Claim 2

Dependent Claim 262 words

An X-ray system for making a shadow image of a layer of an object, which X-ray system comprises an X-ray source and an X-ray detector, as well as driving means which are designed to move the X-ray source and the X-ray detector with respect to each other in at least substantially parallel planes and with a constant velocity ratio in which the driving means comprise, in combination: at least one electric motor driving the X-ray source; at least one electric motor driving the X-ray detector, each electric motor being connected to an electronic control circuit to control the number of revolutions of said motor, an electric coupling existing between the electric motors; wherein the electric coupling comprises: signal generators which are connected to the electric motor and/or to the X-ray radiator and detector driven by electric motors so as to obtain signals which are a measure of the instantaneous position of the X-ray source and detector; at least one comparison circuit which is connected to the signal generators and functions to derive from the signals generated by the signal generators a correction signal for a control circuit of one of the said electric motors, whereby the movements of the X-ray source and detector are coordinated with each other; and a controllable inverter circuit connected between the comparison circuit and the control circuit and selectably functioning in a first or in a second operating condition, as the need may be, a correction signal from the comparison circuit being inverted in the first operating condition and being not inverted in the second operating condition.

Claim 3

Dependent Claim 71 words

An X-ray system as claimed in claim 1, wherein the comparison circuit functions to convert a first signal generated by one of the signal generators into a comparison signal in to an adjustable weighing code, the correction signal being equal to the difference between the comparison signal and a second signal generated by the second signal generator, whereby the weighing code determines the velocity ratio of the X-ray source and detector.

Claim 4

Dependent Claim 99 words

An X-ray system as claimed in claim 1, wherein a velocity selection circuit for controlling the control circuits of the electric motors functions to form from a section-height signal and a movement-width signal a velocity signal which is connected as an input signal for the control circuits of the electric motors, the section-height signal indicating the point of rotation of the connection line between the X-ray source and detector and the movement-width signal indicating an angle to be traversed by the connection line with respect to the point of rotation and a period of time for traversing the angle.

Claim 5

Dependent Claim 91 words

An X-ray system as claimed in claim 3, wherein the section-height signal and the movement-width signal have a digital form and are connected to a velocity selection circuit and a weighing code memory, a combination of the section-height signal and the movement-width signal constituting an address for selecting a velocity signal in the velocity selection circuit for controlling the electric motors and for selecting a weighing code in the weighing code memory to urge the instantaneous position of a second electric motor to the instantaneous position of a first electric motor.

Claim 6

Dependent Claim 171 words

An X-ray system as claimed in claim 2, wherein the comparison circuit comprises the following components in combination: counters for counting pulses generated by the signal generators, from which counters a counter position is read periodically; a first buffer for storing the counter position of a first counter; selection circuit means which in a first operating condition present the counter position of a second counter directly to a second buffer and in a second operating condition present the said counter position to a weighing code memory; the weighing code memory in which the weighing code is stored functioning to convert the counter position of the second counter into the comparison signal; the second buffer being connected for storing either the counter position of the second counter or the counter position which is converted by the weighing code memory; a subtraction circuit for determining the difference of the contents of the first and second buffers; and a third buffer which stores said difference and which determines the value of the correction signal.

Claim 7

Dependent Claim 37 words

An X-ray system as claimed in claim 3, wherein the velocity signal is applied to a rotation control circuit of an electric motor which moves the X-ray source onto the point of rotation of the connection line.

Claim 8

Dependent Claim 54 words

An X-ray system as claimed in claim 6, wherein the velocity signal is supplied to the rotation control circuit via a gate circuit, which gate circuit is switchable to a first operating condition or to a second operating condition, in which the velocity signal is respectively cut off and transmitted to the rotation control.

Claim 9

Dependent Claim 193 words

An X-ray system as claimed in claim 1 wherein the X-ray source and detector are each driven by means of two motors for moving the X-ray source and detector in two substantially parallel planes in two directions normal to each other, the X-ray source and detector having a constant velocity ratio, the X-ray system comprising at least two weighing code memories and at least two velocity selection circuits connected so that a movement in a first direction can be determined by means of a combination of a first weighing code memory and a first velocity selection circuit and a movement extending at rights angles to the first direction can be determined by means of the combination of the second weighing code memory and the second velocity selection circuit by presenting a section-height signal to both memories and to both velocity selction circuits; a movement-width signal being dependent on time and consisting of two components the first component of which is presented to the memory and to the velocity selection circuit of the first combination and the second component being presented to the memory and to the velocity selection circuit of the second combination.

Claim 10

Dependent Claim 256 words

An X-ray system for making a shadow image of a layer of an object, which X-ray system comprises an X-ray source and an X-ray detector, as well as driving means which are designed to move the X-ray source and the X-ray detector with respect to each other in at least substantially parallel planes and with a constant velocity ratio in which the driving means comprise, in combination: at least one electric motor driving the X-ray source, at least one electric motor driving the X-ray detector, each electric motor being connected to an electronic control circuit to control the number of revolutions of said motor, an electric coupling existing betwen the electric motors, wherein the electric coupling comprises signal generators which are connected to the electric motor and/or to the X-ray radiator and detector driven by electric motors so as to obtain signals which are a measure of the instantaneous position of the X-ray source and detector, with means for generating an adjustable weighing-code; and at least one comparison circuit means connected to combine a first signal generated by one of the signal generators with the adjustable weighing code to produce a comparison signal and to subtract said comparison signal from a second signal generated by the second signal generator to produce a correction signal for a control circuit of one of said motors whereby the movements of the X-ray source and the detector are coordinated with each other, the velocity ratio between said source and said detector being determined by the adjustment of said weighing code.

Claim 11

Dependent Claim 256 words

An X-ray system for making a shadow image of a layer of an object, which X-ray system comprises an X-ray source and an X-ray detector, as well as driving means which are designed to move the X-ray source and the X-ray detector with respect to each other in at least substantially parallel planes and with a constant velocity ratio in which the driving means comprise, in combination: at least one electric motor driving the X-ray source, at least one electric motor driving the X-ray detector, each electric motor being connected to an electronic control circuit to control the number of revolutions of said motor, an electric coupling existing betwen the electric motors, wherein the electric coupling comprises signal generators which are connected to the electric motor and/or to the X-ray radiator and detector driven by electric motors so as to obtain signals which are a measure of the instantaneous position of the X-ray source and detector, with means for generating an adjustable weighing-code; and at least one comparison circuit means connected to combine a first signal generated by one of the signal generators with the adjustable weighing code to produce a comparison signal and to subtract said comparison signal from a second signal generated by the second signal generator to produce a correction signal for a control circuit of one of said motors whereby the movements of the X-ray source and the detector are coordinated with each other, the velocity ratio between said source and said detector being determined by the adjustment of said weighing code.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1981-07-17	1982-01-16	1982-07-18	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1985-07-17	1986-01-16	1986-07-18	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1989-07-17	1990-01-16	1990-07-18	$7700.00	Window Closed / Lapsed

X-ray system having a driving mechanism for an x-ray source and an x-ray detector

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