Analog window apparatus for signalling whether a data point represented by a pair of coordinate signals is within a selectably shaped region of two-dimensional space

Claim 2

In combination: detecting apparatus, including a planar detector, responsive to an impingement of signal matter on said detector at particular x and y coordinates in a fixed coordinate system on said detector to produce first and second signals representing said x and y coordinates, respectively; means for producing third and fourth signals representing absolute amplitude versions of said first and second signals, respectively, with respect to a selectably positioned coordinate system on said detector; means for producing first and second periodic signals having the same frequency and a preselected phase and amplitude relationship; first comparison means for producing a first output indication during an interval when the amplitude of said first periodic signal is equal to or greater than the amplitude of said third signal; second comparison means for producing a second output indication during an interval when the amplitude of said second periodic signal is equal to or greater than the amplitude of said fourth signal; and means operative during at least one period of said periodic signals for producing a third output indication during an interval when said first and second output indications are coincident, whereby said third output indication is produced only when said particular x and y coordinates are within an analoG window which is symmetrical around the origin of said selectably positioned coordinate system and has a shape and size determined by said phase and amplitude relationship.

Claim 3

Analog window apparatus for use in connection with a scintillation camera which produces x and y coordinate electrical signals indicating the location at which a quantum of radiation produced a light flash in the scintillating medium therein in a coordinate system fixed on said medium, said apparatus comprising: means for transforming said x and y signals into x'' and y'' signals related to a selectably positioned coordinate system on said medium; means for producing x'' and y'' coordinate electrical signals representing the absolute amplitudes of said x'' and y'' signals, respectively; means for producing first and second periodic signals having the same frequency and a preselected phase and amplitude relationship; first comparison means receiving said x'' signal and said first periodic signal operative to produce an output 1 signal and an output 0 signal when said first periodic signal is, respectively, equal to or greater than said x'' signal and less than said x'' signal; second comparison means receiving said y'' signal and said second periodic signal operative to produce an output 1 signal and an output 0 signal when said second periodic signal is, respectively, equal to or greater than said y'' signal and less than said y'' signal; and gating means operative throughout at least one complete period of said periodic signals to produce an output signal upon coincidence of output 1 signals from said first and second comparison means, said output signal indicating that said light flash occurred within an analog window which is symmetrical about the origin of said selectably positioned coordinate system and has a configuration determined by said phase and amplitude relationship of said periodic signals.

Claim 4

Analog window apparatus for use in connection with a scintillation camera which produces x and y coordinate electrical signals indicating the location at which a quantum of radiation produced a light flash in the scintillating medium therein in a coordinate system fixed on said medium, said apparatus comprising: means for transforming said x and y signals into x'' and y'' signals related to a selectably positioned coordinate system on said medium; means for producing x'' and y'' coordinate electrical signals representing the absolute amplitudes of said x'' and y'' signals, respectively; means for producing first and second periodic signals having the same frequency and a preselected phase and amplitude relationship; first comparison means receiving said x'' signal and said first periodic signal operative to produce an output 1 signal and an output 0 signal when said first periodic signal is, respectively, equal to or greater than said x'' signal and less than said x'' signal; second comparison means receiving said y'' signal and said second periodic signal operative to produce an output 1 signal and an output 0 signal when said second periodic signal is, respectively, equal to or greater than said y'' signal and less than said y'' signal; and gating means operative throughout at least one complete period of said periodic signals to produce an output signal upon coincidence of output 1 signals from said first and second comparison means, said output signal indicating that said light flash occurred within an analog window which is symmetrical about the origin of said selectably positioned coordinate system and has a configuration determined by said phase and amplitude relationship of said periodic signals.

Claim 5

Analog window apparatus for use in connection with a scintillation camera, or the like, which produces x and y coordinate voltage pulses indicating the location at which a quantum of radiation produced a light flash in the scintillating medium therein with respect to a coordinate system fixed on said medium, said apparatus comprising: coordinate transforming means for adding preselected X and Y DC voltages to said x and y coordinate voltage pulses to produce x'' and y'' coordinate voltage pulses related to a selectably positioned coordinate system on said medium; absolute value means for producing x'' and y'' coordinate electrical signals representing the absolute amplitudes of said x'' and y'' signals; sinusoidal waveform generating means for generating a sinusoidal voltage waveform; first network means receiving said sinusoidal voltage wave form operative to produce a first version thereof having a first preselected maximum amplitude; second network means receiving said sinusoidal voltage waveform operative to produce a second version thereof having a second preselected maximum amplitude and a preselected phase relation to said first version; first comparison means receiving said x'' signal and said first version operative to produce an output 1 signal and an output 0 signal when said first version is, respectively, equal to or greater than said x'' signal and less than said x'' signal; second comparison means receiving said y'' signal and said second version operative to produce an output 1 signal and an output 0 signal when said first version is, respectively, equal to or greater than said y'' signal and less than said y'' signal; and gating means operative throughout a time interval at least as great as one period of said sinusoidal voltage waveform to produce an output signal upon coincidence of output 1 signals from said first and second comparison means, said output signal indicating that said light flash occurred within an analog window which is symmetrical about the origin of said selectably positioned coordinate system and has a configuration determined by said preselected relationship phase and said first and second preselected maximum amplitudes.

Claim 6

Analog window apparatus for use in connection with a scintillation camera, or the like, which produces x and y coordinate voltage pulses indicating the location at which a quantum of radiation produced a light flash in the scintillating medium therein with respect to a coordinate system fixed on said medium, said apparatus comprising: coordinate transforming means for adding preselected X and Y DC voltages to said x and y coordinate voltage pulses to produce x'' and y'' coordinate voltage pulses related to a selectably positioned coordinate system on said medium; absolute value means for producing x'' and y'' coordinate electrical signals representing the absolute amplitudes of said x'' and y'' signals; sinusoidal waveform generating means for generating a sinusoidal voltage waveform; first network means receiving said sinusoidal voltage wave form operative to produce a first version thereof having a first preselected maximum amplitude; second network means receiving said sinusoidal voltage waveform operative to produce a second version thereof having a second preselected maximum amplitude and a preselected phase relation to said first version; first comparison means receiving said x'' signal and said first version operative to produce an output 1 signal and an output 0 signal when said first version is, respectively, equal to or greater than said x'' signal and less than said x'' signal; second comparison means receiving said y'' signal and said second version operative to produce an output 1 signal and an output 0 signal when said first version is, respectively, equal to or greater than said y'' signal and less than said y'' signal; and gating means operative throughout a time interval at least as great as one period of said sinusoidal voltage waveform to produce an output signal upon coincidence of output 1 signals from said first and second comparison means, said output signal indicating that said light flash occurred within an analog window which is symmetrical about the origin of said selectably positioned coordinate system and has a configuration determined by said preselected relationship phase and said first and second preselected maximum amplitudes.

Claim 7

Apparatus as claimed in claim 3, wherein said camera also produces a Z pulse upon occurrence of an acceptable light flash and said gating means is operative only upon occurrence of one of said Z pulses.

Claim 8

Apparatus as claimed in claim 4, further comprising a scaler for accumulating the number of said output signals from said gating means.