Photon energy detector generating signal in which durations of first and second half cycles are responsive to photon energy and diode continuity respectively

Claim 2

In a photon energy detector, an oscillator for producing a cyclical output signal having alternate first and second half cycles, the oscillator including a timing circuit having a PIN diode and a PN diode, the PIN diode exhibiting a reverse leakage current responsive to the photon energy incident upon the diode, the timing circuit defining the duration of the first half cycles of the output signal as a function of the reverse leakage current through the PIN diode when photon energy is incident upon the PIN diode and as a function of the forward drive current through the PN diode when photon energy is not incident upon the PIN diode, and the timing circuit defining the duration of the second half cycles of the output signal as a function of the forward drive current through the PIN diode when the PIN diode has continuity and as a function of the reverse leakage current through the PN diode when the PIN diode does not have continuity, whereby the duration of the first half cycles of the output signal is responsive to the photon energy incident upon the PIN diode and the duration of the second half cycles of the output signal is responsive to the continuity of the PIN diode.

Claim 3

In a photon energy detector, a relaxation oscillator for producing a cyclical output signal having alternate first and second half cycles, the oscillator including a resistance-capacitance timing circuit for defining the duration of the first half cycles as a function of the current flow through the resistance in a first direction and for defining the duration of the second half cycles as a function of the current flow through the resistance in a second direction, the resistance including a resistive network having first and second legs connected in parallel, the first leg including a PIN diode and a first resistance connected in series, the PIN diode exhibiting a reverse leakage current responsive to the photon energy incident upon the diode, the second leg including a PN diode and a second resistance connected in series, the PN diode poled in the first direction and the PIN diode poled in the second direction, and the first resistance substantially less than the second resistance, the current flow in the first direction thereby primarily defined as a function of the reverse leakage current through the PIN diode when photon energy is incident upon the PIN diode and primarily defined as a function of the forward drive current through the PN diode when photon energy is not incident upon the PIN diode, and the current flow in the second direction thereby primarily defined as a function of the forward drive current through the PIN diode when the PIN diode has continuity and primarily defined as a function of the reverse leakage current through the PN diode when the PIN diode does not have continuity, whereby the duration of the first half cycles is responsive to the photon energy incident upon the PIN diode and the duration of the second half cycles is responsive to the continuity of the PIN diode.

Claim 4

In a photon energy detector, a relaxation oscillator for producing a cyclical output signal having alternate first and second half cycles, the oscillator including a resistance-capacitance timing circuit for defining the duration of the first half cycles as a function of the current flow through the resistance in a first direction and for defining the duration of the second half cycles as a function of the current flow through the resistance in a second direction, the resistance including a resistive network having first and second legs connected in parallel, the first leg including a PIN diode and a first resistance connected in series, the PIN diode exhibiting a reverse leakage current responsive to the photon energy incident upon the diode, the second leg including a PN diode and a second resistance connected in series, the PN diode poled in the first direction and the PIN diode poled in the second direction, and the first resistance substantially less than the second resistance, the current flow in the first direction thereby primarily defined as a function of the reverse leakage current through the PIN diode when photon energy is incident upon the PIN diode and primarily defined as a function of the forward drive current through the PN diode when photon energy is not incident upon the PIN diode, and the current flow in the second direction thereby primarily defined as a function of the forward drive current through the PIN diode when the PIN diode has continuity and primarily defined as a function of the reverse leakage current through the PN diode when the PIN diode does not have continuity, whereby the duration of the first half cycles is responsive to the photon energy incident upon the PIN diode and the duration of the second half cycles is responsive to the continuity of the PIN diode.

Claim 5

In a photon energy detector, an oscillator for producing a cyclical output signal having alternate first and second half cycles, the oscillator including a timing circuit for defining the duration of the alternate first and second half cycles, the timing circuit including a capacitor connected with a resistor network for defining the duration of the first half cycles as a function of the current flow through the resistor network in a first direction and for defining the duration of the second half cycles as a function of the current flow through the resistor network in a second direction, the resistor network having first and second legs connected in parallel, the first leg including a photo diode alternately connected in series with an oppositely poled first steering diode and a first resistor and in series with a like poled second steering diode and a second resistor, the photo diode exhibiting a reverse leakage current which is responsive to the photon energy incident upon the diode, the second leg including a control diode alternately connected in series with an oppositely poled third steering diode and in series with a third resistor, the control diode poled in the first direction and the photo diode poled in the second direction, and the first resistor much smaller than the third resistor, the resistor network thereby defining the current flow in the first direction as primarily a function of the reverse leakage current of the photo diode limited by the first resistor through the first steering diode when photon energy is incident upon the photo diode and as primarily a function of the forward drive current through the control diode limited by the third resistor when photon energy is not incident upon the photo diode, and the resistor network defining the current flow in the second direction as primarily a function of the forward drive current of the photo diode limited by the second resistor through the second steering diode when the photo diode has continuity and as primarily a function of the reverse leakage current of the control diode through the third steering diode when the photo diode does not have continuity; and an integrator connected to the oscillator for averaging the alternate first and second half cycles of the output signal to provide an output level having a magnitude responsive to the photon energy incident upon the photo diode and responsive to the continuity of the photo diode.

Claim 6

In a photon energy detector, an oscillator for producing a cyclical output signal having alternate first and second half cycles, the oscillator including a timing circuit for defining the duration of the alternate first and second half cycles, the timing circuit including a capacitor connected with a resistor network for defining the duration of the first half cycles as a function of the current flow through the resistor network in a first direction and for defining the duration of the second half cycles as a function of the current flow through the resistor network in a second direction, the resistor network having first and second legs connected in parallel, the first leg including a photo diode alternately connected in series with an oppositely poled first steering diode and a first resistor and in series with a like poled second steering diode and a second resistor, the photo diode exhibiting a reverse leakage current which is responsive to the photon energy incident upon the diode, the second leg including a control diode alternately connected in series with an oppositely poled third steering diode and in series with a third resistor, the control diode poled in the first direction and the photo diode poled in the second direction, and the first resistor much smaller than the third resistor, the resistor network thereby defining the current flow in the first direction as primarily a function of the reverse leakage current of the photo diode limited by the first resistor through the first steering diode when photon energy is incident upon the photo diode and as primarily a function of the forward drive current through the control diode limited by the third resistor when photon energy is not incident upon the photo diode, and the resistor network defining the current flow in the second direction as primarily a function of the forward drive current of the photo diode limited by the second resistor through the second steering diode when the photo diode has continuity and as primarily a function of the reverse leakage current of the control diode through the third steering diode when the photo diode does not have continuity; and an integrator connected to the oscillator for averaging the alternate first and second half cycles of the output signal to provide an output level having a magnitude responsive to the photon energy incident upon the photo diode and responsive to the continuity of the photo diode.