Apparatus for detecting fluorescence of a luminescent material
First Claim
1. An apparatus for detecting the fluorescence of a target luminescent material being excitable at an excitation wavelength and fluorescing at a fluorescing wavelength, comprising:
- a reference luminescent material;
a discharge lamp adapted to be coupled to an alternating current voltage source operating at a source frequency and arranged to excite said target luminescent material and said reference luminescent material at approximately said excitation wavelength;
first response means arranged to be responsive to said target luminescent material at approximately said fluorescing wavelength for providing a first electrical response as a function of the electromagnetic energy received from said target luminescent material at said fluorescing wavelength;
second response means arranged to be responsive to said reference luminescent material for providing a second electrical response as a function of the electromagnetic energy received from said reference luminescent material;
said first response means and said second response means being arranged such that said first electrical response opposes said second electrical response creating a combined output signal;
a band pass filter coupled to said combined output signal selected to pass predominantly signals of a frequency of approximately twice said source frequency to produce a filtered output signal;
a phase detector coupled to said band pass filter to detect the phase of said filtered output signal and producing a first response when said filtered output signal is of a first phase and producing a second response when said filtered signal is of a second phase; and
an indicator coupled to said phase detector to indicate the condition of said fluorescence of said target luminescent material as a function of at least one of said first response and second response.
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Accused Products
Abstract
An apparatus for detecting the fluorescence of a luminescent material. Photo-diodes receiving the visible fluorescence from a target luminescent material and a luminescent reference are coupled "back-to-back" resulting in a single-channel detector inherently balanced and insensitive to variations in the excitation stimulus. The photo-diode output is sent through a second harmonic amplifier making available a phase detection of the fluorescence instead of an amplitude detection. The phase of the signal is compared with a known phase from the excitation power source. By adding signals that either reinforce or oppose, the phase information is converted back to amplitude information at a voltage level that can be easily detected. The detected amplitude is compared against the amplitude of the excitation stimulus to account for amplitude variations in such stimulus. The compared output then triggers an indicator producing an indication of the amount of fluorescence of the target luminescent material.
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Citations
18 Claims
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1. An apparatus for detecting the fluorescence of a target luminescent material being excitable at an excitation wavelength and fluorescing at a fluorescing wavelength, comprising:
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a reference luminescent material; a discharge lamp adapted to be coupled to an alternating current voltage source operating at a source frequency and arranged to excite said target luminescent material and said reference luminescent material at approximately said excitation wavelength; first response means arranged to be responsive to said target luminescent material at approximately said fluorescing wavelength for providing a first electrical response as a function of the electromagnetic energy received from said target luminescent material at said fluorescing wavelength; second response means arranged to be responsive to said reference luminescent material for providing a second electrical response as a function of the electromagnetic energy received from said reference luminescent material; said first response means and said second response means being arranged such that said first electrical response opposes said second electrical response creating a combined output signal; a band pass filter coupled to said combined output signal selected to pass predominantly signals of a frequency of approximately twice said source frequency to produce a filtered output signal; a phase detector coupled to said band pass filter to detect the phase of said filtered output signal and producing a first response when said filtered output signal is of a first phase and producing a second response when said filtered signal is of a second phase; and an indicator coupled to said phase detector to indicate the condition of said fluorescence of said target luminescent material as a function of at least one of said first response and second response. - View Dependent Claims (2, 3, 4, 5, 6)
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7. An apparatus for detecting the fluorescence of a target luminescent material being excitable at an excitation wavelength and fluorescing at a fluorescing wavelength comprising:
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a reference luminescent material; a discharge lamp adapted to be coupled to an alternating current voltage source operating at a source frequency and arranged to excite said target luminescent material and said reference luminescent material at approximately said excitation wavelength; first response means arranged to be responsive to said target luminescent material at approximately said fluorescing wavelength for providing a first electrical response as a function of the electromagnetic energy received from said target luminescent material at said fluorescing wavelength; second response means arranged to be responsive to said reference luminescent material for providing a second electrical response as a function of the electromagnetic energy received from said reference luminescent material; said first response means and said second response means being arranged such that said first electrical response opposes said second electrical response creating a combined output signal; phase conversion means coupled to said first and second photo-diodes for converting amplitude variations of said photo-diode output to phase variations producing a phase output signal; a phase detector coupled to said phase output signal to detect the phase of said filtered output signal and producing a first response when said filtered output signal is of a first phase and producing a second response when said filtered signal is of a second phase; and an indicator coupled to said phase detector to indicate the condition of said fluorescence of said target luminescent material as a function of at least one of said first response and second response. - View Dependent Claims (8, 9, 10, 11)
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12. An apparatus for detecting the fluorescence of a target luminescent material being excitable at an excitation wavelength and fluorescing at a fluorescing wavelength comprising:
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a reference luminescent material; a discharge lamp adapted to be coupled to an alternating current voltage source arranged to excite said target luminescent material and said reference luminescent material at approximately said excitation wavelength; first response means arranged to be responsive to said target luminescent material at approximately said fluorescing wavelength for providing a first electrical response as a function of the electromagnetic energy received from said target luminescent material at said fluorescing wavelength; second response means arranged to be responsive to said reference luminescent material for providing a second electrical response as a function of the electromagnetic energy received from said reference luminescent material; said first response means and said second response means being arranged such that said first electrical response directly offsets said second electrical response creating a combined output signal; an indicator coupled to said first response means and to second response means and responsive to said combined output signal to indicate the fluorescence of said target luminescent material based upon said combined output signal. - View Dependent Claims (13, 14)
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15. An apparatus for detecting the fluorescence of a target luminescent material being excitable at an excitation wavelength and fluorescing at a fluorescing wavelength comprising:
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a discharge lamp adapted to be coupled to an alternating current voltage source operating at a source frequency and arranged to excite said target luminescent material at approximately said excitation wavelength; a photo-diode being arranged to be responsive to said target luminescent material producing a photo-diode output signal; a band pass filter coupled to said photo-diode output signal selected to pass predominantly signals of a frequency of approximately twice said source frequency to produce a filtered output signal; an indicator coupled to said band pass filter and responsive to said filtered output signal to indicate the fluorescence of said target luminescent material based upon said filtered output signal. - View Dependent Claims (16)
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17. An apparatus for detecting the fluorescence of a target luminescent material being excitable at an excitation wavelength and fluorescing at a fluorescing wavelength, comprising:
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a discharge lamp adapted to be coupled to an alternating current voltage source operating at a source frequency and arranged to excite said target luminescent material at approximately said excitation wavelength; a photo-diode being arranged to be responsive to said target luminescent material and operating in photo-voltaic mode and producing a photo-diode output signal; a comparator coupled to said photo-diode which compares the magnitude of the amplitude of said photo-diode output signal to the magnitude of the voltage amplitude of said alternating current voltage source and produces a response as a function of the magnitude of amplitude of said voltage amplitude; and an indicator coupled to said line voltage comparator and responsive to said photo-diode output signal to indicate the fluorescence of said target luminescent material based upon said photo-diode output signal. - View Dependent Claims (18)
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Specification