Portable handheld artificial light detector
First Claim
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1. A light detector comprising:
- a first filter coupled to receive an electrical signal representing received light and to output a first filtered signal;
a second filter coupled to receive in parallel the same electrical signal as the first filter and to output a second filtered signal, the first filtered signal causing a first type of light to be indicated by the light detector unless the second filtered signal is stronger, and the second filtered signal causing a second type of light to be indicated by the light detector unless the first filtered signal is stronger;
a portable, self-contained energy source to power the first filter and the second filter; and
a housing dimensioned to enclose only said light detector.
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Abstract
A portable, handheld artificial light detector distinguishes artificial light from sunlight and identifies low-frequency artificial light from high-frequency artificial light. Artificial light includes light from a lamp powered by an AC source. Low frequency light includes, for example, light produced by a magnetic luminaire ballast, while high frequency light includes light produced by an electronic luminaire ballast.
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Citations
20 Claims
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1. A light detector comprising:
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a first filter coupled to receive an electrical signal representing received light and to output a first filtered signal; a second filter coupled to receive in parallel the same electrical signal as the first filter and to output a second filtered signal, the first filtered signal causing a first type of light to be indicated by the light detector unless the second filtered signal is stronger, and the second filtered signal causing a second type of light to be indicated by the light detector unless the first filtered signal is stronger; a portable, self-contained energy source to power the first filter and the second filter; and a housing dimensioned to enclose only said light detector. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A light detector comprising:
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a photodetector operative to convert received light into an electrical signal; an amplifier coupled to said photodetector, said amplifier operative to amplify an output signal of said photodetector; a first filter coupled to receive an output signal of said amplifier; a first indicator coupled to an output of said first filter; a second filter coupled to receive an output signal of said amplifier; a second indicator coupled to an output of said second filter; and an energy source to power said amplifier, first filter, second filter, first indicator, and second indicator; wherein the first indicator comprises first envelope detection circuitry and the second indicator comprises second envelope detection circuitry, the first and second envelope detection circuitries coupled to each other to prevent both the first and second indicators from activating simultaneously, the first envelope detection circuitry generating a first voltage in response to a first type of light received and the second envelope detection circuitry generating a second voltage in response to a second type of light received simultaneously with the first type of light, the first or second envelope detection circuitry with the higher voltage disabling the other envelope detection circuitry. - View Dependent Claims (9, 10, 11, 12, 13)
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14. A light detector comprising:
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a first filter coupled to receive an electrical signal representing received light; a first indicator coupled to receive an output signal of said first filter; a second filter coupled to receive in parallel the same electrical signal as the first filter; a second indicator coupled to receive an output signal of said second filter, the first indicator causing the output of the second filter to be masked from the second indicator in response to the output signal of the first filter being stronger than the output signal of the second filter, and the second indicator causing the output of the first filter to be masked from the first indicator in response to the output signal of the second filter being stronger than the output signal of the first filter; and a housing dimensioned to be handheld in which said first filter, second filter, first indicator, and second indicator are enclosed, said housing physically isolating said light detector from external electrical power connections. - View Dependent Claims (15, 16, 17, 18, 19, 20)
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Specification