Light level and light level rate of change sensor
First Claim
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1. An optical sensor controlled lighting system comprising:
- an ambient light sensor responsive to ambient light levels for generating an output signal which is proportional to the ambient light level;
a light source having a plurality of operational states;
means responsive to the output signal for developing a rate of change signal;
means for switching the light source between the plurality of operational states, the means for switching including gain or filtering stages and being responsive to the rate of change signal occurring between unidirectional minimum and maximum rates for switching the light source from one to another of the plurality of operational states and the means for switching being further responsive to the rate of change signal indicating increasing ambient light levels for switching the operational state of the light source to an on state;
the means for developing being responsive to an increase in the level of the output signal through a threshold level; and
an average value filter connected to receive a signal proportional to the output signal as an input; and
at least a first comparator connected to receive the output of the average value filter and the signal proportional to the output signal as inputs to generate a difference signal.
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Abstract
An optical sensor controlled lighting system comprises an ambient light sensor responsive to ambient light levels for generating an output signal proportional to the ambient light level. A light source having on and off states is controlled by circuit elements providing for developing a rate of change for the output signal and further providing for, responsive to the rate of change, selectively switching the light source between on and off states based on characteristics of the rate of change.
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Citations
13 Claims
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1. An optical sensor controlled lighting system comprising:
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an ambient light sensor responsive to ambient light levels for generating an output signal which is proportional to the ambient light level; a light source having a plurality of operational states; means responsive to the output signal for developing a rate of change signal; means for switching the light source between the plurality of operational states, the means for switching including gain or filtering stages and being responsive to the rate of change signal occurring between unidirectional minimum and maximum rates for switching the light source from one to another of the plurality of operational states and the means for switching being further responsive to the rate of change signal indicating increasing ambient light levels for switching the operational state of the light source to an on state; the means for developing being responsive to an increase in the level of the output signal through a threshold level; and an average value filter connected to receive a signal proportional to the output signal as an input; and at least a first comparator connected to receive the output of the average value filter and the signal proportional to the output signal as inputs to generate a difference signal. - View Dependent Claims (2)
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3. An optical sensor controlled lighting system comprising:
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an ambient light sensor responsive to ambient light levels for generating an output signal which is proportional to the ambient light level; a light source having a plurality of operational states; means responsive to the output signal for developing a rate of change signal; means for switching the light source between the plurality of operational states, the means for switching including gain or filtering stages and being responsive to the rate of change signal occurring between unidirectional minimum and maximum rates for switching the light source from one to another of the plurality of operational states and the means for switching being further responsive to the rate of change signal indicating increasing ambient light levels for switching the operational state of the light source to an on state; the means for developing including first and second parallel amplifiers of differing gains with the light sensor being connected to supply its output signal as an input to the first and second parallel amplifiers; and the means for developing providing for comparing outputs from the first and second amplifiers to a threshold level and determining the time difference between each output crossing the threshold level.
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4. An optical sensor controlled lighting system comprising:
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an ambient light sensor responsive to ambient light levels for generating an output signal which is proportional to the ambient light level; a light source having a plurality of operational states; means responsive to the output signal for developing a rate of change signal; means for switching the light source between the plurality of operational states, the means for switching including gain or filtering stages and being responsive to the rate of change signal occurring between unidirectional minimum and maximum rates for switching the light source from one to another of the plurality of operational states and the means for switching being further responsive to the rate of change signal indicating increasing ambient light levels for switching the operational state of the light source to an on state; the means for switching being further responsive to the determined rate of change coinciding with decreasing ambient light levels for switching the operational state of the light source to an off state; the means for switching including means for analyzing the waveform shape of the output signal from the light sensor. - View Dependent Claims (5, 6)
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7. An optical sensor controlled lighting system comprising:
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an ambient light sensor responsive to ambient light levels for generating an output signal which is proportional to the ambient light level; a light source having a plurality of operational states; means responsive to the output signal for developing a rate of change signal; means for switching the light source between the plurality of operational states, the means for switching including gain or filtering stages and being responsive to the rate of change signal occurring between unidirectional minimum and maximum rates for switching the light source from one to another of the plurality of operational states; the means for switching being further responsive to the determined rate of change coinciding with decreasing ambient light levels for switching the operational state of the light source to an off state; the means for developing being responsive to a decrease in the level of the output signal through a threshold level; an average value filter connected to receive a signal proportional to the output signal as an input; and at least a first comparator connected to receive the output of the average value filter and the signal proportional to the output signal as inputs to generate a difference signal. - View Dependent Claims (8)
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9. An optical sensor controlled lighting system comprising:
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an ambient light sensor responsive to ambient light levels for generating an output signal which is proportional to the ambient light level; a light source having a plurality of operational states; means responsive to the output signal for developing a rate of change signal; means for switching the light source between the plurality of operational states, the means for switching including gain or filtering stages and being responsive to the rate of change signal occurring between unidirectional minimum and maximum rates for switching the light source from one to another of the plurality of operational states; the means for switching being further responsive to the determined rate of change coinciding with decreasing ambient light levels for switching the operational state of the light source to an off state; the means for developing including first and second parallel amplifiers of differing gains with the light sensor being connected to supply its output signal as an input to the first and second parallel amplifiers; and the means for developing providing for comparing outputs from the first and second amplifiers a threshold level and determining the time difference between each output crossing the threshold level.
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10. An optical sensor controlled lighting system comprising:
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an ambient light sensor responsive to ambient light levels for generating an output signal which is proportional to the ambient light level; a light source having a plurality of operational states; means responsive to the output signal for developing a rate of change signal; means for switching the light source between the plurality of operational states, the means for switching including gain or filtering stages and being responsive to the rate of change signal occurring between unidirectional minimum and maximum rates for switching the light source from one to another of the plurality of operational states; the means for switching being further responsive to the determined rate of change coinciding with decreasing ambient light levels for switching the operational state of the light source to an off state; and the means for switching including means for analyzing the waveform shape of the output signal from the light sensor. - View Dependent Claims (11, 12)
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13. An optical sensor controlled lighting system comprising:
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an ambient light sensor responsive to ambient light levels for generating an output signal which is proportional to the ambient light level; a light source having a plurality of operational states; means responsive to the output signal for developing a rate of change signal; means for switching the light source between the plurality of operational states, the means for switching including gain or filtering stages and being responsive to the rate of change signal occurring between unidirectional minimum and maximum rates for switching the light source from one to another of the plurality of operational states; the means for switching being further responsive to the determined rate of change coinciding with increasing ambient light levels for switching the operational state of the light source to an on state; and the means for switching including means for analyzing the waveform shape of the output signal from the light sensor.
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Specification