# US 2011/0309753 A1 · Modulated light detection system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2011/0309753 A1 - Document ID: US20110309753A1 - Status: Published application - Kind: A1 - Application number: 12/819,168 - Filed: 2010-06-18 - Published: 2011-12-22 - Earliest claimed: 2010-06-18 - Assignees: Sol Inc. - Inventors: Audwin Cash; James Bears; Michael Romeo - Web page: https://patentgrep.com/patent/US20110309753A1 ## CPC - H05B 47/11: by determining the brightness or colour temperature of ambient light - Y02B 20/40: Control techniques providing energy savings, e.g. smart controller or presence detection - H05B: ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL - Y02B: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS ## Abstract A lighting system distinguishes between light from natural and manmade sources to prevent the system's light source from being inadvertently deactivated due to light received from manmade light sources. A sensor converts received light into electrical energy. The system light source and/or some other external light source can emit light with a modulation. The system includes a modulation detector that can detect the modulation in the electrical energy received from the sensor. A system controller selectively adjusts the flow of electrical energy to the system light source responsive to the electrical signals from the sensor. The controller adjusts the flow of electrical energy in response to the non-modulated component of the electrical signals from the sensor. The controller does not adjust the flow of electrical energy in response to the modulated component of the electrical signals from the sensor. ## Claims ### Claim 1 A lighting system comprising: a system light source that is at least partially powered by an electrical energy source, the system light source emitting system light when activated, the system light including modulation; a sensor adapted to convert light received thereby into electrical signals, said sensor generating electrical signals having a modulated component when the system light impinges on the sensor, said sensor generating electrical signals having an non-modulated component when natural light impinges on the sensor; a controller for selectively adjusting the flow of electrical energy between the electrical energy source and the system light source responsive to the electrical signals from the sensor, said controller adjusting the flow of electrical energy in response to the non-modulated component and not adjusting the flow of electrical energy in response to the modulated component. ### Claim 2 (depends on 1) The lighting system of claim 1, further comprising a modulation detector operatively connected to receive the electrical signals from the sensor and detect any modulated component, the modulation detector filtering the modulated component in the electrical signals sent to the controller. ### Claim 3 (depends on 1) The lighting system of claim 1 wherein the sensor is at least one solar cell. ### Claim 4 (depends on 1) The lighting system of claim 1 wherein the sensor is one of a photo detector or a photodiode. ### Claim 5 (depends on 1) The lighting system of claim 1 wherein the modulation is a predetermined modulation. ### Claim 6 (depends on 1) The lighting system of claim 1 wherein the modulation is not perceptible to the human eye. ### Claim 7 (depends on 1) The lighting system of claim 1 wherein the modulation is a variation in at least one of amplitude, waveform, phase or frequency of the light emitted from the system light source. ### Claim 8 (depends on 1) The lighting system of claim 1 wherein a predetermined modulation is applied to the light from the system light source only during an initial interval when the system light source is activated. ### Claim 9 (depends on 1) The lighting system of claim 1 wherein the light from the system light source is modulated continuously while the system light source is activated. ### Claim 10 (depends on 1) The lighting system of claim 1 wherein the light from the system light source is modulated periodically while the system light source is activated. ### Claim 11 (depends on 1) The lighting system of claim 1 wherein the energy source is an energy storage device operatively connected to supply electrical energy to the system light source. ### Claim 12 (depends on 11) The lighting system of claim 11 wherein the energy storage device is a battery. ### Claim 13 (depends on 1) The lighting system of claim 1 wherein the energy source is an electrical grid operatively connected to supply electrical energy to the system light source. ### Claim 14 (depends on 1) The lighting system of claim 1 wherein the energy source is operatively connected to the sensor to receive and store electrical signals generated by the sensor. ### Claim 15 A lighting system comprising: a system light source that is at least partially powered by an electrical energy source; a sensor adapted to convert light received thereby into electrical signals, the sensor receiving light from an external manmade light source that emits light including a modulation such that the electrical signals generated by the sensor include at least a modulated component; a controller for selectively adjusting the flow of electrical energy between the electrical energy source and the system light source responsive to the electrical signals from the sensor, said controller adjusting the flow of electrical energy in response to the non-modulated component and not adjusting the flow of electrical energy in response to the modulated component. ### Claim 16 (depends on 15) The lighting system of claim 15 further comprising a modulation detector operatively connected to receive the electrical signals from the sensor, the modulation detector being operatively connected to the controller to selectively increase or decrease the supply of electrical energy from the energy source to the system light source, the modulation detector being configured to detect the modulated component in the electrical signals generated by the sensor such that, when the modulated component is detected by the modulation detector, the modulated component is ignored. ### Claim 17 (depends on 15) The lighting system of claim 15 wherein the sensor is at least one solar cell. ### Claim 18 (depends on 15) The lighting system of claim 15 wherein the sensor is one of a photo detector or a photodiode. ### Claim 19 (depends on 15) The lighting system of claim 15 wherein the modulation is a predetermined modulation. ### Claim 20 (depends on 15) The lighting system of claim 15 wherein the modulation is not perceptible to the human eye. ### Claim 21 (depends on 15) The lighting system of claim 15 wherein the modulation is a variation in at least one of amplitude, waveform, phase or frequency of the light emitted from the external light source. ### Claim 22 (depends on 15) The lighting system of claim 15 wherein the modulation is applied to the light from the external light source only at the time the external light source is activated. ### Claim 23 (depends on 15) The lighting system of claim 15 wherein the modulation is applied to the light from the external light source continuously while the external light source is activated. ### Claim 24 (depends on 15) The lighting system of claim 15 wherein the modulation is periodically applied to the light from the external light source while the external light source is activated. ### Claim 25 (depends on 15) The lighting system of claim 15 wherein the external light source is one of street lights, stadium lights, signage, advertising displays or decorative lights. ### Claim 26 (depends on 15) The lighting system of claim 15 wherein the system light source emits light when activated, the light having a second modulation, wherein the sensor receives light from the system light source such that the electrical signals generated by the sensor include at least a modulated component corresponding to the second modulation, and wherein, when the modulated component corresponding to the second modulation is detected by the modulation detector, the modulated component corresponding to the second modulation is ignored. ### Claim 27 (depends on 26) The lighting system of claim 26 wherein the modulation and the second modulation are different. ### Claim 28 (depends on 15) The lighting system of claim 15 wherein the energy source is operatively connected to the sensor to receive and store electrical signals generated by the sensor.