USOO9433 065B2

(12) United States Patent (10) Patent No.: US 9.433,065 B2 Raynor (45) Date of Patent: Aug. 30, 2016

(54) SYSTEM INCLUDING TIME OF (56) References Cited FLIGHT RANGING SYSTEM U.S. PATENT DOCUMENTS (71) Applicant: STMicroelectronics (Research & 2004/0114921 A1* 6/2004 Braun ...... B60Q 9/008 Development) Limited, Marlow, 396,661 Buckinghamshire (GB) 2007/0228262 A1* 10, 2007 Cantin ...... GOP 13.00 250,221 2009.0109353 A1* 4, 2009 Liu ...... HOSB 37,0227 (72) Inventor: Jeffrey M. Raynor, Edinburgh (GB) 349.1 2009, O195166 A1* 8, 2009 Chen ...... HOSB 33,0863 315,158 (73) Assignee: STMicroelectronics (Research & 2010, O259.174 A1* 10, 2010 Hou ...... HOSB 37,0227 Development) Limited, Marlow, 315, 149 2010/0295481 A1* 11/2010 Van Endert ...... HO3K 17.96 Buckinghamshire (GB) 315/312 2012/0194479 A1* 8, 2012 Stark ...... G06F 3/0428 (*) Notice: Subject to any disclaimer, the term of this 34.5/175 2012fO262069 A1 * 10/2012 Reed ...... HOSB 37.0245 patent is extended or adjusted under 35 315/130 U.S.C. 154(b) by 16 days. 2013/0194778 A1* 8, 2013 Santos ...... F21V9f 16 362/84 2013/0314711 A1* 11/2013 Cantin ...... GO1S 17/10 (21) Appl. No.: 14/533,634 356,445 (22) Filed: Nov. 5, 2014 * cited by examiner Primary Examiner — Jason M Crawford (65) Prior Publication Data (74) Attorney, Agent, or Firm — Gardere Wynne Sewell LLP US 2016/O128162 A1 May 5, 2016 (57) ABSTRACT A lighting system includes a light emitting array, and (51) Int. Cl. a time of flight ranging system. A logic circuit determines a H05B 37/02 (2006.01) distance to an object using the time of flight ranging system GOIS 17/08 (2006.01) and controls the light emitting diode array based upon the GOIS 17/88 (2006.01) distance to the object. A receptacle is coupled to the logic circuit, and sized and configured to fit within and be pow (52) U.S. Cl. ered from a lightbulb socket. In some applications, the logic CPC ...... H05B 37/0227 (2013.01); G0IS 17/08 circuit may activate the light emitting diode array when the (2013.01); G0IS 17/88 (2013.01) object is less than a threshold distance away from the (58) Field of Classification Search lighting system and deactivate the light emitting diode array CPC ...... H05B33/0869; H05B33/0854; H05B when the object is greater than the threshold distance away 33/086; H05B33/0872; H05B 37/0227; from the lighting system. In further applications, the logic G01S 17/08; G01S 17/88 circuit may activate the light emitting diode array at a duty USPC ...... 315/149-152, 158 cycle that varies based upon the distance to the object. See application file for complete search history. 20 Claims, 9 Drawing Sheets

U.S. Patent Aug. 30, 2016 Sheet 1 of 9 US 9.433,065 B2

POWer OF Ranging PWM From System + Logic Circuit

R Visible Ranging x Light

F.G. 1A

POWer VLOGIC Ranging From System + Socket logic Circuit

R i Visible Ranging Light

FG. 1B U.S. Patent Aug. 30, 2016 Sheet 2 of 9 US 9.433,065 B2

WSPY.

G. U.S. Patent Aug. 30, 2016 Sheet 3 of 9 US 9.433,065 B2

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G 3 U.S. Patent Aug. 30, 2016 Sheet 4 of 9 US 9.433,065 B2

U.S. Patent Aug. 30, 2016 Sheet 5 Of 9 US 9.433,065 B2

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F.G. 6 U.S. Patent Aug. 30, 2016 Sheet 6 of 9 US 9.433,065 B2

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U.S. Patent Aug. 30, 2016 Sheet 8 of 9 US 9.433,065 B2

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FG 9 U.S. Patent Aug. 30, 2016 Sheet 9 Of 9 US 9.433,065 B2

aul TLED 10 TMEASURE 10

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F.G. 11 US 9,433,065 B2 1. 2 LIGHTING SYSTEM INCLUDING TIME OF activating the light emitting diode array at a first duty cycle FLIGHT RANGING SYSTEM when the distance to the object is a first distance, and by activating the light emitting diode array at a second duty FIELD OF THE INVENTION cycle when the distance to the object is a second distance. The logic circuit may be configured to control the light This invention is directed to the field of lighting systems emitting diode array based upon whether the receptacle is that are controlled based upon their distance from an object, powered by the light bulb socket in a first mode, and may be and, more particularly, to lighting systems that utilize time configured to control the light emitting diode array based of-flight ranging systems to determine their distance from upon the distance to the object in a second mode. In addition, the object. 10 the logic circuit may be configured to control of the light emitting diode from the first mode to the second mode BACKGROUND based upon the distance to the object being less than a threshold distance during a first interval of time. The logic Incandescent light bulbs have largely been replaced with circuit may be configured to switch control of the light compact fluorescent lights in today’s world to reduce energy 15 emitting diode from the second mode to the first mode based consumption. These compact fluorescent lights are typically upon the distance to the object being less than a threshold designed and manufactured to be compatible with existing distance during a second interval of time different than the sockets and fixtures so as to ease first interval of time. transition from the incandescent light bulbs to the compact The time of flight ranging system may include a vertical fluorescent lights. cavity Surface emitting configured to emit ranging Similarly, halogen lightbulbs are now being replaced with light, and a Geiger mode avalanche config light emitting diode (LED) arrays. These LED arrays offer a ured to detect reflected ranging light that has reflected off the longer life span and offer greater energy efficiency. How object. ever, the consumer demand for even greater energy effi Another aspect is directed to a lighting system that ciency leads to a desire for the addition of further power 25 includes a light emitting diode array, a ranging light source, saving features to these LED arrays. However, due to the a reflected light detector, and a logic circuit. The logic circuit fact that these LED arrays are designed and manufactured to may be configured to activate the ranging light source to be compatible with existing halogen light bulb sockets, cause the ranging light source to emit ranging light, and space is at a premium, and typical power savings features, monitor output from the reflected light detector to detect Such as proximity sensor, may be difficult to implement. 30 reflected ranging light that has reflected off an object and Consequently, the development of LED arrays with power back to the reflected light detector. The logic circuit may also saving features and that will maintain compatibility with be configured to determine a distance to the object based existing halogen light bulb sockets is desirable. upon time elapsed between activating the ranging light Source and detecting the reflected ranging light, and to SUMMARY 35 control the light emitting diode array based upon the dis tance to the object. This Summary is provided to introduce a selection of The logic circuit may be configured to monitor output concepts that are further described below in the detailed from the reflected light detector during a first interval of description. This Summary is not intended to identify key or time, and to control the light emitting diode array Such that essential features of the claimed Subject matter, nor is it 40 the light emitting diode array is activated during a second intended to be used as an aid in limiting the scope of the interval of time different than the first interval of time and claimed subject matter. deactivated during a third interval of time overlapping the In accordance with this disclosure, one aspect is directed first interval of time. to a lighting system that includes a light emitting diode A logic block may be coupled between the reflected light array, a time of flight ranging system, and a logic circuit. The 45 detector and the logic circuit, and may be configured to logic circuit may be configured to determine a distance to an block signals from the reflected light detector from reaching object using the time of flight ranging system and to control the logic circuit when the light emitting diode array is the light emitting diode array based upon the distance to the activated. object. A receptacle is coupled to the logic circuit, and may The reflected light detector may include a photodetector be sized and configured to fit within and be powered by a 50 capable of operating in Geiger mode, and the logic circuit light bulb socket. may be configured to Supply a Voltage to the photodetector The logic circuit may be configured to control the light at a level sufficient to operate the photodetector in Geiger emitting diode array based upon the distance to the object by mode when the light emitting diode array is not activated, activating the light emitting diode array when the object is and to Supply the Voltage to the photodetector at a level less than a threshold distance away from the lighting system, 55 insufficient to operate the photodetector in Geiger mode and by deactivating the light emitting diode array when the when the light emitting diode array is activated. object is greater than the threshold distance away from the A first Supply node may be configured to Supply a first lighting system. Voltage to the light emitting diode array, and a second Supply The logic circuit may be configured to control the light node may be configured to Supply a second Voltage less than emitting diode array based upon the distance to the object by 60 the first Voltage to the time of flight ranging system. activating the light emitting diode array at a duty cycle that A method aspect is directed to a method of operating a varies based upon the distance to the object. The duty cycle lighting system. The method may include emitting ranging may vary proportionally with the distance to the object, or light from a ranging light source, and detecting reflected may vary inversely proportionately with the distance to the ranging light that has reflected off an object and back to a object. 65 reflected light detector. A distance to the object may be The logic circuit may be configured to control the light determined based upon time elapsed between emitting the emitting diode array based upon the distance to the object by ranging light and detecting the reflected ranging light, using US 9,433,065 B2 3 4 a logic circuit. A light emitting diode array may be con ranging system and logic circuit 15, and is itself powered by trolled based upon the distance to the object, using the logic a light socket. For example, a receptacle may be coupled to circuit. the power source 12, and may be configured to fit within and accept power from the light socket. BRIEF DESCRIPTION OF THE DRAWINGS An example form factor for the lighting system 10 having the receptacle 11 is shown in FIG. 4. The receptacle 11 FIG. 1A is a schematic block diagram of a lighting system includes a housing 80, with a plug 83 extending therefrom. employing a time of flight ranging system in accordance Although the plug 83 illustratively is shown as a pair of pins, with this disclosure. in some applications it may instead be a singular threaded FIG. 1B is a schematic block diagram of a lighting system 10 plug. The housing 80 carries the electronics described similar to that of FIG. 1A, but supplied differently. above, as well as a reflector 81, which LED array 16 is FIG. 2 is a detailed schematic block diagram of a lighting positioned inside. The reflector 81 helps to collect and focus system employing a time of flight ranging system in accor the light emitted from the LED array 16. A lens 82 covers the dance with this disclosure. LED array 16 for protection and further light collection and FIG. 3 is a detailed schematic block diagram of a lighting 15 focusing. The time of flight ranging module 14 may be system similar to that of FIG. 2, but with its LED array located centrally within the LED array 16, as shown in FIG. biased differently. 5. FIG. 4 is a perspective view of a lighting system employ In operation, the logic circuit 15 uses the time of flight ing a time of flight ranging system in accordance with this ranging system to determine the distance to an object, and disclosure. controls the LED array 16 based upon that distance, for FIG. 5 is a front view of the lighting system of FIG. 4 example by activating the LED array 16 at a desired duty showing the LED array and time of flight ranging system. cycle, or deactivating the LED array 16. In some applica FIG. 6 is a timing diagram of a lighting system employing tions, the LED array 16 may operate at a higher Voltage than a time of flight ranging system being Switched between a the time of flight ranging system and logic circuit 15. In Such standard mode and a "smart’ mode. 25 an application, as shown in FIG. 1B, the power source 12 FIG. 7 is a timing diagram of a lighting system employing may provide a higher voltage Vled to the LED array 16 than a time of flight ranging system being operated in a standard the Voltage Vlogic Supplied to the time of flight ranging mode. system and logic circuit 15. FIG. 8 is a timing diagram of a lighting system employing With reference to FIG. 2, greater details of an embodi a time of flight ranging system being Switched between a 30 ment of the system 10 are now provided. Here, the logic standard mode and a "smart dimming mode. circuit 17 and time of flight ranging system 14 are collocated FIG. 9 is a detailed schematic block diagram of a lighting on an 15. The time of flight ranging system system similar to that of FIG. 2 but with a logic block 14 includes a ranging light Source 21, illustratively a vertical between the time of flight ranging system and the logic cavity Surface emitting laser (VCSEL). The ranging light circuit to help reduce detection of ambient light by the time 35 source 21 is driven by a VCSEL driver 20, which is actuated of flight ranging system. by the logic circuit 17. When activated, the ranging light FIG. 10 is a timing diagram of a lighting system employ source 21 emits pulses of laser light, which travel to and are ing a time of flight ranging system being operated so as to reflected off an object 30. help reduce detection of ambient light by the time of flight The time of flight ranging system 14 also includes a ranging system when the LED array is being operated at a 40 reflected light detector 22, illustratively a single photon lower duty cycle. or Geiger-mode avalanche photon diode, FIG. 11 is a timing diagram of a lighting system employ which detects the ranging light that has been reflected from ing a time of flight ranging system being operated so as to the object 30. The logic circuit 17 monitors the output of the help reduce detection of ambient light by the time of flight reflected light detector 22, and determines the distance to the ranging system when the LED array is being operated at a 45 object based upon the time elapsed between activating the higher duty cycle. ranging light source 21 and detecting the reflected ranging light. DETAILED DESCRIPTION The logic circuit 17 generates a pulse width modulation (PWM) signal to drive the LED array 16. The PWM signal One or more embodiments of the present disclosure will 50 is based upon the distance to the object, and the logic circuit be described below. These described embodiments are only 17 may generate the PWM signal differently depending examples of the presently disclosed techniques. Addition upon which mode it is currently in. As an alternative design ally, in an effort to provide a concise description, some choice, in some applications, as shown in FIG. 3, the LED features of an actual implementation may not be described array 16 may be coupled between a LED driving voltage in the specification. When introducing elements of various 55 Vled and a reference voltage, with the logic circuit 15 embodiments of the present disclosure, the articles “a,” “an.” opening or closing a Switch between the LED array 16 and and “the are intended to mean that there are one or more of the reference voltage via the PWM signal. the elements. The terms “comprising,” “including, and For example, the logic circuit 17 may operate in a “smart” “having are intended to be inclusive and mean that there mode in which it generates a constant PWM signal when the may be additional elements other than the listed elements. 60 object is less than a threshold distance away from the With initial reference to FIG. 1A, a lighting system 10 is lighting system 10, and may generate no PWM signal when now described. The lighting system 10 includes a light the object is more than the threshold distance away from the emitting diode (LED) array 16 configured to emit visible lighting system. Thus, in the “smart’ mode, the logic circuit light, and that is controlled by a time of flight ranging system 17 can be said to activate the LED array 16 when the object and logic circuit 15. The LED array 16 is coupled between 65 is less than the threshold distance away, and to deactivate the the logic circuit 15 and a reference Voltage. A power Source LED array 16 when the object is more than the threshold 12 provides a voltage supply Vsupply to the time of flight distance away. US 9,433,065 B2 5 6 The logic circuit 17 may switch from operating in a the upper threshold range RX1 and the lower threshold “normal mode in which it generates a constant PWM signal range RN1 for an interval of time between T3 and T4, and regardless of the distance between the object and the lighting is then removed. Once the object is removed and the range system 10 and the “smart’ mode based upon receiving input observed returns to R0, the logic circuit 17 enters the from a switch (not shown). Alternatively, the logic circuit 17 “smart” or “smart dimming mode, and varies the PWM may switch from operating in the “normal mode to the duty cycle based upon the measured distances between the “smart’ mode based upon the distance between the lighting lighting system 10 and the object. To alert the user that the system 10 and the object being between upper and lower “smart” or “smart dimming mode has been entered, the thresholds during a first interval of time, and may switch logic circuit 17 flashes the LED array 16 on and off two back from operating in the “smart’ mode to the “normal 10 times, as shown by the PWM duty cycle between T5 and T6. mode based upon the distance between the lighting system At a later time, T7, the object is placed between a lower 10 and the object being between the upper and lower threshold RN2 and an upper threshold RN1 for a time thresholds during a second interval of time different than the interval between T7 and T8, and is then removed. Once the first interval of time. object is removed and the range observed returns again to 15 R0, the logic circuit 17 back to the “normal” mode. As another example, the logic circuit 17 may operate in a The values of RN1 and RX1 may be programmed into the “smart dimming mode, in which it varies the duty cycle of logic circuit 17, or could be set by the logic circuit 17 based PWM signal based upon the distance to the object, for upon the range R0 (distance to the static background object). example by varying the duty cycle proportionately or Still further, the values of RN1 and RX1 may be set by the inversely proportionately with respect to the distance. This logic circuit 17 based upon the distance to the object at two serves to dim the light as perceived by a viewer due to the separate times. Similarly, the values of RN2 and RX2 may way the human eye perceives pulses of light. Therefore, in be programmed into the logic circuit 17, could be set by the the “smart dimming” mode, the logic circuit 17 can be said logic circuit based upon the range R0, or could be set by the to brighten or dim the LED array based upon the distance to logic circuit 17 based upon the distance to the object at two the object. 25 separate times. This varying can be done at any rate, for example, by Shown in FIG. 7 is a timing diagram of operation of the lighting system 10 where, between T3 and T4, an object is not detected between the static background and the lighting 1 system, is now descried. Here, “smart” or “smart dimming 30 mode is never entered by the lighting system 10 between T3 and T4, so the PWM duty cycle stays high, despite the fact with d being the distance, so as to maintain a constant that an object is detected between the static background and apparent illumination from the perspective of the object the lighting system at T7-T8 and T10-T11. (which is likely a person). As another example, upper and An alternative method of Switching modes of the logic lower distance thresholds can be set, and the varying can be 35 circuit 17 from “normal to “smart” or “smart dimming is done such that the PWM duty cycle is based upon (Dis now fully described with reference to the timing diagram tance-Lower Threshold)*(Upper Threshold-Lower Thresh shown in FIG.8. A brief period of time after power is applied old). to the receptacle, the Supply voltage V supply goes high at In some applications, the logic circuit 17 may operate the T1. At T2, which is shortly after T1 (typically less than 1 “smart dimming” mode such that it varies the duty cycle of 40 second), the time of flight ranging module 14 begins opera the PWM signal in discrete steps based upon the distance, tion, and the logic circuit 17 uses the time of flight ranging such as 0% when no object is detected or when the object is module 14 to measure the distance between the lighting not within a first distance, 33% when the object is within a system 10 and the static background object, which is at first distance but less than a second distance, 66% when the range R0. The PWM duty cycle is high to indicate that the object is within the second distance but less than a third 45 logic circuit 17 is awaiting instruction. Between T2 and distance, and 100% when the object is within the third T3A, the object is brought between the lower range thresh distance. In addition, the logic circuit 17 may operate the old RN1B and the upper range threshold RX1B, and then “smart dimming” mode such that it varies the duty cycle of removed. Between T3A and T4B, the object is once again the PWM signal between lower and upper nonzero values, brought between RN1B and RX1B, and then removed. The such as 50% when no object is detected or when the object 50 logic circuit 17, based upon the object being brought is not within a threshold distance, and 100% when the object between the upper and lower range thresholds for the is within the threshold distance. intervals of time between T3A and T4A, and between T3B The initial power-up of the lighting system 10 and switch and T4B, then switches into the “smart” or “smart dimming ing of modes from “normal’ to “smart” or “smart dimming mode at time T5, and causes the PWM duty cycle to go high is now fully described with reference to the timing diagram 55 twice, this activating the LED array 16 twice to indicate to shown in FIG. 6. A brief period of time after power is applied the user that the “smart” or “smart dimming mode has been to the receptacle, the Supply voltage V supply goes high at entered. T1. At T2, which is shortly after T1 (typically less than 1 The values of RX1B and RN1B may be programmed into second), the time of flight ranging module 14 begins opera the logic circuit 17, or could be set by the logic circuit 17 tion, and the logic circuit 17 uses the time of flight ranging 60 based upon the range R0 (distance to the static background module 14 to measure the distance between the lighting object). Still further, the values of RX1B and RN1B may be system 10 and a static background object, such as a counter set by the logic circuit 17 based upon the distance to the top, which is at range R0. The PWM duty cycle is high to object at two separate times. indicate to the user that the logic circuit 17 is awaiting In some applications where the logic circuit 17 is pro instruction by activating the LED array 16. At T3, which is 65 grammed with the logic for either the “smart’ mode or the shortly after T2, an object (Such as a user's hand) is placed “smart dimming mode, either of the two above methods for between the background and the lighting system 10 between entering the mode may be used. In the case where the logic US 9,433,065 B2 7 8 circuit 17 is programmed with the logic for both the “smart' emitting diode array when the object is less than a threshold mode and the “smart dimming mode, one of the above distance away from the lighting system and deactivating the methods may be used for entering the “smart’ mode, while light emitting diode array when the object is greater than the one may be used for entering the “smart dimming mode. threshold distance away from the lighting system. Referring again to FIG. 2, the reflected light detector 22 5 4. The lighting system of claim 1, wherein the logic circuit is sensitive to ambient light as well as light from the ranging is configured to control the light emitting diode array based light source 21. As the detection field of the ranging light upon the distance to the object by activating the light detector 22 is likely to be aligned to the light cone from the emitting diode array at a duty cycle that varies based upon LED array 116, a large amount of ambient light could the distance to the object. potentially be detected by the reflected light detector 22 and 10 5. The lighting system of claim 4, wherein the duty cycle degrade accuracy of the range detection. Therefore, as varies proportionally with the distance to the object. shown in FIG. 9, a logic block 27 may be inserted between 6. The lighting system of claim 4, wherein the duty cycle the reflected light detector 22 and the logic circuit 17 and varies inversely proportionately with the distance to the may serve to block signals from the reflected light detector object. from reaching the logic circuit 17 when the duty cycle of the 15 7. The lighting system of claim 1, wherein the logic circuit PWM is high. is configured to control the light emitting diode array based As an alternative, the logic circuit 17 may be configured upon the distance to the object by activating the light to monitor output from the reflected light detector 22 during emitting diode array at a first duty cycle when the distance an interval of time during which the duty cycle of the PWM to the object is a first distance, and by activating the light is low, and to cause the duty cycle of the PWM to be high emitting diode array at a second duty cycle when the during a different interval of time. Thus, the logic circuit 17 distance to the object is a second distance. may be said to monitor output from the reflected light 8. The lighting system of claim 1, wherein the logic circuit detector 22 during a first interval of time, and control the is configured to control the light emitting diode array based LED array 16 such that the LED array 16 is activated during upon whether the receptacle is powered by the light bulb a second interval of time different than the first interval of 25 Socket in a first mode, and is configured to control the light time and deactivated during a third interval of time over emitting diode array based upon the distance to the object in lapping the first interval of time. a second mode; and wherein the logic circuit is configured Example timing diagrams showing this are in FIGS. to switch control of the light emitting diode from the first 10-11, where PWM is high when Vcsel, which activates the mode to the second mode based upon the distance to the ranging light source 21, is low, as the ranging light source 21 30 object being less than a threshold distance during a first is used during the intervals in which the reflected light interval of time. detector 22 is to detect the reflected light. 9. The lighting system of claim 8, wherein the logic circuit As another alternative, the logic circuit 17 may be con is configured to Switch control of the light emitting diode figured to supply a voltage to the reflected light detector 22 from the second mode to the first mode based upon the at a level sufficient to operate it in Geiger mode when the 35 distance to the object being less than a threshold distance LED array is not activated, and to Supply the Voltage to it at during a second interval of time different than the first a level insufficient to operate it in Geiger mode when the interval of time. LED array is activated. 10. A lighting system comprising: While the disclosure has been described with respect to a a light emitting diode array; limited number of embodiments, those skilled in the art, 40 a ranging light source: having benefit of this disclosure, will appreciate that other a reflected light detector comprising a photodetector embodiments can be envisioned that do not depart from the capable of operating in Geiger mode; Scope of the disclosure as disclosed herein. Accordingly, the a logic circuit configured to scope of the disclosure shall be limited only by the attached Selectively activate the ranging light source to cause the claims. 45 ranging light source to emit ranging light, The invention claimed is: Supply a Voltage to the photodetector at a level Sufi 1. A lighting system comprising: cient to operate the photodetector in Geiger mode a light emitting diode array; when the light emitting diode array is not activated, a time of flight ranging system, wherein the time of flight and to Supply the Voltage to the photodetector at a ranging system comprises a vertical cavity Surface 50 level insufficient to operate the photodetector in emitting laser configured to emit ranging light and a Geiger mode when the light emitting diode array is Geiger mode avalanche photodetector configured to activated; detect reflected ranging light that has reflected off an monitor output from the reflected light detector to object; detect reflected ranging light that has reflected off an a logic circuit configured to determine a distance to the 55 object and back to the reflected light detector, object using the time of flight ranging system and to determine a distance to the object based upon time control the light emitting diode array based upon the elapsed between activating the ranging light source distance to the object; and and detecting the reflected ranging light, a receptacle coupled to the logic circuit, and sized and control the light emitting diode array based upon the configured to fit within and be powered by a light bulb 60 distance to the object. Socket. 11. The lighting system of claim 10, further comprising a 2. The lighting system of claim 1, wherein the receptacle receptacle coupled to the logic circuit, and sized and con comprises a housing carrying the logic circuit, with a set of figured to fit within and be powered by a light bulb socket. terminals extending therefrom. 12. The lighting system of claim 10, wherein the logic 3. The lighting system of claim 1, wherein the logic circuit 65 circuit is configured to monitor output from the reflected is configured to control the light emitting diode array based light detector during a first interval of time, and to control upon the distance to the object by activating the light the light emitting diode array Such that the light emitting US 9,433,065 B2 10 diode array is activated during a second interval of time a first supply node configured to supply a first voltage to different than the first interval of time and deactivated during the light emitting diode array, and a second supply node a third interval of time overlapping the first interval of time. configured to supply a second voltage less than the first 13. A lighting system, comprising Voltage to the time of flight ranging system. a light emitting diode array; 15. A method of operating a lighting system comprising: a ranging light source: emitting ranging light from a ranging light source com a reflected light detector; prising a vertical cavity surface emitting laser; a logic circuit configured to detecting reflected ranging light that has reflected off an activate the ranging light source to cause the ranging object and back to a reflected light detector comprising light source to emit ranging light, 10 a Geiger mode avalanche photodetector; monitor output from the reflected light detector to determining a distance to the object based upon time detect reflected ranging light that has reflected off an elapsed between emitting the ranging light and detect object and back to the reflected light detector, ing the reflected ranging light, using a logic circuit; and determine a distance to the object based upon time controlling a light emitting diode array based upon the elapsed between activating the ranging light source 15 distance to the object, using the logic circuit. and detecting the reflected ranging light, and 16. The method of claim 15, the light emitting diode array control the light emitting diode array based upon the is controlled based upon the distance to the object by distance to the object; and activating the light emitting diode array when the object is a logic block coupled between the reflected light detector less than a threshold distance away from the lighting system and the logic circuit, the logic block configured to block and deactivating the light emitting diode array when the signals from the reflected light detector from reaching object is greater than the threshold distance away from the the logic circuit when the light emitting diode array is lighting system. activated. 17. The method of claim 15, wherein the light emitting 14. A lighting system, comprising diode array is controlled based upon the distance to the a light emitting diode array; 25 object by activating the light emitting diode array at a duty a ranging light source: cycle that varies based upon the distance to the object. a reflected light detector; 18. The method of claim 17, wherein the duty cycle varies a logic circuit configured to proportionally with the distance to the object. activate the ranging light source to cause the ranging 19. The method of claim 17, wherein the duty cycle varies light source to emit ranging light, 30 inversely proportionately with the distance to the object. monitor output from the reflected light detector to 20. The method of claim 15, wherein the light emitting detect reflected ranging light that has reflected off an diode array is controlled based upon the distance to the object and back to the reflected light detector, object by activating the light emitting diode array at a first determine a distance to the object based upon time duty cycle when the distance to the object is a first distance, elapsed between activating the ranging light source 35 and by activating the light emitting diode array at a second and detecting the reflected ranging light, and duty cycle when the distance to the object is a second control the light emitting diode array based upon the distance. distance to the object; and ck c: ck ci: c