Patent Publication Number: US-2015061495-A1

Title: Emergency-activated night light and methods for activating same

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     The present application claims the benefit of U.S. Provisional Patent Application No. 61/871,163, which is titled “EMERGENCY-ACTIVATED NIGHT LIGHT AND METHODS FOR ACTIVATING SAME” and was filed on Aug. 28, 2013, the content of which is hereby incorporated by reference herein in its entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     This invention relates generally to lighting devices and more particularly to nightlights incorporating multi-mode operation. 
     Conventional nightlights are configured to plug into a power outlet and be operated using a single on-off switch to activate a low-wattage bulb. A more recent variation on such a nightlight uses a light sensor to turn on the nightlight bulb only when the ambient light drops below a certain threshold, but deactivates the light otherwise. All such nightlights are often used in low-light areas for safety and security purposes. When used along a hallway, for instance, such nightlights provide just enough light during the nighttime to allow one to proceed slowly down such hallway by illuminating potential tripping hazards. 
     During emergencies, such as when rapid egress of a location is needed, more light than is typical for nightlights may be needed. However, conventional nightlights are not intended to provide full ambient illumination as such would be power-prohibitive and would defeat the limited purpose of such nightlights. Instead, a home-owner would typically switch on the regular lights to provide such additional illumination. But such actions may take additional time to accomplish, is made more difficult by people&#39;s panicked reaction to such emergencies, and may be worthless if power is cut-off to the house due to the emergency. 
     While conventional nightlights have typically served a single purpose—that is to provide low, localized light—there is a need for more sophisticated light sources that have an additional activation state during emergencies such as fires, earthquakes, burglaries, etc. 
     SUMMARY OF THE INVENTION 
     One aspect of the invention comprises an emergency lighting device having a lighting device housing and power source. The lighting device includes an illumination circuit powered by the power source. The illumination circuit is configured to trigger a first illumination mode having a first non-zero lumen output responsive to a first condition and a second illumination mode having a second, different, non-zero lumen output responsive to a second condition. In a preferred embodiment, the first non-zero lumen output is lower than the second non-zero lumen output. One or more light sources are retained within the lighting device housing and configured to provide illumination outside of said housing responsive to the first or second illumination mode. Finally, a signal detector retained within the lighting device housing is operative to trigger the second condition responsive to detection of a signal which, in a preferred embodiment is an audible signal such as a fire or smoke alarm signal. 
     In another aspect of the invention, an emergency lighting device comprises a lighting device housing having a translucent peripheral portion. A first set of light sources are spaced along and directed outward from the translucent peripheral portion and configured to illuminate along at least a substantial length of the peripheral portion. A second set of light sources are pivotally coupled along a bottom of the lighting device housing and configured to illuminate downward from the housing. The lighting device further includes means for energizing the first and second set of light sources, with the means including a first mode in which at least one of the first and second set of light sources is energized to illuminate with a first non-zero lumen output and a second mode in which at least one of the first and second set of light sources is energized to illuminate with a second non-zero lumen output. So that an observer can distinguish between modes, and so that additional illumination is provided when an emergency signal is detected, the second non-zero lumen output is higher than said first non-zero lumen output. Finally, an audible signal detector is operatively coupled to at least one of the first and second set of light sources to trigger the at least one of the first and second set of light sources to the second mode responsive to a detected audible signal. 
     Also disclosed herein is a method for operating a nightlight of a type having one or more light sources and a signal detector. The method comprises operating the one or more light sources in a first mode having a first non-zero lumen output, detecting a signal using the signal detector, and, responsive to the step of detecting the signal, operating the one or more light sources in a second mode having a second non-zero lumen output, wherein the second non-zero lumen output is larger than the first non-zero lumen output. 
     The foregoing and other objects, features and advantages of the invention will become more readily apparent from the following detailed description of a preferred embodiment of the invention that proceeds with reference to the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a lighting device according to a preferred embodiment of the invention. 
         FIG. 2  is a plan view of the lighting device from  FIG. 1  with lighting elements, configured according to one embodiment of the invention, shown in broken lines. 
         FIG. 3  is a section side view taken along line  3 - 3  of  FIG. 2 , showing a pivoting housing in a non-pivoted position as configured according to a preferred embodiment of the invention. 
         FIG. 4  is a section side view of the pivoting housing of  FIG. 3  disposed in a pivoted position at an angle to a plane of the lighting device housing. 
         FIG. 5  is a section side view of the lighting device taken along line  5 - 5  of  FIG. 2 . 
         FIG. 6  is an exploded perspective view of the lighting device of  FIG. 1 . 
         FIG. 7  illustrates a first portion of an illumination circuit of the lighting device showing the AC to DC power supply and multiple light sources. 
         FIG. 8  illustrates a signal detector circuit configured according to an embodiment of the invention. 
         FIG. 9  illustrates an optical sensor circuit configured according to an embodiment of the invention. 
         FIG. 10  illustrates a circuit control element configured according to an embodiment of the invention to operate the light sources of  FIG. 7  in one or multiple possible illumination modes. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  illustrates a nightlight  10  as configured according to a preferred embodiment of the invention. Nightlight  10  includes a lighting device housing  12  having front and rear shells  14 ,  16  coupled together to form an interior cavity  42  in which the electronics and light sources are enclosed as described further below. At least a peripheral portion  18  of shells  14 ,  16  are preferably translucent (or possibly transparent) to allow light emanating from the interior cavity  42  of the housing  12  to pass through the portions adjacent the light sources and thence to the exterior of the housing. In one embodiment, the light sources are spaced about and illuminate a substantial length of the peripheral portion  18 . 
     Front and rear shells  14 ,  16  are shaped in a substantially rectangular arrangement and sized to be approximately equal to that of a standard duplex wall plate. A pivot housing  20  is coupled within a notched cutout formed at a bottom of the lighting device housing  12  along a horizontal axis of the pivot housing  20  and in a plane  24  of the lighting device housing  12 . An aperture  26  is formed through the front shell  14  of the light device housing  12  and exposes a photoelectric cell  28  ( FIG. 6 ) whose purpose and operation is discussed further below with reference to  FIG. 9 . 
       FIG. 2  is a plan view of the nightlight lighting device  10 . A plurality of light sources forming a first set—such as LEDs  30   a - 30   d —are retained within a cavity  42  formed within the housing  12  and spaced about a periphery of the housing. In one embodiment of the invention, this first set of light sources project out all sides of the lighting device housing  12  so that, when the device  10  is plugged into a wall socket the LEDs  30   a - 30   b  project onto and illuminate the top, right, bottom, and left wall surfaces, respectively, adjacent the mounted lighting device  10 . A second set of light sources  32   a ,  32   b  are retained within the pivot housing  20  and driven using the same illumination circuit through multiple lighting modes as discussed further below. Although a total of  20  LEDs are shown, the invention is not so limited to this number and any light sources in any configuration may be used so long as the lighting device  10  exhibits two non-zero illumination modes. 
     Examples of illuminations modes are as follows. In a first variation, an illumination circuit is configured to operate all of the one or more light sources (e.g. LEDs  30   a - 30   d  and adjacent elements, and LEDs  32   a  and  32   b ) at a first non-zero lumen output in a first illuminations mode and operate all of the one or more light sources at a second non-zero lumen output in a second illumination mode, wherein the second non-zero lumen output is substantially greater than the first non-zero lumen output. That is, the light sources are driven at a first voltage in a normal/nightlight mode and at a higher voltage, to achieve higher illumination, in an emergency mode. In a second variation, the illumination circuit is configured to operate a first subset of the one or more light sources (e.g. LEDs  30   b  and  30   d  but not  30   a ,  30   c ,  32   a ,  32   b , or adjacent light sources) at a first non-zero lumen output in a first illumination mode and operate a second subset of the one or more light sources (e.g. all the LEDs in the lighting device  10 ) at the second non-zero lumen output in a second illumination mode. The second subset can include the first subset, include only a portion of the first subset, or be an independent group from the first subset. Because more light sources are being driven in the second illumination mode, the second non-zero lumen output is substantially greater than the first non-zero lumen output. An example of the illumination difference between the modes is that the second/emergency mode is ten times the illumination of the normal/nightlight mode. 
       FIGS. 3 and 4  illustrate the direction-adjustable lighting of the lighting device  10 . To effect directional lighting, lighting device housing  12  further includes a pivot housing  20  coupled to a bottom of the lighting device housing  12  along a horizontal axis  22  of the pivot housing and in a plane  24  of the lighting device housing  12 . Pivot housing  20  is axially mounted within a notch  34  formed along a bottom edge of the front and rear shells  14 ,  16  via posts  36   a ,  36   b  extending axially on either side of housing  20 . Posts  36   a ,  36   b  are received within complementary apertures  38   a ,  38   b  formed within either side of the notch  34  with electrical connections, e.g. wire  40 , passing through at least one of the posts  36   a . Such mounting enables illumination to be selectively directed from a second set of light sources—e.g. LEDs  32   a ,  32   b —along an arc A downward in the plane  24  or outward at an angle from said plane of said lighting device housing  12 . 
       FIG. 5  shows a side view of the lighting device  10  taken along section line  5 - 5  in  FIG. 2 . This view shows the assembly of the lighting device using front and back shells  14 ,  16  to complete the lighting device housing  12  and the front and rear sections  20   a ,  20   b  to complete the pivot housing  20 . Pivot housing  20  retains the second set of light sources, comprising LEDs  32   a  and  32   b . Front and back shells  14 ,  16  are assembled together to enclose a cavity  42  into which is received a circuit board  44  and on which is mounted the plurality of light sources such as LEDs  30   a - 30   d , a controller chip  46 , and various circuitry as shown in  FIGS. 7-10 . 
     The front face  48  of front shell  14  is generally planar, and the rear face is planar as well to rest against a power outlet when installed and notched  50  to provide additional space for cavity  42 . An AC power plug  52  extends out the rear face  50  of the lighting device housing and is coupled to circuit board  44 , as via through holes  53 , for providing operating power for lighting device  10 , where plug  52  is configured by electrically inserted into a wall power outlet (not shown). The circuit board  44  is mounted within cavity  42  and spaced from the planar interior surface of rear shell  16  via lower spacers  54  on the proximal end of plug  52  and upper spacer  56 . The assembled lighting device  10  comprises a thin profile with lights illuminating from an approximate radial center within a plane of the device with the exception of the pivot-mounted lights  32   a ,  32   b  that are positioned to direct light toward the floor when the lighting device is plugged into a wall outlet. 
       FIG. 6  shows an exploded perspective view of the lighting device  10  in which front shell  14 . All elements retain numbering as described above. 
       FIG. 7  illustrates a first portion of an illumination circuit of the lighting device showing the AC to DC power supply and lighting elements comprising multiple light sources. AC power is supplied through plug  52  left and right prongs L, R to diode group D 3 , D 4 , D 5  and D 6 . The AC to DC circuit  58  includes a converter chip U 1  and a capacitor group comprising capacitors C 2 , C 3 , C 5 , C 6 , and C 13 . Power is thence transmitted to lighting source circuit  60  through resistor group  1  comprising resistors R 21  through R 28  and coupled to a first set of light sources D 7  through D 31  (which include LEDs  30   a - 30   d ), and a resistor group  2  comprising resistors R 4 , R 5 , R 19 , and R 20  coupled to a second set of light sources D 1 , D 2  (relating to LEDs  32   a ,  32   b ). The first set of light sources are located in spaced positions about the peripheral edge of the circuit board  44  and adjacent and directed out peripheral portions of the lighting device housing  12 . The second set of light sources are mounted within the pivot housing  20  with activation of the light sources through transistor switches Q 4  and Q 5  respectively through programmable PIC microcontroller chip  46  shown in  FIG. 10 . 
       FIG. 8  illustrates a signal detector circuit configured according to an embodiment of the invention. In the preferred embodiment, the signal detector comprises an audible signal detector that includes a microphone  62  that outputs a frequency sensitive signal using the circuit shown in  FIG. 8  to microcontroller chip  46  via input S MC. Microphone  62  is preferably a frequency selective microphone and, in the preferred embodiment, has a peak response from 2.6 to 3.4 kilohertz which includes the alarm signal frequencies of most commercially available smoke alarm devices. Alternately, a wide range microphone could be employed with a suitable bandpass filter (as illustrated in the circuit of  FIG. 8 ). The circuit can be programmed to trigger the second/emergency illumination mode based upon a particular received frequency detected by microphone  62 , by a particular volume detected, or both. In a preferred operation, the emergency nightlight  10  combines decibel level (e.g. 85 dBA) and frequency to activates the emergency mode of the nightlight. That is, the nightlight has standard lumen output when being used normally, but when an audible signal is detected that falls within the proscribed frequency range and exceeds a minimal decibel threshold, the light source output of the nightlight is boosted to a much higher lumen count. By using both, the nightlight  10  may be programmed to ignore false positives where a fire alarm issues from an adjacent property rather than a local one. 
       FIG. 9  illustrates an optical sensor circuit  28  configured according to an embodiment of the invention. Output signal S CDS is transmitted to an illumination circuit characterized by the programmable PIC microcontroller chip  46  for operation as disclosed further below. Circuit  28  includes a photoelectric cell Q 3  operatively connected to the illumination circuit  46   
       FIG. 10  illustrates an illumination circuit control element configured according to an embodiment of the invention to operate the light sources of  FIG. 7  in one or multiple possible illumination modes. Illumination circuit is characterized by a programmable PIC microcontroller chip  46 , powered by the power source, and configured to trigger a first illumination mode having a first non-zero lumen output responsive to a first condition and a second illumination mode having a second non-zero lumen output responsive to a second condition, wherein the first non-zero lumen output is different (preferably greater) than the second non-zero lumen output. In operation, the illumination circuit  46  includes programming to determine whether the light sources—e.g. LEDs D 1 , D 2 , and D 7  through D 31 —are illuminated at 30% power or 100% power. Other illuminations are of course possible without departing from the spirit of the invention comprising the means for energizing any or all of the first and second set of light sources. 
     The illumination circuit is further configured with a third mode in which the first and second set of light sources are not energized responsive to the state of signal received through input S CDS from the photocell circuit of  FIG. 9 . That is, the illumination circuit is configured to operate in the third mode where all LEDs are de-energized in response to sufficient illumination of said photoelectric cell. Otherwise, the illumination circuit is configured to operate in the first mode in the absence of a trigger by the signal detector of  FIG. 8 . 
     A normal nightlight operation, where the photocell does not detect a threshold minimum of ambient light, is treated as a first condition and results in the light sources illuminating with a low general light. As noted above, this operation may include energizing the light sources to low power or lighting only a small subset of the available light sources. 
     An emergency nightlight operation, where the microphone  62  picks up an audible smoke alarm signal, is treated as a second condition and results in the light sources illuminating with a maximal brightness. As noted above, this operation may include raising the power level to all LEDs from a lower to higher power. Alternately, this operation may include energizing additional LEDs to increase the total lumen output of the nightlight. These different sets of light sources can be the peripheral-fixed sources  30   a - 30   d  in a first group, and the pivotable sources  32   a ,  32   b  in a second group, or some mixture of the light sources. 
     Finally, the illumination circuit is further configured to trigger the second/emergency illumination mode responsive to a detected power failure through the AC power plug. In this case, a battery is enclosed in the housing  12  and electrically coupled to the illumination circuit or means for energizing the first and second set of light sources. The battery in this case is configured to provide operating power for said lighting device in the absence of power through the AC plug. 
     The application of the teachings of the present invention, although the design shown is specific to operation from an audible emergency signal, is not intended to be limited only to such an application. The teachings can be applied to any number of different emergencies or detected signal types merely by substituting the circuit of  FIG. 8  with that specifically designed for the particular signal to be detected. For instance, a motion detector circuit may be used in place of the audible signal detector of  FIG. 8  to trigger the second/emergency illumination mode responsive to a detected earthquake. Similarly, an NOAA alert detection circuit can be substituted in place of the  FIG. 8  circuit to trigger the second/emergency illumination mode responsive to a received NOAA alert signal. For instance, the invention may be extended to a nightlight that substantially increases the lumen output responsive to a detected physical (e.g. earthquake shaking) displacement of the device at a particular frequency and/or Richter level. Finally, multiple detector circuits may be included to trigger the second/emergency illumination mode responsive to multiple different triggering events. Each of these may result in the triggering of various illumination types that vary by intensity, color, strobe, or various other lighting effects, etc. 
     Lastly, the sensor circuit ( FIG. 8 ) and illumination circuit ( FIG. 10 ) may be incorporated into various other packages to operate connected devices or devices into which such circuits are incorporated. One example of such a use for the invention includes incorporation of the circuit with battery backup into a light bulb. Another variation includes an outlet interface or remote that triggers a connected electronic device—such as a lamp, stereo, etc.—upon detection of the emergency signal. Such circuits may also be incorporated into lamps and wall sconces, and into alarm systems. Finally, such circuits may be incorporated into flashlights and/or lanterns for automated operation. 
     Having described and illustrated the principles of the invention in a preferred embodiment thereof, it should be apparent that the invention can be modified in arrangement and detail without departing from such principles. What is claimed is all modifications and variation coming within the spirit and scope of the following claims.