Abstract:
A multi-action, battery-powered, trigger-activated lighting system automatically provides soft light upon human motion during the night, even in the event of a power outage, and can additionally be deployed quickly for use as an intense flashlight. Furthermore, it can provide low-battery indication to prompt the user to install fresh batteries whenever necessary, before a critical need arises.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to U.S. provisional patent application Ser. No. 61/010,771, filed 11 Jan. 2008, which application is incorporated herein in its entirety by this reference thereto. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Technical Field 
     The invention relates to lighting systems. More particularly, the invention relates to a multi-action, battery-powered, trigger-activated lighting system. 
     2. Description of the Prior Art 
     For various reasons, people sometimes need to rise from sleep during the night. In such circumstances, it is desirable to have sufficient lighting to support accident-free mobility. For this purpose, some people employ always-on nightlights that operate from mains power. Others use nightlights that incorporate a sensor so as to provide automatic illumination only when there is a warm body in motion near the nightlight. Still others simply rely on a flashlight, or torch as it is also called in some English-speaking countries, that is kept near the bed for nighttime use. Such a flashlight may provide better portability and light intensity than a typical nightlight, and thus be useful in power outages or other emergencies. 
     Each of these nighttime lighting solutions has certain limitations. For example, the mains-operated type does not function in the event of a power outage. The standard automatic nightlight may not supply a sufficiently intense light for more critical nighttime tasks, such as may arise during a power outage or a burglary. The flashlight near the bed may have weak or dead batteries, of which no one may be aware until a time of need. 
     It would be advantageous to provide improvements to address these limitations. 
     SUMMARY OF THE INVENTION 
     A presently preferred embodiment of the invention provides a multi-action, battery-powered, trigger-activated lighting system that can automatically provide soft light upon human motion during the night, even in the event of a power outage, and that can additionally be deployed quickly for use as an intense flashlight. Furthermore, it can provide a low-battery indication to prompt the user to install fresh batteries whenever necessary, before a critical need arises. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIGS. 1   a  and  1   b  are perspective views of a lighting system according to an embodiment of the invention; 
         FIG. 2  is a sectional side view of a lighting system according to an embodiment of the invention; 
         FIG. 3  is a sectional side view of a lighting system according to an alternative embodiment of the invention; 
         FIG. 4  is a plan view of an example of detector/optics-generated fields-of-view according to an embodiment of the invention; and 
         FIG. 5  is a plan view of an example of detecting through an angle less than 360 degrees according to an alternative embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     A lighting system according to a presently preferred embodiment of this invention has any of several modes of operation, including, but not limited to, those described below: 
     OFF Mode 
     To conserve battery life, an embodiment has a user-control means for complete disconnection of its circuits from its battery. 
     QUIESCENT Mode 
     In this mode, the system&#39;s trigger-activation means is enabled. It draws very little current from the system&#39;s battery, so that the system may be operated in this mode indefinitely. The amount of current drawn may be so low as to make unnecessary any battery disconnection means. The system may employ an ambient light sensing means to disable the trigger-activation means whenever sufficient light is present to render unnecessary any of the system&#39;s active lighting modes. 
     FIRST ACTIVE Lighting Mode 
     In response to a first signal from the trigger-activation means, the system activates a first lighting means. 
     SECOND ACTIVE Lighting Mode 
     A second lighting means may be activated by any one of several means: 
     1) a second signal from the trigger-activation means; 
     2) a first signal from a user-control means; or 
     3) a first signal from a sensing means. 
     Example of the Invention 
     As a non-limiting example, shown in  FIG. 1   a , a system according to the invention is embodied in a housing  10  resembling that of a flashlight. That is, an embodiment of the invention comprises an essentially cylindrical housing enclosing batteries  12  and providing one or more light sources  14  emitting light  16  away from the housing along its cylindrical axis, and/or other light sources emitting light into a larger spherical angle, for example, by passing through the housing  10 , if it is made of translucent or transparent material. The system also comprises a sensor window  18  and a user control  20  for activating different operational modes. 
     As shown in the sectional side view of  FIG. 2 , an embodiment of the invention contains optical elements, such as lenses and/or mirrors, etc., within the volume outlined by dashed lines  22  inside the sensor window  18 . The optical elements direct infrared (IR) light from various fields-of-view  24  onto an IR detector  26 , so that IR light from moving warm bodies, e.g. humans, can be converted to an electrical signal and used to create a first signal as a means for triggering the sensor&#39;s FIRST ACTIVE lighting mode, such as activating the light source  14 . An embodiment of the invention provides an ambient light sensor  28  that produces an electrical signal in response to ambient light level. This signal disables the trigger-activation means whenever sufficient light is present, and thus renders unnecessary any of the system&#39;s active lighting modes. 
     For example, a user operates the control  20  to change the system from OFF mode to QUIESCENT mode, sets the system in a vertical position on a surface  32 , for example a dresser or night table, with the light source  14  facing the ceiling, and then goes to sleep. During the night, were the user to rise and pass through one of the fields-of-view  24 , the user&#39;s IR light causes an electrical signal in the detector, which is employed within the system to trigger the system&#39;s FIRST ACTIVE mode, such as activating the light source  14 , which provides indirect light via the ceiling, which is sufficient for the user to navigate through the room. 
     In cases where the soft indirect light is not sufficient, the user operates the control  20  to change the system from FIRST ACTIVE mode to SECOND ACTIVE mode. For example, secondary light source(s)  30  are activated so that the system provides brighter light. The user either leaves the system in place facing the ceiling, or takes the system in hand and uses it as a flashlight. As a system design alternative to requiring the user to employ the control  20  to change the mode, a tilt switch is provided instead, which automatically changes the system from FIRST ACTIVE mode to SECOND ACTIVE mode as soon as the system is taken in hand and moved more than a few degrees away from a vertical orientation. 
     As an indication of low-battery state, the system, for example, emits several pulses of light at the time of mode changes to alert the user to replace the system&#39;s batteries soon, yet while allowing normal use of the system after the pulses. 
     As an alternative to the system being set on a horizontal plane such as the surface  32 , it is placed into a holder such as a candle-sconce  34  mounted on wall  38 , as shown in the sectional side view of  FIG. 3 . For a system that provides floor lighting, an embodiment of the sconce  34  is constructed with a hole  36  under the system, and the system is fitted with a light source  36  emitting light  16  away from the housing along its cylindrical axis, and toward the floor. 
     Viewed from a top perspective, i.e. along the axis of the system&#39;s housing  10 , the plan view of an example of detector/optics-generated fields-of-view  24  is shown in  FIG. 4 . Depending on the system&#39;s detector and electronic signal processing, at distances of several meters or more from the system, moving humans crossing the fields-of-view are detected by the system, and to cause it to change from QUIESCENT mode to FIRST ACTIVE lighting mode. 
     If it is not desirable for the system to detect in all directions, then it can be designed to detect through an angle less than 360 degrees, as shown in  FIG. 5 . Alternately, a 360-degree system can be provided with a mask to adjust its detection angle. 
     As an alternative to the integrated system already discussed, the invention may also be realized in modular fashion.  FIG. 1   b  is a perspective view of a system  40  according to the invention is embodied in a form factor that resembles that of a flashlight, similar to the system  10  of  FIG. 1   a . The modular system  40  comprises a lamp module  42 , a battery module  44 , and a control module  46 , which may comprise an IR detector, an ambient light sensor, a sensor window, a user control, and so forth, as previously discussed. The modular system may be assembled as a simple flashlight by omitting the control module  46 , or as a complete system according to the invention by including the control module  46 . The modules may be retrofitted to a standard flashlight by removing the light bulb from the flashlight, inserting the module into the flashlight&#39;s light bulb socket, and then inserting the flashlight&#39;s bulb into a socket in the module. The module is thus placed in-line between the flashlight&#39;s bulb and the socket. In other embodiments, the module may be inserted into the battery compartment in place of a battery, or it may be joined into the flashlight&#39;s existing structure, for example by screwing the module onto a bottom cap of the flashlight. 
     Although the invention is described herein with reference to the preferred embodiment, one skilled in the art will readily appreciate that other applications may be substituted for those set forth herein without departing from the spirit and scope of the present invention. Accordingly, the invention should only be limited by the Claims included below.