Abstract:
An apparatus and method for strategically illuminating a darkened area. The present invention may be used by law enforcement to illuminate an area without law enforcement officials having to reveal their position, which is the case if flashlights or other lighting means are used. The light emitting device comprises a substantially transparent housing. A circuit comprising light emitting means and battery means is contained within the housing. The circuit further comprises a time delay means, which delays the energizing of the light emitting means. The circuit comprises a switch which, upon activation, closes the circuit providing current from the battery.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     The present invention generally relates to light emitting devices and more specifically to devices and methods which allow a person to illuminate an area without revealing the person&#39;s location.  
         [0002]     There times when it is desirable to illuminate a darkened area without revealing a person&#39;s location. For example, law enforcement officers may wish to ascertain whether someone is within a darkened area. Conventionally, law enforcement officers would shine a flashlight into the darkened area. However, shining a flashlight immediately betrays the officer&#39;s position, making the officer a potential target. Other means of illuminating a darkened area would be to deploy a flare or other light emitting device into the area. However, once again, when the officer deploys such a device into the area, his position is revealed. The present invention addresses this need.  
       SUMMARY OF THE INVENTION  
       [0003]     The present invention is directed to a light emitting device which is deployed into a darkened area to illuminate the area with either visible light or, optionally, with infrared light. While not limited to such use, the present invention may be used by law enforcement to illuminate an area without law enforcement officials having to reveal their position, which is the case if flashlights are used. If infrared lighting means are used, appropriate infrared detection equipment must be used.  
         [0004]     The light emitting device comprises a substantially transparent and generally spherical housing. A circuit is contained within the housing, where the circuit is connected to the light emitting means. The circuit comprises light emitting means, a time delay means, which delays the energizing of the light emitting means, and battery means for providing current to the light emitting means. The circuit further comprises a switch which, upon activation, closes the circuit providing current from the battery.  
         [0005]     Also disclosed is a method of utilizing the present invention to strategically illuminate a darkened area.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0006]      FIG. 1  is a perspective view of a first embodiment of the disclosed invention.  
         [0007]      FIG. 2  is a front view of a first embodiment of the disclosed invention.  
         [0008]      FIG. 3  is a back view of a first embodiment of the disclosed invention.  
         [0009]      FIG. 4  is top view of a first embodiment of the disclosed invention.  
         [0010]      FIG. 5  is bottom view of a first embodiment of the disclosed invention.  
         [0011]      FIG. 6  is a perspective view of a second embodiment of the disclosed invention.  
         [0012]      FIG. 7  is a sectional view of the second embodiment.  
         [0013]      FIG. 8  is a detailed view of a switch assembly for an embodiment of the invention.  
         [0014]      FIG. 9  is a detailed view of a switch assembly for an embodiment of the invention.  
         [0015]      FIG. 10  is a circuit diagram for an embodiment of the invention.  
         [0016]      FIG. 11  is a flow chart showing the logic for an embodiment of the invention. 
     
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS  
       [0017]     Referring now specifically to the drawings,  FIG. 1  shows a front view of a first embodiment of the disclosed device  10 . This embodiment  10  comprises a substantially transparent housing  12  which may be constructed of high impact plastic or other transparent materials such as plexiglass or high strength glass. As shown in  FIGS. 1 through 3 , the housing  12  may be generally spherical. A light emitting means, such as one or more light emitting diodes  14 , are part of a circuit contained within the housing  12 . The light emitting diodes  14  may be of such a color, such as red or green, as to preserve the night vision of the users. Alternatively, the light emitting diodes  14  may emit light within the infrared spectrum. Acceptable infrared diodes are available through AGILENT, such as the model HSDL  4420  infrared emitter. With this embodiment, the only persons capable of seeing the illumination would be those equipped with infrared vision devices, such as infrared goggles. In the event the device is used to illuminate an area in which a criminal suspect may be located, the use of infrared diodes would prevent the suspect, not equipped with an infrared vision device, from knowing that he or she has been illuminated.  
         [0018]     A circuit  16 , such as that depicted in  FIG. 10 , is contained within the housing  12 . The circuit comprises the light emitting diodes  14  and time delay means which delays the energizing of the light emitting diodes. The circuit  16  may comprise an integrated circuit, such as microcontroller  20  having a timer. The microcontroller  20  may be packaged as a thin shrink small outline package (TSSOP). The TSSOP may comprise a plurality of leads  22 , such as the sixteen leads depicted in  FIG. 10 . The circuit may also comprise a voltage regulator  23 . The microcontroller  20  may be in the Motorola 908Q family. An acceptable microcontroller  20  is a Motorola model MC68HC908QY4CDT having in-circuit re-programmable flash memory. This feature allows the time delay to be readjusted as desired such that the light emitting means, such as the light emitting diodes  14 , are energized at a specified time. For example, the time delay might be set at a value of five seconds. However, because of the programmable nature of the microcontroller  20 , the time delay may be set at almost any desired value. As shown in  FIG. 8 , test point numbers  1  through  8  (designated TP 1  through TP 8 ) are utilized as communication links between the microcontroller and a programming device, such as a computer, to download or upload a particular program to or from microcontroller  20 . As shown in  FIG. 8 , the circuit further comprises a plurality of resistors.  
         [0019]     The light emitting diodes  14  may be divided into a first set of light emitting diodes and a second set of light emitting diodes. For example, the light emitting diodes  14  visible in  FIG. 2  may comprise the first set and the light emitting diodes  14  visible in  FIG. 3  may comprise the second set. The microcontroller  20  may then be configured so that the first set of light emitting diodes  14  and the second set of light emitting diodes are not energized at the same time, thereby reducing the current drawn by the circuit  16 . The frequency of energizing the light emitting diodes  14  may be programmed into microcontroller  20 . For example, the first set of light emitting diodes and the second set of light emitting diodes are alternatively energized at 150 cycles per second. At this frequency, it appears that all of the light emitting diodes remain energized, i.e., the blinking of the diodes is not perceptible by the human eye. It is to be appreciated that the frequency of energizing different diodes  14  and the duration of the energized state may be programmed into the microcontroller, resulting in a large number of available combinations. For example, the diodes may be programmed to emit an S-O-S distress call, making the device useful to backpackers, boaters, or others who may be caught in the elements.  
         [0020]     The circuit  16  also comprises a battery means, such as battery  24 . Battery  24  is also enclosed within housing  12 . The battery  24  may be of the nine volt variety, having a positive and negative terminal on the same end. A snap-on connector  25  is connected to the terminals, the lead wires from the connector conductively connected to the other components of circuit  16 . The circuit  16  further comprises a switching means, such as microswitch  26 , which, upon activation, closes the circuit between the battery  24  and the microcontroller  20 , providing current to the various circuit components, such as the microcontroller and light emitting diodes  14 . The apparatus may also comprise a switch extension  28  configured to engage microswitch  26 . The switch extension  28  may comprise a button  30  and a shaft  32 . Because it may be desirable that the device operates silently, the underside of button  30  may comprise insulating member  34 , which prevents any clicking caused by the button  30  engaging the housing  12 . The exterior of housing  12  may also comprise a recessed section  36 , such that a portion of the switch extension  28  extends into the recessed section, allowing the user to engage button  30 . Switch extension  28  may be configured such that there is friction fit between shaft  32  and the surrounding housing  12  so that once button  30  is pushed downwardly, thereby activating microswitch  26  and closing circuit  16  until button  30  is pulled upwardly to deactivate the microswitch and open the circuit.  
         [0021]     The present device may be deployed by propelling it into a dark environment. If the device is rolled or thrown by the user, the resulting impact or vibration may cause the microswitch  26  to switch to the “off” position. Therefore, one embodiment of the present device includes means for causing switch extension  28  to be retained in a positively locked down position after being depressed in order to maintain the microswitch  26  in an “on” position. The device may be deactivated by pulling upwardly on the switch extension  28 .  
         [0022]      FIGS. 8-9  shows one means of maintaining the switch extension in a locked position. In this embodiment, a spring  37  may be used to apply a lateral force to shaft  32 , which biases a contoured segment  38  of shaft  32  to a matching profile  40  of housing  12 , providing a detent to hold the switch extension  28  in a downward position. Spring  37  may be held in position by spring retainer  42 , which may be molded on the inside of housing  12 .  
         [0023]     As shown in  FIG. 4 , housing  12  may comprise a first hemisphere  42  and a second hemisphere  44  attached together with fastening means  46 . As shown in  FIG. 5 , the fastening means may be inserted into access ports  47  to maintain the generally spherical configuration of the housing  12 . In this configuration, a circuit board  48  may be set between the first hemisphere  42  and the second hemisphere  44 . In the first embodiment  10 , the first hemisphere  42  and the second hemisphere  44  may be mirror images of another, thereby simplifying the manufacturing process. The circuit board  48  may be configured to contain the circuit  16 . In order to change out battery  24 , fastening means  46  are released and the two hemispheres separated allowing access to the battery. The circuit board  48  may have a rectangular opening in the approximate mid-section of the circuit board. A battery storage compartment  50  may extend through the rectangular opening in the circuit board  48 . A nine volt battery  24  may be disposed within the battery storage compartment  50 .  
         [0024]     A second embodiment  100  of the disclosed device is shown in  FIG. 6 . This embodiment comprises a generally spherical housing  12 ′ having a flat base  102 . The base  102  is attached to the housing  12 ′ with fastening means  104 . As shown in  FIG. 7 , access to battery  24  may be gained by removing base  102 , allowing the battery to be changed without taking the housing apart as required by the first embodiment  10 . Base  102  may comprise a weighted material, such as iron or lead, which is heavier than the plastic generally used for the rest of the housing  12 ′. The use of weighted material in the base  102  provides a self-righting means which causes the device, following deployment on a surface, to come to a resting position with the flat base  102  engaging the surface. This feature increases the probability that the light emitting diodes  14  will be oriented as desired when the device comes to a resting position.  
         [0025]      FIG. 11  is a flow diagram showing one variation of how the microcontroller  20  may be programmed for the device. In this program, the light emitting diodes  14  are set into a first set and a second set, with each set energized at a frequency of 150 hertz. This program also checks the battery voltage. If the battery voltage is less than 7 volts dc, the light emitting diodes flash once for 0.5 seconds to indicate that the battery voltage is low.  
         [0026]     While the above is a description of various embodiments of the present invention, further modifications may be employed without departing from the spirit and scope of the present invention. For example, the size, shape, and/or material of the various components may be changed as desired. Thus the scope of the invention should not be limited by the specific structures disclosed. Instead the true scope of the invention should be determined by the following claims.