Abstract:
This invention provides method of rapidly charging a glow-in-the-dark material utilizing an ultra violet emitting LED in portable form to produce a long lasting illuminating effect. The method includes providing a structure having a glow-in-the-dark material incorporated therein and exposing the glow-in-the-dark material to ultra violet light emitted from the LED to charge the glow-in-the-dark material for a period of time. The method of charging a glow-in-the-dark material is applicable to all types of sporting activities where such glow-in-the-dark materials are used, such as hunting and fishing, as well as other known applications.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   This invention relates generally to efflorescent material primarily in sporting good applications such as archery and fishing, and more particularly to a method and apparatus for quickly and effectively charges a glow-in-the-dark material for use in such sporting good activities. 
   2. Description of the Art 
   Recently, there has been developed a light emitting diode (LED) that emits visible and invisible ultra violet light. Even more recently, such LED&#39;s have been incorporated into small hand-held pen lights and other small portable flashlights. Such LED pen lights have been produced with specifications which include an output power of 1,000 uW, peak wavelengths of about 375 nm, narrow focus lenses of about 10 degrees or wider field lenses of about 100 degrees, and a spectrum half width of 12 nm. LED&#39;s typically have extensive life spans, compared to conventional fluorescent tubes or light bulbs and will often have an average life span of 2,000 hours or more. The use of 375 nm light is UVA light, or long wave UV, which is generally safer to the human eye than UVB or UVC and is just below the human eye visible light range. 
   Such UV pen lights have been employed for such uses as document and forgery analysis by showing alterations or changes when exposed to UV light, crowd and access control by illuminating invisible marks on a hand or card, and crime scene inspection by illuminating various bodily fluids. In addition, such UV lights have been employed in currency and bill verification since many currencies now include UV fluorescing strips. Leak detection by adding a UC powder or liquid to a system with a leak and using a UC light source to quickly detect leaks is another use for such UV lights, as well as rodent detection by illuminating urine, scientific, laboratory and educational analysis, UV curing, medical skin treatments, EPROM erasure, painting and rug repair detection, and gemstone and mineral inspection. Such LED UV light sources, however, have not been employed to charge a glow-in-the-dark material. 
   Various sporting good products have taken advantage of the illumination properties of various glow in the dark materials to provide illumination in low light conditions. Such efflorescent materials are now used on items from bow sights to fishing lures. When used on bow sights, Bow sights the sight pins are provided with a light-gathering fiber optic element to enable use of the sighting device in low light environments. Various configurations of sight pins using fiber optic members have been proposed. 
   Despite the light-gathering capabilities of fiber optic elements which render sighting devices more useful in low-light conditions (e.g., dusk), there is a point at which the ambient light is so low that the fiber optic element is no longer capable of gathering sufficient light to provide any illumination. Various direct lighting techniques have been employed in which a small light source is directly coupled to the fiber optic element in order to illuminate the sight pins. In addition, it has also been proposed to provide a self illuminating substance such various glow-in-the-dark materials to one end of a fiber optic element or along its length in order to illuminate the opposite visible end in low light conditions. 
   In fishing lure applications, glow-in-the-dark materials have been incorporated into the construction of the lure itself in order to illuminate the fishing lure under water. This is thought to provide better visible for fish to more quickly visually locate the lure, especially in deep water where light conditions are generally poor. 
   In either case, archery or fishing, there is a need to quickly charge the glow-in-the-dark material. In addition, there is a need to quickly charge the glow-in-the-dark material in a manner that will cause the illuminating properties of the material to last. Typically, such glow-in-the-dark materials are charged by exposing them to ambient light, such as sunlight, or by shining light from a light source, such as a flash light, on the material. While such techniques do cause the material to become charged, the illumination time is relatively short lived. Thus, it would be advantageous to provide a means for causing a glow-in-the-dark material quickly and in a manner that produces an extending illumination time of the material. 
   SUMMARY OF THE INVENTION 
   In accordance with the present invention, a UV LED light source is employed to charge the illumination properties of a non-electric light source, hereinafter referred to as a “glow-in-the-dark material,” which provides illumination for a period of time subsequent to being charged. The non-electric light source is a material which emits light, such as a chemically activated material commonly used in such devices as illuminated watches and glow-in-the-dark signage. In addition, zinc sulfide and copper mixed phosphorescent pigments and powder materials can be incorporated into many materials such as plastics. Such luminescent plastic materials may be formed by mixing luminescent pigment powder with transparent plastic resin. The luminescent plastic can then be formed into the desired shape or applied to the product by casting, molding, extruding, dipping and/or coating. The luminescent pigment is compatible with acrylics, polyester, epoxy, polyvinyl chloride, polypropylene and polyethylene polymers. 
   In the case of fishing lures, the UV LED is turned on and shined upon the entire surface of the glow-in-the-dark material. Because of the unique illuminating properties of the UV light, as compared to white light, the portions of the glow-in-the-dark material that have been exposed to the UV light will appear to glow, even under high ambient light conditions such as direct sunlight, when exposed to the UV light. As such, a user will easily be able to see which portions of the glow-in-the-dark material have been charged in order to ensure that all surfaces of the entire glow-in-the-dark structure have been charged. 
   In the case of a bow sight, the UV LED light source may separate from or integrated with the bow sight so as to be selectively positionable relative to the glow-in-the-dark features of the bow sight, such as those used to illuminate various fiber optic elements to provide illumination thereto. Likewise, the UV LED light source may be employed to charge sighting elements that themselves that are constructed of glow-in-the-dark materials, as by casting, molding, extruding, dipping and/or coating so that the luminescent material is incorporated into the sighting element. 
   In the case where the UV LED light source is attached to the bow sight, the UV LED light source may be mounted to a bracket or component of the sight, such as the pin guard or pin plate. In addition, various light shields may be employed to shield the UV light from being directed toward the user, while allowing the light to shine upon the glow-in-the-dark sighting element. As such, the UV LED may be activated to cause the efflorescent material to glow while continuing to allow the user to focus upon the sighting elements without risk of UV light exposure to the eyes of the user. 
   This same concept of quick charging glow-in-the-dark material may be employed for other uses, such as firearm sighting elements, safety measures as when providing glow-in-the-dark indicia on aircraft or sea craft and the like, charging the face of a watch containing glow-in-the-dark indicia as when diving, and any other use in which it may be desirable to charge a glow-in-the-dark material. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a side view of a portable UV LED flash light directing UV light onto a fishing lure comprised of a glow-in-the-dark material; and 
       FIG. 2  is a front view of an archery bow sight having an LED UV light source attached to the bow sight. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1  illustrates a method of quickly charging a glow-in-the-dark material disposed on a fishing lure, generally indicated at  10 . The fishing lure  10  is provided to show a representative example of a fishing lure that is known in the art and contains one or more glow-in-the-dark elements for providing self-illumination of the fishing lure  10  under water. The fishing lure  10  is comprised of a plurality of beads  11 – 17 , which are strung together and thus interconnected between a head member  18  and a hook  19 . One or more of the beads  11 – 17  is comprised of a material, such as plastic, that has been impregnated with glow-in-the-dark material. 
   The glow-in-the-dark material is a material which emits light after being exposed to a light source, such as a chemically activated material commonly used in such devices as illuminated watches and glow-in-the-dark signage. Zinc sulfide and copper mixed phosphorescent pigments and powder materials can be incorporated into many materials such as plastics. Such luminescent plastic materials may be formed by mixing luminescent pigment powder with transparent plastic resin. The luminescent plastic can then be formed into the desired shape or applied to the product by casting, molding, extruding, dipping and/or coating. The luminescent pigment is compatible with acrylics, polyester, epoxy, polyvinyl chloride, polypropylene and polyethylene polymers. 
   The light source, generally indicated at  20 , is a relatively small, portable flashlight containing one or more LED&#39;s  22  that emit ultra violet light. The flashlight  20  is comprised of an elongate cylindrical battery housing  24  having an end cap  26  attached to a proximal end  28  and a the LED light assembly  30  housed within a rotatable switch housing  32 . A plurality of batteries  33 ,  34  and  35  are contained within the battery housing  24 . By rotating the switch housing  32 , contact is made between the circuit board  36  to which the LED  22  is coupled and the housing  24  to cause a current to flow through the LED  22 . Electrical contact is also made between the circuit board  36  and the battery  35 , by a small spring  38  interposed between the circuit board  36  and the battery  35 . 
   The LED  22  emits visible and invisible ultra violet light. The LED has an output power of approximately 1,000 uW, a peak wavelength of about 375 nm, a narrow focus lense of about 10 degrees, and a spectrum half width of 12 nm. By utilizing a 375 nm light, UVA light, or long wave UV light, is produced which is generally safer to the human eye than UVB or UVC and is just below the human eye visible light range. Such light, however, rapidly charges glow-in-the-dark materials at a much more rapid rate than white light alone, which includes UV light, but at a much lower intensity than that emitted by sunlight or other portable light sources, such as conventional flashlights utilizing a light bulb. For example, a glow-in-the-dark material may be charged in five seconds or less using a single UV LED, while an equivalent intensity charge would take several more seconds using a conventional bulb-type flashlight. In addition, because of the frequency range of the UV light and the visibility thereof, it is less susceptible to being detected by game than is white light, that may otherwise startle any game being hunted in low light conditions. Thus, there is an enormous advantage to using low intensity visible light to charge the glow-in-the-dark material of an archery sight as compared to conventional methods of white light flashlights. 
   In addition to charging at a faster rate, the use of an LED light source to charge a glow-in-the-dark material produces a much more intense glowing effect than can be achieved using conventional white light sources. Thus, once charged by a UV LED, the glow-in-the-dark material will continue to glow for an extended period of time compared to charging by a white light source of similar intensity. 
   Thus, in the case of the fishing lure  10 , the UV LED flashlight  20  is turned on and directed toward one or more surfaces of fishing lure comprised of glow-in-the-dark material. As previously mentioned, because of the unique illuminating properties of the UV light and its effect on charging such glow-in-the-dark materials, as compared to white light, the portions of the fishing lure  10  containing glow-in-the-dark material that have been exposed to the UV light will appear to glow, even under high ambient light conditions such as direct sunlight, when exposed to the UV light. As such, a user will easily be able to see which portions of the glow in the dark material have been charged in order to ensure that all surfaces of the entire glow in the dark structure have been charged. 
     FIG. 2  illustrates a bow sighting device, generally indicated at  100  configured for attaching or coupling to an archery bow (not shown). The sighting device  100  is comprised of a pin plate  104 , a pin guard  106  and a sight window  108  formed therebetween. A plurality of sight pins  110 ,  112 , and  114  are secured to the pin plate  104  by threaded fasteners  116 ,  118  and  120 , respectively, which engage the sight pins  110 ,  112  and  114  and extend through a slot  124  formed in the pin plate  104 . The sight pins  110 ,  112 , and  114  extend transversely from the pin plate  104  into the sight window  108 . Each sight pin  110 ,  112  and  114  is provided with a glow-in-the-dark housing  110 ′,  112 ′ and  114 ′ that covers at least a portion of a fiber optic element of each sight pin to provide illumination of the fiber optic element in low light conditions. The sighting device  100  is attached to a first bracket  128  by securement member  130 . The first bracket  128  may be adjustably connected to a second bracket (not shown) for attachment to a bow. 
   A LED UV flashlight, generally indicated at  140  is attached to the bracket  128  with a mounting member  142 . The mounting member  142  is comprised of an attachment portion  144  and a clamping portion  146 . The attachment portion is attached to the bracket  128  as with a threaded fastener  148 . The clamping portion is provided with a transversely extending aperture  150  for receiving a portion of the flashlight  140  therein and a clamping fastener  152  for tightening the aperture  150  around the body of the flashlight  140 . The mounting member  142  allows a user to orient the LED flashlight  140  at any angle relative to the sight pins  110 ,  112  and  114  so as to direct the UV light directly toward the glow-in-the-dark portions thereof. 
   In this example, the LED flashlight  140  is comprised of an elongate housing  154  to which a UV emitting LED  156  is secured. The housing  154  is encased in a protective sleeve  158 , formed from a flexible plastic or rubber material, that encases the housing  154  and allows the clamping portion  146  to grasp the housing  154  without damaging it. A light shield  160  is provided over the distal end  162  of the housing and the LED  156 . The light shield  160  is provided with an opening  162  that allows light being emitted from the LED  156  to shine through the opening  162 . By orienting the opening  162  toward the glow-in-the-dark portions  110 ′,  112 ′ and  114 ′ of the sight pins  110 ,  112  and  114 , when the LED is turned on, the glow-in-the-dark portions will be quickly charged while at least partially shielding UV light from being directed toward the eyes of the user. 
   In addition, the light shield  160  may be rotated relative to the housing  154  so as to change the direction of light being emitted through the opening  162 . Thus, the intensity of light from the UV LED  156  onto the pins  110 ,  112  and  114  may be altered by orienting the opening  162  toward or partially away from the sight pins  110 ,  112 , and  114 . Moreover, the light shield  160  can be oriented so as to expose the sight pins  110 ,  112 , and  114  to UV light while shielding such light in a direction away from the user. As such, the light shield prevents, at least to a large extent, UV light being directed toward a target that may otherwise startle such game. 
   Furthermore, the mounting member  142  is configured to be pivotable relative to the bracket  128  about the fastener  148  to move the led  156  closer to or further from the sight pins  110 ,  112 , and  114  as desired to change the intensity of the UV light exposure on the pins. In addition, the fastener  152  is a knob which can be grasped by a user to adjust the clamping force on the housing  154 . By decreasing the clamping force, the user can then slide the housing  154  relative to the mounting member  142  to further position the LED  156  closer to or further from the pins. Moreover, to further increase the exposure of the UV light on the pins, the light shield  160  may be completely removed in order to fully expose the LED  156 . Thus, the intensity of exposure to the pins can be selectively adjusted by the user. This has particular utility when using such an UV LED light source with sight pins or other sighting devices known in the art that utilize fiber optic elements without an associated glow-in-the-dark material. Because the fiber optic elements, such as fiber optic element  110 ″, exhibit flourescent properties under UV light, they will glow at a relatively high intensity when exposed to UV light. In some conditions, however, as when shooting from a darkened blind into a brightly light area, it may be desirable to decrease the intensity of the illumination of the fiber optic element. Thus, the adjustability of the UV LED light and its intensity or amount of exposure on the fiber optic element of the present invention allows the user to change the brightness of the fiber optic sighting element as desired. 
   The UV LED flashlight  140  is provided with an exposed and/or user accessible on button  170 , which may be selectively accessed by a user so as to activate the LED light  156 . If it is desirable to keep the LED light on, one or more o-rings  172  may be placed around the sleeve  158  so as to hold the button  170  in a depressed or on position as desired. 
   The bow sight  100  and fishing lure  10  are but single examples of the types of archery and fishing products available that incorporate glow-in-the-dark materials therein. As such, the present invention is intended to cover use of a portable UV LED light source with such fishing and hunting devices. In addition, the present invention is intended to cover any use of a UV LED flashlight which includes the charging of a glow-in-the-dark substance, with fishing and hunting examples providing what is believed to be the best application of the invention at the present time. For example, such use may extend to toys, licenced property, light sabers, marine applications such as locating buoys for lobster traps by shining the UV light to locate the buoys, mining industry, and the like. 
   Thus, while the present invention has been described with reference to certain embodiments to illustrate what is believed to be the best mode of the invention, it is contemplated that upon review of the present invention, those of skill in the art will appreciate that various modifications and combinations may be made to the present embodiments without departing from the spirit and scope of the invention as recited in the claims. The principles of the present invention may be adapted to any use of an UV LED light for charging a glow-in-the-dark material for use in low light conditions. The claims provided herein are intended to cover such modifications and combinations and all equivalents thereof. Reference herein to specific details of the illustrated embodiments is by way of example and not by way of limitation.