text: the present invention has been realized , in a particular embodiment , under the tradename nighthunterii ™ by xenonics , inc . the nighthunterii ™ has been described as the world &# 39 ; s longest - range handheld illumination system that employs the same type of xenon lamp technology as described in u . s . patent application ser . no . 09 / 440 , 105 , apparatus and method for operating a portable xenon arc search light , that is hereby incorporated by reference in its entirety . the technology employed by the handheld searchlight delivers a uniform beam with a range in excess of three - quarters of a mile , without the “ black hole ” that obstructs the field of view in prior searchlights or flashlights . another significant advancement of handheld searchlight of the present invention is its light weight . this is primarily due to the successful manufacture and implementation of a 20 - watt xenon arc lamp . previous lamps of similar comparison have been typically over 50 watts . consequently , a lighter battery pack and associated charging and lamp circuitry is employed by the invention . as a result , the nighthunter ™ of the present invention , weighs approximately 4 . 8 pounds , while prior art comparable devices weigh greater that ten pounds . similarly , the battery - run time achieved by the invention is significantly improved compared to prior devices . in practice , the battery - run time of the invention is approximately greater than 90 minutes while recharge time is approximately less than 90 minutes . also , the nighthunter ™ can be recharged from a vehicular battery or via an external ac / dc converter . referring initially to fig1 a and 1 b , the external housing configuration for a handheld searchlight 10 is shown . the components include a body 12 , a head 14 , a bezel 16 , a lens protector / filter 18 , and an end cap 17 . additionally , a magnetic switch 15 is provided . the switch 15 has an on / off position corresponding to a position of the magnet that controls closure of a contact to start operation of the handheld searchlight 10 . the magnetic switch 15 is preferred because it eliminates an electrical penetration to the housing that would otherwise be needed to improve watertight integrity . a further external feature is the knurl design of body 12 that provides a secure grip for the end user . this feature also enhances the ability to glue switch 15 part to body 12 . the filter 18 is an optional feature that may be an infrared filter , for example , that only permeates light having wavelengths of 850 nm and longer . the infrared filter 18 serves to boost the range of night vision illumination or may also be useful in low light video equipment applications . the filter 18 , may alternatively be an ultraviolet filter to fluoresce objects for marking that can be achieved with the beam spread in low angle “ spot ” mode . yet still , the filter 18 may alternatively be a simple piece of glass or transparent plastic material for added protection of the lens 24 . it is contemplated that a wide variety of filters for many applications could be employed by the present invention . fig1 c is an illustration of the present invention showing a handheld searchlight 10 without a filter / lens protector of the present invention . referring to fig2 , a handheld searchlight 10 of the present invention showing the internal components is illustrated . the components fit inside the body 12 and head 14 sections that are not illustrated in fig2 . lens 24 is normally secured to head 14 with threaded bezel 16 . the threaded bezel 16 , is also used to vary the optical characteristic of the light within the reflector 22 , so that the beam spread can be changed . the illumination beam spread can be varied from flood mode to spot mode , or an intermediate beam spread as preferred by the particular application . the lamp 26 must be properly aligned within the reflector &# 39 ; s 22 optical axis of symmetry as secured by lamp socket assembly 28 . the lamp socket assembly 28 has springs 44 ( see fig3 a - d ) that serve as floating electrical contacts to provide for proper alignment of the lamp 26 . in the illustrated embodiment , the lamp 26 is a xenon arc lamp , however the invention is expressly intended to include other kinds of incandescent or plasma lamps , including without limitation mercury - xenon , metal halide and halogen lamps . the plasma region within the lamp comprises a small , well - defined plasma ball where excited ions release energy in the form of photons . the lamp 26 , with pin electrodes 46 and 47 is secured into lamp socket assembly 28 ( fig3 a - d ). additionally , the lamp 26 has a unique single - ended design wherein both the cathode 46 and the anode 47 ( fig3 d ) are secured on the same end of the lamp 26 . the single - ended design allows for easier removal and replacement of lamps than if a lamp is secured on both ends . ease of lamp 26 removal is necessary because it is envisioned that this may occur in the field and at night . the glass bulb surrounding the plasma region is also named the glass envelope . importantly , the glass envelope should remain free of contamination from oil or dirt that may come from a user &# 39 ; s fingers , especially due to the high operating temperatures attained by the lamp 26 . as an alternative feature , the lamp may be encircled by a lamp protector ( not shown ). also as an alternative feature , the lamp 26 may be removed and replaced using a lamp extraction tool ( not shown ) that is able to clamp onto the lamp 26 , also to prevent contamination of the glass envelope . still referring to fig2 , the lamp socket assembly is electrically connected to a pcb 32 via spring contacts 44 ( see fig3 a - d ). the pcb 32 contains circuitry for powering and controlling illumination produced by the lamp 26 . additionally , power converter circuits are contained on the pcb 26 to provide proper dc voltages for start up and sustained use . also , the converter circuitry can provide the capability to power the handheld searchlight 10 from an external power ac source . battery 36 is provided to power the handheld searchlight 10 for normal operation . the handheld searchlight 10 circuitry can also recharge the battery 36 from an external ac power source . additionally , heatsink 34 is mounted on the pcb 32 to dissipate heat generated by the circuits . heatsink 34 is effectively coupled to the housing body 12 to further increase thermal conductivity and improve heat transfer . the heatsink 34 is further designed so that external penetrations to the body 12 are not needed to provide sufficient contact for heat transfer . it is preferred that the heatsink 34 and body 12 are both made from extruded aluminum material for optimum heat transfer characteristics . it is also preferred that battery 36 comprises sliding contacts 39 to electrically connected it to the pcb 36 . the sliding contacts 39 provide an inherent self - cleaning capability because the contacts 39 slide relative to their connections . referring now to fig3 a , a partial cross - sectional view of the lamp socket assembly 28 taken along line 3 a is shown . the assembly 28 contains two socket holes 42 to receive the lamp electrodes 46 and 47 ( see fig3 d ). a bulkhead 41 provides support for receiving the lamp 26 . the bulkhead , however has openings in it to allow removal of the lamp 26 from the lamp socket hole 42 . fig3 b through 3 d further illustrate how the pin electrodes 46 and 47 are received by the socket holes 42 . the holes 42 contain spring contact assemblies 44 to provide proper alignment of the pin electrodes 46 and 47 , and to provide an electrical interconnect between the lamp 26 and the pcb 36 . proper alignment will continually be affected by forces imparted by the reflector sleeve 22 a ( fig2 ) on the lamp collar 26 a during beam - spread adjustments . therefore , spring contact assemblies 44 allow for circular movements in an x - y plane to precisely align lamp 26 along reflector &# 39 ; s 26 axis of optical symmetry . referring now to fig4 a , an enlarged view of end cap 17 is shown . circular contacts 52 - 55 are provided to electrically interface the pcb 32 to an external power source . two of the four contacts are positive and negative power terminals . a third contacts connects directly to led 56 ( fig4 b ). lastly , a fourth contact provides for remotely controlling on / off power to the handheld searchlight 10 . remote control capability may be ideally preferred for military and covert applications where the light source does not revel the user &# 39 ; s location . the end cap 17 is threaded and may also have an o - ring ( not shown ) to improve watertight integrity . also for watertight integrity , the end cap is able to be configured to receive external power through a watertight connector or inductive coupling , thereby eliminating an electrical penetration that would otherwise be needed . inductive coupling could also be achieved through the body 12 of the present invention . referring to fig4 b , connections 52 a - 55 a correspond to circular contacts 52 - 55 . led 56 provides charging indication . according to the invention , led 56 flashes while the battery is charging and led 56 will go solid when the battery is fully charged . referring to fig5 a and 5 b , a shoulder strap 63 of the present invention is illustrated that is provided for using and transporting the handheld searchlight 10 . the strap 63 is designed to slip over the handheld searchlight where it is secured between the switch 15 and the head section 14 . the weight of the handheld searchlight 10 is able to be supported by the strap 63 that should naturally extend along a user &# 39 ; s 56 side . the strap 63 primarily provides support during transport and operation of the handheld searchlight 10 . finally , referring to fig6 , a side plane view of a lamp 26 of the present invention is shown , as configured with a sectional view of a reflector 22 of the present invention . the reflector 22 has a collar 221 disposed around a cylindrical neck portion 261 . importantly , the collar 221 and neck 261 are designed to maintain a close interface between the two so that the lamp 26 is maintained centered and aligned with respect to the optical access of symmetry 65 . the close interface should also allow axial movement between the lamp 26 and reflector 22 while changing beam spread of the hand held searchlight . additionally , the close interface is maintained so that it provides a path for heat transfer from the lamp 26 to the reflector 22 . the reflector is coupled to the head section 14 to further dissipate heat generated in the lamp 26 . by way of reference , the electrodes 46 and 47 extend from the base portion 263 of the lamp 26 . fig6 also illustrates the single - ended design of the lamp , allowing electrodes 46 and 47 to be physically located adjacent to one another rather than on opposing sides of the lamp 26 . glass envelope 262 is also illustrated . many alterations and modifications may be made by those having ordinary skill in the art without departing from the spirit and scope of the invention . therefore , it must be understood that the illustrated embodiment has been set forth only for the purposes of example and that it should not be taken as limiting the invention as defined by the following claims . for example , notwithstanding the fact that the elements of a claim are set forth below in a certain combination , it must be expressly understood that the invention includes other combinations of fewer , more or different elements , which are disclosed in above even when not initially claimed in such combinations . the words used in this specification to describe the invention and its various embodiments are to be understood not only in the sense of their commonly defined meanings , but to include by special definition in this specification structure , material or acts beyond the scope of the commonly defined meanings . thus if an element can be understood in the context of this specification as including more than one meaning , then its use in a claim must be understood as being generic to all possible meanings supported by the specification and by the word itself . the definitions of the words or elements of the following claims are , therefore , defined in this specification to include not only the combination of elements which are literally set forth , but all equivalent structure , material or acts for performing substantially the same function in substantially the same way to obtain substantially the same result . in this sense it is therefore contemplated that an equivalent substitution of two or more elements may be made for any one of the elements in the claims below or that a single element may be substituted for two or more elements in a claim . although elements may be described above as acting in certain combinations and even initially claimed as such , it is to be expressly understood that one or more elements from a claimed combination can in some cases be excised from the combination and that the claimed combination may be directed to a subcombination or variation of a subcombination . insubstantial changes from the claimed subject matter as viewed by a person with ordinary skill in the art , now known or later devised , are expressly contemplated as being equivalently within the scope of the claims . therefore , obvious substitutions now or later known to one with ordinary skill in the art are defined to be within the scope of the defined elements . the claims are thus to be understood to include what is specifically illustrated and described above , what is conceptually equivalent , what can be obviously substituted and also what essentially incorporates the essential idea of the invention .