Abstract:
A marker system has a first section of an enclosure and a second section of the enclosure with a pivot rotatably connecting the first section to the second section. In such, the first section is adjustable from being in line with the second section to forming an arc with the second section, thereby conforming to multiple surface curvatures. There are several emitters within the enclosure and there is electronics (discrete electronics and/or a processor) for controlling the emitters responsive to user controls. For example, in a first mode, the emitters emit a light that is visible to the human eye through the enclosure and in a second mode; the emitters emit a light that is invisible to the human eye through the enclosure.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims the benefit of U.S. provisional application No. 62/163,104 filed on May 18, 2015. This application is related to U.S. patent application Ser. No. 14/515,918, filed Oct. 16, 2014, the disclosure of which is hereby incorporated by reference. 
     
    
     FIELD 
       [0002]    This invention relates to the field of helmet-mounted or helmet-integrated marker lights and in particular to a system that mounts to objects with different radii and curvature. 
       BACKGROUND 
       [0003]    Marker systems are known and used in various scenarios. In some uses, marker systems are used to provide indications of the location of other personnel, for example in dark-of-night situations when parachuting from an aircraft. In some marker systems, light is emitted in either visible or non-visible (to the naked eye) wavelengths. Non-visible wavelengths of light provide support for covert operations, requiring night-vision devices to see others. In some marking systems, complex switching between OFF and ON/Covert, and/or between OFF and ON/Visible is provided to reduce human error. It is dangerous to mistakenly enable visible-wavelength light during a covert operation. 
         [0004]    Some such marking systems include a receiver that receives and decodes a signal from another party and, if a correct sequence is received, the marker responds in a predicted way to indicate that the associated object (e.g., a combatant, a military dog, a vehicle) is a “friend” as opposed to being a “foe.” Also, some such marking systems include mechanisms to program functions, either at the factory or in the field. 
         [0005]    In the past, such devices were provided for helmet mounting, typically having a concave base where the radius of the concave surface matches the anticipated, typical curvatures of a typical helmet. Such packaging works well for some surfaces on a typical helmet, but the fixed concavity of the mounting surface does not match the curvature of all helmets, or all the varying curvatures on any given helmet, or other mounting locations such as on a soldier&#39;s battle dress, modular light-weight load carrying equipment (MOLLE), or equipment or the harness of a military dog, etc. 
         [0006]    What is needed is a marking system that will adapt to and mount on a range of surfaces of different curvatures. 
       SUMMARY 
       [0007]    In one embodiment, a marker system is disclosed including a first section of an enclosure having a first bottom surface and a second section of the enclosure having a second bottom surface. A pivot (or hinge) rotatably connects the first section to the second section, such that the first bottom surface is adjustable from being in line with the second bottom surface to forming an angle with respect to the second bottom surface, thereby conforming to multiple surface curvatures. There are a plurality of emitters within the enclosure and electronics for controlling the emitters responsive to user controls such that in a first mode, the emitters emit a light that is visible to the human eye through the enclosure; and in a second mode, the emitters emit a light that is invisible to the human eye through the enclosure. 
         [0008]    In another embodiment, a marker system is disclosed including a an enclosure having a first section and a second section; the first section of the enclosure has a first bottom surface and the second section of the enclosure has a second bottom surface. A pivot rotatably connects the first section to the second section such that the first bottom surface is adjustable from being in line with the second bottom surface to forming an angle with respect to the second bottom surface, thereby conforming to multiple surface curvatures. A controller (e.g., processor and memory) is housed within the enclosure. A plurality of emitters are located within the enclosure and electrically interfaced to the controller such that, upon the controller initiating a flow of electric current though one or more of the emitters, the one or more of the emitters emit light through the enclosure. The controller controls the flow of electric current through the emitters such that in a first mode, the emitters emit a light that is visible to the human eye through the enclosure; and in a second mode, the emitters emit a light that is invisible to the human eye through the enclosure. 
         [0009]    In another embodiment, a marker system is disclosed including an enclosure that has a first section and a second section. The first section of the enclosure has a first bottom surface and the second section of the enclosure has a second bottom surface. A hinge rotatably connects the first section to the second section such that the first bottom surface is adjustable from being in line with the second bottom surface to forming an angle with respect to the second bottom surface, thereby conforming to multiple surface curvatures (e.g. different helmet styles, etc.). A controller (e.g., processor and memory) is housed within the enclosure and a first switch is physically interfaced to the enclosure and electrically interfaced to the controller for selectively choosing a function. A second switch is also physically interfaced to the enclosure and electrically interfaced to the controller for selectively choosing an operating mode. At least one light emitting diode is mounted within the enclosure and electrically interfaced to the controller. An operating status configuration switch is physically interfaced to the enclosure and electrically interfaced to the controller for determining the status of the marker system by a user. A vibration device electrically interfaced to the controller. Software stored on a non-transitory storage associated with the controller runs on the controller to determine a mode based upon signals from the first switch and the second switch and, based upon the mode, the controller selectively provides electrical current to one or more of the at least one light emitting diode such that the one or more of the at least one light emitting diode emit light that exits the enclosure. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]    The invention can be best understood by those having ordinary skill in the art by reference to the following detailed description when considered in conjunction with the accompanying drawings in which: 
           [0011]      FIG. 1  illustrates a perspective view of a hinged marker system. 
           [0012]      FIG. 2A  illustrates a side plan view of the hinged marker system in a fully extended, flat configuration. 
           [0013]      FIG. 2B  illustrates a side plan view of the hinged marker system in an articulated configuration to fit a contoured mounting surface. 
           [0014]      FIG. 3  illustrates a top plan view of the hinged marker system. 
           [0015]      FIG. 4  illustrates a bottom plan view of the hinged marker system. 
           [0016]      FIG. 5  illustrates a schematic view of a marker system circuit. 
           [0017]      FIG. 6  illustrates a perspective view of the hinged marker system showing a power source. 
           [0018]      FIG. 7  illustrates a side plan view of the hinged marker system in a linear mode relating to mounting on a flat surface. 
           [0019]      FIG. 8  illustrates a side plan view of the hinged marker system in a curved mode. 
           [0020]      FIG. 9  illustrates a side plan view of the marker system in a partially curved mode conforming to a helmet. 
           [0021]      FIG. 10  illustrates a top plan view of a second example of the marker system with a mechanical hinge/pivot. 
           [0022]      FIG. 11  illustrates a bottom plan view of the second example of the marker system with a mechanical hinge/pivot. 
           [0023]      FIG. 12  illustrates a side plan view of the second example of the marker system with a mechanical hinge/pivot in a linear mode relating to mounting on a flat surface. 
           [0024]      FIG. 13  illustrates a side plan view of the second example of the marker system with a mechanical hinge/pivot in a curved mode. 
           [0025]      FIG. 14  illustrates a perspective view of the second example of the marker system with a mechanical hinge/pivot with an, opaque cover. 
           [0026]      FIG. 15  illustrates a top plan view of a fourth example of the marker system with a flexible material between sections. 
           [0027]      FIG. 16  illustrates a bottom plan view of the fourth example of the marker system. 
           [0028]      FIG. 17  illustrates a side plan view of the fourth example of the marker system in a linear mode relating to mounting on a flat surface. 
           [0029]      FIG. 18  illustrates a side plan view of the fourth example of the marker system in a curved mode. 
       
    
    
     DETAILED DESCRIPTION 
       [0030]    Reference will now be made in detail to the presently preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. Throughout the following detailed description, the same reference numerals refer to the same elements in all figures. 
         [0031]    Referring to  FIGS. 1, 2, 3, and 4 , perspective, top and bottom views of a marker system  220  are shown. The marker system  220  has two sections  230 / 232  connected by a hinge or pivot  222 , enabling a predetermined amount of rotation of a first section  230  with respect to a second section  232  as will be shown in later figures. In some embodiments, one or both sections  230 / 232  include a concavity on their respective equipment mounting surfaces  234 / 236  to facilitate mountable conformity to various helmet outer surfaces. In some embodiments, the concave mounting surfaces  234 / 236  further include an attachment media such as hook and loop material or double-sided adhesive tape material. 
         [0032]    As will be shown with  FIG. 5 , the marker system  220  has, within either a first enclosure  230  and/or a second enclosure  232 , any number of emitters  58   a / 58   b / 58   c  (e.g., LEDs), photo detectors  92 , vibrators  108 , power sources  223 , processing elements  270 , radio receiver or transceivers  194 , speakers  262 , microphones  260 , etc. The components within the marker system  220  function to provide the marker functionality, emitting specific wavelengths of light through the first enclosure  230  and/or the second enclosure  232  under control of the switches  54 / 56  and, in embodiments having the ability to respond to interrogations as to friend or foe (IFF), the sensors  92  (e.g. photodiodes) receive light waves such as pulses of infrared light in a specific pattern or code and relay the pulses as an electrical signal to the processor  270 . In some scenarios, the interrogations are initiated by remote a weapon-mounted infrared laser pointed by one combatant toward another unknown combatant. Software on the processor analyzes the pulses and determines if the pulses represent an incoming friendly interrogation, by determining if the pulses are of a predetermined sequence based upon one or more modulation schemes. If the software determines that a proper, friendly interrogation has been received, the software controls one of more of the emitters  58   a / 58   b / 58   c  to emit light in a prescribed wavelength and/or sequence. For example, responsive to an interrogation, the software controls the infrared emitters to flash a predetermined number of times, on for a predetermined period of time and off for a predetermined period of time, etc. Additionally, in some embodiments, the software, upon determining that a proper interrogation was received, alerts the wearer that an interrogation has occurred through one or more mechanisms such as a vibrator  108  (either located within the marker system  220  or located external to the marker system such as mounted within a helmet) or an audible output through, for example, a speaker  262 , or a visual alert through, for example, a fiber optic cable or LED positioned on or near the front edge of the helmet so as to be seen by the wearer and not visible to other persons. 
         [0033]    In this exemplary marker system, there are two switches  56 / 54  shown in a preferred location, though there is no requirement on any number of switches and/or location of such, when present. In this example, a first switch  54  is a sliding, three-position function switch (Function “0” [Off], Function “1”, Function “2”) and the second switch  56  is a two-position mode switch (for example, Mode “A” is overt/visible, and Mode “B” is covert/infrared) that requires a specific reorientation to change modes, therefore being difficult to move from covert to overt as such presents the possibility to spoil a covert military operation and put lives of friendly combatants in danger. 
         [0034]    Referring to  FIG. 5 , a schematic view of a marker light circuit  200  is shown. The example marker light circuit  200  represents one possible circuit for achieving the desired marker light functionality, housed within any of the enclosures  230 / 232 / 1230 / 1232 / 1430 . This exemplary marker light circuit  200  is shown in one form with a specific set of features, though other circuits are known to achieve similar results with more or less features, all of which are included here within. Different architectures are known that accomplish similar results in a similar fashion and the present invention is not limited in any way to any particular marker light architecture or implementation. In this exemplary marker light circuit  200 , a processor  270  executes or runs programs in a random access memory  275 . The programs are generally stored within a persistent memory  274  and loaded into the random access memory  275  when needed. The processor  270  is any processor, typically a processor designed for low-power, portable operation consuming the minimal amount of power, e.g., a programmable interrupt controller, etc. The persistent memory  274  and random access memory  275  are connected to the processor by any architecture known in the computer industry, for example, by a memory bus  272 . The random access memory  275  is any memory  275  suitable for connection and operation with the selected processor  270 , such as SRAM, DRAM, SDRAM, RDRAM, DDR, DDR-2, etc. The persistent memory  274  is any type, configuration, capacity of memory  274  suitable for persistently storing data, for example, flash memory, read only memory, battery-backed memory, magnetic memory, etc. In some embodiments, the persistent memory  274  is removable, in the form of a memory card of appropriate format such as SD (secure digital) cards, micro SD cards, compact flash, etc. 
         [0035]    Also connected to the processor  270  is a system bus  282  for connecting to input ports  189 / 192  for receiving signals from sensors  92 , microphones  260 , and switch inputs  54 / 56 . Likewise output ports/drivers  284  drive emitters  58   a / 58   b / 58   c  (e.g., LEDs), vibrators  108 , and speakers/sounders  262 . 
         [0036]    In general, some portion of the memory  274  is used to store programs, executable code, and parameters such as operating states and programmable features. 
         [0037]    The radio  194 , when present, is any known radio in the industry such as a Global Positioning Subsystems receiver  194 , Bluetooth transceivers  194 , Wi-Fi transceivers  194 , etc., the likes of which are not shown for brevity and clarity reasons. 
         [0038]    For communications with operations and/or programming, some embodiments include a radio receiver and/or transceiver  194 , operating on any wavelength as desired. In some embodiments, a base station communicates with the radio transceiver  194  to ascertain that the wearer of the marking system  220  is a friend. In some embodiments, a signal (e.g., an encoded signal) is transmitted to the radio  194  and decoded by the processor  270  and software, and responsive to recognition of the signal, the processor  270  illuminates one or more LEDs  58   a / 58   b / 58   c , in some embodiments in a sequence or pattern, informing personnel that operate the base station that the wearer is a friend (lack of response indicates a possible foe). In some embodiments, a response signal is transmitted through the radio  194  to indicate that a “friend” is being interrogated. 
         [0039]    In some embodiments, a first, operating function switch  54  and a second, operating mode switch circuit  56  are interfaced to the processor  270  through an input port  192 . The switches  54 / 56  control multi-function, multi-emission, multi-mode features of the marker system  220 , through signals provide to software running on the processor  270 . For example, steady illumination, flashing patterns, sequencing, and/or brightness of one or several of the emitters  58   a / 58   b / 58   c  are programmed and controlled by software running on the processor  270 . In one embodiment, the sliding main switch  54  has three positions: OFF (Function“0”) and two selectable operating functions (Functions “1” and “2”). The sliding main switch  54  is ergonomically actuated by the wearer without the wearer needing to see the sliding main switch  54  by way of tactile feel while the marker light is mounted, for example, on a helmet. The sliding operating mode switch  56  is also in electrical communication with the processor  270 . In some embodiments, the sliding operating mode switch  56  has two operating modes, e.g., Mode “A” (such as overt or visible) or Mode “B” (such as covert or infrared). In such, it is preferred that the sliding operating mode switch  56  requires an overt operation to change state to prevent inadvertent changes to the operating mode, as changing from covert (infrared) to overt (visible) during covert military operation is often very dangerous. 
         [0040]    In embodiments in which radiation is received by one or more light sensors  92  enclosed on or within the enclosure of the marker system  220 , the light of one or more wavelengths of light are detected by the one or more light sensors  92 , indicating such through an electrical interface to the processor  270  for impacting of the software running on the processor  270 . 
         [0041]    Any number of emitters  58   a ,  58   b ,  58   c  comprises, for example, any variety, type, and light spectrum of LEDs disposed on or within the first enclosure  230  and/or the second enclosure  232  of the marker system  220 . The emitters  58   a ,  58   b ,  58   c  are, for example, Red/Green/Blue (RGB) three-chip LEDs  58   a , multiple high-intensity “white” light LEDs  58   b , and multiple infrared (IR) emitters and/or LEDs  58   c  which may emit in one or more different infrared wavelengths. 
         [0042]    The emitters  58   a ,  58   b ,  58   c  and sensors  92  are located on or within the enclosure of the marker system  220  such that light from outside of the marker system  220  is exposed to the sensors  92  and light from the emitters  58   a ,  58   b ,  58   c  exits the enclosure. 
         [0043]    Any of the emitters  58   a ,  58   b ,  58   c  are illuminated under control of the processor  270  at the same time individually or in tandem with other emitters  58   a / 58   b / 58   c , in any pattern (flashing) or steadily illuminate. For example, in one operating mode four RGB light sources  58   a  are operating in constant Green/Steady while two high intensity white light sources  58   b  are simultaneously operating intermittently in a flashing mode. 
         [0044]    In some embodiments, a tactile signal to the wearer of the marker system is provided by a vibration device  108 . The tactile signal (e.g. vibration) is provided, under program control by the processor, after, for example, a specified military infrared friend or foe interrogation has been received by the sensors  92  or radio  194  and properly decoded by software running on the processor  270 . The vibration device is one or more vibration motors either embedded in the marker system  220  or located in a remote vibratory pad interfaced to one of the enclosures or sub-enclosures (not shown, but for example, positioned within the helmet). When an interrogation is received, vibration from the vibration device  108  is felt by the wearer either through the vibratory pad that is placed within the helmet, or through vibrations imparted to the helmet through the vibratory motor within the marker system  220 . 
         [0045]    Referring to  FIG. 6 , a perspective view of the marker system  220  showing a power source  223  is shown. In some embodiments, the power source  223  (e.g., a battery  223  or rechargeable battery  223 ) is housed in the hinge or pivot  222 , being removable by way of a cap  221  that attaches to the pivot  222  by, for example, threads or snaps, preferably making a water resistant seal against the pivot  222  to reduce potential for moisture intrusion into the battery holding area (not visible). In alternate embodiments, the power source  223  (e.g., battery  223 ) is located in other enclosures or sub-enclosures  230 / 232 / 1230 / 1232 / 1430  within or external to the marker system  220 . 
         [0046]    In some embodiments, the hinge or pivot  222  adapts to different sizes and/or geometries of power sources  223  through adapters or tooling changes. 
         [0047]    Referring to  FIG. 7 , a side plan view of the marker system  220  is shown in a linear mode. In this view, the marker system  220  is rotated along the pivot  222  to approximate a flat surface  402  or a nearly flat surface  402  such as modular light-weight load carrying equipment (MOLLE), including armor plate carriers and tactical back packs or an object such as an aerial delivery load, military vehicle, or other military equipment, etc. 
         [0048]    Referring to  FIG. 8 , a side plan view of the marker system  220  is shown in a curved mode. In this view, the marker system  220  is rotated along the pivot  222  to approximate a highly curved surface  401  such military helmet, or a harness installed on the back of a military dog, etc. 
         [0049]    Note that, although not required, in some embodiments there are features to limit the rotation of the first enclosure  230 / 1230 / 1430  of the marker system  220  with respect to the second enclosure  232 / 1232 / 1432  of the marker system  220 . For example, the rotation/curvature is limited between substantially linear (as in  FIG. 7 , and  FIG. 12 ) and curved along on specific arc at an angle with respect to each other (as in  FIG. 8  and  FIG. 14 ) and any curvature/angle between such.  FIGS. 12 and 13  provide an example of rotation-limiting features  1250 ,  1256 ,  1258  that apply to the second marker system  1220  and the third marker system  1420 . 
         [0050]      FIG. 9  illustrates a side plan view of the marker system  220  in a partially curved mode conforming to a helmet  400 . This is shown as an example of how the marker system  220  mounts to a helmet  400 . Note that in some embodiments, the marker system  220  is mounted using hook and loop materials, rails, adhesive, straps, etc. (all not shown for brevity) on equipment mounting surfaces  234 / 236 . 
         [0051]    Referring to  FIGS. 10 and 11 , top plan views of a second example 1220 of the marker system are shown. In this example, the second marker  1220  has two separate enclosure portions  1230 / 1232  that are allowed to pivotally change orientation with respect to each other by way of a pivot  1222  (see  FIGS. 12 and 13 ). The operation of the second marker  1220  is similar to that of the marker system  220 . Emitters  58   a / 58   b / 58   c , marker light circuit  200 , and optionally detectors  92  are housed within the first sub-enclosure  1230  while operation control switches  54 / 56  and a power source (not visible) are interfaced or contained within the second sub-enclosure  1232 . There is an electrical interface  1231  running between the first sub-enclosure  1230  and the second sub-enclosure  1232  for providing electrical signals to the emitters  58   a / 58   b / 58   c  and receiving detection signals from the optional detectors  92 , etc. 
         [0052]    Referring to  FIGS. 12 and 13 , side plan views of the second marker system  1220  are shown in a linear mode relating to mounting on a flat surface ( FIG. 12 ) and in a curved mode ( FIG. 13 ). As with the marker system  220 , the second marker system bends along the pivot  1222  to conform to surfaces ranging from linear surfaces to curved surfaces as would be expected in helmet mounting. In  FIG. 12 , the second marker system  1220  is shown slightly curved while in  FIG. 13 , the second marker system  1220  is shown substantially linear. Note that the formation of the second sub-enclosure  1232 , in some embodiments, includes limit edges  1256 / 1258  on the second sub-enclosure  1232  that interface with an edge  1250  of the first sub-enclosure  1230  to limit the amount of bending between, for example, linear and a maximum angle between the first sub-enclosure  1230  and the second sub-enclosure  1232 . 
         [0053]    Referring to  FIG. 14 , a perspective view of a third marker system  1420  with a separate cover  1440  is shown. In this example, the third marker  1420  has two separate enclosure portions  1430 / 1432  that are allowed to pivotally change orientation with respect to each other by way of a pivot  1222 . The operation of the third marker  1420  is similar to that of the marker  220 . Emitters  58   a / 58   b / 58   c , optionally the marker light circuit  200 , and optionally detectors  92  are housed within a substantially clear, or translucent first sub-enclosure  1430  while operation control switches  54 / 56  and a power source (not visible) are interfaced or contained within the second sub-enclosure  1432 . In the third marker  1420 , a cover  1440 , being a separate component than the first sub-enclosure  1430 , covers and forms a seal over a cavity in the first sub-enclosure  1430 , encapsulating the emitters  58   a / 58   b / 58   c , optionally the marker light circuit  220  and optionally detectors  92 . At least a portion of the top surface of the cover  1440  is preferably opaque, preventing light from the emitters  58   a / 58   b / 58   c  from escaping the first sub-enclosure  1420  through the cover  1440  and preventing light from external sources from entering the first sub-enclosure  1430  through the cover  1440 . The other surfaces of the first sub-enclosure  1430  are anticipated as being at least translucent, allowing light to pass through the other surfaces of the first sub-enclosure  1430 . 
         [0054]    In some embodiments, the lower/interior surface of the cover  1440  includes reflective, refractive, or light guiding surfaces to guide and optimally disperse the light generated by the emitters  58   a ,  58   b ,  58   c  through the clear or translucent top surface of the first sub-enclosure  1430  bounded by the opaque cover  1440 , and through the clear/translucent sides of the first sub-enclosure  1430 . In some embodiments, the optional detectors  92  are mounted in the cover  1440  for detection of incoming interrogations. It is also anticipated that in some embodiments, the cover  1440  be added at later stages of manufacturing to provide last-minute production configurability (e.g., one configuration having only emitters  58   a / 58   b / 58   c  and another configuration having emitters  58   a / 58   b / 58   c  and detectors  92 , etc.). in some embodiments, the cover  1440  is removable to facilitate easy access for later repair and/or replacement of emitters  58   a / 58   b / 58   c  and detectors  92 . 
         [0055]    Referring to  FIGS. 15 and 16 , top and bottom plan views of a bendable marker system  1520  are shown. In this example, the bendable marker system  1520  has two separate enclosure portions  1530 / 1532  that are allowed to change orientation with respect to each other by way of a flexible material  1522  that joins the enclosure portions  1530 / 1532 . The flexible material  1522  is molded or fabricated of a flexible, environmentally robust rubber-like material(s) and does not rely upon rotating mechanical pivots or hinges. The operation of the second marker  1520  is similar to that of the marker system  220 . Emitters  58   a / 58   b / 58   c , marker light circuit  200 , and optionally detectors  92  are housed within the first sub-enclosure  1530  while operation control switches  54 / 56  and a power source  223  are interfaced to or contained within the second sub-enclosure  1532 . The electrical interface  1531  runs between the first sub-enclosure  1530  and the second sub-enclosure  1532  which provides for electrical signals to the emitters  58   a / 58   b / 58   c  and receiving detection signals from the optional detectors  92 , etc. In some embodiments, the electrical interface  1531  is embedded within the flexible material  1522  as part of an injection over-mold process or permanently bonded between two flexible substrates that comprise the flexible material  1522 . The ends of the flexible material  1522  mate and secure, preferably in a waterproof manner, to both the first sub-enclosure  1530  and the second sub-enclosure  1532 , in some embodiments, leaving a middle section of the flexible material  1522  exposed between the first and second sub-enclosures  1530  and  1532 , thus providing bendability between the sub-enclosures  1530 / 1532 . 
         [0056]    Referring to  FIGS. 17 and 18 , side plan views of the bendable marker system  1520  are shown in a linear mode relating to mounting on a flat surface ( FIG. 17 ) and in a curved mode ( FIG. 18 ). Similar to the marker system  220 , the bendable marker system  1520  bends or flexes along the flexible material  1522  to allow the first and second sub-enclosures  1531  and  1532  to conform to surfaces ranging from linear surfaces  402  (as in  FIG. 17 ) to curved surfaces  401  (as in  FIG. 18 ) for example, when mounted to a helmet. In  FIG. 17 , the bendable marker system  1520  is shown substantially linear while in  FIG. 18 , the bendable marker system  1520  is shown slightly curved to fit a helmet curvature. 
         [0057]    Equivalent elements can be substituted for the ones set forth above such that they perform in substantially the same manner in substantially the same way for achieving substantially the same result. 
         [0058]    It is believed that the system and method as described and many of its attendant advantages will be understood by the foregoing description. It is also believed that it will be apparent that various changes may be made in the form, construction and arrangement of the components thereof without departing from the scope and spirit of the invention or without sacrificing all of its material advantages. The form herein before described being merely exemplary and explanatory embodiment thereof. It is the intention of the following claims to encompass and include such changes.