IMPROVEMENTS IN LIGHT EMITTING DEVICES

TECHNICAL FIELD

The present invention relates to improvements in or relating to light emitting devices. More particularly the invention relates to a rechargeable device comprising a processor, and more particularly still to light emitting devices which can be used to signal information using particularly, light emitting diodes (LED ¹ S). In preferred embodiments, the invention relates to: o Personnel identifiers and illuminators; o Friend or foe identifiers; and o Equipment locators and illuminators.

The primary use of such devices is in military applications but such devices also have commercial applications where safety is an issue e.g. for transport/ maintenance personnel workers, identifying stationary equipment e.g. skips, identifying emergency exits (in which case the lights can be used to either illuminate a sign or be arranged to spell a word such as "exit") or to light moving objects e.g. bicycles.

BACKGROUND OF THE INVENTION

Currently, the military use chemical glow sticks as their primary means of lighting for identification purposes, be that to identify personnel e.g. friend or foe, equipment e.g. vehicles, or to identify locations, where they might be used as e.g. zone markers.

These chemical glow sticks take various forms as exemplified below:

• Infrared 6 inch military glow stick. These may be used for marking targets and objects that are only visible when viewed with infrared (IR) goggles. These typically have a bright glow duration of about 8 hours and may be hung from an integral hook present at one end of the stick;

• 6 Inch ultra glow stick. These sticks are designed to provide a short duration, 5 minute, high intensity glow. They are designed to burn a regular 12 hours of light in, say just 5 minutes. They are thus of particular use as e.g. signal flares for helicopters or sea rescue. They too typically come with hooks for ease of attachment. They come in a range of colours including: Aqua, Green, Pink, Purple, Red, White, and Yellow.

• The 6 inch industrial glow stick. These are the most common size of stick and are intended for a range of uses - depending on the colour. They may be used for just about anything including personnel identification, emergency lighting, and map reading. Colours include: o Blue & White (for more intense lighting and they typically provide 8 hours of light) and o Yellow, Red, Orange & Green (which last about 12 hours but provide a lower light intensity);

• The 6 inch, high intensity, glow stick. This is a super bright 30 minute high Intensity glow stick. It's designed to be extremely bright upon initial activation but then diminishes in brightness quickly over a period of about 30 minutes. It is primarily used as a signal glow stick for emergencies. It comes in the colours white and yellow.

• The 4 inch glow stick. This is a small and light stick made from a particularly transparent plastics to enhance it's glow. Being small it has a shorter duration - approx 6 hours. It comes with a serrated clip and is designed for attachment to e.g. clothing and "gear". Typically it comes in green, orange and pink.

• The flexible 8 inch glow stick/ bracelet. These are often used for marking troop locations and can be "strung" together. They too come in a variety of colours.

• The 1.5 inch mini glow stick. These are excellent for situations where a small compact light is required, that won't be seen by others from a distance. They provide a bright glow for about four hours and are ideally suited to e.g. map reading. They too come in a variety of colours.

In addition to chemical light sticks it is also possible to get LED light sticks. They are battery operated and can be turned on and off. They last about 20 hours and come in red and blue colours. The three AG13 batteries can be replaced.

These glow sticks are considered the primary starting point for the invention claimed.

In the torches field, where the primary objective is the illumination of objects via the projection of a (white) light beam, there has been a move from battery powered torches to rechargeable torches. These include:

• Wind up torches; and

• Solar powered torches.

However, the solar recharged torches currently available have limitations which make them unsuitable for many of the uses envisioned by the present invention.

Thus, for example:

• A Cyba-lite solar powered LED torch has a nickel metal hydride (NiMH) battery which, when fully charged by 24 hours of daylight, provides light via 5mm Nichia white LED bulbs. It offers a single LED focussed spot beam or a double LED flooding beam and can provide between 5 and 9 hours of light depending on it's mode of use;

• A Highlander torch will charge in 3 hours but will only provide 4 hours running time;

• A StingRay LED torch will give 1 hour light on 5 hours of direct light charging.

In addition to the above prior art, the applicant has also identified:

US 2006/0101685 which discloses a substrate with a light display. It recognises that it would be beneficial to have a low-cost, internally powered lighted and or dynamic display, such as an advertising hoarding. It teaches a controller which is programmable to change at least one of a sequence or intensity of activation in response to light conditions. The power source may include a solar cell and / or a battery;

US 2005/00021886 which describes a multi-function flash light comprising different light sources that can be used in different situations. The main essence of the described invention is that at least two different light sources draw different current such that, for example, the device can operate in a "long life" mode if required;

WO 2007/071251 which describes a reflective illumination device comprising two or more colours of light disposed at different ends which are configured to blink independently of one another. The device, with typically red and white lights, is of a type recognised for use as front and rear bicycle lights, the lights being arranged such that the different colours may be viewed from, at least, two directions;

US 2003/0185018 which describes a stroller light comprising a photovoltaic cell allowing it to be recharged during daylight;

WO 2007/048503 which describes a fibre optics illuminated glow stick apparatus which may serve as a safety device or novelty;

US 2005/0275193 which describes a vehicle safety lighting and signalling unit;

FR 2832489 which describes a distress beacon which can transmit infra red or white light; and

WO 93/14971 which describes a tactical survival beacon which is solar powered and can transmit either a flashing visible light or an infra red signal.

None of the above identified prior art devices addresses the primary issues of providing, in particular armed forces personnel, a flexible and robust light emitting system which enables them to: • Avoid the necessity to carry a number of different light emitting devices; and

• Avoid carrying spare batteries. The devices of the present invention offer

• Flexibility; • An "in the field" recharge system;

• A more environmentally acceptable lighting solution then chemical glow sticks; and

• Improved personnel safety.

PRESENT INVENTION

Generally the present invention provides an improved lighting device comprising:

• one or a plurality of lights,

• a rechargeable power source, • a means for recharging the power source,

• a processor to control different input and/ or output operational modes for the device, and

• a user input means for controlling the processor functions.

According to a first aspect of the present invention there is provided an improved light emitting device (10) comprising:

• one or a plurality of lights (16) comprising light emitting diodes (LED) (16a),

• a rechargeable power source (18), • a means for recharging the power source comprising at least one solar cell or panel (20),

• a processor (22) to control different input and/ or output operational modes for the device, and

a user input means (24) for controlling the processor functions.

Preferably the means for recharging the power source additionally includes contacts for connecting the device to an external power source.

The devices of the invention may serve as communication devices. More particularly they can signal: presence, identity and other information.

The communication of identity is capable of distinguishing personnel, an object and / or a location. The object may, for example, be a vehicle, a building or an aerial. It could also be, for example, a hazard, such as a skip.

In a preferred embodiment the lighting device is an identifier. Different forms of identifier include: • Personnel identifiers,

• Vehicle identifiers,

• Aerial identifiers.and

• Location identifiers

The first three are described more fully in the examples.

The personnel identifier may distinguish, for example: teams or sides, individuals, their role or function, rank and health status.

A vehicle identifier may distinguish, for example: teams or sides, function, and operational status.

A location identifier may distinguish between a landing zone, a deployment zone and e.g. a hazardous area, such as, for example, a mine field.

Alternatively the lighting device may be an illuminator. Different forms of illuminator include:

• A helmet or head mounted illuminator; and

• A mountable torch.

Preferred features of the respective devices include:

1. The light source.

The light source is preferably a light emitting diode (LED) or an organic LED. In some circumstances a fluorescent light, an incandescent light or an electroluminescent light may be used.

The light may comprise at least two differently coloured lights, a variable colour light or a white light with a filter for changing the colour. Preferred are LED's. The advantage of LED's compared to many other light sources are that they offer increased durability, reduced weight, reduced power consumption and flexibility in that fixed or variable colour lights may be used.

Additionally, an infra red light may also be provided. Again an infrared LED is preferred.

The light may be a point light source or a diffused light source in which case one or more diffusers or light pipes may be incorporated.

2. The Processor

The processor's function is to control different input and/ or output operational modes for the device. It may comprise a single or multiple outputs, a single or multiple inputs and be static or dynamically programmable.

The combination of processor and light is significant in providing flexibility of operation. The single or multiple outputs connect to the one or a plurality of lights and allow the control of one or more of the intensity, direction, duration, frequency, colour and or flash pattern of the lights.

The single or multiple outputs may additional connect to an auxiliary output device, such as an audio feedback device or other sensory means such as a vibration mode.

Similarly, the single or multiple inputs connect to the one or a plurality of lights to allow control of one or more of the intensity, direction, duration, frequency, colour and or flash pattern of the lights.

The processor may be statically programmed during manufacture or dynamically programmed either after manufacture or by the user.

The advantage of a processor is that it allows flexibility in operation mode and more direct control over power consumption, e.g. use of a sleep mode.

3. The user input means

The user input means may take the form of a mechanical switch, resistance based touch contacts, pressure contacts, a magnetic switch and an infrared emitter/ receiver pair. In order to avoid the risk of accidentally turning a device on or off or changing it's mode it is preferred to use a switch requiring two independent actions which actions may be done simultaneously or sequentially.

4. Thejechargeable power source.

The rechargeable power source can take a variety of forms and is preferably selected to provide adequate power to meet the operational requirements of the device.

Suitable devices include nickel cadmium, nickel metal hydride, lithium ion, or lithium ion polymer batteries or a super capacitor.

5. A means to support recharging of the power source.

One or more means may be provided. The means may comprise at least one solar cell or panel and or contact points for recharging via a cradle or like device.

The solar cells may take the form of mono-crystalline, poly-crystalline cells or flexible cells and will usually be arranged in an array or panel.

6. Integration

All or a plurality of the components may be integrated and mounted on or in a tray or encased in an electronic potting compound for insertion into a casing. This helps ensure robustness. A suitable electronic potting compound is an epoxy resin.

Preferably the components may be interconnected using flexible printed circuits (FPC). Accordingly, the tray may be shaped with e.g. channels to support them in an optimal manner.

Where the means supporting recharging is or include solar cells or a panel it is preferred that they are arranged in a manner ensuring maximum efficiency. The cells or panels are preferably disposed on one or more exposed faces.

The benefits of the devices of the invention arise from the fact a single device may be controlled via the processor through the user input means to operate in a plurality of modes.

Thus, for example, in a first mode the lights may operate on a dim setting, in a second mode they may operate on a bright setting and in a third mode they may operate on an emergency setting.

In an emergency setting they may, for example, displays two differently coloured lights which may be made to, for example, flash or light alternately.

The user input means can be used to switch the mode of operation based on e.g. a period of contact.

As a back up or an alternative to solar cells the device may be provided with contacts for an external charger or adapted to take reusable batteries as well or in the alternative. Additional contacts may also be provided to allow the device to be dynamically programmed.

Preferred operational specifications would ensure the device is able to operate continuously for up to 96 hours on a dim mode, to operate continuously for up to 48 hours on a bright mode, and to operate continuously for up to 12 hours in an emergency mode.

Additionally, exposure to full daylight for 8 hours should provide a recharge sufficient to provide 24 hours of light on a dim mode, 12 hours of light on a bright mode and 4 hours of light on an emergency mode.

In order to provide aesthetics and to enhance functionality the components are retained in an appropriately shaped casing.

In the case of a personnel identifier the shaped casing preferably has a curved face for fitting against a helmet and comprises an attachment means such as a buckle.

For military applications the device preferably offers a three light colour combinations, typically green, red and blue.

It is particularly preferred to use a full spectrum light source which allows for colour control via the processor.

In the case of a personnel identifier it may be desirable to have three sets of lights, a central set and two peripheral sets. The number of sets increases flexibility in operational modes.

In the case of a vehicle identifier it may be desirable to have the lights disposed around a central solar panel on the casing. Again, the casing further comprises an attachment means preferably a magnet, an attachment for hook and loop fasteners, sticky pads, straps, and/ or bolts.

Most preferably the casing has a flat face.

For an aerial identifier the casing is preferably tubular. The tube may be an open or closed tube. Most preferably the lights are disposed around the tube such that the light may be emitted radially in all outermost directions.

As well as identifiers, the invention covers illuminators. These include a head torch and a generally cylindrical torch.

Such illuminators have a light source which emits white light.

In a preferred embodiment of a head torch device comprises at least three groups of lights arranged in an arc or a plane. The central group of lights are arranged such that at least one light is disposed to project light at the perpendicular and at least one is arranged to project light downwards at an angle of from 50-70 degrees to the perpendicular. The peripheral groups of lights are arranged such that at least one light is disposed to project light outwards at an angle of from 10-30 degrees to the perpendicular and another is arranged to project light downwards at an angle of from 20-40 degrees to the perpendicular.

Preferably the head torch offers four modes of operation;

• a first low intensity narrow beam mode;

• a second high intensity narrow beam mode; • a third low intensity wide beam mode; and

• a forth high intensity wide beam mode.

Preferably such a device has a casing with a curvature to ensure a close fit to a user's forehead or helmet and a buckle or clip for a strap attachment.

Preferably the user input means is provided on both the top face and underside of the casing and operation is achieved by squeezing the two buttons. In a preferred embodiment it has an option allowing it to project coloured light.

The various aspects of the invention will be described further, by way of example only, with reference to a personnel device in which:

Fig 1 is an exploded perspective view illustrating the key components of a personnel identifier of Example 1 ; and

Fig 2 is a perspective view of the device.

DETAILED DESCRIPTION

Examples of specific identifiers are described in Examples 1 - 3 below:

Example 1 - Personnel Identifier

Figs 1 and 2 illustrates a "Personnel indicator" light emitting device (10) specifically designed to be fitted to the rear of a helmet. It comprises a shaped casing (12a; 12b) and the functional components (14). The basic functional components include: • a plurality of LED's (16a) (including one or more of white, infra red, and coloured LED'S) in a light assembly (16),

• a rechargeable battery (18),

• at least one solar cell or panel (20),

• a processor (22) to control the LED's, and • a means (24a; 24b) for switching between programs.

For robustness the functional components (14) including the LED's and light assembly, the rechargeable battery, the solar cells or panels and the processor,

are held together on a tray (26) or are embedded in a resin or resin like material. This tray is than sealed in the casing (12a; 12b) comprising a lens or clear cover (12a) and a backing (12b) which gives the end product it's aesthetic qualities and a degree of water resistance.

The "miniaturization" of the device reduces weight, an important consideration in military applications.

In the embodiment illustrated the casing can be as little as 9cm x 4cm x 1.5cm (length, width, depth).

The casing (12) may be configured in a number of ways including, for example, i) a hollow injection molded plastics (as illustrated) with a clear front face (12a) and an opaque back housing (12b). The hollow being filled by the tray (26) (which may be a one piece or two piece construct) onto or into which are fitted the major components (14). The front (12a) and back (12b) of the casing (12) are sealed around the tray (14; 26). The opaque back housing assists in reducing stray lighting; ii) an injection molded plastic case, filled with a suitable electronic potting compound, such as, for example, an epoxy resin, to provide, amongst other properties, structural reinforcement and waterproofing; and iii) an epoxy resin case (not injection molded) comprising a clear resin front face and an opaque back.

Significantly the "Personnel indicator" light emitting device (10) comprises at least three light boxes (16), each lit by at least one LED (16a) which may be either:

• a single colour LED;

• a multi (tri) - colour LED (which can be caused to emit light of a different wavelengths); or • a white LED (the light box (16) being coloured).

One of the three light boxes or an additional light box may additionally, or in the alternative, carry an infra red LED.

By providing the device with the ability to signal a different identity or status by selecting:

• a different colour; • a different combination of colours, and / or

• different signaling patterns (permanent or pulsed light) allows a single device to have multiple uses, thereby reducing the number of devices which need to be carried by, for example a soldier. This is further enhanced by the additional inclusion of an infrared light source (used where a non-visible light signal may alternatively be required).

In the illustrated example the tray (26) houses three light boxes (16) in recesses (28) which are lit by:

. a red LED (16a); • a green LED (16a) and additionally an infra red LED (16a); and

• a blue LED (16a) (when viewed from left to right).

The different colours/ combinations enable at least 3 modes of operation (independent of the infrared signaling capacity) to be pre- programmed.

The LED's used can be controlled via the processor (22) to provide light at different intensity (dim or bright settings). However, a similar effect can be achieved by, for example, lighting one or two LED's.

Alternatively, the LED's can be used to generate a point light source rather than a diffused light as achieved using the light box.

Thus, as well as the LED's there is appropriate circuitry (not shown) a processor (22) and a switch (24) enabling the different modes of operation.

Thus, in the device of Example 1 both the coloured and infrared "light intensity" can be varied and respective light boxes can be switched between an "on", an

"off" and a "pulsed" mode. Pulsing can also be controlled so that either a single colour is pulsed or alternate colours (including infrared) are pulsed.

The product illustrated in Fig 1 is programmed so that it can be switched between at least 3 modes of operation which can be controlled from a switch (24) which can be either a contact or a contact-less switch.

The 3 modes of operation include:

• 1 ^st mode of operation - first intensity (dim), first colour (e.g. green) with optionally infra red on (central light box);

• 2 ^nd mode of operation - second intensity (bright), first colour (e.g. green) with optionally infra red on (central light box); and

• 3 ^rd mode of operation - second intensity (bright), second colour (e.g. red) (left light box) and second intensity (bright) third colour (e.g. blue) (right light box), flashing in an alternating manner to indicate a personnel emergency.

In the embodiment illustrated, the switch is a contact switch and the mode of operation is time sensitive. Thus, holding down the switch will take the program through the alternative cycles (mode 1 to mode 3) in a time dependant manner. It will be apparent that alternative switching modes and initiation/ change programs may be used.

Preferably, though not essentially, an audible indicator is additionally provided to let the user know which mode he has selected. This is significant as the identifier is attached to the rear-of a helmet.

Thus, in practice, the indicator will be activated by depressing the contacts (via the switch) in the following manner: • When the contacts touch for a 1 ^st preset period, in this case 1 continuous second, the indicator activates the first mode of operation;

• If the contact is maintained for a 2 ^nd preset period, an additional 1 second, the indicator activates the second mode of operation; and

• If the contact is maintained for a 3 ^rd preset period, yet another 1 second, the indicator activates the third and final mode of operation.

The indicator is programmed such that, whichever mode of operation is active when the contacts are released (1 ^st , 2 ^nd or 3 ^rd depending on length of contact time) it will remain active until the indicator is powered off. To power off the indicator, the user will hold the contacts for a given period, 2 seconds. This action will shut off the indicator regardless of which mode of operation it is in.

The unit may optionally be configured to automatically shut down when exposed to daylight for an excess of a predetermined time period, say 10 minutes, to preserve battery life. Additionally, if it turns off in these circumstances, the indicator can be programmed to provide an audio feed back warning.

The rechargeable battery should be able to provide sufficient power for the duration of use required. Preferred batteries include those selected from the group consisting of Nickel Cadmium, Nickel Metal Hydride, and Lithium ion.

In the embodiment with the tray (26) the batteries will be capable of replacement independently of the other components. This is significant given new recycling requirements.

However, in the other embodiments described, where the batteries are encased with the other functional components (14) in e.g. a suitable electronic potting compound, such as, for example, epoxy resin, the batteries will not be independently replaceable.

Power consumption and the ability to recharge quickly and efficiently are key requirements for the military applications described as personnel safety is at stake.

Accordingly, the device should preferably be able to operate from a full battery charge within the following parameters:

• The device should use minimal power when in sleep/off mode;

• It should be able to operate continuously for up to 96 hours in a dim first colour (green) plus IR on mode;

• The device should be able to operate continuously for up to 48 hours in the brighter first colour (green) plus IR on mode;

• The device should be able to operate continuously for up to 12 hours in the brightest, alternating second and third colour (red and blue) emergency mode.

Preferably the device is charged solely by solar power. However, in another embodiment, external charging points may be provided allowing mains or battery charging and/ or an auxiliary battery provided.

Where an external charging caddy is used, full charge should be reached after a maximum of 4 hours in the charging bay.

Where an external charging caddy (not shown) is provided, the device will require additional contacts (34) capable of docking into the charging caddy. These contacts will need to be unaffected by moisture or stray contact. Alongside such contacts it may be desirable to include a set of contacts for dynamic programming of the device.

In either of the solar configurations, the unit should be able to recharge with the following characteristics: • 24 hours of dim first colour (green) plus IR usage will be recharged by exposure to full daylight for 8 hours;

• 12 hours of brighter first colour (green) plus IR usage will be recharged by exposure to full daylight for 8 hours;

• 4 hours of brightest, alternating second and third colours (red and blue) emergency usage will be recharged by exposure to full daylight for 8 hours.

To ensure effective recharge, the configuration of the solar cells/ panels (20) is important. Preferably, the device has solar panels positioned on a substantial portion of the front face of the device (the primary surface). In the embodiment illustrated two curved solar panels are used and these are fixed in the tray (26) within recesses (30). In an alternative embodiment solar cells or a panel may additionally provided along an upper surface of the device.

The reverse of the tray (26) not shown is shaped to house the rechargeable battery(s) (18), the processor (22) and the audible means (not shown). It may also house an auxiliary battery.

The shaped casing (12) is further provided with an attachment means (32) which takes the form of a buckle allowing the device to be attached using a webbing strap or similar means to a helmet.

To preserve battery life the device may be controlled to automatically shut down when exposed to daylight for a given time, say in excess of 10 minute.

Example 2 - Vehicle identifier

A vehicle identifier is described without reference to additional figures as the component elements (14) are substantially as per Example 1. However like number references are used by way of explanation. The primary difference lies in the shaped casing (12) and the attachment means (32) provided thereon.

The vehicle identifier is primarily intended for use by the military for vehicle marking.

Three alternatively coloured LED's (16) (or a single tri-colour LED whose colour can be controlled via the processor (22) is/ are provided, optionally in a light box (16). The three colours are typically:

• Green - used as a tactical indicator;

• Red - used on manoeuvres to denote "enemy" forces; and

• Blue - used on manoeuvres to denote "friendly" forces.

Preferably the LED's are arranged around the perimeter of the device which may, for example be a square device of approx 150mm by 150mm, (depth 25mm). The central region comprises one or more solar panels or an array of solar cells (20). In one embodiment 8 LED's (16a) are equidistantly disposed around the perimeter to provide 8 point lights. Alternatively, four light boxes (16) may be used to light the perimeter. The light boxes, function by reflecting the light from the LED in a manner that the box is evenly lit. This provides a more even light than that generated by a single LED which typically generates a point light. One or more infrared LED's may also be provided.

In use, the LED'S can be operationally controlled so that the number of depressions (or alternatively time period of depression) selects the colour. An example of this is set out below: Press once Red

Press twice Blue

Press three times Green

Generally, which ever mode of operation is selected it will remain active until the device is powered off.

To power off the device, the user may, for example, depress the button for a set period, e.g. 2 seconds. This action will shut off the device regardless of which mode of operation it is in.

As in Example 1, the device may be configured to automatically shut down when exposed to daylight for a given time, say in excess of 10 minute.

As in Example 1 , the device should be able to recharge with the following characteristic:

• 36 hours of red, green, or blue usage will be recharged by exposure to full daylight for 8 hours.

The design and specification of solar panels and batteries is selected to achieve the desired performance.

An external charging point and or an auxiliary charge may optionally be provided.

Preferably the device is designed for flat mounting. Thus, the casing (12) is preferably a hollow injection moulded plastics with a clear non reflective front face and an opaque back housing. A range of fastening options may be used and include, without limitation, magnets, hook and loop fasteners, sticky pads, straps, and bolts. Strong magnets are particularly favoured.

Example 3 - Aerial Identifier

This device is designed specifically to fit as a sleeve over a vehicle antenna but in other respects is similar to the devices of Examples 1 and 2.

As in Examples 1 and 2, it is desirable to be able to select from three operational colours, e.g. green, red and blue and preferably have an infra red capability.

The LED's/ light boxes may be arranged in any variety of configurations, depending on the size and shape of the sleeve.

By way of example only, the sleeve may be of generally tubular construction in which case the LED's or light boxes may be disposed circumferentially around the tube. Typically, three LED's of each colour will be disposed at say 120° intervals, such that coloured light may be emitted radially in all outwardly directions. Of course if other shaped sleeves are used, e.g. a boxed construction, different arrangement of LED's will be appropriate.

In one embodiment the LED'S may be disposed from top to bottom as follows:

Top - Blue

Centre - Green / IR (With IR positioned between the respective green LED's) Bottom - Red The tube may be an open or closed tube.

As in Example 1 , the modes of operation will include: a dim, a bright and an emergency mode of operation and the controls will operate in a similar manner.

In some instances the antennae will be difficult to access so in an alternative embodiment the device may be operated remotely.

The casing (12) preferably comprises a hollow injection moulded plastics with a clear non reflective outer face and an opaque back housing and is shaped to fit over or around a radio aerial. Preferably, it is light weight.

Examples of specific illuminators are described in Examples 4 and 5 below

Example 4 - helmet/ head illuminator

In contrast to the identifiers where different coloured LED's or displays are used to signal different identities, the illuminators are designed primarily, but not exclusively, to project white light. However, the use of a processor distinguishes them from standard torches.

The MAMBA has been specifically designed as a personal lighting device which is mounted on a helmet or is attached to the forehead via a strap. Its applications are as:

• a (map) reading lamp, • a path illuminator, (narrow/ shorter beam) or

• an area illuminator (wider/ longer beam).

Accordingly, the light intensity, and angles of illumination are of paramount importance.

The casing (12) has a curvature to ensure a close fit to the helmet or forehead.

Preferably the casing has a maximum size of 90 x 40 x 15 mm

The LED's are either white (with a movable coloured filter) or are paired so that either white or coloured light may be generated (depending on the requirement). Preferably the filter or coloured light is green.

Preferably the LED's are arranged in a manner that allows the lighting direction to be carefully controlled for the intended mode of operation.

Thus depending on their positioning the LED's will be angled either:

• outwardly to allow a wide beam of light (useful for area illumination) or • downwardly to allow for map reading and path illumination (depending on intensity.) There intensity will also be controllable via the processor.

In one embodiment, the personal lighting device will comprise 8 LED's. Three will be disposed to the left, three to the right and two centrally.

Those to the right and left will be disposed respectively at:

• Between 10 to 30 degrees, preferably about 20 degrees out to the perpendicular; and • Between 20 to 40 degrees, preferably about 30 degrees to the perpendicular down.

The two central LED's will be disposed respectively at:

• At the perpendicular; and • Between 50 to 70 degrees, preferably about 60 degrees down.

These angles have been determined to provide the best light for the intended uses.

To enable the user to move between the different operational modes a switch is provided. Ideally this is provided on the underside (allowing thumb operation) and to the right (the majority users are right handed). Alternatively a double button operation may be preferred.

The three modes of operation together with the functionality are set out below:

• Mode 1. Press once. Centre 2 LED's lit. Function focused for map reading;

• Mode 2. Press twice. Centre 2 LED's lit; Outward 6 LED's on dim. Function 20ft illumination; and

• Mode 3. Press three times. Centre 2 LED's lit; Outward 6 LED's on bright. Function 50ft illumination.

Again, as in Example 1, which ever mode of operation is active when the button is pressed will remain active until the device is powered off.

To power off the unit, the user will hold the button down for a defined period, say 2 seconds. This action will shut off the unit regardless of which mode of operation it is currently in.

Again, like the device of Example 1 , the device may be configured to automatically shut down when exposed to daylight for an excess of 10 minute.

The battery, LED's and solar panels should be selected and configured to meet the functional requirements of the device, such as:

• 24 hours of dim focused light (for map reading usage);

• 12 hours of bright focused light (for walking usage); and

• 4 hours of bright wide beam light (for area illumination) all on a recharged by exposure to full daylight for 8 hours.

The casing (12) is a hollow, injection moulded plastics with a clear non reflective front face and an opaque back housing. The rear moulding is curved to accommodate the shape of the head or headgear. Buckles / clips enable the unit to be attached to a webbing strap.

Example 5 - mountable torch light

The mountable torch light has the basic components and functionality of the torch light described with reference to Example 4. The main difference lies in the fact that the components (14) are encased in a tubular casing (12) of approximate size 20 mm diameter x 140 mm length and the device has a push button at or towards the end of the tube.

The device is suitable for hand operation or for mounting on a piece of equipment.