WO2000001096A1

WO2000001096A1 - Infrared communication system for simulated wargame

Info

Publication number: WO2000001096A1
Application number: PCT/GB1998/001891
Authority: WO
Inventors: Peter Glyn Llewellyn; Nicholas Rosewell Squire; Richard Inge Wigram; John Colin Moore
Original assignee: Eclipse Concepts Limited
Priority date: 1998-06-29
Filing date: 1998-06-29
Publication date: 2000-01-06

Abstract

A communications apparatus is described which comprises a headset for a person to wear, the headset being provided with first transmitting and first receiving means. A control device having second transmitting and second receiving means allows for user-control of both transmitting and both receiving means. The apparatus may be used to transmit and receive signals modulated with vocal messages or to transmit and receive signals representing bullets in a simulated wargame. The first transmitting and receiving means may be omni-directional whilst the second transmitting and receiving means may be uni-directional.

Description

INFRARED COMMUNICATION SYSTEM FOR SIMULATED WARGAME

This invention relates to communications, and in particular but not exclusively

to a method of and apparatus for voice communications implemented by the

transmission and reception of infrared light signals.

Background of the nvention

A new type of simulated weapon for use in wargames is described in

GB-A-2290483. The weapon comprises a directional transmitter for simulating the firing of the weapon and an omni-directional receiver for receiving such a received

signal. A reply signal is generated and broadcast by an omni-directional transmitter. A directional receiver for the reply signal, sharing a common field of view with the

directional transmitter provides the weapon from which the offensive signal originated, and none other, with the capability of monitoring the effect of its offensive signal. This weapon is designed for use at outdoor and indoor sites.

Also described in GB-A-2290483 is an autonomous simulated weapon which

has no direct human operator. Known as a "mine", the weapon comprises a rotatable

turret on which is mounted an infrared light-emitting cannon. A motor under the

control of a microprocessor rotates the turret in a random or pseudo-random manner,

and the cannon emits bursts of bullet signals which players must avoid. In turn,

players can attempt to disable the mine by shooting their own weapons at it and hitting it a predetermined number of times. The mine has four photodetecting diodes

for receiving players bullet signals. The diodes are arranged to divide the region

around the mine into different angular sectors which in total cover a full 360° in a

plane around the mine. It is described how, under the control of the microprocessor.

the mine can detect from which of the sectors a received players weapon signal has

emanated and how. in response to this the random rotation of the turret is terminated

and the cannon/turret rotated to face and sustain fire on that particular sector.

According to one aspect of the present invention there is provided a

communications apparatus the apparatus comprising: a head unit for a person to wear;

first transmitting means provided on the head unit for transmitting light signals: and

first receiving means provided on the head unit for receiving light signals; and a

control device for a user to control the first transmitting and first receiving means,

wherein said first transmitting means comprises a set of transmitters regularly

arranged about an axis to provide a transmission pattern which is substantially omni-

directional in a transmitting plane, and said first receiving means comprises a set of

receivers regularly arranged about substantially the same axis to provide a reception

pattern which is substantially omni-directional in a receiving plane.

An advantage of this aspect is that it provides for a head-mounted

communicator in which an omni-directional light transmitter and an associated omni-

directional light receiver may be compactly arranged. According to a further aspect of the invention there is provided an apparatus

for transmitting and/or receiving signals in a simulated wargame. the device

comprising: a transmitter for transmitting a signal along a direction and/or a receiver

for receiving a signal from a direction: and means for varying, substantially

independenth' of the position of the transmitter and/or the receiver, the direction along

which the transmitter can transmit a signal and/or for varying the direction from

which the receiver can receive a signal.

This aspect has the advantage that the transmitter and/or receiver may be

mounted statically, thus reducing the complexity of the arrangement.

According to a yet further aspect of the invention, there is provided a method

of providing combined facial protection and communications capability for a plurality

of participants, the method comprising: providing each of said participants with a

mask for facial protection, and an infrared communicator for mutual communication

between the participants.

An advantage of this aspect is that enhanced communications capabilities may

be conveniently provided for participants, for example in a "paintball" game,

requiring means for facial protection which may otherwise reduce their capability of

communicating.

According to a further aspect of the invention there is provided apparatus

comprising: a mask for facial protection: and

a communications device comprising an audio pick-up portion.

a loudspeaker and transceiving means,

said communications device being adapted in use to be attached to the head of

a user in conjunction with said mask so as to provide facial protection and voice

communications in combination.

An advantage of this aspect is that it provides an improved means of

communication for any person operating in an environment where facial protection is

required.

In the Drawings

Figure 1(a) is a side view of a headset of a signalling apparatus embodying the

invention.

Figure 1 (b) is a front view of the headset of Figure 1(a).

Figure 2(a) is a cross-sectional view of the headset of Figure 1. taken along

line A-A in Fig. 1(b).

Figure 2(b)(1) is a top view of a first pcb having an arrangement of infrared

emitting diodes, (ii) is a bottom view of the first pcb, (iii) is a bottom view of a second

pcb having an arrangement of infrared detecting diodes, (iv) is a top view of the

second pcb. Figure 3(a) is a top view of a device of a control device embodying the

invention which contains a uni-directional receiver and transmitter and means for

controlling the same and the omni-directional receiver and transmitter of the headset

of Figure 1.

Figure 3(b) is a side view of the device of Figure 3(a).

Figure 3(c) is a rear view of the device of Figure 3(a).

Figure 4 is a top view cut-away illustration of the device of Figure 3.

Figure 5 is a diagram of an alternative optical arrangement which can be

contained in the control device illustrated in Figures 3 and 4.

Figure 6 is a schematic of the control electronics of a communications

apparatus embodying the invention.

Figures 7(a) and 7(b) are schematics illustrating the operation of

communications apparatus embodying the invention.

Figure 8(a) is a vertical cross-section of an autonomous simulated weapon.

Figure 8(b) is a top view of the weapon of Figure 8(a), having the top and

mirror support removed.

Detailed Description of the Preferred Embodiments

Figures 1 and 2 illustrate a headset 1 of a communications apparatus

embodying the invention. The headset 1 , to be located at one side of the head of a

user, comprises a moulded plastic casing. At the lower end of the casing is an earpiece 2. which when the headset is worn is disposed close to the wearer's ear. At

the top of the casing is a dome 3. which when the headset is worn is disposed at least

approximately above the centre of the wearer's head.

A bridging portion 4 connects the earpiece 2 to the dome 3. The bridging

portion 4 comprises a substantially straight lower portion which is substantially

straight in cross-section shaped to rest against the side of a wearer's head and a curved

upper portion shaped to conform to and rest against one side of the top of a wearer's

head.

The dome 3 disposed at the top of the casing is substantially transparent to

infrared light and covers a group of infrared photoemitting diodes which serve as a

transmitter together with another group of infrared photoreceiving diodes which serve

as a receiver.

The earpiece 2 contains a loudspeaker (not shown) behind a grille 5 which is

used to reproduce audio signals received by the communications apparatus. The

loudspeaker has a conventional structure such as that of a moving coil sounder as used

in hi-fi earphones or other types of earphone.

The earpiece 2 further contains a microphone (not shown) which is located at

one end of a flexible plastic tube 6 of a length allowing the other end to be located

close to the headset wearer's mouth. The tube provides acoustic coupling of the

headset wearer's voice to the microphone. A cable 7 connects the headset to a hand- held control device, described below in relation to Figures 3(a) to (c). which provides

for control of the communications device.

Figure 2(a) shows a cut-away drawing of the headset 1 , along the line A-A of

Figure 1(b), which illustrates the headset's internal structure, although internal

connecting electrical wires have been omitted. A transmitter 8 comprises a group of

infrared emitting diodes 9. attached either side of a first printed circuit board (pcb) 10.

The pcb 10 is secured on a central mounting on the inside of the dome 3.

In this embodiment there are ten transmitting diodes 9. five attached to each

side of the pcb 10. The set of five diodes secured to the upper side of the pcb 10 (see

Fig. 2(b)(i)) ^ε mutually spaced equiangularly (a 72° spacing) about the

circumference of the pcb 10, as are the set of five diodes secured to the lower side of

the pcb 10 (see Fig. 2(b)(ii)). The two sets are positioned with an angular offset with

respect to each other, an arrangement which ensures that, even though the transmitting

diodes 9 have individual outputs which vary angularly, the first transmitting means

has a transmission pattern which is substantially independent of radial direction in the

transmitting plane (which is substantially coincident with the plane of the pcb 10).

Hereinafter we will refer to this transmission pattern as omni-directional.

The receiver 1 1 comprises a cluster of four infrared detecting diodes 12

attached to a second pcb 13. The second pcb 13 is attached to the central mounting of

the dome 3 below the first pcb 10 and the infrared detecting diodes 12 are attached to the lower side of the pcb 13 (see Fig. 2(b)(iii)). This arrangement shields the

detecting diodes 12 from infrared radiation in direct sunlight, when the headset is in

use in an outdoor environment.

As is illustrated in Figure 2(b) the infrared detecting diodes 12 are mutually

spaced equiangularly (a 90° spacing) about the circumference of the pcb 13. The

detecting diodes 12 each have a field of view which is wider than individual output

patterns of the transmitting diodes 9. and receiver 1 1 has a response pattern which is

substantially independent of radial direction in the receiving plane (which is

substantially coincident with the plane of the second pcb 13). Again, this pattern is

referred to herein as omni-directional.

Figures 3(a), 3(b) and 3(c) illustrate a hand-held control device 14 for

controlling the transmitter 8 and the receiver 1 1. The outer body of the device 14

comprises a moulded plastic case 15. A substantially rigid clip 17 is provided on the

protective case 15 to enable the control device 14 to be attached to a belt or such like.

Three buttons (an "on/off button 18, a "call" button 19, and a "talk" button

20) are disposed on the top of the protective case. The buttons 18, 19, 20 are provided

on a moulded rubber underlay which provides for a grippy surface and also seals the

three openings in the protective case over the switches.

Figure 4 shows a side view cut-away illustration of the device 14. The second

transmitter comprises an infrared light emitting diode 23 placed at the focal point of a first plano-aspheric optical lens 22. When activated the diode 23 emits light towards

the lens 22 which collimates the light to form a substantially parallel beam which

exits the device. The second transmitter is therefore a substantially uni-directional

(line of sight) transmitter.

The second receiver comprises an infrared detecting diode 25 located at the

focus of a second plano-aspheric optical lens 24, which is essentially similar to the

first plano-aspheric lens 22. The second receiver 25 is therefore a substantially uni¬

directional (line of sight) receiver.

An alternative to the use of the second plano-aspheric lens 24 is a Cassegrain

mirror arrangement 26. which is illustrated in Figure 5. A substantially parallel light

beam which is incident through the window 21 is reflected by a concave mirror 27

onto a convex mirror 28 which focuses the light into a narrower substantially parallel

beam impinging on the receiving diode 25. The first plano-aspheric lens 22 of the

uni-directional transmitter may also be replaced by a similar Cassegrain mirror

arrangement.

Audio signals received by the second receiver 25 are FM demodulated in the

control device 14 and transmitted to the loudspeaker in the earpiece 2 of the headset 1

by means of wire in cable 7. Furthermore, signals produced by the microphone

contained in the headset 1 are transmitted to the hand-held controller 14 by means of

wire in cable 7 and FM modulated onto carrier signals transmitted by the second transmitter 23. Power for the components contained in the device 14 and the headset

1 is provided by the batteries 29. The batteries are contained in holders moulded into

the inner side of the case 15.

In order to facilitate aiming of the second transmitter and the second receiver a

view finder is provided in the control device 14.

As shown in Fig. 4 the view finder comprises a visible light emitting (red)

diode 30 located behind a shield 31 which has a small pinhole 32. The pinhole 32 is

at the focus of a lens 33 so that light emitted by the diode 30 which passes through the

hole 32 is focused substantially at infinity by the lens 33. The viewfinder is contained

in a darkened tube behind lens 33 at the rear of the control device 14 (see Figure 3(c)).

To aim the device the user first focuses both eyes on the target (which is also

substantially at infinity when a reasonable distance away), then brings the handset

approximately 50 cm from one eye until the red dot produced by the pinhole and the

target are coincident.

We refer now to Figure 6 which is a schematic of the control electronics for

the communications apparatus. The control electronics are located in the headset 1.

on a controller pcb 35 in the control device 14, and omni-directional receiver control

pcb 36, and omni-directional transmitter control pcb 37. The electronics are

controlled by microprocessor 38 which is located on the controller pcb 35 (the control

lines of the processor 38 are not shown in Fig. 6). Power is provided by battery 29 which is connected and disconnected by an on/off switch operated by the on/off

button 18.

It can thus be seen from the above description that the communications

apparatus of this embodiment comprises an omni-directional transmitter, a uni-

directional transmitter, an omni-directional receiver and a uni-directional receiver.

To send a uni-directional transmission a user depresses both call button 19 and

talk button 20 of control device 14. In response to this microprocessor 38 generates a

carrier signal at an appropriate frequency, which is supplied to uni-directional

transmission unit 39. Here the carrier signal is FM modulated with a signal

representing the voice of the user which has been supplied via microphone 40 and

amplifier 41. The modulated signal is then supplied to the infrared emitting diode 23

for transmission.

To send an omni-directional transmission the user depresses only talk button

20. In this instance the carrier signal generated by microprocessor 38 is supplied to

omni-directional transmission unit 42 for modulation with a_. signal representing the

user's voice which again is provided via microphone 40 and amplifier 41. The

modulated signal is then supplied to omni-directional infrared transmitter diodes 9 for

transmission.

When a signal is being transmitted either uni-directionally or omni-

directionally the depression of the talk button 20 both activates the appropriate transmitter and causes squelch unit 43 to deactivate both the uni-directional receiver

circuit and the omni-directional receiver circuit.

When neither talk button 20 nor call button 19 are depressed. FM modulated

signals received from another communications apparatus by the omni-directional

infrared detecting diodes 12 are, after amplification by pre-amplifier 69. FM

demodulated by a demodulator contained in the omni-directional receiver unit 44.

The extracted audio signal is supplied to the earphone 45 via a sum unit 46, squelch

unit 43 and amplifier 47.

Similarly, when only call button 19 is depressed. FM modulated signals

received by the uni-directional receiving diode 25 are FM pre-amplified and

demodulated in the uni-directional receiver unit 48 and supplied to the earphone 45

via the sum unit 46 and squelch unit 43.

When call button 19 is depressed, the sum unit 46 only passes signals supplied

via the uni-directional detecting diodes 25. When the call button 19 is not depressed

the sum unit 43 will only pass signals supplied via the omni-directional detecting

diodes 12.

As transmission and reception cannot occur simultaneously, the

communication process is half duplexed. This avoids feedback problems (the

microphone is located relatively close to the loudspeaker in the headset) and

conserves power. Referring now to Figure 7 it will be described how users, each of whom are

equipped with a communications apparatus embodying the invention, are able to

communicate.

Person A (not shown) in possession of device 14' wishes to initiate long-range

communications with person B. Person A uses his viewfinder to aim the uni¬

directional transmitter of device 14' at the omni-directional receiver on the headset 1"

of person B. Person A depresses talk button 20' and call button 19' and speaks into

the microphone provided in his headset. An infrared signal FM modulated with

person A's voice signal is generated by the uni-directional transmitter of the device

14'. Providing person B is within range of person A, the FM signal is received by the

omni-directional receiver provided in the headset 1 " of person B who hears person A's

voice by means of the earpiece provided in his headset.

To reply, person B depresses only his talk button 20" and speaks into his

microphone. This generates an FM signal on B's omni-directional transmitter which

is modulated with his message. Since this reply message is transmitted omni¬

directionally B does not need to ascertain the exact location of A. Person A, having

finished his message, releases talk button 20 and receives B's reply message via the

uni-directional receiver in control device 14' by keeping call button 19' depressed and

maintaining his aim of the device 14' at the omni-directional transmitter in the headset

ofB. Should he so wish. B can forewarn A and reply by using his uni-directional

transmitter and aiming at A's omni-directional receiver. A must then ensure that both

call button 19 and talk button 20 are released so that he receives the message via his

omni-directional receiver. A can also initiate communications by depressing only his

talk button 20' to transmit via his omni-directional transmitter, providing B has his

uni-directional receiver switched on and aimed at A. Indeed, if B is within short-

range, A can initiate communications by depressing only his talk button 20', even

when B has only his omni-directional receiver switched on.

One application of the present invention is in relation to outdoor games such

as "paintball". Paintball games are usually organized and conducted over outdoor

rugged terrains where teams or individuals enact various wargame strategies and fire

at each other with gas powered guns which shoot vegetable dye pellets. A hit is

indicated by a characteristic dye stain left on a participants body or clothes. A face

mask is used to prevent dye pellets hitting and injuring a persons face or eyes.

The headset of a communications apparatus embodying the present invention

may be attached to a face mask as illustrated in Figure 7. The headset is attached to

the face mask 49 either at the earpiece section or the bridging portion. In a preferred

embodiment the headset is releasably attached to the face mask for example by screws

which pass through holes in the headset and face mask and secure the two together.

Pre-existing face masks may be adapted for the attachment of a headset by punching in the mask holes for receiving the screws. This arrangement has the advantage that if

the mask component or the headset component is broken, the two may be mutually

detached and the broken component replaced. Alternatively, the headset and face

mask are formed as an integral unit from the same plastic material.

The face mask 49 comprises a transparent eye protecting portion 49a, a face

protecting portion 49b and an elasticated headstrap 49c. The transparent eye

protecting portion 49a is composed of a shatterproof material, such as plastic. The

face protecting portion 49b which is shaped to cover and protect the remaining parts

of a user^'s face, is also composed of a shatterpro of material. The face protecting

portion 49b is provided with holes 49d at a region which when the mask is worn is in

front of the user^'s mouth. These holes improve ventilation and allow the user to

breath properly. Holes 49e are also provided at regions on both sides of the mask

which cover the user^'s ears. These holes ensure that the user^'s hearing is not

inhibited. Further ventilation holes 49f are also provided in the mask.

The interior of the face protecting portion 49b is lined with padding to provide

extra protection and improve comfort. The headstrap 49c passes over the earphone

section of the headset to further secure the headset in place. Thus, a communications

apparatus embodying the invention, when used in combination with a face mask,

allows paintball players to communicate with each other without inhibiting their

mobility whilst providing face protection from the dye bullets. The embodiment of the invention described hereinabove is primarily

concerned with apparatus for sending voice communications. In our earlier

application GB-A-2290483. the teaching of which is incorporated herein by reference.

there is discussed a simulated weapon comprising both uni- and omni-directional

transmitters and receivers which are operable to transmit and receive infrared signals.

It is to be noted that any or all of the weapon functions described therein such as the

"bullet", "identity of friend or foe" or "range finding" signals may be incorporated into

apparatus embodying the invention of this application. Furthermore, any of the

simulated wargames described therein in may be played by players equipped with

apparatus embodying the invention described herein.

A new mine, similar in some respects to that described in GB-A-2290483, the

pertinent contents of which are incorporated herein by reference, is described

hereinbelow with reference to Figures 8(a) and 8(b). The mine comprises a base 50

which supports frame 51 by means of a spring ball joint 52. The ball joint 52 allows

the mine to be kept level when situated on uneven ground. An infrared emitting diode

53 serves as a transmitter, with light emitted from the diode 53 being collimated into a

parallel beam by lens 54 before being reflected by mirror 55 and exiting the mine

through an infrared transparent protection dome 56.

An infrared detecting diode 57 serves as a receiver with incoming signals

reflected by mirror 55 onto lens 58 which has diode 57 at its focus. The mirror 55 is mounted on a mirror frame 59 which is attached to and is

encircled by a rubber O-ring 60. The O-ring 60 is in contact with three idler pulleys

61, 62, 63. one of which 61 is acted on by a motor 64. When the motor 64 drives the

idler pulley 61 a torque is transmitted to the mirror frame 59 via the O-ring 60 and the

frame 59 and mirror 55 rotate about the axis indicated by line B-B. Power is supplied

by batteries 65. which are connected/disconnectedby on/off switch 69.

When a constant or regular signal is output from the transmitter 53 the rotating

mirror reflects the signal such that it is regularly broadcast along various directions in

a horizontal plane surrounding the mine.

Furthermore, since in one cycle the mirror turns a full 360° a signal received

from any direction during that cycle will be directed by the mirror onto the detecting

diode 57.

If the rotation of the mirror 55 is stopped the mine then acts as a uni¬

directional (line of sight) transmitter/receiver with the direction of transmission and

reception depending upon where the mirror 55 is facing when the rotation is stopped.

The control electronics including a processor may be suitably housed in the base 50 of

the mine. Advantages of this mine include improved reliability since most

components including the electronics and connecting wiring may be located in fixed

positions. Furthermore, only one detecting diode is required to allow detection of

signals originating from any direction surrounding the mine. The lower rim 66 of the mirror support frame 59 is toothed and passes through

an optical reader 67. The optical reader 67 comprises a light emitting diode (not

shown) which in use emits a continuous signal which is detected by an opposing light

receiving diode (not shown). When a tooth separates an emitting diode and a

detecting diode the signal is interrupted. The interrupt signal is passed to the

processor providing the processor, which uses the information therein to determine

speed and direction characteristics of the mirror 55.

Effectively, the region surrounding the mine is thus divided into angular

sectors. The greater the number of interrupting teeth provided, the smaller the size

each sector can be and the greater the accuracy with which the direction in which the

mirror is facing may be determined by the processor. As described in

GB-A-2290483. the mine is thus able to determine from which direction a "bullet"

signal has been received. The random rotation of the mirror can then be interrupted

and the mirror rotated to face and direct (return fire) fire towards the direction from

which the "bullet" signal originated. The mine can also detect opponents (if used in a

team game) during one rotation by means of "identifying friend or foe" signals and

shoot at a "foe" once identified on the next rotation.

Lights 68 are provided on the outside of the mine, each light corresponding to

an angular sector. When the mirror is covering a particular sector the light

corresponding to that sector illuminates to alert players to the direction of alignment of the mirror. It is to be understood that the mine described herein is capable of am^¬

or all of the wargame functions of the mine described in GB-A-2290483.

Having thus described the present invention by reference to a preferred

embodiment it is to be well understood that the embodiment in question is exemplary

only and that modifications and variations such as will occur to those possessed of

appropriate knowledge and skills may be made without departure from the spirit and

scope of the invention as set forth in the appended claims and equivalents thereof.

For example, even though the above-described communications apparatus

embodying the invention comprises a headset having omni-directional transmitters

and receivers and a hand-held control device containing a uni-directional transmitter

and a uni-directional receiver, the uni-directional receiver and the uni-directional

transmitter could be fixed to the headset. The control switches could then also be

attached to the headset, or still provided in a separately-held device.

Furthermore, the Cassegrain mirror arrangement of the control device 14

should not be taken as limiting because other suitable, although less advantageous,

arrangements of lenses and/or mirrors capable of focusing a signal onto the receiving

diode 25 would be apparent to those skilled in the art.

Embodiments of the invention are not limited to uses in simulated wargames.

A similar apparatus could be used by workmen in relatively dangerous environments (for example on construction sites or in steel works) or in other environments where

improved communication over distances whilst retaining mobility is desired.

In this regard, a headset similar to that described above may be detachably

fixed to a standard hard hat of the type worn by construction workers. Alternatively,

the headset arrangement may be integrally formed with such a hard hat. The

invention is also suitable for applications (for example policing) in which secure

communications are desired, as provided by the unidirectional transmitter/receiver

part of the communications arrangement.

In this regard, a headset similar to that described above may be detachably

fixed to a helmet of the type worn by policemen in various different duties.

Alternatively, the headset may be integrally formed with such a helmet.

It will be appreciated by the skilled addressee that other variations and

modifications may be employed in relation to the above-described embodiments,

without departing from the scope of the invention.

Claims

CLAIMS:

1. A communications apparatus, the apparatus comprising:

a head unit for a person to wear;

first transmitting means provided on the head unit for transmitting light

signals; and

first receiving means provided on the head unit for receiving light

signals; and

a control device for a user to control the first transmitting and first

receiving means,

wherein said first transmitting means comprises a set of transmitters

regularly arranged about an axis to provide a transmission pattern which is

substantially omni-directional in a transmitting plane, and said first receiving

means comprises a set of receivers regularly arranged about substantially the

same axis to provide a reception pattern which is substantially omni-directional

in a receiving plane.

2. An apparatus according to claim 1, further comprising second

transmitting means for transmitting a light signal and second receiving means

for receiving light signals.

3. An apparatus according to claim 2, wherein the second

transmitting means is a substantially uni-directional transmitting means.

4. An apparatus according to claim 2 or 3, wherein the second

receiving means is a substantially uni-directional receiving means.

5. An apparatus according to claim 2, 3 or 4, wherein the control

device comprises the second transmitting and receiving means.

6. An apparatus according to any of claims 2 to 5, wherein the

control device is also for controlling the second transmitting means and the

second receiving means.

7. An apparatus according to any of claims 2 to 6, wherein the first

transmitting means are operable independently of the second transmitting

means.

8. An apparatus according to any of claims 2 to 7, wherein the first

receiving means are operable independently of the second receiving means.

9. An apparatus according to any of claims 2 to 8. wherein the first

and second transmitting means are operable independently of the first and

second receiving means.

10. An apparatus according to any of claims 2 to 9, comprising a

Cassegrain mirror arrangement for focusing a light signal onto the second

receiving means.

1 1. An apparatus according to any of claims 2 to 10. comprising an

aiming means associated with the second transmitting means, said aiming

means comprising a visible light emitting diode, a screen having a pin hole, and

a lens wherein the screen is between the diode and the lens and the pin hole is at

the focus of the lens.

12. An apparatus according to any preceding claim, wherein the

control device is adapted to be hand held.

13. An apparatus according to any preceding, wherein said signals

are infrared signals.

14. An apparatus according to any preceding claim, wherein said

signals are modulated to carry audio signals.

15. An apparatus according to claim 14, wherein the modulation is

frequency modulation.

16. An apparatus according to any preceding claim, wherein said

first receiving means is located below said first transmitting means when the

head unit is worn.

17. An apparatus according to any preceding claim, wherein the first

transmitting means comprises a first set of infrared emitting diodes spaced

equiangularly about the circumference of a first side of a printed circuit board,

and a second set of infrared emitting diodes arranged and spaced equiangularly

about the circumference of a second side of the printed circuit board, with the

first set and the second set positioned with an angular offset with respect to each

other.

18. An apparatus according to any preceding claim, wherein the first

receiving means comprises a set of infrared detecting diodes arranged and

spaced equiangularly about the circumference of one side of a printed circuit

board.

19. An apparatus according to any preceding claim, wherein the

head unit comprises a microphone for receiving voice signals for modulating

carrier signals transmitted by either the first or second transmitter

20. An apparatus according to any preceding claim, wherein the

head unit comprises an earphone for reproducing audio-signals modulated onto

carrier signals received by either the first or second receiving means.

21. An apparatus according to any preceding claim, wherein said

axis is arranged to be substantially vertical when the head unit is worn.

22. An apparatus according to any preceding claim, wherein the first

transmitting means and the first receiving means are disposed on the head unit

such that the first transmitting and receiving means are located substantially at

the apex of the head of the wearer when the head unit is worn.

23. An apparatus according to any preceding claim, further

comprising a face mask to which the head unit is removably attached.

24. An apparatus for transmitting and/or receiving signals in a

simulated wargame. the device comprising: a transmitter for transmitting a signal along a direction and or a receiver

for receiving a signal from a direction; and

means for varying, substantially independently of the position of the

transmitter and/or the receiver, the direction along which the transmitter can

transmit a signal and/or for varying the direction from which the receiver can

receive a signal.

25. An apparatus according to claim 24, wherein the varying means

comprises a mirror.

26. An apparatus according to claim 25, wherein the mirror is

supported on a movable support which is movable to vary a direction along

which the apparatus can transmit a signal and/or to vary a direction from which

the weapon can receive a signal.

27. An apparatus according to claim 26. wherein the support is

rotatably movable.

28. An apparatus according to claim 27, further comprising:

a frictional O-ring attached around a portion of the support;

a rotating means in contact with the O-ring; and

a motor for driving the rotating means to transmit torque to the support.

29. An apparatus according to any of claims 24 to 28. further

comprising detection means for detecting a direction along which the apparatus

transmits a signal and/or for detecting from which direction the apparatus

receives a signal.

30. An apparatus according to claim 29, wherein the detection

means comprises at least one device which comprises an optical emitter

opposing an optical reader and a lower rim of the mirror support has at lease one

extended portion, which in use, interrupts once during one rotation of the

support a signal transmitted from the emitter to the reader.

31. An apparatus according to any of claims 24 to 30 as dependent

therein, wherein the detector and/or receiver comprise an infrared diode.

32. A method of providing combined facial protection and

communications capability for a plurality of participants, the method

comprising:

providing each of said participants with a mask for facial protection, and

an infrared communicator for mutual communications between the

participants.

33. A method according to claim 32. each of said communicators

comprising a communications apparatus according to any of claims 1 to 30.

34. A method according to claim 32 or 33 further comprising

providing each of said participants with a gun, wherein the masks are for

providing protection from projectiles fired from said guns.

35. Apparatus comprising:

a mask for facial protection; and

a communications device comprising an audio pick-up portion,

a loudspeaker and transceiving means,

said communications device being adapted in use to be attached to the

head of a user in conjunction with said mask so as to provide facial protection

and voice communications in combination.

36. An apparatus according to any of claims 1 to 22 wherein the

head unit is a hard hat.