Hands-free illumination system controlled by the mouth

The present invention relates to a hands-free lighting system, and more particularly to a lighting system to be controlled by mouth.

The control lighting systems by mouth are used in aeronautics, where they are fixed on the helmets of pilots or cabin crew. During night flights, it allows for example the lighting of the cockpit, map reading, viewing poorly lit instruments or interventions in dark areas like the bunkers of the aircraft.

For such lighting systems are practical for use, a simple movement of the mouth, especially a movement of the lower lip, should enable effortless to commission the lighting.

For this reason, conventional lighting systems controlled by the mouth are generally equipped with momentary control switches are well known to those skilled in the art under the name of "microswitches", which have the advantage of being switched with a low effort. Recall that a momentary control switch includes a contact holder blade mounted under constraint in a first shaped position, the blade being pivotable into a second position under the effect of a thrust applied through a body command. Thus, the force exerted by the user with its lip on the control member merely serves to tilt the blade, the electrical contact between the inner contact pads of the switch being ensured by the elasticity of the blade . As a further advantage, the tilting of the blade produces a characteristic click accompanied by a tactile effect due to relaxation of the elastic strain. Finally, there are commercially operated momentary switch models with levers further reducing the control effort, which can then fall below 10 grams.

In return, the momentary operated switches have the drawback of not allowing the locking of the lighting, the blade contact carrier returning to its initial position when the control member is released. The user is thus forced to maintain its support lip on the switch during periods of use.

For this reason, other conventional lighting control by mouth are equipped with lock switches or switches called "pushed-pushed" (push switches). Although allowing to lock lighting, locking switches have the disadvantage of not being ergonomic. Indeed, the member for controlling a locking switch, usually a push button, has a depressed position and a released position so that the walking distance to the lip to achieve the push button is not the same for locking or unlocking the lighting. This disadvantage is particularly sensitive for use when the user tries to set the distance between his mouth and the push button so that the latter is far enough away not to prevent him from speaking while being close enough to not require excessive stretching of the lip at the time of the order. Moreover, another drawback of interlock switches is requiring significant control effort, which in the best case is about 100 grams. This is explained by the fact that the electrical contact between the inner contact pads of a latch switch is achieved by springs, so that the force to be exerted on the push button to bring it into the depressed position must overcoming the resistance of the springs. To overcome this second drawback, it could equip a locking switch a lever, as is done with instant control switches, but would worsen the aforementioned ergonomic drawback since the lever amplify the differences between the depressed position and the position released.

Thus, the general objective of the present invention to provide a lighting system controlled by the mouth that can be locked while being ergonomic.

More particularly, the present invention provides the following advantages:<ul><li>a low force on the control member of the lighting, for example of the order of 10 to 60 grams,</li><li>maintains the lighting when the user releases the control member,</li><li>a constant distance between the control member and the lip, that the lighting is switched on or not.</li></ul>

These objectives are achieved by a lighting system to be controlled by mouth, including lighting means and means switches to lock or unlock the lighting, in which the switch means comprise a low momentary switch control efforts electrically coupled to a bistable electronic switch, the lighting being locked by the bistable electronic switch, the bistable electronic switch being controlled by the momentary control switch.

The bistable electronic switch can be realized simply, for example by means of a D flip-flop

According to one embodiment, the bistable electronic switch controls the lighting means via at least one transistor.

According to an embodiment, the momentary control switch and the lighting means are arranged in a first lighting box and the bistable electronic switch arranged in a second housing.

According to one embodiment, the light housing is mounted at the end of a flexible rod. The other end of the flexible rod may comprise fastening means arranged to be slidably mounted on a microphone arm.

According to one embodiment, the system comprises lighting means in the visible, lighting means in the infrared and a general switch with three positions to choose between a lighting position in the visible, a position light in the infrared, and a position of decommissioning lighting.

These features, advantages and others of the present invention will be discussed in more detail in the following description of a particular embodiment of a lighting system according to the invention for an aircraft pilot's helmet, in relation with the accompanying drawings:<ul><li>1 shows an aircraft steering headset with a microphone and a lighting system according to the invention,</li><li>Figure 2 shows in more detail the microphone and the lighting system of Figure 1,</li><li>3 shows a profile view of a portion an illumination housing according to the invention and its control member, and </li><li>Figure 4 is the circuit diagram of a lighting system according to the invention.</li></ul>

1 shows a steering headset aircraft 1 equipped with a microphone 2 and an illumination system 3 according to the present invention. 2 shows in more detail the microphone 2 and the illumination system 3. The illumination system 3 according to the invention comprises a light housing 30 equipped in a conventional manner by two green LEDs 31 and an infrared LED diode 32 flights scheduled for the night vision goggles. The light housing 30 is mounted at the end of a flexible rod 33 whose other end is fixed to the distal portion 21 of an arm 22 carrying the microphone 2. Here, the distal portion 21 of the microphone arm comprises two parallel bars 21-1, 21-2 on which is slidably mounted a fixing piece 34 of the flexible shaft 33, the position of the fastening part 34 can be locked by a clamping screw. At the end of the flexible shaft 33, the light housing 30 has a substantially elongated shape curved so as to match the rounded shape of the microphone 2.

As seen in Figure 3, the lighting unit 30 includes a switch 35 of the momentary control Low-effort type, the control member 36 is a lever acting on a 36-1 36-2 push. Conventionally, the 36-1 lever takes the form of a metal or plastic strip facing the mouth of the driver. Thanks to the flexible shaft 33, to the slide fastener 34 and to the particular shape of the light housing 30, the lamp housing 30 can be disposed closer to the microphone 2 so that the lever 36-1 is easily accessible. The switch 35 is for example a microswitch of the series "SM Series Subminiature micro switch" sold by the company ZIPPY, switchable with a force of about 30 grams.

According to the invention, the switch 35 is combined with a bistable electronic switch, an example embodiment will be described below in connection with Figure 4. The function of the bistable switch is to memorize, that is to said lock, the status of the lighting system after the switch 35 has been actuated. So when the user pushes the lever 36-1 with its lip (or language), the lighting is switched on and the lever can be released. To turn the light housing 30, the user must activate again the lever 36-1.

With such a combination of mechanical interlocking function and an electronic locking function, the user enjoys the benefits of the momentary control switch, already exposed to the preamble (low force, distance between the lever 36- 1 and the mouth of the user constant, snap effect, tactile effect), while benefiting, virtually, the benefits of interlock switches.

Here, the electronic function is given in a second housing 37 secured to the proximal portion 24 of the arm 21 of the microphone, the casing 37 being connected by an electric cable 38 to the light housing 30. The second housing 37 is further equipped with a main switch 39 with three positions to choose between a lighting position in the visible (green LED), an infrared illumination position (red LED) and a position of decommissioning in which an action on the lever 36 -1 does not trigger the lighting.

Figure 4 shows the electric diagram of the illumination system 3 of the invention. The bistable electronic circuit is here achieved by means of a referenced D flip-flop 40, whose inverted output / Q is fed back to the control input D. The clock CLK input of the D flip-flop is driven by the output Wall Switch momentary control 35, whose input receives a system supply voltage Vcc. Thus, when the user performs with his lip pressure on the lever 36-1, the CLK input receives a voltage pulse that is changing the state of the D flip-flop, the output Q alternately passing the value 1 (Vcc ) or 0 (ground) according to previous state of the latch. For shaping the voltage pulse, the CLK input is connected to ground via a resistor "pull-down" (or resistance to "pull down") R1 of high value in parallel with a capacitor C1, and voltage Vcc by a resistor "takes up" (or resistance to "pull up") R2 also high value. The resistors R1 and R2 are for example 10 kOhms and 100KΩ, respectively

The Q output of the D flip-flop 39-1 is applied to an input terminal of the power switch 39 with three positions. The switch 39 has three output terminals 39-2, 39-3, 39-4 respectively corresponding to the above three possibilities: lighting in the visible (green), off lighting, lighting in the infrared. The terminal 39-2 drives the base of a transistor 41 for controlling the green LED 31, via a pull-down resistance R3 of high value and a resistance R4 buffer. The terminal 39-3 is not connected. The terminal 39-4 drives the base of a transistor 42 of the infrared diode control 32, via a pull-down resistor R5 high value and a resistance R6 buffer. The green LED 31 and the infrared diode 32 receive their cathodes on the supply voltage Vcc and their anodes are connected through buffer resistors R7, R8, R9 to the collectors of transistors 41, 42 respectively, whose emitters are connected to ground. For example, when the main switch 39 is in position light in the visible and the user momentarily activates the switch lever 36-1 Low effort 35, the Q output of the D passes rocker 1 and makes the transistor 41 passing, the green LEDs 31 being well fed. To turn off the diodes 31, the user must activate again the switch 35 so that the output Q goes to 0.

As already mentioned, these various electronic components are arranged in the housing 37 of Figure 2, with the exception of the switch 35 and diodes 31, 32 which are secured to the lamp housing 30. In addition the housing 37 may contain batteries which provide the voltage supply Vcc.

It goes without saying that the present invention is not limited to the embodiment of a lighting system for an aircraft pilot's helmet. Due to the ergonomic benefits of the system according to the invention, other applications can be envisaged, including the realization of lighting systems for the disabled, achieving hands-free infrared remote control systems used by persons with disabilities, in the field of surgery for the commissioning of some equipment (respiratory, laser generators, ...) during an operation in the industrial field, etc. Also, the present invention can be applied to the production of sighting systems, the previously described diode being replaced by one or more laser diodes. Thus, in the present application, the word "light" should be understood as generally emitting a light beam, this light beam is for illuminating objects, order equipment, or designate a target .