The present invention relates to eyeglasses suitable for blind and/or deaf-blind people.

More particularly, the invention relates to eyeglasses provided with sensors allowing to reveal obstacles and to indicate their distance to the user.

As it is well known, systems suitable for blind people for revealing of obstacles have been realised by ultrasounds, but the weak angular definition, along with the parasitic echoes, do not allow to reach suitable ranges, and furthermore the information about the distance generally is given by intermittent sound signals disturbing the essential information source for blind people. More or less recently, very much sophisticated systems have been realised, aiming to provide to the blind a rather precise tridimensionai image of the surrounding environment. They employ optic profilometers comprising a visible laser and provide information up to many meters, with a high angular definition, either about the distance and the emission of the stricken body. However, the amount of information involves vibrating interfaces rather bulky, or sound interfaces having different timbres and tones and mixtures of the same heavily occupying the hearing of the blind. Also the sizes of the electronics is not negligible, being made heavier under the senso al point of view due to the needing of preserving the retina of people occasionally in front of the system with respect to damages. Further, the visible ray does not allow to the blind to unobserved, giving him an unpleasant psychological condition.

IN this context, it was lacking a intermediate system which, without aiming to give information precise with a centimetre tolerance, can give to the blind the necessary information relevant to the environment close to him and that without employing lights and sounds or bulky appendixes, does not put the blind at the centre of the public attention. Further, there was the need of a system provided with a simple interface which do not require too much attention and concentration to interpret the data.

It is also known that blind people mainly need: a) to know the configuration of the obstacles that could prevent its movement freedom within some meters;

b) a system which does not create psychological problems during its use; c) not to create problems to people approaching the blind; d) an easy usable system. In this context it is included the solution suggested according to the present invention.

The finding has the aim of allowing to individuate eventual obstacles in front of the blind people, from the ground level to the view line of the same blind, within 6 - 7 meters, and to give the distance and the direction.

At the same time, the solution suggested according to the present invention is light so as to be possible to house the same within an eyeglasses frame to allow to the blind, by little rotations of the head, to create a tridimensionai approximate image of the surrounding environment.

In fact, the finding is substantially comprised of a group of infrared emitters focalized on selected directions, for example coming out from a lens of the eyeglasses, and of an analogous group of suitable sensors, preferably provided on the other lens, or even in the same lens, revealing the echo of the return radiation from eventual obstacles. The distance of the obstacle is electronically obtained by the triangulation of the emission line, of the echo line and of the emitter - sensor distance.

The information obtained by the various directions can be parallel transmitted to the blind person by tactile vibrators, or they can be transmitted sequentially (one direction after another direction according to a cyclic mode) by an auditory way. The vibrating or audio frequency is connected with the distance of the obstacle.

The technical solution suggested according to the present invention, and that will be described in greater detail in the following, are such to allow the realisation of the finding within a pair of normal eyeglasses (dark sunglasses). The problem mentioned at point b) in this way overcome. It is easily overcome also point c) since the finding utilises as emitters LED in the close infrared field. It is also used a series of systems of the kind employed in the autofocus cameras, which employing a suitable optic individuate a series of survey directions on a vertical plane in front of the blind person and passing through the same blind person. In this way the obstacles in front of the person are individuated

and the distances are determined employing a very light system. Furthermore, the control, detection and data transmission electronic is small and by an hybrid integration it can be housed within the side rods of the eyeglasses, if said rods are of the high kind. The data communication system, preferably of the tactile vibration kind (necessary for the deaf - blind people and not limiting for those not deaf), is housed within the ends of the same rods.

Therefore specific object of the present invention are eyeglasses suitable for blind and/or deaf - blind people comprising at least one infrared ray emitter, connected to a first optical system, to lighten eventual obstacles according to pre-established directions, at least one reflected infrared ray receiver, connected to a second optical system, an electronic providing a signal function of the distance from the obstacle, and a tactile and/or sound vibrating interface providing to the blind people an indication about the distance of the obstacles.

Particularly, according to the invention, said at least one infrared ray emitter is of the LED of laser diode kind emitting within the close infrared field, so as not to be dangerous for eventual observer which are close to the device. Preferably, according to the invention, between one and three emitters and between one and three receivers are provided, still more preferably two emitters and two receivers.

Further, said emitters and said receivers can be provided on different lenses or on the same lens. Always according to the invention, it can be provided a sole first optical emission system for all the emitters, or it can be provided one optical system for each emitter.

Still according to the invention, it can be provided a sole second optical receiving system for all the receiver, or it can be provided one optical system for each receiver.

Particularly, said detectors can be of the PSD kind or CCD kind bars, sensitive to the infrared emitted by the emitters.

Furthermore, according to the invention, said electronic controls the emitters, detects the echo signals, generates signals proportional to the distances of the obstacles, associates to the same signals corresponding vibrations transmitted to the tactile interface, or

corresponding frequencies codified for each sensor, sequentially applied to an earphone.

Further, said electronic can be integral and housed within said eyeglasses, or within one lens, or discrete and remote and connected to the eyeglasses by a wire directly or by a connector device.

Finally, according to the invention, the eyglasses lenses can be realised in such a way to let the infrared passing and to strongly reduce the visible light, so that from the outer the components (emitters, sensors, mirrors, ecc.) housed inside cannot be observed. The present invention will be now described, for illustrative but not limitative purposes, according to its preferred embodiments, with particular reference to the figures of the enclosed drawings, wherein: figure 1 shows one person wearing eyeglasses according to the invention; figure 2 is a top view of the head of the person wearing the eyeglasses according to the invention; figure 3 is a front view of the head of a person wearing the eyeglasses according to the invention; and figure 4 is a perspective view of eyeglasses according to the invention.

In figure 1 it is represented the solution of the eyeglasses having three directions, which is deemed to be a good compromise between the information for the blind people and the encumber of the electronic in case the aim is to realise a solution completely housed within the eyeglasses frame.

In figures 2 and 3 the position of the emitters 1 , of the detectors 4 and of the optical systems 2, 3 are schematically shown from the top and frontal, respectively.

In figure 4 a solution for the positioning of the vibrators is shown.

Referring in particular to figure 2, the operation of the finding is disclosed evidencing the preferred choices, made during the realisation of the prototype but that are not limitative of the scope of the application.

One sensor 4 corresponds to each emitter 1, while the two optical systems 2 and 3 are common to the various emitters and sensors. The position of the emitter 1 / detector 4 with respect to the corresponding optical system defines the direction.

The emitters 1 are infrared LEDs, the spectrum of emission which is connected to the spectral response of the detectors 4. Their directivity is enough pronounced so as to allow to exploit at best the focal opening of the next optical system: in the prototype LED having a peak wavelength of 890 nm, radiant flux of 15 mW and directivity of 50% at + or - 40° have been used.

An infrared radiation pulse is generated by the emitter 1 and sent toward the obstacle by the optical system 2. For size reasons, the optical system has been realised by a mirror and an optic having a .5 focal.

The part of radiation reflected by the obstacle is collected by an optical system 3 and sent to the detector 4. PSD detectors have been used, said detectors having an output determined by the position of the image on their sensitive area. The spectral response has the peak at 920 nm, but is wide almost twice the emission spectrum of the used LED, so that the fitting between source and detector is very good.

An integrated circuit, e.g. the one manufactured by HAMAMATSU, H2476, executes the different needed functions: it memorises the value of the output from PSD immediately before the emission of the LED pulse, subtracts the memorised value from the value measured during the pulse in such a way not to be influenced by the background, and finally amplifies the signal. Further, it creates, among other things, an analogic signal proportional to the position of the image on the sensitive area of the PSD, directly performing the measure of the triangulation among emitter, obstacle and sensor. The minimum cycle between two following measures is 1.5 ms.

The analogic signal, suitably modified, controls the frequency of a not stable multivibrator directly controlling the vibrator 7. In case an auditory transduction is chosen, the analogic signal controls a VCO followed by a BUFFER operating the earphone.

In the prototype version, not having been already done the necessary integration for the electronic part, in order to house it within the lateral rods, the same electronics remote and is connected to the eyeglasses by the wire 6. This solution can be taken into consideration for cheaper products.

By the above choices, obstacles at a distance of 6 meters can be well individuated and distinguished with respect to obstacles at 5 meters of distance.

Lenses 5 are treated: upon them an optic "coating" is laid, so that they are transparent only for infrared rays. From outside it is not possible to see the devices housed within the eyeglasses. The same kind of effect can be obtained employing a suitable plastic material for lenses.

In case the solution employing a remote electronic is realised, it is advisable that a connecting device readily usable is interposed between the eyeglasses and the electronic in order to much more easily separate the two units.

The present invention has been described for illustrative but not limitative purposes, according to its preferred embodiments, but it is to be understood that modifications and/or changes can be introduced by those skilled in the art without departing from the relevant scope as defined in the enclosed claims.