Eyeglasses with a photosensitive sensor arranged on temples

Abstract

The present invention relates to an eyeglass device (1) comprising an electronic frame (3) comprising a front frame element (7) arranged to at least partially house an electrochromic lens (5), a temple (11) connected to the front frame element, a photosensitive sensor (15) arranged on the temple to measure data relating to light reflected from a part of a wearer's face when the electronic frame is worn by said wearer, and a control circuit (17) configured to control the electrochromic lens depending on the measured data.

Description

[Technical field]

[0001] The present invention relates to the field of eyewear equipment, more particularly eyewear equipment including electronic frames adapted for electrochromic lenses. [Background technology]

[0002] Ophthalmic lenses help correct vision defects and refractive errors, also called refractive errors, such as myopia, hyperopia, astigmatism, and presbyopia. Ophthalmic lenses are manufactured based on the wearer's ophthalmic prescription, which includes various information such as sphere, astigmatism, prism, and add power.

[0003] However, even though ophthalmic lenses are manufactured to be adjusted to the different situations of the wearer, and especially progressive lenses that make it possible to correct both near and far vision, there is a demand for smart glasses with greater adaptability.

[0004] To this end, the ophthalmic lens industry has developed electro-active lenses, i.e. lenses whose certain characteristics can be electronically modulated. These modifications can be controlled by the wearer or by a medical professional, typically an ophthalmologist. These modifications can also be automatic, in which case the electro-active lens may include sensors configured to measure certain parameters of the environment, such as the intensity of light or the wavelength of light.

[0005] In particular, among electroactive lenses, electrochromic lenses are capable of changing light transmission value and color.

[0006] Typically, an electrochromic lens is an optical system comprising a wafer manufactured according to prescription data and an electrochromic cell that allows the electrochromic lens thus formed to be adapted to the brightness, i.e. the light intensity. Part of the prescription can also be provided by the electrochromic cell.

[0007] An electrochromic cell is typically a structure that includes two planar or afocal transparent outer layers, e.g., two surfaces made of organic or mineral materials, on whose inner surfaces a transparent conductive coating is deposited. An electrochromic composition fills the cavity formed between the two conductive coatings. Thus, by applying an electric field to the conductive coating, the light transmission value of the cell can be changed.

[0008] However, electronic frames fitted with electrochromic lenses present problems.

[0009] In some electronic frames, sensors are placed on the electronic frame to measure ambient light. These sensors are directed to the external environment and are located on the front side of the electrochromic lens to measure incident light, or on the back side to measure reflected light. However, ambient light can be quite different from the light that the wearer's eyes actually receive, and therefore has no valid relationship to the modulation of the light transmission of the electrochromic lens. For example, when sunlight is shining from behind the wearer and the wearer is looking at the screen of an electronic device such as a computer, the measurements that the sensor collects will be affected by the sunlight, and therefore the light transmission of the electrochromic lens will not be adapted to the brightness of the screen.

[0010] In addition, the sensor is generally placed on a ring of the electronic frame or on a bridge between the rings. As a result, the controller of the electrochromic lens is located on one of the temples of the electronic frame, so that the electrical components connecting the sensor and the controller necessarily pass through the hinge of the electronic frame. However, making the electrical components pass through the hinge is complicated and technically difficult. The presence of the sensor on the front side also creates aesthetic constraints. Summary of the Invention [Problem to be solved by the invention]

[0011] The present invention seeks to improve this situation. [Means for solving the problem]

[0012] The present invention relates to an eyeglass device including an electronic frame. - a front frame element arranged to at least partially house the electrochromic lens; - a temple connected to the front frame element; - a light-sensitive sensor arranged on the temple to measure data relating to light reflected from parts of the wearer's face when the electronic frame is worn by the wearer; - a control circuit configured to control the electrochromic lens in response to the measured data; Includes.

[0013] According to an embodiment, the eyewear equipment further comprises an optical system arranged to deflect light reflected from parts of the wearer's face towards the light sensitive sensor when the electronic frame is worn by the wearer.

[0014] The optical system includes, for example, a deflector disposed on the temple.

[0015] According to certain embodiments, the eyewear device further includes an electrochromic lens at least partially housed in the front frame element, and the optical system includes a deflector disposed on the electrochromic lens.

[0016] Advantageously, the deflector disposed on the electrochromic lens includes a coating covering at least a portion of the electrochromic lens.

[0017] According to one embodiment, the photosensitive sensor is housed in a blind hole in the temple, which is directed towards a portion of the wearer's face when the electronic frame is worn by the wearer.

[0018] According to one embodiment, the light-sensitive sensor is positioned to measure data relating to light reflected from the wearer's eye when the electronic frame is worn by the wearer.

[0019] Advantageously, the light-sensitive sensor is adapted to measure data relating to light in the ultraviolet range or in the near infrared range.

[0020] More precisely, the photosensitive sensor is adapted to measure data relating to light having a wavelength between 900 nm and 1100 nm, for example.

[0021] In fact, the reflection coefficient of the eye reaches higher values ​​in the ultraviolet and near infrared range than in the visible range.

[0022] According to an embodiment, the light-sensitive sensor is positioned to measure data relating to light reflected from an area of ​​the wearer's skin when the electronic frame is worn by the wearer.

[0023] Advantageously, the photosensitive sensor is adapted to measure data relating to light in the visible range or in the near infrared range.

[0024] In fact, the reflectance coefficient of the skin reaches higher values ​​in the visible and near infrared range than in the ultraviolet range.

[0025] In certain embodiments, the photosensitive sensor is positioned to measure data relating to light reflected from the wearer's eye and from the skin area, the photosensitive sensor being adapted to measure data relating to light having a wavelength in the near infrared range, preferably between 900 nm and 1100 nm.

[0026] According to one embodiment, the control circuit is disposed on the temple and is electrically connected to the light sensitive sensor by an electrical component that extends across only a portion of the temple.

[0027] In other words, the electrical components connecting the light-sensitive sensor and the control circuitry do not pass through the hinge connecting the temple 11 to the end of the front frame element. The structure of the electronic frame is therefore less complex and easier to manufacture.

[0028] According to one embodiment, the photosensitive sensor is configured to measure data including the intensity, illuminance, wavelength, or polarization of the reflected light, and the control circuit is configured to control the electrochromic lens in response to the data.

[0029] For example, the control circuitry may be configured to control at least one of the following characteristics of the electrochromic lens: - Light transmission depending on the intensity of the reflected light or the illuminance; - filtering in one or more spectral bands according to the wavelength of the reflected light; and - The uniformity of intensity or illuminance over the range of degrees of polarization of the reflected light.

[0030] The control circuit may be a closed loop control circuit having one or more of the following inputs: - To control light transmission: The intensity or illuminance set point to be approached for reflected light; The minimum intensity or illuminance that must be achieved for reflected light, or The maximum intensity or illuminance of reflected light that should not be exceeded; - for filtering one or more spectral bands: The wavelength range to be filtered for reflected light, - to vary the intensity or illuminance uniformity over a range of degrees of polarization: The intensity or illuminance in relation to the degree of polarization that should be approached for the reflected light.

[0031] According to one embodiment, the closed loop control circuit is a proportional-integral-derivative controller, also called a PID controller.

[0032] Other characteristics and advantages of the invention will become apparent from the following description, given for illustrative and non-limiting purposes, with reference to the accompanying drawings, in which: [Brief description of the drawings]

[0033] [Figure 1] 1 illustrates, in perspective view, an eyewear device according to an embodiment of the present invention. [Diagram 2] 2 shows a top view of eyewear equipment according to another embodiment of the present invention. [Diagram 3] 2 shows a partial view of eyewear equipment according to another embodiment of the present invention. [Figure 4] 1 shows the variation of the eye's reflection coefficient as a function of wavelength. [Diagram 5] 1 shows the variation of the reflectance coefficient of skin as a function of wavelength. [Figure 6] 2 illustrates a schematic representation of a control circuit configured to control an electrochromic lens of an eyewear device depending on data measured by a photosensitive sensor. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0034] FIG. 1 shows an eyewear device 1 .

[0035] The eyewear equipment 1 is adapted to improve the visual comfort of the individual wearing the eyewear equipment 1. This visual comfort relates in particular to the brightness and illuminance obtained from the environment and from the ambient light.

[0036] The eyewear device 1 may also be configured to correct a visual defect or refractive error, also called refractive error, of the wearer, for example if the wearer is myopic, hyperopic, astigmatism or presbyopic.

[0037] As shown in FIG. 1, the eyewear device 1 includes an electronic frame 3 and at least one electrochromic lens 5 .

[0038] The electrochromic lens 3 is adapted to be worn by a wearer. For example, if the eyewear equipment 1 is adapted to correct a visual impairment, the electronic frame 3 is adapted to be worn by a wearer to whom the prescription data used to manufacture the eyewear equipment 1 pertains. Indeed, in such a case, the electrochromic lens 5 is designed and manufactured on the basis of prescription data characterizing the visual impairment of that wearer.

[0039] In a classical manner, similar to non-electrical frames, the electronic frame 3 comprises at least one front frame element 7, at least one bridge 9, at least one temple 11, and in some embodiments at least one hinge 13.

[0040] The front frame element 7 is configured to at least partially store the lens 5, e.g. an ophthalmic lens. Typically, the front frame element 7 includes a holder configured to store and hold an upper portion of the lens 5 and a cradle configured to at least partially surround a lower portion of the lens 5.

[0041] 1, the electronics frame 3 comprises two front frame elements 7, each at least partially housing a lens 5. The front frame elements are also referred to in the literature as "rims".

[0042] The front frame elements 7 are interconnected by bridges 9 .

[0043] Similarly, the electronic frame 3 shown in FIG.

[0044] Each temple 11 is connected to an end of the front frame element 7 by a hinge 13. More precisely, one temple 11 is connected to an end of the front frame element 7 and the other temple 11 is connected to an end of the front frame element 7 that is the other limb.

[0045] The temples 11 are configured to rest on the wearer's ears to ensure stability of the eyeglass device 1 when it is worn by the wearer. The hinges 13 allow the temples 11 to be opened when the wearer wants to wear the eyeglass device 1 and to be folded when the wearer wants to take it off.

[0046] In the context of the present invention, the frame 3 is an electronic frame and the lens 5 is an electrochromic lens.

[0047] Electrochromic lenses 5 are electroactive lenses, i.e. lenses that have certain properties that can be electronically modulated. In particular, the light transmission value and / or color of electrochromic lenses 5 can be electronically modulated. For example, electrochromic lenses 5 can be controlled by the wearer or by a medical professional, typically an ophthalmologist. Alternatively, the light transmission value and color can also be modulated automatically.

[0048] The electrochromic lens 5 comprises an electrochromic cell. An electrochromic cell typically has a structure comprising two flat or afocal transparent outer layers, e.g. two surfaces made of organic or mineral materials, on whose inner surface a transparent conductive coating is deposited. The cavity formed between the two conductive coatings is filled with an electrochromic composition. Therefore, the light transmission value of the cell can be changed by applying an electric field between the conductive coatings.

[0049] It should be noted that an electrochromic lens may also include a wafer that is designed and manufactured to meet the wearer's ophthalmic prescription. The wafer is preferably made of a transparent material and adapted to impart ophthalmic properties to the electrochromic lens 5.

[0050] The ophthalmic prescription of a wearer is a set of data specified by a medical professional, for example an ophthalmologist, also called prescription data. The prescription data includes various information about the wearer, such as sphere, astigmatism, prism, and, if relevant, add power. Such prescription data is necessary to design and manufacture the ophthalmic lenses that will be worn by the wearer to correct a visual defect or refractive error, also called refractive error. For example, if the wearer is presbyopic, the prescription data includes the add power to manufacture a progressive ophthalmic lens adjusted to this refractive error.

[0051] In such a case, the electrochromic lens 5 is an electrochromic ophthalmic lens.

[0052] In the present invention, the light transmission value of the electrochromic lens 5 can be automatically modulated. To this end, the electronic frame 3 includes at least one photosensitive sensor 15 and a control circuit 17, as shown in FIG.

[0053] The light sensor 15 is configured to measure data relating to a light beam. The data measured by the light sensor 15 may include, for example, the intensity, illuminance, wavelength, or degree of polarization of the light beam reaching the light sensor 15.

[0054] The light-sensitive sensor 15 may be an illumination sensor or illumination microsensor, such as a photodiode. The light-sensitive sensor 15 therefore measures the illuminance in the form of the luminous flux received per unit surface area (units are lux or W m -2 ) can be measured. As a variant, the photosensitive sensor 15 can also measure other values ​​of the luminous flux, such as intensity, or photometric or photometric luminance. The photosensitive sensor 15 can, for example, measure the luminous flux in the visible and / or ultraviolet range.

[0055] The photosensitive sensor 15 can also be a photo sensor adapted to measure the degree of polarization of light, for example to enable a polarization cutoff function. The photosensitive sensor 15 can also be adapted to measure the visible and / or invisible light spectrum to enable a wavelength selective cutoff function.

[0056] 1, the photosensitive sensor 15 is disposed on the temple 11. Furthermore, the photosensitive sensor 15 is disposed to measure data related to light reflected from a portion of a wearer's face when the electronic frame 3 is worn by the wearer.

[0057] More precisely, the skilled person will now understand that the photosensitive sensor 15 is advantageously arranged to measure data relating to light diffracted by, and therefore transmitted through, the electrochromic lens 5 and subsequently reflected from parts of the wearer's face. Light rays reflected from parts of the wearer's face but not transmitted through the electrochromic lens 5 are therefore stray light, and the photosensitive sensor 15 is arranged so as not to receive such stray light.

[0058] In other words, when the wearer puts on the eyewear device 1, the temples 11 are opened and the electronic frames 3 are stabilized on the wearer's ears. The light-sensitive sensors 15 are arranged on the temples 11, so that the light rays received by the light-sensitive sensors 15 are light rays previously reflected from a part of the wearer's face. This part of the face can be a skin area or an eye.

[0059] Those skilled in the art know that sensors can be placed on the front side of the electrochromic lens 5 to measure data related to the incident light. It is also known that sensors can be placed on the rear side of the electrochromic lens 5 to measure the intensity of light transmitted through or reflected by the electrochromic lens 5.

[0060] However, according to the present invention, a light-sensitive sensor 15 is arranged on the temple 11 to measure data relating to light reflected from parts of the wearer's face when the electronic frame 3 is worn by the wearer.

[0061] In addition, the photosensitive sensor 15 is configured to transmit the measured data to the control circuit 17 .

[0062] 1, the electronic frame 3 includes only one light-sensitive sensor 15. However, the electronic frame 3 may include several light-sensitive sensors, for example light-sensitive sensors 15 arranged on both temples 11. In such a case, the light-sensitive sensors may be the same or different.

[0063] The control circuit 17 is configured to electronically control the electrochromic lens 5 and modulate certain properties thereof based on the measurement data received from the photosensitive sensor 15. In particular, the control circuit 17 is configured to modulate the light transmission value of the electrochromic lens 5. The control circuit 17 thus makes it possible to adapt the eyewear device 1 to the light beam.

[0064] 1, the control circuit 17 is disposed on the temple 11. As a result, the control circuit 17 can be electrically connected to the light sensor 15 by an electrical component (not shown) that extends over only a portion of the temple 11. In other words, such an electrical component can directly connect the light sensor 15 and the control circuit 17 without passing through the hinge 13.

[0065] The function of the control circuit 17 is explained in more detail below with reference to FIG.

[0066] As mentioned above, the light-sensitive sensor 15 is disposed on the temple 11 to measure data relating to light reflected from parts of the wearer's face when the electronic frame 3 is worn by the wearer.

[0067] In order to conduct the light reflected from parts of the wearer's face to the photosensitive sensor 15, the invention proposes several embodiments. According to a first embodiment, shown in figures 1 and 2, the eyewear equipment 1 comprises optics arranged to deflect the light reflected from parts of the wearer's face when the electronic frame 3 is worn by said wearer towards the photosensitive sensor 15. According to a second embodiment, shown in figure 3, such optics is not necessary and the positioning of the photosensitive sensor 15 is adapted accordingly. EXAMPLES

[0068] First embodiment According to a first embodiment, the eyewear equipment 1 comprises an optical system arranged to deflect light reflected from parts of the wearer's face when the electronic frame 3 is worn by the wearer towards the light sensitive sensor 15.

[0069] For example, as shown in FIG. 1, the eyewear equipment 1 further includes a deflector 19 .

[0070] The deflector 19 is disposed on the temple 11 so as to deflect light reflected from parts of the wearer's face towards the light sensitive sensor 15 when the electronic frame 3 is worn by the wearer.

[0071] The deflector 19 can for example deflect light only from certain directions, in which case the deflector is a holographic deflector, a prism or a diffraction grating.

[0072] The deflector 19 may, for example, include one or more reflectors arranged to reflect light reflected from parts of the wearer's face when the electronic frame 3 is worn by the wearer towards the light sensitive sensor 15.

[0073] The enlarged view of Fig. 1 shows a possible arrangement of the deflector 19 with respect to the photosensitive sensor 15. The photosensitive sensor 15 and the deflector 19 are housed in a cavity in the temple 11. The deflector 19 has a deflection surface that is inclined compared to the outer surface of the photosensitive sensor 15. Thus, light rays entering from parts of the wearer's face are deflected by the inclined surface of the deflector 19 towards the photosensitive sensor 15.

[0074] Advantageously, the cavity protects the light sensor 15 from parasitic reflections and prevents additional light rays from being reflected towards the light sensor 15. Likewise, some parts of the deflector 19 are hidden to avoid deflections that do not come from the wearer. In other words, the cavity has a specific shape configured to avoid reflected light itself and to prevent light rays that do not come from the wearer's eye from being deflected towards the light sensor 15.

[0075] FIG. 2 also shows an embodiment in which the eyewear equipment 1 includes an optical system.

[0076] Indeed, as shown in FIG. 2, the eyewear equipment 1 further comprises a deflector 21 .

[0077] 1, the deflector 21 is not placed on the temple 11 of the electronic frame 3 but on the electrochromic lens 5. If the electrochromic cell is on the front surface of the electrochromic lens 5, the deflector 21 is preferably on a wafer on the rear surface of the electrochromic lens 5.

[0078] Like deflector 19 in the embodiment of FIG. 1, deflector 21 may include one or more reflectors.

[0079] The deflector 21 disposed on the electrochromic lens 5 may, for example, comprise a coating that covers at least a portion of the electrochromic lens 5. Such a coating may cover the entire electrochromic lens 5 or only a portion thereof.

[0080] The coating must have a high enough coefficient of reflection to reflect the light reflected from the wearer's face, but the coefficient of reflection should not be such that all of the incident radiation transmitted by the electrochromic lens 5 is filtered.

[0081] The deflector 21 is, for example, a mirror. Such a mirror can be obtained, for example, by a coating having a high reflectance in the near infrared range. In fact, in the near infrared range, disturbances to the wearer through the electrochromic lens 5 are avoided. In such a case, the coating has, for example, a high transmittance between 400 nm and 800 nm and a high reflectance in the range above 880 nm.

[0082] More precisely, the deflector 21 is a holographic mirror used in the near infrared or visible range. Advantageously, the holographic mirror has a narrow bandwidth, perhaps less than 10 nm, which allows most parts of the spectrum to pass through the electrochromic lens 5 and preserve the natural field of vision for the wearer. The holographic mirror can be a flat or curved off-axis mirror. A curved off-axis mirror can include a focusing action that is used to increase the light collection efficiency by the photosensitive sensor 15. A curved off-axis mirror allows a higher angular acceptance on the side of the wearer's face.

[0083] In addition, Fig. 2 shows a top view of the eyewear device 1 when stabilized on the wearer's ear. It should be noted that certain parts of the wearer's face are shown, namely the left eye LE, the right eye RE and the skin area SA.

[0084] As shown in this figure, a light ray L1 is transmitted by the electrochromic lens 5 and reaches a skin area SA on the face of the wearer. This light ray L1 is reflected by the skin area SA as a light ray L2. More precisely, this is a diffuse reflection from the skin area SA. The light ray L2 then reaches a deflector 21 arranged on the electrochromic lens 5. The light ray L2 is then deflected as a light ray L3. The deflector 21 has a deflection surface configured such that the light ray L3 obtained by deflection of the light ray L2 is deflected towards a photosensitive sensor 15 arranged on the temple 11. The configuration of the deflector 21 corresponds, for example, to a particular orientation of its deflection surface.

[0085] In this example, the photosensitive sensor 15 receives light reflected from the skin area SA of the wearer's eye. However, instead of or in addition to light reflected from the skin area SA of the wearer, the photosensitive sensor 15 may also receive light reflected by the left eye LE or right eye RE of the wearer.

[0086] Regarding this first embodiment of the invention, in which the eyewear device 1 includes an optical system, a person skilled in the art will obviously understand that the deflector 19 of Fig. 1 and the deflector 21 of Fig. 2 can be combined together to form a more complex optical system. For example, in such a case, with reference to Fig. 2, the light ray L3 is deflected by the deflector 21 arranged on the electrochromic lens 5 towards the deflector 19, which deflects this light ray L3 towards the photosensitive sensor 15.

[0087] Second embodiment According to the second embodiment, no optical system is required and the positioning of the photosensitive sensor 15 is adjusted accordingly.

[0088] 3, the photosensitive sensor 15 is housed in a blind hole 23 in the temple 11. The blind hole 23 is directed toward a portion of the wearer's face when the electronic frame 3 is worn by the wearer.

[0089] A blind hole 23 is formed in the temple 11 of the electronic frame 3. The blind hole 23 is sized such that it can accommodate the light sensitive sensor 15.

[0090] Advantageously, only the outer face of the photosensitive sensor 15 is exposed to the outside environment. This outer face is directed towards the opening of the blind hole 23 and thus towards the face part of the wearer. Conversely, the remaining faces of the photosensitive sensor 15 are hidden and protected by the electronic frame 3.

[0091] Such a configuration makes it possible to avoid parasitic radiation, i.e. light rays that are not reflected by the wearer's face, here the left eye LE. A diaphragm (not shown here) can be placed at the opening of the blind hole 23 to limit the amount of light received by the photosensitive sensor 15.

[0092] In the example shown in Fig. 3, the light ray L1 is transmitted by the electrochromic lens 5 and reaches the left eye LE of the wearer's face. The light ray L1 is reflected by the left eye LE as a light ray L2. The light ray L2 then reaches the photosensitive sensor 15 through a blind hole 23 with the correct orientation.

[0093] In this example, the photosensitive sensor 15 receives light reflected from the left eye LE of the wearer's face, however, the photosensitive sensor 15 may receive light reflected from the right eye RE or skin area SA instead of or in addition to light reflected from the wearer's left eye LE.

[0094] As mentioned above, in this second embodiment, no optical system is required to conduct the light reflected from parts of the wearer's face to the photosensitive sensor 15. However, the first and second embodiments are not inconsistent and can be combined. In particular, the photosensitive sensor 15 can be housed in a blind hole 23 to receive the light beam at the exit of an optical system, such as that described above in the first embodiment.

[0095] Regarding photosensitive sensors: As already explained, the light-sensitive sensor 15 is arranged on the temple of the electronic frame 3 to measure data related to light reflected from the wearer's face when the electronic frame 3 is worn by the wearer. The part of the wearer's face may be the wearer's eye or skin area.

[0096] More specifically, the light-sensitive sensor 15 is configured to measure data including the intensity, illuminance, wavelength, or polarization of the reflected light.

[0097] However, the reflection coefficient C varies with wavelength. In addition, the variation of the reflection coefficient C with wavelength is not the same for the eye and the skin area.

[0098] FIG. 4 shows the variation of the reflection coefficient C of the eye as a function of wavelength.

[0099] The curve E shown in FIG. 4 makes it possible to identify, for a given wavelength value, the reflection coefficient C of the wearer's eye, whether the left eye LE or the right eye RE.

[0100] The reflection coefficient C appears to reach higher values ​​in the ultraviolet and near infrared range than in the visible range. As known to those skilled in the art, the ultraviolet range corresponds to the wavelength range from 100 nm to 400 nm. The near infrared range corresponds to the wavelength range from 780 nm to 2500 nm.

[0101] As a result, in an embodiment in which the photosensitive sensor 15 is arranged to measure data relating to light reflected from the wearer's eye when the electronic frame is worn by the wearer, the photosensitive sensor 15 is advantageously adapted to measure data relating to light in the ultraviolet range or in the near infrared range. Obviously, the photosensitive sensor 15 may also be adapted to measure data relating to light in the visible range in addition to or instead of the ultraviolet range or the near infrared range.

[0102] In particular, if the selected photosensitive sensor 15 is adapted to measure data relating to light in the ultraviolet range, a silicon carbide (SiC) photodiode is suitable, since its detection range is between 215 nm and 330 nm.

[0103] Furthermore, as shown in Figures 2 and 3, the light ray reflected from a part of the wearer's face, i.e. the skin area SA in Figure 2 and the left eye LE in Figure 3, and then received by the photosensitive sensor 15, generally results from light diffracted and transmitted by the electrochromic lens 5. After diffraction, this light ray is indicated by L1 in Figures 2 and 3. Usually, the electrochromic lens 5 is configured to filter out ultraviolet light. In such a case, therefore, the photosensitive sensor 15 does not receive light rays in the ultraviolet range, so it may be sufficient that the photosensitive sensor 15 is adapted to measure data related to light in the near infrared range.

[0104] Several photosensitive sensors are suitable for the near infrared range. For example, silicon (Si) photodiodes are suitable. The detection range of silicon photodiodes corresponds to the interval from 200 nm to 1200 nm, with low efficiency at the extremes and maximum efficiency from 800 nm to 1000 nm. Above 1100 nm, indium-gallium-arsenide (InGaAs) photodiodes can also be used, which detect wavelengths from 800 nm to 1700 nm.

[0105] 4, the eye's reflection coefficient C reaches a maximum value, i.e. a peak, in the near infrared range between 900 nm and 1100 nm, and therefore the light-sensitive sensor 15 is advantageously adapted to measure data relating to light having a wavelength between 900 nm and 1100 nm.

[0106] FIG. 5 shows the variation of the reflection coefficient C of the skin as a function of wavelength.

[0107] More specifically, FIG. 5 shows two curves depending on the skin coloration.

[0108] Curve DS shows the variation of the reflectance coefficient C for dark skin, and curve FS shows the variation of the reflectance coefficient C for fair skin. In particular, for a given wavelength value, the reflectance coefficient C for fair skin generally appears to be higher than the reflectance coefficient C for dark skin.

[0109] Furthermore, for the ultraviolet range, the reflectance coefficient C of the skin appears to be very low, while the reflectance C of the eye appears to be very high.

[0110] More generally, the curves DS and FS show that in an embodiment in which the photosensitive sensor 15 is arranged to measure data relating to light reflected from the wearer's skin area SA when the electronic frame is worn by the wearer, it is advantageous for the photosensitive sensor 15 to be adapted to measure data relating to light in the visible range or in the near infrared range. Obviously, the photosensitive sensor 15 may also be adapted to measure data relating to light in the ultraviolet range in addition to or instead of the visible range or the near infrared range.

[0111] As known to those skilled in the art, the visible range corresponds to the wavelength range from 400 nm to 780 nm.

[0112] In the field of photosensitive sensors for the visible range, silicon (Si) photodiodes and ambient light sensors (known under the acronym ALS) are particularly suitable. Ambient light sensors are silicon (Si) photodiodes equipped with a photopic filter to simulate human vision.

[0113] Furthermore, as already explained, a photosensitive sensor 15 can be arranged on the temple 11 to measure both data relating to light reflected from the wearer's eye and data relating to light reflected from the wearer's skin area SA.

[0114] For example, in Fig. 2, the light ray L3 results from the reflection of the light ray L1 from the wearer's skin area SA. However, it is also possible that the light ray is reflected from the wearer's right eye RE to a deflector 21 arranged on the electrochromic lens 5 and then deflected again by the deflector 21 to the photosensitive sensor 15. In such a case, the light ray received by the photosensitive sensor 15 is the light ray reflected by the skin area SA and the wearer's right eye RE. Similarly, in the example shown in Fig. 3, the light ray can also be reflected from the wearer's skin area SA and reach the photosensitive sensor 15 through the blind hole 23.

[0115] Consequently, according to an embodiment, the photosensitive sensor 15 is arranged to measure data relating to light reflected from the eye and from a skin area of ​​the wearer. In such a case, the photosensitive sensor 15 is adapted to measure data relating to light in the near infrared range and preferably having a wavelength between 900 nm and 1100 nm.

[0116] Indeed, the near infrared range corresponds to a high reflection coefficient C for both the eyes, as illustrated by curve E in FIG. 4, and for the skin, as illustrated by curves DS and FS in FIG.

[0117] Control circuit The control circuit 17 is configured to control the electrochromic lens 5 depending on the data MSR measured by the photosensitive sensor 15 .

[0118] The electrochromic lens 5 can be seen as an active multi-layer system having one or more features controlled by the control circuit 17 based on the data MSR measured by the photosensitive sensor 15. The electrochromic lens 5 has at least one of the following features: a light transmitting layer, a spectral band filtering layer, and a polarizing layer.

[0119] Advantageously, as shown in Figure 1, the control circuit 17 is located on the temple 11 of the electronic frame 3. Although the control circuit 17 is not shown in Figures 2 and 3, it will be obvious to those skilled in the art that in these embodiments the control circuit 17 can also be located on the temple 11.

[0120] In such a case, as previously discussed, the control circuitry 17 is electrically connected to the light sensitive sensor 15 by electrical components that extend across a portion of the temple 11 and therefore do not pass through the hinge 13 .

[0121] The function of the control circuit 17 is illustrated in FIG.

[0122] In the example shown in Fig. 6, the photosensitive sensor 15 is arranged to measure data MSR relating to light reflected from the wearer's right eye RE when the electronic frame 3 is worn by the wearer. Typically, the measured data MSR includes the intensity, illuminance, wavelength, and polarization of the reflected light.

[0123] The measured data MSR are then transmitted from the photosensitive sensor 15 to a control circuit 17 .

[0124] The control circuit 17 is configured, for example, to control at least one of the above-mentioned features of the electrochromic lens 5: - Light transmission depending on the intensity of the reflected light or the illuminance; - filtering in one or more spectral bands according to the wavelength of the reflected light; and - The uniformity of intensity or illuminance over the range of degrees of polarization of the reflected light.

[0125] Advantageously, the control circuit 17 is a closed loop control circuit. In such an embodiment, the operation of the control circuit 17 is dictated not only by the data MSR measured by the photosensitive sensor 15, but also by one or more inputs. As already explained, the control unit 17 controls one or more characteristics of the electrochromic lens 5.

[0126] The inputs for controlling the light transmission of the electrochromic lens 5 are for example: - the intensity or illuminance set point to be approached for the reflected light; - the minimum intensity or illuminance to be reached for reflected light, or - The maximum intensity or illuminance that should not be exceeded for reflected light.

[0127] The input for filtering one or more spectral bands is, for example, a wavelength range over which the reflected light is to be filtered.

[0128] Finally, for varying the uniformity of intensity or illuminance for a range of degrees of polarization of the reflected light, the input may be, for example, the intensity or illuminance for a certain polarization direction or degree of polarization that the reflected light should approach.

[0129] As already explained, the electronic frame 3 may include several light-sensitive sensors 15. The electronic frame 3 has, for example, one light-sensitive sensor 15 per temple 11. The data MSR measured by several light-sensitive sensors 15 can be compared with each other. The measured values ​​MSR may also be processed to determine the minimum, maximum or average value of the measured values ​​MSR. If each light-sensitive sensor 15 obtains several measured values ​​MSR, for example illuminance or intensity for different polarization degrees, the measured data MSR can be processed to determine the polarization degree at maximum illuminance or intensity, the corresponding excess of illuminance or intensity defined as the difference from that measured illuminance or intensity, and the average illuminance or intensity for all polarization degrees.

[0130] In addition, if the light sensors measure erroneous data, these measurements can be rejected based on the measurements MSR collected by the other light sensors.

[0131] Typically, the closed loop control circuit is a proportional-integral-derivative controller, also called a PID controller.

[0132] 6, the control circuit 17 receives as input data the MSR measured by the photosensitive sensor 15 as well as a target value of intensity or illuminance, also called a set point. The control circuit 17 is then configured to measure the difference between the measured intensity or illuminance and the target intensity or illuminance. In the embodiment described herein, the control circuit 17 is therefore configured to determine proportional, integral and derivative responses to this difference.

[0133] Of course, the PID controller is also suitable for wavelength filtering: the control circuit 17 can receive as input one or more wavelength ranges that have to be filtered by the electrochromic lens 5, for example the ultraviolet range or the infrared range. In such a case, the set point is not necessarily the exact wavelength, but may be a wavelength range that corresponds to the visible range.

[0134] In addition, the set point can relate to the degree of uniformity of the intensity or illuminance for a range of degrees of polarization. The control circuit 17 then calculates, for each degree of polarization, the difference between the intensity or illuminance measured at that range and the average intensity or illuminance. In an embodiment in which the control circuit 17 is a PID controller, proportional, integral and derivative responses to this difference are determined. The calculated difference for a degree of polarization characterizes the uniformity of the intensity or illuminance for a range of degrees of polarization and is compared, for example, to a predefined threshold value.

[0135] The set point can be set by use. In addition, the set point can also be updated automatically by taking into account several parameters such as the sensitivity of the wearer and the ambient light. For example, if the wearer is in a dark environment for a long time and then notices that the surroundings are brighter, the set point can be adjusted automatically without the wearer's intervention. A change in the set point is triggered, for example, when the difference in the light intensity or illuminance measurements from one moment to another is greater than a predefined threshold. The updated set point is therefore calculated based on the previous set point, the detected difference, and the previous illuminance.

[0136] In a PID controller, each of the responses, thus the proportional, integral and derivative responses, is characterized by a coefficient, also referred to in the literature as a gain.

[0137] Additionally, it may be advantageous to use fuzzy logic to configure the operation of the PID controller. In one embodiment, the gain or weighted sum of the control terms, i.e., proportional, integral, and derivative terms, is replaced with a fuzzy logic function. The inputs of the fuzzy logic function are the error, the error variance, and the error sum. Alternatively, the gain or weighted sum of the PID controller is specified using fuzzy logic. Of course, other uses of fuzzy logic are possible.

[0138] Fuzzy logic is particularly suitable when the electrochromic lens 5 has a non-linear behavior. Indeed, fluctuations in light transmission or polarization can occur when the measured values ​​are close to the setpoints, i.e. when the intensity, illuminance or polarization is lower or higher than the target value for short intervals. This situation is uncomfortable for the wearer. It is therefore interesting to improve the functioning of the control circuit 17 by including fuzzy logic or other predictive filters, such as a Kalman filter, in order to smooth the reaction of the electrochromic lens 5.

[0139] The present invention has several advantages.

[0140] Firstly, the measurement of data relating to the light reflected by parts of the wearer's face, such as the eyes and skin areas, makes it possible to have highly relevant data, since these data relate to the light that actually reaches the wearer's face. The measurement sensors are therefore less affected by the ambient light. The control of the electrochromic lens by the control circuit is therefore improved and is better suited to correct the wearer's visual discomfort.

[0141] In addition, locating the photosensitive sensor on the temple allows for easier electrical connection with the control circuitry, and indeed the electronic components electrically connecting the photosensitive sensor and the control circuitry do not pass through the hinge, thereby avoiding problems during manufacturing of the eyewear equipment.

[0142] Finally, the choice of the photosensitive sensor allows different configurations to be used, especially when the light received by the photosensitive sensor is reflected by the skin area or the eye of the wearer: in fact, the respective reflection coefficients of the eye and the skin area are not the same, and the photosensitive sensor must be calibrated for the wavelengths reflected by the selected part of the wearer's face.

Claims

1. An eyeglass device (1) comprising an electronic frame (3), said electronic frame comprising: a front frame element (7) that at least partially houses the electrochromic lens (5); - a temple (11) connected to said front frame element; a photosensitive sensor (15) arranged on the temple so as to measure data relating to the light refracted, transmitted by the electrochromic lens and reflected from parts of the wearer's face when the electronic frame is worn by the wearer; a control circuit (17) configured to control said electrochromic lens depending on said measured data; Including, the data measured by the photosensitive sensor includes the intensity, illuminance, wavelength, and / or polarization of the light; The control circuit controls the following features of the electrochromic lens: - light transmission according to said intensity or said illuminance of said light; filtering one or more spectral bands according to the wavelengths of the light; and - uniformity of intensity or illuminance over a range of degrees of polarization of said light based on the measured data.

2. 2. The eyewear device of claim 1, further comprising an optical system arranged to deflect the light reflected from the portion of the wearer's face towards the light sensor when the electronic frame is worn by the wearer.

3. The eyewear device according to claim 2 , wherein the optical system includes a deflector (19) arranged on the temple.

4. An eyewear device as described in claim 2 or 3, wherein the optical system includes a deflector (21) arranged on the electrochromic lens.

5. 5. The eyewear device of claim 4, wherein the deflector (21) disposed on the electrochromic lens comprises a coating covering at least a portion of the electrochromic lens.

6. The eyewear device according to any one of claims 1 to 5, wherein the light-sensitive sensor is housed in a blind hole (23) in the temple, the blind hole being directed towards the part of the wearer's face when the electronic frame is worn by the wearer.

7. The eyewear device according to any one of claims 1 to 6, wherein the light-sensitive sensor is arranged to measure data relating to the light reflected from the wearer's eyes (LE, RE) when the electronic frame is worn by the wearer.

8. The eyewear device according to claim 7 , wherein the light-sensitive sensor is adapted to measure data relating to light in the ultraviolet range or the near infrared range.

9. An eyewear device according to claim 7 or 8, wherein the light-sensitive sensor is adapted to measure data relating to light having a wavelength between 900 nm and 1100 nm.

10. The eyewear device according to any one of claims 1 to 9, wherein the light-sensitive sensor is arranged to measure data relating to the light reflected from a skin area (SA) of the wearer when the electronic frame is worn by the wearer.

11. The eyewear device according to claim 10, wherein the light-sensitive sensor is adapted to measure data relating to light in the visible range or the near infrared range.

12. 11. The eyewear device according to claim 10, wherein the photosensitive sensor is arranged to measure data relating to the light reflected from the wearer's eyes (LE, RE) and the light reflected from the skin area (SA), the photosensitive sensor being adapted to measure data relating to light in the near infrared range.

13. An eyewear device according to any one of claims 1 to 12, wherein the control circuit is disposed on a temple and electrically connected to the light sensitive sensor by an electrical component that extends across only a portion of the temple.

14. The control circuitry has the following inputs (SP): for controlling the light transmission: an intensity or illuminance setpoint to be approached for said light; a minimum intensity or illuminance that must be reached for said light, or a maximum intensity or illuminance that should not be exceeded for said light; for filtering one or more spectral bands: a wavelength range for filtering said light; to vary the intensity or illuminance uniformity over said range of polarization degrees: Intensity or illuminance for the degree of polarization to be approached for said light The eyewear equipment of claim 1 , wherein the control circuit is a closed loop control circuit having one or more of the following:

15. The eyewear device according to claim 14, wherein the closed loop control circuit is a proportional-integral-derivative controller, also called a PID controller.