Classifications

• • G—PHYSICS
  • G02—OPTICS
  • G02C—SPECTACLES; SUNGLASSES OR GOGGLES INSOFAR AS THEY HAVE THE SAME FEATURES AS SPECTACLES; CONTACT LENSES
  • G02C7/00—Optical parts
  • G02C7/10—Filters, e.g. for facilitating adaptation of the eyes to the dark; Sunglasses
  • G02C7/101—Filters, e.g. for facilitating adaptation of the eyes to the dark; Sunglasses having an electro-optical light valve
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60J—WINDOWS, WINDSCREENS, NON-FIXED ROOFS, DOORS, OR SIMILAR DEVICES FOR VEHICLES; REMOVABLE EXTERNAL PROTECTIVE COVERINGS SPECIALLY ADAPTED FOR VEHICLES
  • B60J3/00—Antiglare equipment associated with windows or windscreens; Sun visors for vehicles
  • B60J3/04—Antiglare equipment associated with windows or windscreens; Sun visors for vehicles adjustable in transparency
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60Q—ARRANGEMENT OF SIGNALLING OR LIGHTING DEVICES, THE MOUNTING OR SUPPORTING THEREOF OR CIRCUITS THEREFOR, FOR VEHICLES IN GENERAL
  • B60Q1/00—Arrangement of optical signalling or lighting devices, the mounting or supporting thereof or circuits therefor
  • B60Q1/02—Arrangement of optical signalling or lighting devices, the mounting or supporting thereof or circuits therefor the devices being primarily intended to illuminate the way ahead or to illuminate other areas of way or environments
  • B60Q1/04—Arrangement of optical signalling or lighting devices, the mounting or supporting thereof or circuits therefor the devices being primarily intended to illuminate the way ahead or to illuminate other areas of way or environments the devices being headlights
  • B60Q1/14—Arrangement of optical signalling or lighting devices, the mounting or supporting thereof or circuits therefor the devices being primarily intended to illuminate the way ahead or to illuminate other areas of way or environments the devices being headlights having dimming means
  • B60Q1/1415—Dimming circuits
  • B60Q1/1423—Automatic dimming circuits, i.e. switching between high beam and low beam due to change of ambient light or light level in road traffic
  • B60Q1/143—Automatic dimming circuits, i.e. switching between high beam and low beam due to change of ambient light or light level in road traffic combined with another condition, e.g. using vehicle recognition from camera images or activation of wipers
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
  • G01J1/00—Photometry, e.g. photographic exposure meter
  • G01J1/42—Photometry, e.g. photographic exposure meter using electric radiation detectors
  • G01J1/4204—Photometry, e.g. photographic exposure meter using electric radiation detectors with determination of ambient light
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B5/00—Optical elements other than lenses
  • G02B5/20—Filters
  • G02B5/22—Absorbing filters
  • G02B5/23—Photochromic filters
• • G—PHYSICS
  • G02—OPTICS
  • G02C—SPECTACLES; SUNGLASSES OR GOGGLES INSOFAR AS THEY HAVE THE SAME FEATURES AS SPECTACLES; CONTACT LENSES
  • G02C7/00—Optical parts
  • G02C7/10—Filters, e.g. for facilitating adaptation of the eyes to the dark; Sunglasses
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
  • Y02T10/00—Road transport of goods or passengers
  • Y02T10/80—Technologies aiming to reduce greenhouse gasses emissions common to all road transportation technologies
  • Y02T10/88—Optimized components or subsystems, e.g. lighting, actively controlled glasses

Definitions

• the present invention relates to glasses adapted to equip drivers and / or passengers of motor vehicles, to allow them an improved vision of the road scene in front of the vehicle they occupy.
• the light beams emitted by the lighting devices fitted to the vehicles are governed by international regulations, which set maximum and minimum intensities to be respected, for example on a screen placed at a distance and in the axis of the lighting device. In the particular case of passing beams, the purpose of these regulations is to simultaneously
• the closing glass of these devices is dirty so that the beam emitted is dazzling.
• the dirt present on the closing glass then behave as centers of light diffusion, that is to say as secondary light sources, which emit light in all directions. The more dirty a closure glass, the brighter the beam emits.
• the crossing headlamps of the crossed vehicles can still be dazzling in another situation, in which the trunk of these vehicles contains relatively heavy luggage. In this case, the attitude of the vehicle is changed and is no longer horizontal, the front of the vehicle being raised.
• Manually operated or automatic correctors are normally provided to fold down the light beam so that it becomes compliant with the regulations. In the case where the corrector has not been activated or if it fails, the passing beam shall include light rays located above the upper regulatory limit, dazzling and prohibited by regulation.
• the present invention is placed in this context, and proposes to equip the driver and passengers of a vehicle with glasses allowing them not to be dazzled during the day by a very sunny road scene, and not to be dazzled at night. by crossed vehicles whose crossing beam is dazzling especially in one of the situations mentioned above.
• a classic solution is to wear sunglasses, to avoid being dazzled by the sun and to better distinguish the details of the road scene in front of the vehicle.
• the screen comprises a series of juxtaposed and contiguous vertical cells, which can be electrically controlled, for example liquid crystals, these cells being transparent in the absence of applied voltage, and becoming darker depending on the applied voltage.
• a row of photosensitive sensors whose electrical resistance increases with brightness is associated with the series of cells. Covers are placed in front of the sensors to create shadows on these sensors. Electrical control means are interposed between the sensors and the cells of the screen to control the transmission factor of the cells as a function of the signals received from the different sensors.
• Such a structure is relatively complex to achieve and adjust, the goal being to obscure only the cells located between the source of glare and the driver's eyes.
• This screen which is fixed on the windshield of the vehicle or which can take the form of spectacle lenses, comprises an ambient light sensor, a measurement circuit and a comparison of the measured value with a control threshold value. state of transparency of the liquid crystals constituting the spectacle lenses. These are completely transparent in the absence of a measurement signal. Such an arrangement has the disadvantage of operating in binary mode, all or nothing, the glasses being in a state of maximum or minimum transparency if the brightness is less than or greater than a predetermined threshold.
• document FR 2 846 756 discloses a method for improving the nocturnal perception of conductors which comprises a first polarizing filter in the vicinity of the light sources, and a second polarizing polarization direction filter perpendicular to that of the first filter, in the field of view of drivers.
• a solution is theoretically satisfactory, but would imply, to be effective, that the entire fleet of rolling stock is provided with polarizing filters on the protective glass of the lighting devices, and that the driver is also provided with polarizing glasses.
• an anti-glare device comprising an optical sensor providing a signal proportional to the value of the ambient brightness in a predetermined measurement angle.
• the sensor transmits this signal to a measurement and comparison circuit with a predetermined threshold value.
• the comparison circuit outputs a control signal of the power supply of an electrosensitive screen which is designed to go from a state of total transparency in the absence of a signal to a state. partially transparent or colored when the signal is transmitted, then to return to the transparent state during the extinction of the signal.
• the disadvantage of this device is that it affects the perception of the entire road scene. If the ambient brightness exceeds the allowed threshold, the entire road scene will be obscured, while the excess brightness may be caused only by a point element in the road scene. The driver equipped with this anti-dazzle device may not see some important elements in this road scene, such as a road sign warning of the imminence of a danger or the road surface illuminated by its own lighting beam.
• US 2009/213282 discloses medical glasses for treating age-related macular degeneration (AMD) using adjustable variable-goggles. These glasses have liquid crystals whose transmission changes depending on the application of an electrical potential, depending on the ambient brightness. The transmission of the liquid crystals depends on the duty cycle of the PWM signal applied to the liquid crystals.
• AMD age-related macular degeneration
• Such a device for medical or therapeutic purposes requires a relatively complex electronic and computer infrastructure, and is therefore inapplicable to drivers of vehicles.
• the document WO 92/10130 discloses glasses whose glasses comprise a film of liquid crystals, alternately transparent and opaque as a function of an electric field, itself a function of the ambient luminosity measured by a sensor carried by the spectacle frame. This document also describes that the liquid crystal film is divided into a plurality of cells, each of which can be made alternately transparent and opaque when it is on the path between a bright light source and the eye of the spectacle wearer, with as application the night driving of motor vehicles.
• 3,961,181 or GB 2,445,365 disclose anti-glare devices for driving vehicles at night, comprising a camera filming the road scene in front of the vehicle, and a liquid crystal screen comprising pixels of which transparency is controlled according to the sources illuminated in the road scene if they are on the path between the light sources and the driver's eyes.
• the present invention is placed in this context and its purpose is to provide, as well to the driver as to the passengers of a vehicle, an aid to the observation of the road scene in front of the vehicle. providing them with glasses for:
• o reduce the brightness of a highly sunny road scene, and avoid glare for the driver and passengers, and o provide a view of the road scene with a gradually decreasing attenuation as the brightness of the scene decreases of road, up to a maximum transparency for a low brightness of the road scene,
• these glasses do not require complex and expensive infrastructure, do not interfere with the movements of the driver or passengers, and do not restrain their field of vision.
• the present invention relates to adaptive glasses for driver or passenger of a motor vehicle, glasses comprising glasses having a screen whose transmission coefficient is variable between a maximum value and a minimum value.
• the control of the transmission coefficient of spectacle lenses is performed according to a wireless communication protocol.
• control of the transmission coefficient of the spectacle lenses is carried out by a control unit
• the control of the transmission coefficient of spectacle lenses is carried out by radio, infrared or ultrasonic waves;
• the control unit is controlled by a sensor for measuring the brightness of the road scene in front of the vehicle;
• the measurement of the brightness of the road scene in front of the vehicle is performed by a sensor located on the inside of a windshield fitted to the vehicle;
• control of the transmission coefficient of the spectacle lenses is carried out by a control unit, receiving the signals of the sensor for measuring the brightness of the road scene in front of the vehicle, and the signals of a measuring sensor of the amount of light transmitted by the glasses;
• the sensor of the amount of light transmitted by the glasses of glasses measures the amount of light reflected by the cornea of the driver's eye
• control unit which synchronously controls the variation in intensity of the light beam emitted by at least one projector fitted to the vehicle;
• control unit receives the signals from a sensor for measuring the quantity of light transmitted by the spectacle lenses;
• the sensor of the amount of light transmitted by the glasses of glasses measures the amount of light reflected by the cornea of the driver's eye
• the transmission coefficient of the spectacle lenses is controlled in synchronism with luminous visual indications, presented by the vehicle dashboard and relating to the operation or the environment of the vehicle; the transmission coefficient of the spectacle lenses is controlled in synchronism with the interior lighting of the vehicle, the interior lighting being switched on only when the transmission coefficient of the variable transmission screen is at its minimum value;
• the glasses have their own power supply
• the spectacles comprise a liquid crystal screen or a microelectromechanical system
• the transmission coefficient is variable according to PWM Width Modulation mode PWM.
• FIG. 1 shows schematically in partial section a vehicle in which the spectacles according to the present invention are used
• FIGS. 3A to 3C show diagrams of the time evolution of the different signals used in the circuits of the present invention in the diurnal driving configuration
• FIG. 4 schematically represents a road scene as it can be observed by the driver or passengers of a vehicle
• FIG. 5 shows schematically in a view from above a passing beam regulatory issued by a vehicle
• Figures 6A and 6B show a road scene as observed by the driver of the vehicle shown in Figure 1; Figure 6A without the device according to the present invention, and Figure 6B the vehicle being equipped with the device according to the present invention,
• FIGS. 8A to 8C represent diagrams of the time evolution in the night driving configuration: the electric power supplied to the light sources of the vehicle headlamps of Figure 1 in Figure 8A, the light intensity emitted by these headlamps in Figure 8B, and the temporal change in transmission coefficient of a variable transmission display in Figure 8C, and
• FIGS. 9A and 9B represent variants of FIGS. 8B and 8C respectively, with diagrams of the temporal evolution of the luminous intensity emitted by the projectors in FIG. 9A, and the time evolution of the transmission coefficient of FIG. a variable transmission screen in Figure 9B.
• FIG. 1 a partial section of a vehicle, generally designated by the reference 20, traveling on a road 10 being controlled by a driver 24, symbolized by his eye.
• the driver 24 can be dazzled by elements of the road scene SR in front of the vehicle,
• FIG. 1 It can be seen in FIG. 1 that in sunny weather, particularly at the end of the day when the height of the sun S on the horizon is small, the road scene SR in front of the vehicle 20 is strongly illuminated, and that the driver 24 is at risk. only to be dazzled, but can also not distinguish details of this road scene important for its safety, such as signs warning of the proximity of a hazard, or the condition of the roadway on which it runs.
• the invention therefore provides the driver 24 with a pair of adaptive glasses 28 to modulate the amount of light reaching the driver's eye 24.
• a single spectacle lens has been shown for clarity of the drawing.
• the glasses 28 are designed to have a very low response time, and allow a rapid variation in their transmission coefficient. Liquid crystals make it possible to obtain such screens with a variable transmission coefficient whose reaction time is very fast, of the order of a millisecond. Microelectromechanical systems, for example of the type described in document US Pat. No. 7,684,105, also make it possible to obtain such response times.
• the glasses 28 have their own power supply (not shown) in the form of a button cell or rechargeable miniature battery, like the glasses used to watch animated images in three dimensions.
• the invention provides for the use of a photosensitive sensor 31 for measuring the brightness of the road scene SR in front of the vehicle.
• the photosensitive sensor 31 is located on the inside face of the windshield 26 of the vehicle 20, at the interior rearview mirror (not shown), that is to say in the middle of the upper part of the windshield 26. This position allows to collect information particularly representative of the brightness outside the vehicle, from the SR road scene.
• the measurement signals of the photosensitive sensor 31 may also be used to control the illumination of the dipped beam when the brightness of the road scene SR becomes below a predetermined threshold, as on most modern vehicles.
• the output signal S L of this photosensitive sensor 31 is received and processed by a circuit 33 adapted to transform this output signal S L into a control signal S c of FIG. transmittance of the spectacle lenses 28, this signal S c being in turn received by a control unit 30 of the transmission coefficient of the bezel glasses 28 with variable transmission.
• the control unit 30 controls a control circuit 34 for controlling the transmission coefficient of the spectacle lenses, which itself comprises a transmitter 38, for example of radio, infrared or ultrasonic waves, according to a wireless communication protocol, for example according to the Bluetooth or Wi-Fi standards (registered trademarks).
• remote control waves These waves will be called in the following description "remote control waves" O T.
• the glasses 28 are provided with a receiver 40 of these same remote control waves O T.
• the modulation of the transmission coefficient of spectacle lenses 28 is carried out in real time, as a function of the brightness of the road scene SR measured by the photosensitive sensor 31.
• the circuit 33 in response to the output signal S L of the photosensitive sensor 31, representative of the brightness of the road scene SR in front of the vehicle 20, the circuit 33 generates a control signal S c , which is a function of the signal S L .
• the control signal S c is then transmitted by the transmitter 38 of the control circuit 34 via the waves O T and the receiver 40 to the spectacle lenses 28.
• the transmission coefficient of the spectacle lenses 28 will thus be modulated according to the signal S c received, that is to say according to the brightness measured by the sensor 31, according to a well-known principle.
• the vehicle 20 passes from a very sunny area to a shaded area, for example a tunnel, then the brightness of the road scene SR drops sharply.
• the value of the signal S L also varies abruptly, as does the value of the signal S c . This variation is transmitted by the O T waves to spectacle lenses 28 whose transmission coefficient increases sharply, thus enabling the driver to immediately have a clear view of this new darker environment.
• the lightening of spectacle lenses 28 occurs long before the pupil of the driver's eyes expands to adapt to sudden darkness.
• the advantage of the spectacles according to the invention is thus amplified by the fact that, since the spectacle lenses 28 have become clearer, the variation in the amount of light reaching the eye is of a lower amplitude than if the driver were not wearing no glasses, and the pupil, having less to dilate, will reach its new opening more quickly.
• the same phenomenon is reproduced in the opposite direction at the exit of the tunnel, the spectacle lenses 28 almost instantly resuming their lesser transparency, and allowing the driver to have a much faster vision of the sunny road scene.
• the glasses 28 not giving him any discomfort since they are not dependent on any wired connection, the control of the transmission coefficient CT of spectacle lenses 28 being carried out according to a wireless communication protocol.
• an eye sensor 50 measures the amount of light reflected from the cornea of the driver's eye 24.
• the sensor 50 is for example integrated into the frame of the glasses 28 worn by the driver.
• the measurement by the sensor 50 of the amount of light reflected by the cornea of the eye 24 is a measure of the amount of light reaching this eye 24, possibly after calibration or preliminary calibration, and thus constitutes an indirect measure of the amount of light transmitted through spectacle lenses 28.
• the link 52 will advantageously be constituted by a wireless link, for example using radio, infrared or ultrasonic waves according to a wireless communication protocol, for example according to the Bluetooth or Wi-Fi standards (brands filed).
• control unit 30 has both:
• the control unit 30 contains a comparator, which compares the measured value L
• This reference value V c can be fixed in memory 54, or, preferably, adjustable, for example by being adjusted by the driver to the dashboard of the vehicle 20, as shown in FIG.
• the driver 24 can adjust the degree of darkening of the spectacle lenses 28 to any value desired to observe in the best possible conditions the road scene in front of his vehicle, the amount of light reaching his eye remaining constant, and equal to one predetermined value, as assigned by the driver to memory 54.
• the signals may be transmitted no longer continuously and analogically, as described above, but in a digital manner, that is to say so alternatively, preferably PWM (pulse width modulation) pulse modulation, at a predetermined frequency, according to the diagrams of FIG. 3.
• the photosensitive sensor 31 transmits an analog signal whose value is a function of the light intensity it receives from the road scene in front of the vehicle.
• the sensor 31 is associated with a circuit which transforms this analog signal into a digital signal S L encoded in PWM. As seen in FIG.
• this signal S L varies between a value S Lm in during a duration (t1) and an value S LMAX for a duration t 2 , the sum of the durations t-, and t 2 defining the period T of the alternative signal S L , which is further characterized by a duty cycle ⁇ .
• the duty cycle ⁇ of the signal S L is determined by the ratio between the duration t 2 during which the signal is maximum, and the duration T of the period, and thus varies from 0 to 100%:
• the duty cycle ⁇ of the signal S L thus appears as a direct function of the light intensity received by the sensor 31.
• This signal S L is received by the circuit 33, which transforms it into a control signal S C shown in FIG. 3B.
• the circuit 33 in response to the signal S L provided by the photosensitive sensor 31, a function of the value of the brightness of the road scene SR in front of the vehicle 20, the circuit 33 generates an alternating signal S c
• this transmission coefficient varies, in response to the signal S c , between a value CT MAX during the duration t-, and a value CT min during the duration t 2 , with the same ratio cyclic has the signal S c and the same frequency v.
• the CT MAX value is that for which the spectacle lenses 28 have their maximum transparency. In most cases, liquid crystal displays have this state in the absence of any electrical excitation, that is to say in the state of rest, and are opaque only under the effect of a field electric. In these cases, the CT MAX value corresponds to a minimum excitation of the liquid crystals constituting the spectacle lenses 28.
• the state of rest of a liquid crystal screen or microelectromechanical system may be one where they exhibit their maximum opacity, becoming transparent only under the effect of an electric field.
• the CT MAX value corresponds to a maximum excitation of the liquid crystal or the microelectromechanical system constituting the spectacle lenses 28.
• the diagram of FIG. 3C thus represents the variation of the transmittance coefficient CT of spectacle lenses 28, and not the variation of the excitation signal of these spectacle lenses.
• the driver 24 can therefore observe the road scene SR through the spectacle lenses 28, whose transmission coefficient is adjusted in real time according to the brightness of the road scene: the brighter the road scene, the more glasses of variable transmission glasses attenuate light reaching the driver 24.
• the automatic adjustment of the transmission coefficient of spectacle lenses 28 is obtained by a succession of states of maximum and minimum transparency of these spectacle lenses, at a frequency v and with a cyclic ratio.
• the frequency v is chosen high enough to avoid any flicker phenomenon for the driver 24 of the vehicle 20.
• the frequency v will for example be greater than 100 Hz to fully benefit from the phenomenon of retinal persistence.
• the photosensitive sensor 50 emits an analog signal whose value is a function of the light intensity that it receives from the cornea of the driver's eye.
• the sensor 50 is associated with a circuit that converts this analog signal into a digital signal encoded in PWM.
• control unit 30 receives:
• these two signals being coded in PWM, just as the signal representing the setpoint value V c .
• the comparator of the control unit 30 can use these signals to continuously adjust the control signal transmitted by the waves O T so that the measured value L
• FIG 4 there is shown schematically a road scene SR such that it can be perceived by the driver or his passengers in a usual night driving situation.
• Figures 6A and 6B show views of this road scene, driving at night, after lighting dipped headlights.
• the road scene SR typically comprises, in addition to the road 10 itself, roadside elements, for example constructions or, as in the example shown, aisles and trees, road signs, and other vehicles, tracked or crossed.
• Visible elements can be classified in a road scene illuminated by the dipped beam of a vehicle in several categories:
• passive elements or passive sources such as the elements of the scenery, for example the road 10, the aisles and the trees 12, the neighboring constructions, etc., that is to say the elements which receive the light emitted by the projectors of the vehicle, and which diffuse it indifferently in all directions or, in other words, which have only an induced luminosity: the more they are illuminated, the more they are luminous;
• semi-active elements or semi-active sources such as traffic signs 14, fluorescent marking lines 16 of the roadway, retro-reflectors of other vehicles tracked 19 (traveling in the same direction), etc., that is, the elements which receive the light emitted by the projectors of the vehicle, and which return a notable part of this light in a privileged direction, generally approximately in the direction from which it originates; in other words, these elements also have an induced brightness, but greater than that of the passive elements,
• active elements or active sources such as lighting devices 18 of other crossed vehicles (circulating in the opposite direction), signaling traffic lights, street lamps, etc., that is to say the elements which are themselves light sources and emit light by themselves, irrespective of the light they receive; in other words, these elements have intrinsic brightness, regardless of the lighting they receive.
• the passive sources such as the road 10, the aisles and the trees 12,
• semi-active sources such as the road sign 14, the marking lines 16 of the roadway and the reflex reflectors 19 of vehicles tracked, and
• Active sources such as projectors 18 of a vehicle traveling in the opposite direction.
• the adaptive spectacles 28 according to the present invention also constitute a solution to this problem, by decreasing the brightness of the active elements, potential sources of glare, without however modifying the brightness of the passive or semi-active elements, which can constitute elements of important security.
• the invention provides that the glasses 28 equipping the driver and passai t) ters:
• the projectors 22 emit a light beam of variable intensity, the variation of the intensity of the passing beam emitted by the projectors 22 being synchronous with the variation of the transmission coefficient of the spectacle lenses 28 .
• the maxima of luminous intensity emitted by the projectors 22 coincide with the maxima of the transmission coefficient of spectacle lenses 28, and the minimum luminous intensity emitted by the projectors 22 coincide with the minimum of the coefficient transmission of spectacle lenses 28.
• the perception of the road scene by the driver through the glasses 28 is optimal when the latter is illuminated with the maximum light intensity.
• control unit 30 controls:
• a driver or management circuit 32 for supplying the light sources of the projectors 22, and the control circuit 34 for controlling the transmission coefficient of the spectacle lenses 28, comprising the transmitter 38.
• the operation of the control unit 30 is triggered automatically, when the measuring signal of the sensor 31 corresponds to that of a brightness of the road scene SR less than a predetermined threshold, and thus controls the switching on of the dipped beam.
• the operation of the central unit 30 can also be triggered manually, when the driver of the vehicle itself controls the dashboard lighting dipped.
• the control unit operates as follows:
• control carried out by the control unit 30 is such that:
• the management circuit 32 controls the supply of the light sources of the projectors 22, so that the projectors 22 emit a light beam of periodically variable intensity, between a maximum value and a minimum value, and that
• the circuit 34 controls the transmission coefficient of the spectacle lenses 28, so that these glasses periodically pass from a maximum transparency to a minimum transparency
• the circuits 32 and 34 are controlled in synchronism, the intensity emitted by the projectors 22 being maximum at the same time as the transparency of the glasses glasses 28 is maximum, and vice versa, the intensity emitted by the projectors 22 being minimal at the same time as the transparency of the spectacle lenses 28 is minimal.
• the illumination provided by the projectors 22 being variable, it is appropriate that the light sources equipping these projectors do not exhibit too much inertia, in other words that the emitted light power is directly a function of the electric power they receive.
• Incandescent lamps, as well as discharge lamps, fulfill this condition only with a response time which is unsuitable for solving the problem of the present invention, which therefore provides for the use of the light sources of the projectors 22. , semiconductor sources.
• Such sources may be constituted by light-emitting diodes, or LEDs, emitting white light, of the type that are used to equip modern vehicles. They may also be constituted by laser diodes, whose radius strikes a layer of phosphorus, which in turn emits white light.
• spectacle lenses 28, liquid crystal or microelectromechanical system allow a very low response time, and a rapid variation in their transmission coefficient.
• the glasses 28 comprise their own electrical power supply (not shown), in the form of a button cell or rechargeable miniature battery, to like glasses used to watch animated images in three dimensions, and
• control of the transmission coefficient of the spectacle lenses 28 is effected wirelessly by remote control waves via the transmitter 38 and the receiver 40.
• the control unit 30 drives the management circuit 32 so that the light sources of the projectors 22 are fed periodically, according to the diagram of Figure 8A.
• the duty cycle a is determined by the ratio between the duration t-, during which the electric power is maximum, and the duration T of the period, and thus varies from 0 to 100%:
• a diode, LED or laser has a virtually instantaneous response to a variation of the electrical power that powers it.
• the illumination emitted by the light sources of the projectors 22 varies substantially with the same duty cycle a.
• the minimum illumination E min is also equal to zero.
• the average illumination E emitted by the PWM-powered light sources with a duty cycle a is equal to:
• This frequency v is chosen high enough to avoid any scintillation phenomenon, both for the driver of the vehicle 20 and for the drivers of the other vehicles, crossed or followed.
• the frequency v will for example be greater than 100 Hz to fully benefit from the phenomenon of retinal persistence.
• the driver of the vehicle 20 observes this road scene through the glasses 28, whose transmission coefficient is variable with the same frequency as that of the operation of the projectors 22 and the same duty cycle, and as shown in the diagram of Figure 8C.
• the glasses 28 thus have a transmission coefficient CT which varies between:
• the duration t-i during which the transmission coefficient has its maximum value CT MAX is greater than the duration t-, during which the illumination has its maximum value E MAX , so as to start a moment ⁇ before t-, and to end a moment ⁇ ' ⁇ after t
• the transmission coefficient CT switches to its minimum value CT min
• the light source 22 has already switched to its minimum illumination state E MIN .
• the offset ⁇ between the illumination E and the transmission coefficient CT is in the other direction, that is to say that:
• the first variant above (CT becomes equal to CT MAX when the source 22 has already reached E MAX , and the source 22 switches to E min when CT is already equal to CT MIN ) allows s' ensure that the transmission coefficient will have its maximum CT MAX value for the entire duration during which the light source will be in its maximum illuminated state E MAX , and therefore that the driver will have an optimal view of the illuminated road scene by the light source 22.
• the CT MAX value is that for which the spectacle lenses 28 have their maximum transparency.
• liquid crystal displays or microelectromechanical systems have this state in the absence of any electrical excitation, that is to say in the state of rest, and are opaque only under the effect an electric field.
• the CT MAX value corresponds to a minimum excitation of the liquid crystals or microelectromechanical systems constituting the spectacle lenses 28.
• the state of rest of a liquid crystal screen or microelectromechanical system may be one where it has its maximum opacity, becoming transparent only under the effect of an electric field.
• the CT MAX value corresponds to a maximum excitation of the liquid crystal or the microelectromechanical system constituting the spectacle lenses 28.
• the diagram of FIG. 3C thus represents the variation of the transmission coefficient CT of spectacle lenses 28, and not the variation of the excitation signal of these spectacle lenses.
• the minimum value CT min of the transmission coefficient CT is zero during the time t 2 or, in other words, the variable transmission screen is opaque during the time t 2 .
• the glasses 28 are opaque during the time t 2 , that is to say while the light sources of the projectors 22 are extinguished, and
• the transparency of the glasses 28 is maximum during the time t-i, that is to say while the light sources of the projectors 22 illuminate the road scene SR with the maximum intensity.
• the driver 24 therefore has the impression to see the road scene SR as if it were lit by conventional projectors, continuous lighting.
• the glasses are opaque, and the driver 24 therefore sees nothing of the road scene.
• the driver's eye 24 integrates its observations, during which the passive elements are illuminated periodically during the times ti,
• the average of the successive observations of the passive elements is thus equal to the observation which would be made with a constant illumination E REG .
• the driver 24 therefore has a vision of the passive elements unchanged compared to conventional lighting.
• the semi-active elements are illuminated under the same conditions as the passive elements, and return a significant part of the light they receive approximately in the direction from which it comes. If, for example, the duty ratio a is equal to 50%, they will receive a quantity of light Q 2 that is twice the prescribed quantity Q RE G, for a time half as long. They will therefore return as much light as if they had been lit continuously with the prescribed quantity Q RE G-
• the average of the successive observations of the semi-active elements is therefore equal to the observation that would be made with a constant illumination E REG .
• the driver 24 therefore has a vision of the semi-active elements unchanged compared to conventional lighting.
• the active elements receive a quantity of light completely negligible compared to the one they emit. On the other hand, they can only be observed by the driver 24 during the time t 1, during which the spectacle lenses 28 have their maximum transmission.
• the active elements are therefore visible only for a fraction of time equal to the duty cycle a. Their apparent brightness, through the variable transmission screen, is therefore reduced compared to their actual brightness by a factor a.
• the desired result is thus obtained: considering FIG. 5, all the passive and semi-active elements situated in the passing beam 42 are visible under the same conditions as in conventional lighting. On the other hand, all the active elements, such as the projectors of the crossed vehicles, are observed with a luminosity diminished by a factor a.
• Figure 6A shows a conventional road scene in which the road, off-road elements, traffic signs and cross-vehicle projectors can be seen.
• Figure 6B shows the same road scene, seen through the glasses 28 of the invention. It is clear that all the elements of this road scene are visible under the same conditions as in Figure 6A, whether passive elements or semi-active elements such as traffic signs, with the exception of active elements such as headlamps of crossed vehicles, whose luminosity has been reduced.
• the invention by varying the duty ratio ⁇ , it will be possible to maintain a constant visibility of the passive and semi-active elements, and to reduce at will the brightness of the active elements present in the road scene. Even if the headlamps of the crossed vehicles are dazzling, the invention makes it possible to reduce the brightness, until they are much less dazzling, without changing the perception of other details of the road scene.
• the driver's visual field includes, in addition to the road scene in front of him through the windshield 26, the dashboard of the vehicle, with various useful visual indications for the driver.
• These visual indications may be dials 44 speed indicators or tachometers, or indicator lights 46 witnesses the operation of certain equipment of the vehicle.
• the dials 44 and the indicators 46 are lit when the projectors 22 are lit, and are visual indications bright.
• luminous visual indications 48 may be presented to the driver outside the dashboard, for example as shown in FIG. 7, by a so-called “head-up” vision system, or “HUD” for the Anglo-Saxon expression. "Head Up Display”, forming a virtual image using the windshield 26.
• the brightness of the visual indications 44, 46 and / or 48 is increased by a factor equal to the inverse of the duty ratio a during the time t- ,.
• the glasses 28 thus have the effect of weakening the luminosity of all the objects situated in the driver's visual field, with the exception of:
• FIG. 1 Another potential source of inconvenience to the driver is the interior lighting system of the vehicle, for example when one or more passengers wish to use it to be able to read.
• the use of the ceiling light 60, as shown in FIG. 1, can disturb the driver by illuminating details in his visual field which may distract his attention.
• the present invention also solves this problem. Indeed, the invention can provide that the interior lighting 60 is turned on only during periods t 2 , that is to say during the periods when glasses glasses 28, are opaque. The illumination of the interior lighting is then not perceived by the driver, while the passengers can dispose of it at leisure.
• the glasses 28 allow the driver to have in his field of vision: all the passive and semi-active elements illuminated in the road scene by the passing beam emitted by the headlamps of his vehicle, with a luminous intensity equal to that which he is accustomed to,
• each of the adaptive glasses in "day" mode of operation, the driver of the vehicle and his passengers can wear each of the adaptive glasses according to the invention, each pair of glasses receiving the same control signal depending on the brightness outside the vehicle.
• the glasses include an adapter, allowing the wearer to modulate the degree of attenuation provided by the spectacle lenses, depending on the visual sensitivity of each.
• a passenger can adjust his glasses so that they darken less than those of the driver in case of intense illumination of the road scene.
• the skilled person in “night” operating mode, the skilled person can achieve a variable transmission screen according to the teachings of the present invention, which is not made of spectacle lenses, but by a folding screen, the way a sunshade, or through the windshield of the vehicle. It will then be possible to have two successive variable transmission screens, for example:
• the windshield 26 and a sun visor type of mobile screen to affect the upper part of the driver's field of vision (through the sun visor-type screen and the windshield) attenuation higher than that from the bottom (through the windshield alone), or - The windshield 26 and the glasses 28 worn by the driver.
• the driver will benefit from the fixed attenuation provided by the cumulative windshield at an adjustable attenuation that it can control on the dashboard, while passengers will benefit from the fixed attenuation provided by the windshield. alone.
• These same glasses can advantageously be used by the passengers of the vehicle, to avoid being dazzled during the day by a sunny road scene, and at night by the headlights of vehicles traveling in the opposite direction, or to allow them to switch on the overhead light without disturbing the driver.

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• Physics & Mathematics (AREA)
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• Ophthalmology & Optometry (AREA)
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• 2012
  • 2012-03-26 FR FR1252678A patent/FR2988493B1/fr active Active
• 2013
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  • 2013-03-22 WO PCT/EP2013/056042 patent/WO2013144003A1/fr active Application Filing
  • 2013-03-22 KR KR1020147027113A patent/KR102033194B1/ko active IP Right Grant
  • 2013-03-22 EP EP13711401.3A patent/EP2831668A1/de active Pending
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