Glasses device and method for driving a variable light transmittance ophthalmic lens

Abstract

The present disclosure relates to an eyewear device including a variable light transmittance ophthalmic lens (101), a method for driving the light transmittance of such a lens, a computer program product, and a non-transitory computer-readable storage medium for implementing such a method. The eyewear device includes a light sensor (200) configured to measure the amount of light in the environment of the wearer, and a control circuit (301) configured to receive at least light data from the light sensor (200) and drive the light transmittance of the ophthalmic lens (101) based on the light data. The control circuit (301) is further configured to drive the light transmittance of the ophthalmic lens (101) based on motion data obtained from an estimation of the head movement of the wearer.

Description

Technical Field

[0001] The present invention belongs to the field of ophthalmic lenses.

[0002] In particular, disclosed below are spectacle devices including variable light transmittance ophthalmic lenses, and methods for controlling the optical transmittance of such variable light transmittance ophthalmic lenses, as well as computer-readable storage media, computer programs, and base stations for implementing such methods. Background Art

[0003] Some known variable light transmittance ophthalmic lenses include electrochromic materials (e.g., in the form of liquid crystals or dyes immersed in fluids).

[0004] The light transmittance of an optical element made of an electrochromic material is controllable by arranging the optical element between two electrodes and adjusting the potential difference between the two electrodes.

[0005] Thus, instead of switching between prescription glasses and sunglasses, the user can simply use a single optical device including such an electrochromic material and switch the electrochromic material from a transparent state to a dark state and back again.

[0006] It is further known to automatically adjust the light transmittance of an optical lens including an electrochromic material according to the amount of ambient light incident on the optical lens. In other words, it is known to sense the amount of ambient light in the direction in which the wearer is looking and automatically adjust the light transmittance of the optical lens based on the sensed amount of ambient light.

[0007] In certain situations, such as when looking at the sun or away from the sun, this is quite advantageous. In fact, automatically switching from a transparent state to a dark state when looking at the sun can avoid glare. Automatically switching from a dark state to a transparent state when away from the sun can provide a brighter view.

[0008] However, in other situations, the light transmittance change automatically caused by the brightness change may be quite uncomfortable and undesirable.

[0009] One such example is when the wearer briefly observes the rearview mirror or side mirror while driving. In this example, the reflection of a light source (e.g., the sun or the headlights of another vehicle) in the mirror may cause a sudden increase in brightness. In this example, due to this increase in brightness, the light transmittance of the optical lens will be automatically changed from a bright state to a dark state, and then when the wearer has finished observing the mirror, the light transmittance of the optical lens will be automatically changed back to the bright state, which may be obstructive to the wearer and is therefore undesirable.

[0010] Another such example is when the wearer is playing tennis during broad daylight and looks down during a serve. In this example, looking down causes a sudden reduction in the incident light. In this example, due to this increase in brightness, the light transmittance of the optical lens is automatically changed from a dark state to a bright state, and then when the wearer no longer looks down, the light transmittance of the optical lens is automatically changed back to the dark state, which may interfere with the wearer and is thus undesirable.

[0011] Accordingly, there is a need for an eyewear device having a variable light transmittance ophthalmic lens that can automatically adapt the light transmittance to ambient light conditions while also preventing undesirable changes in light transmittance from interfering with the wearer. Summary of the Invention

[0012] The present invention is defined by the appended independent claims. Additional features and advantages of the concepts disclosed herein are set forth in the following description.

[0013] The present disclosure aims to improve this situation.

[0014] In particular, an object of the present invention is to provide a method for controlling a variable light transmittance ophthalmic lens that improves the comfort of a wearer whose head is undergoing instantaneous or sudden movement.

[0015] To this end, the present disclosure describes an eyewear device for a wearer, the eyewear device comprising at least:

[0016] - a variable light transmittance ophthalmic lens,

[0017] - a light sensor configured to measure the amount of light in the environment in which the wearer is located,

[0018] - a control circuit configured to receive at least light data from the light sensor and drive the light transmittance of the ophthalmic lens based on the light data,

[0019] wherein the control circuit is further configured to drive the light transmittance of the ophthalmic lens based on motion data obtained from an estimate of the movement of the wearer's head.

[0020] In the context of the present disclosure, the variable light transmittance ophthalmic lens has an initial light transmittance value at an initial time.

[0021] In the context of the present disclosure, the light sensor is configured to measure or sense the amount of light in the environment in which the wearer is located over time.

[0022] In the context of the present disclosure, the light data received by the control circuit from the light sensor may indicate a change over time in the amount of light sensed by the light sensor between an initial time and a subsequent time. The change over time may be extracted by the control circuit from the light data.

[0023] In the context of the present disclosure, motion data can be derived based on an estimate of one or more motions of the wearer's head between an initial time and a subsequent time.

[0024] Of course, the control circuit can be configured to receive light data from a plurality of such light sensors.

[0025] Of course, the control circuit can be configured to drive a plurality of such variable light transmittance ophthalmic lenses.

[0026] By automatically driving the light transmittance of the ophthalmic lens based on both the light data and the motion data, the light transmittance can be adjusted differently for two different events even if similar changes in incident light intensity occur in both events.

[0027] In fact, by automatically driving the light transmittance of the ophthalmic lens based on the light data, such a spectacle device can provide a suitable light transmittance taking into account the ambient light intensity to the wearer. For example, during the day, the wearer can be provided with a dark state when facing the sun and a transparent state when facing away from the sun.

[0028] In addition, different from existing spectacle devices, an undesired change in light transmittance due to automatically driving the light transmittance of the ophthalmic lens can also be avoided based on the motion data. An example of such an undesired change in light transmittance corresponds to an event where the wearer turns their head towards a light source, which results in a change in incident light intensity.

[0029] In the context of the present disclosure, it is implied that the control circuit is configured to obtain the motion data before driving the light transmittance of the ophthalmic lens based on the motion data.

[0030] The motion data can be obtained directly from a motion sensor, which may or may not be part of the spectacle device.

[0031] In fact, optionally, the spectacle device can further include a motion sensor configured to sense the motion of the wearer's head, and the control circuit can further be configured to obtain the motion data by receiving from the motion sensor motion data indicating the motion of the wearer's head sensed by the motion sensor. In this example, the device is independent.

[0032] Alternatively, the control circuit includes a communication interface with a remote device (such as a smartphone) equipped with a motion sensor, and the control circuit is further configured to receive motion data from the motion sensor of the remote device indicating the motion of the wearer's head sensed by the motion sensor between an initial moment and a subsequent moment. In this example, the proposed spectacle device can be obtained simply by updating the embedded software of the control circuit of an existing spectacle device that includes a light sensor but does not have a motion sensor, so that the control circuit is configured to drive the light transmittance of the ophthalmic lens based on the motion data received from the remote device.

[0033] The motion data can be obtained directly from a plurality of motion sensors, and each motion sensor may or may not be part of the spectacle device. In fact, optionally, the device further includes additional motion sensors, and the control circuit is further configured to receive additional motion data from the additional motion sensors and detect characteristic motions of the wearer's head based on both the motion data and the additional motion data. The plurality of motion sensors can be used to more accurately determine and characterize the motion of the wearer's head, for example, in a given reference frame, the rotation of the wearer's head according to two spatial coordinates. Thus, the up / down component and left / right component of a given rotation of the head can be sensed more accurately.

[0034] In addition, the additional motion sensors can provide additional motion information that is not necessarily directly related to the motion of the wearer's head. For example, a geolocation sensor can help identify different predefined situations or activities of the wearer. An example of such a situation is a rapid geographical movement of the wearer, which may be associated with, for example, a driving activity. Another example of such a situation is that the wearer remains substantially stationary. Considering a given motion of the wearer's head detected by the motion sensor, the control device can be configured to drive the light transmittance of the ophthalmic lens according to different possible control functions depending on the additional motion data, that is, based on the wearer's current situation or activity.

[0035] The motion data can also be estimated by the control circuit instead of being obtained from a motion sensor. In fact, optionally, the control circuit is further configured to obtain motion data by estimating the motion of the wearer's head based on the received light data.

[0036] More precisely, a specific change in the amount of light in the environment over time can be interpreted as corresponding to the motion of the wearer's head, so the motion of the wearer's head can be estimated based on a specific change in the light data obtained from the light sensor over time.

[0037] In this example, the proposed spectacle device can be obtained simply by updating the software to configure the control circuit of an existing spectacle device that includes a light sensor but does not have a motion sensor, so that the motion data is inferred from the light data obtained from the light sensor.

[0038] Optionally, the control circuit is configured to:

[0039] - Determine whether the sensed movement of the wearer's head matches a predefined movement based on the movement data, and then

[0040] - In the case of determining a mismatch, drive the light transmittance of the lens according to a first control function, which defines a first light transmittance value that the lens is to achieve based on a first set of rules based on the light data, so that the control circuit operates in a default mode, and

[0041] - In the case of determining a match, drive the light transmittance of the lens according to a second control function, which defines a second light transmittance value that the lens is to achieve based on a second set of rules, so that the control circuit operates in a specific mode,

[0042] The second set of rules is different from the first set of rules.

[0043] In this example, the light transmittance values to be achieved are different based on whether the movement of the wearer's head matches a predefined movement. More precisely, only when the sensed movement matches the predefined movement is the light data considered to determine the light transmittance value to be achieved.

[0044] Examples of such predefined movements can be turning the head to the left at a predefined speed and / or tilting the head up to a predefined angle.

[0045] To determine whether the sensed movement of the wearer's head matches at least one predefined movement based on the movement data, reference movement data indicating several such predefined movements can be pre-stored in the memory of the controllable circuit as a movement database, and the controllable circuit can be configured to retrieve the movement database and compare the obtained movement data with the movement database.

[0046] Optionally, when a change in the amount of light measured by the light sensor is detected,

[0047] - The first control function varies between an initial light transmittance value and a target light transmittance value, and the target light transmittance value to be achieved is determined as a function of the amount of light measured according to a first rule in the first set of rules, and

[0048] - The second control function varies between an initial light transmittance value and a target light transmittance value, and the target light transmittance value to be achieved is determined as a function of the illuminance measured according to a first rule in the second set of rules,

[0049] wherein the first rule in the first set of rules is different from the first rule in the second set of rules, so that the target light transmittance value of the first control function is different from the target light transmittance value of the second control function.

[0050] Optionally, when a change in the amount of light measured by the light sensor is detected:

[0051] - The first control function varies between an initial light transmittance value and a target light transmittance value according to a first conversion function, the first conversion function defining a first conversion duration for reaching the target light transmittance value,

[0052] - The second control function varies between an initial light transmittance value and a target light transmittance value according to a second conversion function, the second conversion function defining a second conversion duration,

[0053] The first conversion duration is different from the second conversion duration.

[0054] In this example, the control function can be adapted to motion data, related not only to the light transmittance value to be achieved, but also to the conversion duration from the initial light transmittance value to the light transmittance value to be achieved. For example, for some predefined head movements of the wearer, the transition from the transparent state to the dark state can be deliberately slow to enable the wearer to better adapt to the dark state, thus providing better comfort for the wearer.

[0055] Optionally, the light transmittance of the ophthalmic lens is equal to the initial light transmittance value at an initial moment, and the control circuit is configured to:

[0056] - Determine whether the sensed movement of the wearer's head based on the motion data matches a predefined movement, and then

[0057] - In the case of determining a mismatch, drive the light transmittance of the lens according to the first control function, the first control function defining a first light transmittance value to be achieved by the lens based on the first set of rules, so that the control circuit operates in a default mode, and

[0058] - In the case of determining a match, drive the light transmittance of the lens according to the second control function, the second control function defining a second light transmittance value to be achieved by the lens based on the second set of rules, so that the control circuit operates in a specific mode,

[0059] The second set of rules is different from the first set of rules, and

[0060] Both the first light transmittance value and the second light transmittance value to be achieved are different from the initial light transmittance value.

[0061] As a result, depending on the combination of the motion data and the light data, the control circuit selects a default light transmittance mode or a specific light transmittance mode. Both modes define corresponding light transmittance values to be achieved. The two corresponding light transmittance values are different from the initial light transmittance value of the lens when the light transmittance mode is selected. Then the light transmittance of the lens is driven and varies according to the corresponding light transmittance value to be achieved.

[0062] Optionally, the second control function is a constant function, so that driving the light transmittance of the lens according to the second control function corresponds to keeping the light transmittance of the lens unchanged relative to the initial light transmittance value. In this example, if the current head movement of the wearer is recognized as part of a database of predefined head movements of the wearer, the state of the ophthalmic lens can be deactivated from automatically switching due to changes in the intensity of the incident light. This can suppress unwanted changes in light transmittance.

[0063] The present disclosure further describes a method for driving the light transmittance of a variable light transmittance ophthalmic lens, which is implemented by a control circuit and includes:

[0064] - Receiving at least light data from the light sensor configured to measure the amount of light in the environment where the wearer is located, from the light sensor

[0065] - Driving the light transmittance of the ophthalmic lens based on the light data and further based on motion data, the motion data being obtained according to an estimation of the head movement of the wearer.

[0066] Optionally, the method further includes:

[0067] - When no characteristic movement of the wearer detected based on the motion data is detected, determining a first control function that defines the light transmittance value to be achieved by the variable light transmittance ophthalmic lens based on the light data according to a first set of rules, so that the control circuit operates in a default mode, and

[0068] - When a characteristic movement of the wearer's head is detected based on the motion data, determining a second control function that defines the light transmittance value to be achieved by the variable light transmittance ophthalmic lens according to a second set of rules, so that the control circuit operates in a specific mode,

[0069] The second set of rules is different from the first set of rules.

[0070] Optionally, the light transmittance of the ophthalmic lens is equal to the initial light transmittance value at the initial moment, and the method further includes:

[0071] - Determining whether the sensed head movement of the wearer matches a predefined movement based on the motion data, and then

[0072] - When no characteristic movement of the wearer is detected based on the motion data, determine a first control function that defines, based on a first set of rules, the transmittance value to be achieved by the variable transmittance ophthalmic lens based on the light data, thereby controlling the circuit to operate in a default mode, and

[0073] - When a characteristic movement of the wearer's head is detected based on the motion data, determine a second control function that defines, based on a second set of rules, the transmittance value to be achieved by the variable transmittance ophthalmic lens, thereby controlling the circuit to operate in a specific mode,

[0074] The second set of rules is different from the first set of rules, and

[0075] The transmittance values to be achieved are all different from the initial transmittance value.

[0076] Optionally:

[0077] - When a change in the amount of light measured based on the information provided by the ambient light sensor is detected, the first control function varies between an initial transmittance value and a target transmittance value, and the target transmittance value to be achieved is determined as a function of the amount of light measured according to the first rule in the first set of rules, and

[0078] - The second control function varies between an initial transmittance value and a target transmittance value, and the target transmittance value to be achieved is determined as a function of the illuminance measured according to the first rule in the second set of rules, where the first rule in the second set of rules is different from the first rule in the second set of rules, so that the target transmittance value of the first control function is different from the target transmittance value of the second control function.

[0079] Optionally, when a change in the amount of light measured by the light sensor is detected:

[0080] - The first control function varies between an initial transmittance value and a target transmittance value according to a first conversion function, and the first conversion function defines

[0081] - The second control function varies between an initial transmittance value and a target transmittance value according to a second conversion function, and the second conversion function defines a second conversion duration, and the first conversion duration is different from the second conversion duration.

[0082] Optionally, the second function is a constant function, so that the initial transmittance value remains unchanged when a specific head movement is detected while a change in the amount of light is detected.

[0083] The present disclosure further describes a computer program product including a series of instructions that, when executed by a processor, cause the processor to execute any of the above methods.

[0084] The present disclosure further describes a non-transitory computer-readable storage medium storing the above computer program. BRIEF DESCRIPTION OF THE DRAWINGS

[0085] Figure 1 An exemplary glasses device is shown.

[0086] Figure 2 Depicts a flowchart of a general algorithm of an exemplary software for performing a method of a device for performing the proposed control Figure 1 of. DETAILED DESCRIPTION

[0087] Now referring to Figure 1 , which shows an exemplary glasses device.

[0088] An alternative term for the glasses device is a head-mounted device.

[0089] The glasses device includes:

[0090] - A pair of spectacle lenses (101, 102) mounted on a spectacle frame,

[0091] - A light sensor (200) configured to sense the level of visible light incident on the spectacle lenses (101, 102), and

[0092] - For each spectacle lens (101, 102), a processing circuit (301, 302) operably coupled to the light sensor (200).

[0093] The processing circuit (301, 302) is operably coupled to the spectacle lenses (101, 102), for example, by transmitting command signals to the spectacle lenses to drive their light transmittance. Alternatively, the glasses device may include a single processing circuit for driving the light transmittance of both spectacle lenses.

[0094] The glasses device may further include one or more motion sensors (400) configured to sense position, velocity, or acceleration related to linear or rotational motion of the glasses device, and the one or more motion sensors (400) are operably coupled to the processing circuit (301, 302).

[0095] The glasses device may include one or more power supplies (500) for supplying power to the spectacle lenses (101, 102), sensors (200, 400), and processing circuit (301, 302).

[0096] The spectacle lenses (101, 102) are electrically switchable variable light transmittance ophthalmic lenses, either directly or indirectly.

[0097] For example, the spectacle lenses (101, 102) may include an electrochromic material, the visible light transmittance characteristics of which are electrically switchable.

[0098] For example, the spectacle lenses (101, 102) may include a thermochromic material, the visible light transmittance characteristics of which are thermally switchable, and the thermochromic material is associated with an electrical conductor, the temperature of which can be controlled by the current flowing through it.

[0099] More generally, the spectacle lenses (101, 102) may be based on any smart glass technology or a combination thereof, such as electrochromic, thermochromic, photochromic, suspended particle, micro-blind or polymer dispersed liquid crystal technology.

[0100] A light sensor is an optoelectronic device that converts the light energy of visible light detected by the device into electrical energy. Examples include photoresistors, photodiodes and phototransistors.

[0101] The light sensor (200) may be mounted on the spectacle frame, such as on the bridge of the nose, on the lens holder, on the hinge, on the temple, etc.

[0102] The spectacle device may include one or more additional light sensors (200).

[0103] For example, the spectacle device may include a pair of identical light sensors (200), each light sensor being mounted close to a corresponding ophthalmic lens so as to sense the incident light directed towards each spectacle lens (101, 102) respectively.

[0104] For example, the spectacle device may include a plurality of light sensors (200), each light sensor being sensitive to a different visible light wavelength so as to sense, for example, blue light and red light respectively, so as to apply different control functions to the ophthalmic lens according to the spectrum of the incident visible light.

[0105] A motion sensor is a device capable of measuring the position or orientation, linear or rotational speed, or linear or rotational acceleration of a monitored body. In the context of the present invention, the monitored body is the wearer's head.

[0106] Examples of motion sensors include position encoders, accelerometers, gyroscopes and gyrocompasses. The spectacle device may include a combination of different types of motion sensors as an inertial measurement circuit, which may allow the sensing and reporting of, for example, the specific force, angular rate and orientation of the wearer's head.

[0107] Each motion sensor (400) may be mounted on the spectacle frame, such as on the bridge of the nose, on the lens holder, on the hinge, on the temple, etc.

[0108] The processing circuits (301, 302) may include one or more processors operatively coupled to one or more memories and one or more communication interfaces with the eyeglass lenses (101, 102) and sensors (200, 400). The communication between the processing circuit and the sensors may be wired or wireless. In particular, wireless communication may allow information to be collected not only from sensors embedded in the eyewear device, but also from any remote device equipped with sensors.

[0109] For example, the processing circuit may be configured to collect activity data from the processing circuit of a remote device and / or geolocation data from a GPS embedded in the remote device. Examples of such remote devices include smartphones, the electronic control circuit of a vehicle, or an electronic watch. Driving activities, running activities, etc. may be inferred based on the geolocation data.

[0110] At the initial moment when the wearer wears the eyewear device, the eyeglass lenses (101, 102) have an initial light transmittance value.

[0111] Now refer to Figure 2 , which shows a software algorithm that may be stored in the memory and executed by the processor of the processing circuits (301, 302) to perform a method for driving the light transmittance of the eyeglass lenses (101, 102) starting from the initial light transmittance value at the initial moment.

[0112] The processing circuits (301, 302) obtain OBT LGT DATA(S1) of light data from at least one light sensor (200).

[0113] For example, consider a photodiode mounted on the eyewear device as the light sensor (200). The photodiode outputs an electrical signal at any given moment, and its current is a function of the amount of visible light incident on the photodiode.

[0114] More generally, at least one light sensor (200) outputs electrical signals over time. These electrical signals carry or contain light data indicating the amount of visible light incident in the environment where the wearer is located. The light data is transmitted to the processing circuits (301, 302).

[0115] For example, the obtained light data may indicate:

[0116] - The initial amount of visible light incident in the environment where the wearer is located at the initial moment, and

[0117] - At the current moment, i.e., after the initial moment, the current amount of visible light incident in the environment where the wearer is located.

[0118] The obtained light data may be stored by the processing circuit as a time series for further processing.

[0119] The movement data is obtained by the processing circuits (301, 302) as OBT MVT DATA (S2).

[0120] In some examples, the movement data can be derived from the light data. In fact, some specific changes in the incident visible light sensed by one or more light sensors may be due to the movement of the wearer's head.

[0121] For example, when driving at night, the light conditions are mostly dim. A strong light source (such as the vehicle's headlights) may appear in the mirror. In this case, when the driver turns their head towards the mirror, the amount of incident light sensed by the light sensors equipped in the glasses device worn by the wearer increases. The movement data indicating such head movement can be obtained by the processing circuits (301, 302) based on the obtained light data indicating such an increase. For example, some specific changes in the light data over time can be associated with some predefined head movements of the wearer through a correspondence table.

[0122] In some examples, the movement data can be obtained from one or more motion sensors (400) of the glasses device.

[0123] For example, consider the accelerometer installed on the glasses device as the motion sensor (400). The accelerometer outputs an electrical signal at any given moment, the current of which is a function of the linear acceleration of the glasses device in a given direction. Since in the context of the present disclosure, the glasses device is worn, this linear acceleration can be used to estimate the movement of the wearer or the wearer's head in the given direction.

[0124] More generally, if the glasses device is equipped with one or more motion sensors (400), the one or more motion sensors (400) can output electrical signals over time. These electrical signals carry or contain movement data related to the movement of the wearer's head. The movement data is transmitted to the processing circuits (301, 302).

[0125] In some examples, the movement data can be obtained from one or more motion sensors of a remote device.

[0126] For example, consider a smartphone equipped with a camera as a remote device. If the wearer is currently driving a vehicle and the smartphone is located in the vehicle and facing the wearer, the camera of the smartphone can be used to determine the true movement of the wearer's head, which is independent of the movement of the vehicle. This determination can be transmitted as movement data to the processing circuit of the glasses device. More generally, a remote device equipped with motion sensors can be used to determine the movement of the wearer's head. The movement data is transmitted to the processing circuits (301, 302).

[0127] Additional sensors, such as additional motion sensors, geolocation sensors, acoustic sensors, pulse sensors, etc., can be used to detect the type of activity of the wearer. For example, an electronic watch equipped with a pulse sensor and / or a geolocation sensor can be used to determine the time when the wearer is currently running. This determination is transmitted as activity data to the processing circuits (301, 302).

[0128] It has been described above that motion data can be obtained from various sources, namely, for example, obtained from light data, or received from a motion sensor (400) equipped in the glasses device, or received from a motion sensor equipped in a remote device. It should be noted that motion data can also be obtained from a combination of these sources.

[0129] In some examples, the change in the amount of incident visible light over time is detected or monitored by the processing circuits (301, 302) based on the obtained light data DET LGT VAR(S3).

[0130] An example of the change in incident light over time is the difference between the initial amount of incident visible light in the environment where the wearer is located at the initial moment and the current amount of incident visible light in the environment where the wearer is located at the current moment (i.e., after the initial moment).

[0131] In fact, the amount of incident visible light is a function of time, and the change in this amount over time can be detected by differentiating the function.

[0132] Therefore, if the amount of incident light continuously decreases within a predetermined time interval starting from the initial moment and ending at the current moment, the first derivative is negative within the predetermined time interval. On the contrary, if the amount of incident light continuously increases within the predetermined time interval, the first derivative is positive within the predetermined time interval.

[0133] The determined change in incident visible light over time is related to the change in the level of ambient visible light in the environment where the wearer is located. The ambient visible light comes from one or more light sources in the environment where the wearer is located, and the amount of visible light sensed depends on the relative position of the one or more light sources with respect to the glasses device. The position of the glasses device over time is closely related to the change in the position and / or orientation of the wearer's head over time.

[0134] Based on the foregoing, it can be considered that the determined change in incident visible light is related not only to the change in the amount of ambient visible light in the environment where the wearer is located, but also to the change in the position and / or orientation of the wearer's head.

[0135] In some examples, the change in the position and / or orientation of the wearer's head over time is detected or monitored by the processing circuits (301, 302) based on the obtained motion data.

[0136] In some examples, a specific movement of the wearer's head is identified by the processing circuitry (301, 302) as ID MVT (S4) based on the acquired movement data or based on the determined changes in the position and / or orientation of the wearer's head over time.

[0137] Examples of specific movements can include a specific linear movement along a given axis, such as a vertical axis or a horizontal axis.

[0138] The specific linear movement can include a linear movement over a predetermined distance, or a linear movement over a predetermined speed, or a linear movement over a predetermined acceleration.

[0139] In an example, the specific movement can correspond to a movement of the wearer's head in a specific direction with a specific speed or acceleration curve or value.

[0140] Examples of specific movements can include a specific rotational movement around a given axis, such as a vertical axis or a horizontal axis.

[0141] The specific rotational movement can include a rotational movement over a predetermined angle, or a rotational movement over a predetermined angular velocity, or a rotational movement over a predetermined rotational acceleration.

[0142] Examples of specific movements can include a combination of rotational and linear movements, which correspond to simultaneous changes in the position and orientation of the wearer's head.

[0143] Examples of specific movements can include a series of the above-identified movements, which correspond to a series of successive changes in the position and / or orientation of the wearer's head.

[0144] Various examples of specific movements can be stored in a movement database and can correspond to different situations.

[0145] As an example, the specific movement can be a back-and-forth movement corresponding to the wearer driving and briefly turning their head to one side of the side mirror and back.

[0146] As an example, the specific movement can be a downward movement corresponding to the wearer bending down towards the ground (such as when playing golf or serving in tennis).

[0147] In some examples, a rule set can be selected by the processing circuitry (301, 302) as SLC RULE SET (S5) based on light data and / or based on movement data. The rule set is selected from a plurality of predetermined rule sets. Then, the selected rule set is used to determine a driving function for driving the light transmittance of the spectacle lenses (101, 102). In other words, the light transmittance of the spectacle lenses (101, 102) can be driven based on different possible driving functions, where each possible driving function is determined based on the corresponding rule set.

[0148] The selection of a rule set may be triggered based on at least one preset condition, which depends on one or more of light data, motion data, activity data and any other data available to the processing circuit (301, 302), such as time data provided by an internal clock or meteorological data downloaded from a remote server.

[0149] In some examples, the preset condition may correspond to whether the amount of incident visible light changes. In those examples, the selection of the rule set is triggered based on detecting that the amount of incident visible light changes over time by more than a predetermined level. In fact, if no or little change in the amount of incident visible light is detected between the initial moment and the current moment, there is no reason to modify the transmittance of the eyeglasses (101, 102) at the current moment, and the current transmittance value may remain equal to the initial transmittance value. On the contrary, if a large change in the amount of incident visible light is detected between the initial moment and the current moment, it may be necessary to drive the transmittance of the eyeglasses (101, 102) so that the current transmittance value at the current moment is different from the initial transmittance value, for example, to compensate for the change in the amount of incident visible light.

[0150] In some examples, the preset conditions can be inferred from data available to the processing circuit (301, 302) and correspond to current activity, current time, current weather conditions, etc. In particular, the wearer's current activity type can provide additional conditions to be met to trigger the selection of the rule set. For example, during a cloudy to sunny day period, during outdoor activities, brightness changes can be expected, and the transmittance of the eyeglass lenses (101, 102) can be driven accordingly to adapt to the alternation of sunny and cloudy periods.

[0151] In contrast, for example when driving at night, it is expected that ambient light conditions will remain substantially constant, and the transmittance of the eyeglass lenses (101, 102) can be driven accordingly to ignore any temporary substantial changes in the amount of incident visible light.

[0152] A plurality of rule sets may be predefined, and the plurality of rule sets may correspond to different situations.

[0153] In some examples, a specific rule set may be associated with a predetermined specific movement of the wearer's head. In those examples, the selection of the specific rule set is based on motion data, in particular motion data regarding whether the current movement of the person's head matches the predetermined specific movement. For example, upon detection of brief and frequent movements of the wearer's head (such as during sports or other physical activities), a specific rule set may be selected so that the eyeglasses (101, 102) may be driven in a specific mode in which the transmittance of the eyeglasses (101, 102) is maintained at a constant value to avoid changes in transmittance that may be detrimental to the wearer during the activity.

[0154] Multiple expected motion data (each motion data corresponding to a predetermined specific motion) can be associated with corresponding specific rule sets via a database.

[0155] The motion data currently obtained by the processing circuits (301, 302) can be compared with the expected motion data, and upon finding a match, the specific rule set associated with the matching motion data is selected.

[0156] In combination with the motion data, additional data can also be considered to select a specific data set. In fact, in some examples, multiple expected activity data (each expected activity data corresponding to a specific activity type of the wearer) can be associated with an array of expected motion data and corresponding specific rule sets via a database. In this way, as long as the activity data matches the expected type of activity data, the motion data currently obtained by the processing circuits (301, 302) can be compared with the expected motion data associated with the expected type of activity data. Upon finding a match, the specific rule set associated with the matching motion data and the matching activity data type can be selected.

[0157] If the current motion of the wearer's head does not match any predetermined specific motion, or if the wearer's head remains substantially stationary for a long time, a default rule set can be selected, so that the lens (101, 102) can be driven in a default mode, in which the light transmittance of the lens (101, 102) can be adapted, for example, to compensate for the change in the sensed visible light amount over time.

[0158] Based on the selected rule set (which is a specific rule set or a default rule set), a control function can be determined by the processing circuits (301, 302) in view of the light transmittance of driving the lens (101, 102).

[0159] The control function defines how to drive the light transmittance from an initial light transmittance value to a target light transmittance value to be achieved. The control function can be continuous or discrete, which means different intermediate levels of light transmittance. The control function can specify a transition duration that defines the time span for driving the light transmittance from the initial light transmittance value to the target light transmittance value to be achieved.

[0160] In some examples, the target light transmittance value to be achieved can be determined by the processing circuits (301, 302) based on the selected rule set DET TGT T(S6).

[0161] More specifically, each rule set can include a first rule for determining the target light transmittance value to be achieved according to the incident light amount measured at the current moment.

[0162] The first rule may differ between a given specific rule set and the default rule set. Since the rule set can be selected based on the current movement of the wearer's head, for example, the determined target light transmittance value to be achieved may be different regardless of whether the movement matches a predefined specific movement.

[0163] In an example, the first rule in the specific rule set can cause the specific target light transmittance value to be achieved in a specific mode to always remain within specific boundary values, and these specific boundary values define a part of the range of allowable conversion values in the default mode.

[0164] In an example, the first rule in the specific rule set can cause the specific target light transmittance value to be achieved in a specific mode to be set equal to the initial light transmittance value.

[0165] In an example, the first rule in the default rule set can cause the default target light transmittance value to be achieved in the default mode to be a function of the currently sensed light amount. For example, if the currently sensed light amount is greater than the initially sensed light amount, the default target light transmittance value to be achieved in the default mode is less than the initial light transmittance value, so the spectacle lenses (101, 102) will change from a transparent state to a darker state. For example, if the currently sensed light amount is less than the initially sensed light amount, the default target light transmittance value to be achieved in the default mode is greater than the initial light transmittance value, so the spectacle lenses (101, 102) will change from a dark state to a more transparent state.

[0166] However, it is not required that the first rules in all rule sets be different. In fact, even in some examples, for all specific modes and for the default mode, the target light transmittance values to be achieved may be the same, but the driving functions may still be different regardless of whether a given specific rule set or the default rule set is applied.

[0167] For example, based on the selected rule set, the transition duration can be determined by the processing circuits (301, 302) DETTGT DUR(S7). More specifically, each rule set can include a second rule that defines the transition duration between the initial light transmittance value and the target light transmittance value.

[0168] The second rule may differ between a given specific rule set and the default rule set. Since the rule set can be selected based on the current movement of the wearer's head, for example, the determined transition duration may be different regardless of whether the movement matches a predefined specific movement.

[0169] In some examples, the second rule in the specific rule set can cause the transition duration to be much longer in the corresponding specific mode, such as twice or ten times the transition duration in the default mode.

[0170] In such an example, as long as the wearer has a specific head movement, the light transmittance of the spectacle lenses (101, 102) can slowly adapt to the change in ambient light so as to minimize the apparent change in light transmittance that may interfere with the wearer. In addition, in the default mode, as long as the wearer does not have any specific head movement, the light transmittance of the spectacle lenses (101, 102) can adapt to the change in ambient light as quickly as possible to optimize the comfort of the wearer.

[0171] The light transmittance of the spectacle lenses (101, 102) is then driven by the processing circuit based on the obtained light data and the obtained motion data DRIV T (S8).

[0172] For example, the light transmittance of the spectacle lenses (101, 102) can be driven according to a determined control function.

[0173] Thus, if the light data indicates a change in light between the initial time and the current time, and the motion data indicates that the wearer's head has experienced a predetermined movement, the light transmittance of the spectacle lenses (101, 102) can be driven according to a specific mode.

[0174] Conversely, if the light data indicates a change in light between the initial time and the current time, and the motion data indicates that the wearer's head has not experienced a predetermined movement, the light transmittance of the spectacle lenses (101, 102) can be driven according to the default mode.

[0175] At least one combination of a specific mode and the default mode allows the processing circuit (301, 302) to control the light transmittance of the spectacle lenses (101, 102) so as to provide the benefit of automatic change in light transmittance when the ambient light conditions change over time, without providing an unwanted change in light transmittance when the sensed light amount changes due to the wearer's head movement rather than the actual change in ambient light conditions over time.

Claims

1. A spectacle device for a wearer, the spectacle device comprising at least: - a variable light transmittance ophthalmic lens, - a light sensor configured to measure the amount of light in the environment where the wearer is located, - a control circuit configured to receive at least light data from the light sensor and drive the light transmittance of the ophthalmic lens based on the light data, wherein the control circuit is further configured to drive the light transmittance of the ophthalmic lens based on motion data obtained from an estimation of the movement of the wearer's head, wherein the light transmittance of the ophthalmic lens is equal to an initial light transmittance value, and the control circuit is configured to: - determine whether the sensed movement of the wearer's head matches a predefined movement based on the motion data, and then - in the case of a determination of non - matching, drive the light transmittance of the lens according to a first control function, the first control function defining a first light transmittance value to be achieved by the lens based on a first set of rules according to the light data, such that the control circuit operates in a default mode, and - in the case of a determination of matching, drive the light transmittance of the lens according to a second control function, the second control function defining a second light transmittance value to be achieved by the lens according to a second set of rules, such that the control circuit operates in a specific mode, wherein the second set of rules is different from the first set of rules, and both the first light transmittance value and the second light transmittance value to be achieved are different from the initial light transmittance value.

2. The device according to claim 1, wherein The control circuit is further configured to obtain the motion data by estimating the movement of the wearer's head based on the received light data.

3. The device according to claim 1, wherein: - the device further comprises a motion sensor configured to sense the movement of the wearer's head, and - the control circuit is further configured to obtain the motion data by receiving, from the motion sensor, the motion data indicating the movement of the wearer's head sensed by the motion sensor.

4. The device according to claim 3, wherein: - the device further comprises an additional motion sensor, and the control circuit is further configured to receive additional motion data from the additional motion sensor and detect a characteristic movement of the wearer's head based on both the motion data and the additional motion data.

5. The apparatus according to claim 1, wherein, When a change in the amount of light measured by the light sensor is detected, - the first control function varies between the initial light transmittance value and a target light transmittance value, the target light transmittance value to be achieved being determined as a function of the amount of light measured according to a first rule in the first set of rules, and - the second control function varies between the initial light transmittance value and a target light transmittance value, the target light transmittance value to be achieved being determined as a function of the illuminance measured according to a first rule in the second set of rules, wherein the first rule in the first set of rules is different from the first rule in the second set of rules, such that the target light transmittance value of the first control function is different from the target light transmittance value of the second control function.

6. The device according to claim 1, wherein When a change in the amount of light measured by the light sensor is detected: - The first control function varies between an initial light transmittance value and a target light transmittance value according to a first conversion function, the first conversion function defining a first conversion duration for reaching the target light transmittance value, - The second control function varies between the initial light transmittance value and the target light transmittance value according to a second conversion function, the second conversion function defining a second conversion duration, The first conversion duration is different from the second conversion duration.

7. The spectacle device according to claim 1, wherein, The second control function is a constant function, such that driving the light transmittance of the lens according to the second control function corresponds to keeping the light transmittance of the lens unchanged relative to the initial light transmittance value.

8. A method for driving the light transmittance of a variable light transmittance ophthalmic lens, the method being implemented by a control circuit and comprising: - Receiving at least light data from a light sensor configured to measure the amount of light in the environment of the wearer, - Driving the light transmittance of the ophthalmic lens based on the light data and further based on motion data, the motion data being derived from an estimation of the head movement of the wearer, wherein the method further comprises that the light transmittance of the ophthalmic lens is equal to an initial light transmittance value: - Determining a first control function when no characteristic movement of the wearer detected based on the motion data is detected, the first control function defining a first light transmittance value to be reached by the variable light transmittance ophthalmic lens based on the light data according to a first set of rules, such that the control circuit operates in a default mode, and - Determining a second control function when a characteristic movement of the head of the wearer is detected based on the motion data, the second control function defining a second light transmittance value to be reached by the variable light transmittance ophthalmic lens according to a second set of rules, such that the control circuit operates in a specific mode, The second set of rules is different from the first set of rules, and Both the first light transmittance value and the second light transmittance value to be reached are different from the initial light transmittance value.

9. The method according to claim 8, wherein: - When a change in the amount of light measured based on the information provided by the ambient light sensor is detected, the first control function varies between an initial light transmittance value and a first target light transmittance value, the first target light transmittance value to be reached being determined as a function of the amount of light measured according to a first rule in the first set of rules, and - The second control function varies between an initial light transmittance value and a second target light transmittance value, the second target light transmittance value to be reached being determined as a function of the measured illuminance according to a first rule in the second set of rules, wherein the first rule in the first set of rules is different from the first rule in the second set of rules, such that the first target light transmittance value of the first control function is different from the second target light transmittance value of the second control function.

10. The method according to claim 8, wherein, When a change in the amount of light measured by the light sensor is detected: - The first control function varies between the initial light transmittance value and the first target light transmittance value according to the first conversion function, and the first conversion function defines a first conversion duration. - The second control function varies between the initial light transmittance value and the second target light transmittance value according to the second conversion function, and the second conversion function defines a second conversion duration, and the first conversion duration is different from the second conversion duration.

11. The method according to claim 8, wherein, The second control function is a constant function, so that the initial light transmittance value remains unchanged when a specific head movement is detected while a change in the amount of light is detected.

12. A computer program product comprising a series of instructions which, when executed by a processor, implement the method according to claim 8.

13. A non-transitory computer-readable storage medium storing the computer program according to claim 12.

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