Dynamic control of transmittance values

Abstract

The present disclosure relates to a method, a control unit, a pair of glasses, a computer program and a computer readable storage medium for controlling the optical transmission of a variable-transmission ophthalmic lens, the method comprising: * receiving (S1) from a light sensor a measured illuminance of the wearer's environment, * calculating (S2) a change in illuminance measured during a predetermined time interval, * comparing (S3) the calculated change in illuminance to a first threshold, * when the calculated change in illuminance is greater than the first threshold, implementing (S4) a first command configured for varying the transmission of the variable-transmission ophthalmic lens from an initial transmission value corresponding to a current transmission value to a first target transmission value according to a first variation profile, the first variation profile comprising a first phase during which the transmission overshoots the first target transmission value and a second phase during which the transmission returns to the first target transmission value.

Description

Technical Field

[0001] This invention relates to a method for controlling the optical transmittance of a variable transmittance ophthalmic lens. Background Technology

[0002] As those skilled in the art know, variable transmittance ophthalmic lenses can limit glare discomfort while maintaining visual performance.

[0003] For example, variable transmittance ophthalmic lenses may include an electrochromic layer or liquid crystal layer that is controlled to modify the lens's optical transmittance when changes in the wearer's ambient light are detected. Typically, the brighter the environment (E, for example, in lux), the darker the lens, i.e., the lower the lens's optical transmittance, and vice versa.

[0004] Typically, a variable transmittance lens is controlled to adjust its transmittance when a change in ambient illuminance is detected, and a transmittance set is determined based on the illuminance measured after the change in illuminance is detected.

[0005] In reality, ambient light can vary from tens of lux (quite dark inside) to tens of k. lux (bright outside) – without mentioning conditions corresponding to night vision. This means that a ratio of around 1000 in some extreme cases, and some ratios that are usually over 100, will characterize the changes in ambient light experienced by the wearer.

[0006] Considering photochromic lenses, their transmittance can vary between 90% and 10% for Class 3 eyewear and between 90% and 4% for Class 4 eyewear. Therefore, the corresponding attenuation factors are 9 (90 / 10) and 22.5 (90 / 4), respectively.

[0007] Therefore, it is impossible to sufficiently attenuate changes in the wearer's light environment to maintain a essentially constant perceived light level during these changes. This may lead to discomfort for the wearer when the transmittance of a variable transmittance ophthalmic lens changes.

[0008] In view of the above, it is necessary to mitigate at least some of the inconveniences of the existing technology.

[0009] In particular, there is a need to provide a method for controlling ophthalmic lenses with variable transmittance, thereby improving wearer comfort during sudden changes in ambient light. Summary of the Invention

[0010] Therefore, this disclosure describes a method for controlling the optical transmittance of a variable transmittance ophthalmic lens, the method being implemented by a control unit and comprising:

[0011] * Receives measurement parameters related to the wearer's ambient light level from the ambient light sensor.

[0012] *Illuminance variation is calculated based on the values ​​of parameters measured during a predetermined time interval.

[0013] * Compare the calculated change in illuminance with the first threshold.

[0014] When the calculated change in illuminance is greater than a first threshold, a first command is executed. This first command is configured to change the transmittance of the variable transmittance ophthalmic lens from an initial transmittance value corresponding to the current transmittance value to a first target transmittance value according to a first change curve. The first change curve includes a first stage and a second stage, during which the transmittance exceeds the first target transmittance value and during which the transmittance returns to the first target transmittance value.

[0015] "Ambient light sensor" should be understood as any sensor that is sensitive to light (such as visible light, IR light, or UV light) and can measure the amount of said light.

[0016] "Parameters related to the wearer's ambient illuminance" should be understood as the light level within the wavelength range that the ambient light sensor is sensitive to.

[0017] The wearer’s ambient illuminance can be derived or calculated from the measured values ​​of the parameters, for example by using a light emission spectrum model associated with a given light source, such as the light emission spectrum model of the sun.

[0018] The "first threshold" can be understood as, for example:

[0019] - Absolute threshold, in other words, the change in illuminance over time can be compared to an absolute value, or

[0020] - Relative threshold, in other words, the change in illuminance over time can be divided by the initial illuminance value, and the resulting ratio can be compared with the absolute value, or

[0021] - The variable threshold is a function of the initial illuminance; in other words, the variable threshold may have different values ​​regardless of whether the ambient light is initially dark or bright.

[0022] It is believed that the initial transmittance value of an ophthalmic lens is the transmittance value at the initial moment when the calculated change in illuminance is compared with the first threshold.

[0023] It is believed that overshoot means exceeding the target. Therefore, if the transmittance is to be increased to reach the first target transmittance value, then exceeding the first target transmittance value means reaching a transmittance value higher than the first target transmittance value.

[0024] Conversely, if the transmittance is to be reduced to the first target transmittance value, then a transmittance exceeding the first target transmittance value means reaching a transmittance value lower than the first target transmittance value.

[0025] It is understood that implementing the first command and implementing the second command correspond to applying a corresponding command signal, which causes a change in the transmittance of the ophthalmic lens. For example, the ophthalmic lens may include one of an electrochromic layer and a liquid crystal layer placed between two command electrodes. Implementing the first command or the second command may involve applying a command signal to the command electrodes.

[0026] By providing successive overshoot and return, the transmittance variation based on the first command is allowed:

[0027] By quickly buffering the risk of immediate glare for the wearer, the sudden change in brightness is mitigated.

[0028] It restores some dynamics of transmittance to prepare for drastic changes in future brightness, while following the eye's adaptation to light and improving contrast.

[0029] By conditionally implementing the first command based on a calculation-based comparison of illuminance changes with a first threshold, the transmittance of ophthalmic lenses can be commanded and controlled using a dedicated change curve to prevent the immediate risk of glare when illuminance changes particularly rapidly.

[0030] In some examples, the method further includes: when the absolute value of the calculated illuminance change is less than or equal to the absolute value of a first threshold, implementing a second command to change the transmittance of the transmittance-variable ophthalmic lens according to a monotonic change curve.

[0031] This allows for the provision of, for example, classic variation curves, provided that the illuminance changes slowly enough, so that the transmittance of ophthalmic lenses can smoothly adapt to the evolution of illuminance.

[0032] In some examples, the method further includes maintaining the transmittance value of the variable transmittance ophthalmic lens at the initial transmittance value when the absolute value of the calculated illuminance change is less than or equal to the absolute value of a first threshold.

[0033] This allows for consistently providing the same transmittance value as long as the rate of change in illuminance does not exceed a first threshold, thus avoiding unnecessary transmittance variations that might disturb the wearer. This can be useful for certain activities where ambient illuminance is typically kept at a constant low level, but may occasionally rise rapidly to a high level due to brief passage through the main light source.

[0034] In some examples, the method includes: further comparing the calculated illuminance change with a first threshold, comparing the current value of the measured parameter with the parameter threshold, and then:

[0035] - When the current value of the measured parameter is greater than the parameter threshold and the calculated illuminance change is greater than the first threshold, execute the first command.

[0036] In addition, the method may include: when the current value of the measured parameter is less than a parameter threshold, implementing a command configured to maintain the transmittance at an initial transmittance value.

[0037] This is particularly useful in situations such as nighttime driving, where illuminance remains at a low absolute value, but detected illuminance changes may have a high relative value. In situations where the wearer must not be disturbed, any commands that might cause changes in transmittance should be ignored or not implemented, so that transmittance remains constant over time.

[0038] More generally, the implementation or non-implementation of the first command can be based on:

[0039] - Compare the current value of parameters related to ambient illuminance with the corresponding threshold, or

[0040] - Compare the change of the parameter over the time interval with another corresponding threshold, or

[0041] - The result of a function that combines the current value of the parameters with their change over time is compared with the corresponding threshold.

[0042] Such a function, for example, can allow the transmittance to be maintained at a predetermined constant value under low illumination conditions, and under high illumination conditions, the transmittance to be controlled to change over time according to a specific command selected based on the relative change of illumination over time.

[0043] In some examples, the method further includes: when the absolute value of the calculated change in illuminance is less than or equal to the absolute value of a first threshold,

[0044] * Compare the calculated change in illuminance with the second threshold, and then...

[0045] *When the absolute value of the calculated illuminance change is greater than the absolute value of the second threshold, a second command is executed to change the transmittance of the variable transmittance ophthalmic lens from the initial transmittance value to the second target transmittance value according to the monotonic change curve, and

[0046] *When the absolute value of the calculated change in illuminance is less than or equal to the absolute value of the second threshold, the transmittance value of the variable transmittance ophthalmic lens is maintained at the initial transmittance value.

[0047] Then, the ophthalmic lens can be controlled according to one of three different modes, depending on whether the change in illuminance is drastic (above the first threshold), normal (above the second threshold), or negligible.

[0048] In some examples, the first command includes instructions for changing the transmittance of the transmittance-variable ophthalmic lens over time based on the sum of a standard function and an overshoot function.

[0049] *The standard function defines the monotonic change in transmittance from the initial transmittance value to the first target transmittance value, and

[0050] The overshoot function defines the transmittance overshoot value, the duration of the overshoot phase, and the duration of the decay phase.

[0051] In some examples, the second command includes instructions for changing the transmittance of a transmittance-variable ophthalmic lens over time according to a standard function.

[0052] For example, the standard function can be the default function applied to all transmittance changes, while the overshoot function can be applied over the standard function only in specific cases where the illuminance change is drastic, as a result of implementing the first command signal.

[0053] In some examples, different overshoot functions are used depending on whether the calculated change in illuminance is positive or negative.

[0054] This allows for improved comfort for the wearer. For example, the selection of the overshoot function can be adapted to the wearer's physiological parameters, respectively, regarding their adaptation to increases and decreases in transmitted light.

[0055] In some examples, the first target transmittance value is determined based on illuminance.

[0056] For example, the transmittance value of the first target can be determined based on the illuminance change that triggers the implementation of the first command.

[0057] Additionally, the first target transmittance value can be updated based on further illuminance changes obtained after the first command has been triggered.

[0058] This allows for the determination of the desired transmittance value in order to compensate for successive variations in illuminance values.

[0059] In some examples, the transmittance overshoot value is determined based on the difference between the calculated illuminance change and a first threshold.

[0060] By overshooting the first target transmittance value, the response time is minimized. When the calculated illuminance change is significantly higher than this first threshold, the response time can be preferably reduced, or even further. This can be achieved by setting, or even further, transmittance overshoot values.

[0061] In some embodiments, the method further includes: after the first command is executed, the transmittance function of the variable transmittance ophthalmic lens has a temporary value.

[0062] *Based on the received measurements, calculate further changes in illuminance during subsequent time intervals.

[0063] *The calculated further changes in illuminance are compared with the first threshold.

[0064] *When the absolute value of the calculated further illuminance change exceeds the absolute value of the first threshold, the transmittance change generated by the first command is interrupted, and a third command is executed to change the transmittance of the variable transmittance ophthalmic lens from a temporary transmittance value to a third target transmittance value.

[0065] *When the absolute value of the calculated further illuminance change is less than or equal to the absolute value of the first threshold, the transmittance change generated by the first command continues.

[0066] This allows the change in transmittance to be interrupted when the current illuminance is detected to have returned to near its initial value, thus eliminating the need for a fast response time to prevent glare.

[0067] In some examples, the second target transmittance value corresponds to the initial transmittance value.

[0068] This allows the cancellation of the first command and associated transmittance changes during the process.

[0069] In some examples, the first threshold is based on the wearer's physiological parameters.

[0070] This allows for rapid transmittance changes when a change in the detected light intensity exceeds a threshold customized for each specific wearer. Consequently, comfort for each individual wearer is optimized.

[0071] This disclosure further describes a control unit configured to implement the above-described method.

[0072] This disclosure further describes an eyeglass intended for wear by a wearer, the eyeglass comprising:

[0073] - At least one ophthalmic lens with variable transmittance

[0074] - An ambient light sensor, configured to measure values ​​of parameters related to ambient illuminance, and

[0075] -The aforementioned control unit is coupled to a variable transmittance ophthalmic lens and an ambient light sensor.

[0076] This disclosure further describes a computer program product comprising a series of instructions that, when executed by a processor, implement the above-described method.

[0077] This disclosure further describes a non-transitory computer-readable storage medium storing the aforementioned computer program. Attached Figure Description

[0078] To gain a more complete understanding of the descriptions and advantages provided herein, please refer now to the following brief description in conjunction with the accompanying drawings and detailed description, wherein the same reference numerals denote the same parts.

[0079] Figure 1 An exemplary eyeglasses device is shown.

[0080] Figure 2 The proposed control is described. Figure 1 A flowchart of a general algorithm for an exemplary software method of the apparatus.

[0081] Figure 3 The superposition of two curves depicting the variation of the transmittance function of a transmittance-variable ophthalmic lens according to the exemplary first command and the exemplary second command, respectively. Detailed Implementation

[0082] Now for reference Figure 1 The figure shows an exemplary eyeglass device.

[0083] The eyeglasses device includes:

[0084] -A pair of variable transmittance ophthalmic lenses (100) mounted on the eyeglass frame.

[0085] - A light sensor (200) configured to sense the level of visible light, or illuminance, incident on the lens (100), and

[0086] - Control unit (300), which is coupled to the light sensor and the lens.

[0087] The eyewear device may include one or more power sources (400) for providing power to the lenses (100), the light sensor (200), and the control unit (300).

[0088] Each lens (100) has a transmittance function that can be directly or indirectly controlled by an electrical command signal.

[0089] For example, each lens (100) may include an electrochromic material whose visible light transmittance characteristics are electrically switchable, for example, as a layer placed between two command electrodes. For example, each lens (100) may include a thermochromic material whose visible light transmittance characteristics are thermally switchable, the thermochromic material being associated with an electrical conductor whose temperature can be controlled by a flowing current. More generally, each lens (100) may be based on any smart glass technology or a combination thereof, such as electrochromic technology, thermochromic technology, photochromic technology, suspended particle technology, micro-blind technology, or polymer-dispersed liquid crystal technology.

[0090] 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. The light sensor (200) can be mounted on an eyeglass frame, such as on a nose bridge, lens holder, hinge, temple, etc. An eyeglass device may include one or more additional light sensors (200). For example, an eyeglass device may include a pair of identical light sensors (200), each mounted close to a corresponding ophthalmic lens, to sense incident light incident on each lens (100) respectively. Alternatively, an eyeglass device may include multiple light sensors (200), each sensitive to different wavelengths of visible light, to sense, for example, blue and red light respectively, thereby applying different control functions to the ophthalmic lenses according to the spectrum of the incident visible light.

[0091] The control unit (300) may include one or more processors operatively coupled to one or more memories and one or more communication interfaces with the lens (100) and the light sensor (200). Communication between the control unit, the lens, and the light sensor may be wired or wireless.

[0092] At the initial moment when the wearer puts on the glasses device t i Each of the lenses (100) has an initial transmittance value T. i Initial transmittance value T i It can be preset based on the ambient illuminance at the initial moment. For example, in a bright environment, the initial transmittance value T i It can be preset to a low value, such as 20% or lower, to darken the incident light and protect the wearer from glare. For example, in a dark environment, the initial transmittance value T i It can be preset to a high value, such as 80% or higher, to allow incident light to pass through and improve the wearer's comfort.

[0093] Now for reference Figure 2 The figure illustrates a software algorithm that can be stored in memory and executed by the processor of the control unit (300) to perform a method for driving the transmittance of the lens (100).

[0094] The control unit (300) obtains successive measurements of the ambient illuminance of the wearer over time from the light sensor (200) for RECE(S1). These measurements can be collected, for example, at fixed time intervals dt (e.g., per second).

[0095] In the context of this disclosure, the illuminance measurement indicates the total amount of incident light energy in a predetermined wavelength range that can be sensed by the light sensor (200). This predetermined wavelength range is specific to the light sensor (200) and corresponds to at least a portion of the visible light wavelength range.

[0096] Each measurement value obtained can be stored by the control unit as a timestamp indicating the ambient illuminance of the wearer at the time of measurement.

[0097] Based on the obtained measurements, the control unit (300) calculates CPTΔE1(S2) at the initial time t. i initial illuminance E i With the current time t cur Current illuminance E cur The change in illuminance between them is ΔE1=E cur –E i Initial time t i With the current time t cur The time interval can include the integral time used to filter out significant changes in illuminance from sudden events.

[0098] The absolute value of the illuminance change ΔE1, |ΔE1|, indicates the magnitude of the change.

[0099] The sign of the illuminance change ΔE1 indicates the initial time t. i With the current time t cur Whether the illuminance increases (if the sign is positive) or decreases (if the sign is negative).

[0100] The control unit (300) compares the calculated illuminance change with a first threshold ΔE. lim1 Compare CMPΔE1 / ΔE lim1 (S3).

[0101] First threshold ΔE lim1 It is a preset non-null value, which corresponds to a limit beyond which the change in illuminance is considered steep or drastic.

[0102] First threshold ΔE lim1 It can be preset as, for example, an absolute value or a calculated value (e.g., as a relative value of the initial illuminance).

[0103] First threshold ΔE lim1 For example, presets can be made based on the wearer's physiological parameters such as sensitivity to glare, average contrast recovery time after glare, pupil size, and dynamics.

[0104] First threshold ΔE lim1 It can be adjusted through possible interaction with the wearer based on artificial intelligence, machine learning, deep learning, supervised learning, etc.

[0105] In the example, the first threshold is different regardless of whether the illuminance change ΔE1 is positive or negative. For example, a positive value of the first threshold ΔE... lim1+ and negative value ΔE lim1-Each can be predetermined. Then, the first threshold ΔE lim1 It can be selected as a predetermined value whose sign matches the sign of the illuminance change ΔE1.

[0106] Based on the results of this comparison, the processing circuit (300) controls the transmittance of the lens according to different change curves, regardless of whether the detected change in illuminance is considered drastic.

[0107] More precisely, when the absolute value of the illuminance change ΔE1, |ΔE1|, is greater than the first threshold ΔE lim1 The absolute value of |ΔE lim1 At that time, the control unit (300) implements the first command of GEN CMD1 (S4) to change the transmittance of the ophthalmic lens (100).

[0108] The first command allows control over the transmittance of the ophthalmic lens (100) from the initial transmittance value T based on a change curve. i To the first target transmittance value T f1 The change curve includes two consecutive phases: an overshoot phase and a decay phase. During the overshoot phase, the transmittance exceeds the first target transmittance value, and during the decay phase, the transmittance returns toward the first target transmittance value.

[0109] Conversely, when the absolute value of the illuminance change ΔE1, |ΔE1|, is less than or equal to the first threshold ΔE lim1 The absolute value of |ΔE lim1 When |, the first command is not executed.

[0110] In summary, when a change in illuminance is detected, the change is compared with a first threshold to detect whether the change is drastic.

[0111] Then, in cases of drastic changes in illuminance, the first command is executed to alter the transmittance of the ophthalmic lens.

[0112] Otherwise, the first order will not be carried out.

[0113] The following describes possible further actions in the case of a smoother illuminance change. Therefore, in this case, consider the following comparison: the absolute value of the illuminance change ΔE1, |ΔE1|, is less than or equal to the first threshold ΔE. lim1 The absolute value of |ΔE lim1 |

[0114] The control unit (300) continues to compare the calculated illuminance change with the second threshold ΔE. lim2 Compare CMPΔE1 / ΔE lim2 (S51).

[0115] Second threshold ΔE lim2It is a preset non-null value, which is lower than the first threshold ΔE. lim1 .

[0116] With the first threshold ΔE lim1 Similarly, the second threshold ΔE lim2 It can be a preset absolute or relative value, and it can also vary depending on the sign of the calculated change in illuminance.

[0117] Second threshold ΔE lim2 The value can be related to the wearer's physiological parameters, such as the wearer's perception threshold.

[0118] For example, the second threshold could correspond to a limit beyond which the detected change in illuminance can be perceived by the wearer and needs to be compensated for by adjusting the transmittance of the ophthalmic lens.

[0119] Based on the results of this comparison, the processing circuit (300) can execute a second command and change the transmittance of the lens.

[0120] More precisely, when the absolute value of the illuminance change ΔE1, |ΔE1|, is greater than the second threshold ΔE lim2 The absolute value of |ΔE lim2 At that time, the control unit (300) implements the second command of GEN CMD2 (S52) to change the transmittance of the ophthalmic lens (100).

[0121] The second command allows control of the transmittance of the ophthalmic lens (100) from the initial transmittance value T based on a change curve that does not include any overshoot phase. i To the second target transmittance value T f2 .

[0122] Conversely, when the absolute value of the illuminance change ΔE1, |ΔE1|, is less than or equal to the second threshold ΔE lim2 The absolute value of |ΔE lim2 At that time, no command is executed.

[0123] all in all:

[0124] If the illuminance change is drastic, a first command is executed to change the transmittance of the ophthalmic lens. This first command means exceeding a first target transmittance value during the overshoot phase and then returning to the first target transmittance value during the decay phase.

[0125] - If the change in illuminance is perceptible rather than drastic, a second command is issued to alter the transmittance of the ophthalmic lens, meaning achieving a second target transmittance value without exceeding that value, and

[0126] If the change in illuminance is imperceptible, no command is executed, and the transmittance value of the ophthalmic lens remains equal to the initial transmittance value T. i .

[0127] Now for reference Figure 3 The figure shows an exemplary illuminance that varies over time, with a solid line labeled E1 = f(t).

[0128] In this example, we can see that during the time interval, the light intensity level changes from an initial light intensity value to a first light intensity value. This value may correspond to, for example, two successive measurements.

[0129] For simplicity, the illumination E is assumed to have two stable states within the time period under consideration.

[0130] In this example, the first light intensity value is much larger than the initial light intensity value, causing a sharp increase in light intensity during that time interval, thus reaching a positive value of ΔE1, which is greater than the first threshold ΔE. lim1 The absolute value of . As a result, the control unit (300) executes the first command.

[0131] exist Figure 3 The above is marked as τ V =f EE′t The solid line (E, E′, t) represents a schematic diagram of an exemplary transmittance that varies over time according to a first variation curve, which is the result of implementing such a first command.

[0132] According to the first change curve, the transmittance value of the ophthalmic lens (100) changes from the initial transmittance value T. i Change to the first target transmittance value T f1 The first target transmittance value T can be determined, for example, based on the measured illuminance, such as a first light intensity value. f1 .

[0133] The first change curve includes two consecutive phases.

[0134] The first stage starts from the initial transmittance value T. i To exceed the first target transmittance value T f1 Transmittance overshoot value T OS The overshoot phase (11).

[0135] In this example, the change in illuminance is positive, thus causing the first target transmittance value T to... f1 Less than the initial transmittance value T i Transmittance overshoot value T OS It is less than the transmittance value of the first target.

[0136] In another example (not shown), the change in illuminance is negative, thus causing the first target transmittance value T to... f1 Greater than the initial transmittance value T i In this other example, the transmittance overshoot value T OS It is greater than the transmittance value of the first target.

[0137] In both cases, the transmittance change during the overshoot phase has the same sign as the transmittance value reached at the first target value, but with a larger magnitude. Formally,

[0138] Based on the transmittance value T of the first target f1 The fixed offset determines the transmittance overshoot value (T). OS Alternatively, the illuminance change ΔE1 can be calculated based on the first threshold ΔE. lim1 The difference between them determines this offset.

[0139] Reaching the transmittance overshoot value T OS This corresponds to reaching the inflection point on the change curve and marks the beginning of the second stage.

[0140] The second stage involves analyzing the transmittance overshoot value T. OS To the first target transmittance value T f1 The attenuation phase (12). As seen from the preceding content, the transmittance change during the attenuation phase (12) has the opposite sign to the transmittance change during the overshoot phase (11).

[0141] The duration of the decay phase can be one or two orders of magnitude longer than the duration of the overshoot phase. For example, if the overshoot phase lasts for a few seconds, the subsequent decay phase can last for about a few minutes.

[0142] This continuity between the overshoot and decay phases allows for:

[0143] - Buffers drastic changes in brightness by quickly avoiding the risk of immediate glare for the wearer, then

[0144] - Restore some dynamics of transmittance to prepare for drastic changes in future brightness, while following the eye's adaptation to light and improving contrast.

[0145] In some embodiments, the first variation curve can be represented as the sum of the standard function and the overshoot function.

[0146] *The standard function defines the initial transmittance value T. i To the first target transmittance value T f1 The monotonic change in transmittance, and

[0147] *The overshoot function defines the transmittance overshoot value T. OS The duration of the overshoot phase (11) and the duration of the decay phase (12).

[0148] Formally, this is equivalent to τ V =f EE′t (E, E′, t) = f Et (E, t) + h(E, E′, t), where h(E, E′, t) is a lifting function consisting of two parts: an overshoot phase followed by a decay phase.

[0149] h(E, E′, t) can depend (temporally, in terms of intensity, shape, etc.) on the wearer and some specific physiological parameters (i.e., sensitivity to glare, mean contrast recovery time after glare, pupil size and dynamics, or other physiological parameters), and can be modulated through interaction with the wearer using AI, machine learning, deep learning, supervised learning, or other methods. h(E, E′, t) can vary depending on the sign of the light intensity change, allowing for different overshoot management for darkening and brightening.

[0150] Regarding the overshoot phase, when the first derivative E′ of the light intensity with time approaches zero, h(E, E′, t) can approach zero, which means that when the rate of change of light intensity is suppressed, the overshoot amplitude is minimized.

[0151] The duration of the overshoot phase can be predetermined, so that the decay phase occurs when a specific time interval expires.

[0152] The duration of the overshoot phase can be predetermined based on specific rules (e.g., management rules for Class 4 eyewear in driving situations), and / or based on the magnitude of the illuminance change ΔE1 and / or based on the previous value of the transmittance of the ophthalmic lens (100) before the illuminance change ΔE1 is detected and / or based on the physical limitations of the eyewear (e.g., the maximum possible rate of whitening or darkening of the ophthalmic lens (100)).

[0153] Regarding the decay phase, h(E, E′, t) can approach zero at infinity, meaning that the transmittance of the ophthalmic lens is moving towards the first target transmittance value T. f1 Evolution. The shape of the decay phase can be linear, exponential, orthogonal, or other types.

[0154] exist Figure 3 The above is marked as E 1′ The dashed line for f(t) illustrates an alternative example of illuminance that varies over time.

[0155] In this example, a smoother increase in light intensity was detected during this time interval, resulting in ΔE. 1’A positive value, which is greater than the second threshold ΔE. lim2 The absolute value, but less than the first threshold ΔE lim1 The absolute value of . As a result, the control unit (300) executes the second command.

[0156] exist Figure 3 The above is marked as τ v =f Et The dashed line (E, t) represents an exemplary transmittance that varies over time according to a second variation curve, which is the result of implementing such a second command.

[0157] According to the second change curve, the transmittance value of the ophthalmic lens (100) changes from the initial transmittance value T. i Change to the second target transmittance value T f2 without exceeding the second target transmittance value T f2 .

[0158] For example, the second variation curve may include a single monotonic phase (20) based on a standard function that defines the transition from the initial transmittance value T. i To the second target transmittance value (T) f2 The monotonic change in transmittance of ).

[0159] This variation curve allows the light to be followed without any drastic changes in transmittance, as there is no risk of immediate glare.

[0160] Therefore, by selectively implementing the first and second commands, the wearer can always be provided with transmittance changes at a rate appropriate to the current rate of change in ambient light intensity.

[0161] In an exemplary embodiment, the implementation of the first command can be interrupted. This interruption can be triggered based on predefined criteria relating to further evolution of the detected ambient light intensity.

[0162] In this example, the light sensor (200) performs repeated measurements of the ambient light intensity over time and transmits the measured values ​​to the processing circuit (300). In this example, it is further assumed that an increase in the ambient light intensity from an initial value to a first larger value has been detected. It is further assumed that the processing circuit (300) has determined that the detected increase exceeds a first threshold. As a result, the execution of a first command has been triggered.

[0163] In this example, it is assumed that at the current moment:

[0164] - The implementation of the first command is in progress.

[0165] - The transmittance of ophthalmic lenses (100) has a temporary value, and

[0166] Further measurement of ambient light intensity by the light sensor (200) is obtained by the processing circuit (300) and indicates a second value.

[0167] Based on this second value, it can be confirmed that the change in illuminance from the initial value is drastic, or conversely, it can indicate that the first value only reflects a brief, instantaneous state and that the change in illuminance from the initial value to the second value is not actually drastic.

[0168] To do this, the processing circuit can be further configured to calculate the difference ΔE2 between the initial value and the second value of the light intensity of CPTΔE2(S41).

[0169] The processing circuit can be further configured to compare the calculated difference ΔE2 with the first threshold ΔE lim1 Compare CMPΔE2 / ΔE lim1 (S42).

[0170] The result of this comparison indicates whether the change in light intensity between the initial and second values ​​is drastic.

[0171] Then, based on the result of the comparison, the processing circuit (300) can continue to implement the first command or interrupt the implementation of the first command.

[0172] More precisely, when the absolute value of the illuminance change ΔE2, |ΔE2|, is greater than the first threshold ΔE lim1 The absolute value of |ΔE lim1 At that time, the control unit (300) continues to execute the first command for changing the transmittance of the ophthalmic lens (100) in PROC CMD1 (S45).

[0173] In this situation, both the change in light intensity from the initial value to the first value and the change in light intensity from the initial value to the second value exceed the first threshold. This confirms that the change in light intensity is drastic and that the transmittance of the ophthalmic lens (100) needs to be adjusted immediately to prevent glare.

[0174] Conversely, when the absolute value of the illuminance change ΔE2, |ΔE2|, is less than or equal to the first threshold ΔE lim1 The absolute value of |ΔE lim1 At that time, the control unit (300) interrupts the implementation of the first command by INT CMD1 (S43) for changing the transmittance of the ophthalmic lens (100).

[0175] In this case, the change in light intensity from the initial value to the second value does not exceed the first threshold and is not considered drastic. Therefore, the transmittance change of the ophthalmic lens (100) can be performed without overshoot.

[0176] In this case, the control unit (300) further generates a third command, GEN CMD3 (S44), to change the transmittance of the ophthalmic lens (100) from a temporary transmittance value to a third target transmittance value.

[0177] The third target transmittance value is determined based on the second value of light intensity. For example, if the absolute value of the illuminance change ΔE2, |ΔE2|, is less than or equal to the second threshold ΔE... lim2 The absolute value of |ΔE lim2 This means that the illuminance change ΔE2 does not require a transmittance change starting from the initial value. In this case, the third target transmittance value is set to the initial transmittance value T. i .

Claims

1. A method for controlling the optical transmittance of a variable transmittance ophthalmic lens, the method being implemented by a control unit and comprising: The wearer receives measurement parameters related to the ambient light level from the ambient light sensor. The illuminance change is calculated based on the values ​​of the measured parameters during a predetermined time interval. The calculated change in illuminance is compared with a first threshold. The sign of the calculated illuminance change matches the sign of the first threshold, and when the absolute value of the calculated illuminance change is greater than the absolute value of the first threshold, a first command is executed. The first command is configured to change the transmittance of the variable transmittance ophthalmic lens from an initial transmittance value corresponding to the current transmittance value to a first target transmittance value according to a first change curve. The first change curve includes a first stage and a second stage, during which the transmittance exceeds the first target transmittance value, and during the second stage, the transmittance returns to the first target transmittance value.

2. The method according to claim 1, further comprising: When the absolute value of the calculated illuminance change is less than or equal to the absolute value of the first threshold, a second command is executed to change the transmittance of the variable transmittance ophthalmic lens according to the monotonic change curve.

3. The method according to claim 1, further comprising: When the absolute value of the calculated illuminance change is less than or equal to the absolute value of the first threshold, the transmittance value of the variable transmittance ophthalmic lens is maintained at the initial transmittance value.

4. The method of claim 1, further comprising: When the absolute value of the calculated illuminance change is less than or equal to the absolute value of the first threshold: The calculated change in illuminance is compared with a second threshold, and then... When the absolute value of the calculated illuminance change is greater than the absolute value of the second threshold, a second command is executed to change the transmittance of the variable transmittance ophthalmic lens from the initial transmittance value to a second target transmittance value according to a monotonic change curve, and When the absolute value of the calculated illuminance change is less than or equal to the absolute value of the second threshold, the transmittance value of the variable transmittance ophthalmic lens is maintained at the initial transmittance value.

5. The method according to claim 1, wherein, The first command includes instructions for changing the transmittance of the variable transmittance ophthalmic lens over time according to the sum of a standard function and an overshoot function. The standard function defines the monotonic change in transmittance from the initial transmittance value to the first target transmittance value, and The overshoot function defines the transmittance overshoot value, the duration of the first stage, and the duration of the second stage.

6. The method according to claim 2, wherein, The first command includes instructions for changing the transmittance of the variable transmittance ophthalmic lens over time according to the sum of a standard function and an overshoot function. The standard function defines the monotonic change in transmittance from the initial transmittance value to the first target transmittance value, and The overshoot function defines a transmittance overshoot value, the duration of the first stage, and the duration of the second stage, wherein the second command includes instructions for changing the transmittance of the transmittance-variable ophthalmic lens over time according to the standard function.

7. The method according to claim 5, wherein, Different overshoot functions are used depending on whether the calculated change in illuminance is positive or negative.

8. The method according to claim 1, wherein, The transmittance value of the first target is determined based on the illuminance.

9. The method according to claim 5 or 6, wherein, The transmittance overshoot value is determined based on the difference between the calculated illuminance change and the first threshold.

10. The method of claim 1, further comprising: After the first command is executed, the transmittance function of the variable transmittance ophthalmic lens has a temporary transmittance value. Based on the received measurements, further changes in illuminance are calculated during further time intervals. The calculated further change in illuminance is compared with the first threshold. When the absolute value of the calculated further illuminance change is greater than the absolute value of the first threshold, the transmittance change generated by the first command is interrupted, and a third command is executed to change the transmittance of the variable transmittance ophthalmic lens from the temporary transmittance value to the third target transmittance value. When the absolute value of the calculated further illuminance change is less than or equal to the absolute value of the first threshold, the transmittance change generated by the first command continues.

11. The method according to claim 1, wherein, The first threshold is based on the wearer's physiological parameters.

12. A control unit configured to implement the method according to any one of claims 1 to 11.

13. A pair of eyeglasses intended to be worn by a wearer, the eyeglasses comprising: - At least one ophthalmic lens with variable transmittance, - An ambient light sensor, configured to measure values ​​of parameters related to ambient illuminance, and - A control unit coupled to the variable transmittance ophthalmic lens and the ambient light sensor, the control unit being configured to implement the method according to any one of claims 1 to 11.

14. A computer program product comprising a series of instructions which, when executed by a processor, implement the method according to any one of claims 1 to 11.

15. A non-transitory computer-readable storage medium storing a computer program product according to claim 14.

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