Method for controlling a directional lighting beam and directional lighting device for a vehicle
The method optimizes directional LED lighting by calculating intensity and masks based on desired angles, addressing non-compliance and intensity issues in existing technologies, ensuring regulatory compliance and enhanced visibility.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- VALEO VISION SA
- Filing Date
- 2025-11-24
- Publication Date
- 2026-06-11
AI Technical Summary
Existing methods for controlling directional LED lighting in vehicles do not optimally comply with regulatory templates and do not optimize luminous intensity, particularly in intermediate lighting angles.
A method for controlling directional lighting that calculates intensity and a lighting mask based on a desired lighting angle, combining these to provide lighting commands to a LED matrix, using weighted averaging and expansion/compression techniques to achieve optimal lighting.
The method ensures compliance with regulatory templates and optimizes luminous intensity, providing a directional lighting beam that meets regulatory standards and enhances visibility without dazzling oncoming vehicles.
Smart Images
Figure EP2025084050_11062026_PF_FP_ABST
Abstract
Description
Description Title of the invention: Method for controlling a directional lighting beam and directional lighting device for a vehicle technical field
[0001] The invention relates to a method for controlling a directional lighting beam and to a directional lighting device for vehicles. Previous technique
[0002] A vehicle's headlights illuminate the road. In recent years, light-emitting diode (LED) headlights have emerged to reduce vehicle power consumption. To improve nighttime visibility, dynamic cornering lights, or DBL (Dynamic Bending Light), are also used. Dynamic cornering lights improve road visibility, particularly on curves, by shifting the beam to the right or left according to a desired lighting angle. This desired lighting angle can be calculated based on various parameters such as steering wheel angle, vehicle speed, road curvature as seen by a camera, navigation data, and / or inertial data.The use of LEDs, and in particular LED matrices, makes it possible to achieve dynamic lighting by playing only on the control of the LEDs by displaying an image corresponding to a desired lighting.
[0003] French patent application FR 3 130 938 describes an example of a method for controlling a directional LED lighting device. This patent application proposes moving the light beam of an LED array by calculating a lighting image adjusted according to the direction of the light. In this patent application, the lighting image is calculated from three lighting images. The first image corresponds to extreme left-hand lighting, the second to extreme right-hand lighting, and the third to optimal central lighting. All three images comply with a lighting template imposed by regulations to avoid dazzling oncoming vehicles while maximizing the lighting appropriate to their position. To direct the light beam, a light intensity image is calculated from the third image and one of the first and second images.The calculation of the luminous image involves shifting the images according to a lighting angle and then weighting them based on that angle. However, the resulting luminous image is not optimal. Indeed, the intermediate luminous images calculated between the first and third images do not sufficiently comply with the regulatory template, and the luminous intensity is not optimized. Summary of the invention
[0004] The invention aims to provide an optimized dynamic directional lighting solution. The invention provides a method and a lighting device that calculates intensity based on a lighting direction and then calculates a lighting mask. The intensity and mask calculations are then combined to provide lighting commands to a plurality of LEDs forming a beam of light.
[0005] More specifically, the invention relates to a method for controlling the directional lighting of a vehicle lighting system comprising an array of light-emitting diodes (LEDs), based on a desired lighting angle. The method comprises the following steps: - Determining a light intensity image as a function of the desired lighting angle, - Determining a lighting mask based on the desired lighting angle, - superimposing the lighting mask onto the light intensity image to obtain a control image, - sends the command image to a control circuit for the LED matrix.
[0006] According to a first embodiment, the step of determining a light intensity image may include the following steps: - determination of at least three initial images of luminous flux, each initial image of luminous flux corresponding to a luminous emission by the lighting device at a predefined angle, - when the desired lighting angle is equal to one of the predefined angles, fixing the image with a light intensity equal to the initial image whose predefined angle is equal to the desired lighting angle, - when the desired lighting angle does not correspond to one of the predefined angles, determination of an intermediate image of the luminous flux according to the desired lighting angle by a weighted average of two of the three initial images of the luminous flux corresponding to the predefined angles framing the desired lighting angle as closely as possible, and fixing the image of luminous intensity as being equal to the intermediate image.
[0007] Preferably, weighted averaging can consist of adding pixels from each of the initial images by assigning the pixels of each initial image a multiplier coefficient less than 1 and inversely proportional to the difference between the desired lighting angle and the predefined angle associated with the initial image.
[0008] According to a second embodiment, the step of determining a light intensity image may include the following steps: - determination of an optimum image for a central angle of illumination, said optimum image comprising a central axis, corresponding to the central angle of illumination, between two equal parts situated between said central axis and each lateral edge of the optimum image, - when the desired lighting angle is equal to the central angle, fix the image with a light intensity equal to the optimum image, - when the desired lighting angle does not correspond to the central angle, calculation of the light intensity image by expansion and compression of the optimum image, the expansion and compression being done by moving the points of the optimum image corresponding to the central axis onto an axis of the light intensity image corresponding to the desired lighting angle and then by performing the expansion or compression of each of the parts of the optimum lighting image to correspond to parts located between the axis of the light intensity image and each of the lateral edges of the light intensity image.
[0009] According to a third embodiment, the step of determining a light intensity image comprises the following steps: - determination of at least three initial luminous flux images, each initial luminous flux image corresponding to a luminous emission by the lighting device at a predefined angle, each initial image comprising a predefined axis corresponding to the predefined angle associated with the initial image and two parts situated between said predefined axis and each lateral edge of the initial image, - when the desired lighting angle corresponds to one of the predefined angles, fixing the image with a light intensity equal to the initial image whose predefined angle is equal to the desired lighting angle, - when the desired lighting angle does not correspond to one of the predefined angles, determination of two intermediate images according to the desired lighting angle from two of the three initial images of the luminous flux corresponding to the predefined angles framing the desired lighting angle as closely as possible, the determination of the two intermediate images being done by expansion and compression of the two initial images of the luminous flux, in which the expansion and compression is done by moving the points of an initial image corresponding to the predefined axis on an axis of the intermediate image corresponding to the desired lighting angle then by performing the expansion or compression of each of the parts of the two initial images to correspond to parts located between the axis of the intermediate image and each of the lateral edges of the intermediate image, calculation of the luminous intensity image by a weighted average of the two intermediate images thus obtained.
[0010] Preferably, weighted averaging can consist of adding pixels from each of the intermediate images, assigning the pixels of each intermediate image a multiplier less than 1, and vice versa. proportional to the difference between the desired lighting angle and the predefined angle associated with the initial image from which the intermediate image is derived.
[0011] When three initial images are used, the three initial luminous flux images may include: - an initial left-hand image corresponding to the emission of a luminous flux having a maximum orientation angle of the luminous flux to the left, - an initial upright image corresponding to the emission of a luminous flux having a maximum orientation angle of the luminous flux to the right, and - an initial central image corresponding to an emission of a luminous flux having a maximum luminous flux towards the front of the vehicle.
[0012] Regardless of the implementation method, determining a lighting mask involves the following steps: - determination of an optimum mask for a central lighting angle, said optimum mask respecting a regulatory template and including a central axis, - when the desired lighting angle is equal to the central angle, fix the lighting mask as being equal to the optimum mask, - when the desired lighting angle is not equal to the central angle, translation of the optimum mask to the right or to the left by a number of pixels corresponding to the desired lighting angle to obtain the lighting mask.
[0013] The invention also relates to a directional vehicle lighting device comprising optics placed in front of a diode matrix, a diode driver circuit and a lighting control circuit, in which the lighting control circuit implements the method. Brief description of the drawings
[0014] Other features and advantages of the invention will become apparent from the following description, with reference to the attached figures, among which:
[0015] [Fig 1] shows an example of a vehicle directional lighting device according to the invention,
[0016] [Fig 2] shows a method for controlling directional lighting according to the invention,
[0017] [Fig 3] details a first method for determining a light intensity image,
[0018] [Fig 4] and [Fig 5] illustrate the light intensity images of the embodiment of [Fig 3],
[0019] [Fig 6] details a second method of determining a light intensity image,
[0020] [Fig 7] illustrates the light intensity images of the embodiment of the [Fig 6],
[0021] [Fig 8] details a third method of determining a light intensity image,
[0022] [Fig 9] and [Fig 10] illustrate the light intensity images of the embodiment of [Fig 8],
[0023] [Fig 11] illustrates the formation of a lighting mask,
[0024] [Fig 12] and [Fig 13] illustrate control images obtained by the processes of [Fig 2] and [Fig 8], Detailed description
[0025] In the embodiments of the invention, the same object represented in several figures uses the same reference frame. Furthermore, the figures are not necessarily drawn to scale.
[0026] Figure 1 shows a vehicle directional lighting device 1 that implements the method of the invention to produce an improved directional beam. This directional lighting device 1 is a component of a vehicle headlight that produces only a single directional beam. Those skilled in the art will understand that other directional or fixed lighting devices can be combined with the directional lighting device 1 of the invention to obtain a complete headlight capable of producing all or part of the daytime running lights, position lights, low beams, and / or high beams. The present example of a directional lighting device 1 is particularly suitable for providing all or part of a low beam directional beam.
[0027] For example, the directional lighting device 1 may include an optic 10 positioned in front of a light-emitting diode (LED) array 11, a driver circuit 12, and a lighting control circuit 13. The optic 10 is positioned in front of the LED array 11 and may consist of one or more lenses. The LED array 11 may, for example, comprise one or more rows of LEDs, each row containing one or more dozen LEDs. For the sake of example and for the remainder of this description, the LED array comprises 80 rows of 320 LEDs. The optic 10 focuses the light rays 15 emitted by the LED array 11 so as to illuminate an area forming a cone of light. The optic is sized to direct the light rays emitted by the LEDs with a lateral deflection that depends on the position of each LED on its row.Thus, a light beam 15 emitted by an LED located in the center of a line illuminates a frontal area, a light beam 15 emitted by an LED located on the left of a line is deflected to the left, and a light beam 15 emitted by an LED located on the right of a line is deflected to the right. For example, the 20 pixels located in a central area... The 11 LED matrix features do not undergo any lateral deviation, and the lateral deviation is increased by 0.1 degrees per pixel to the left or right from the center area.
[0028] Thus, when a central group of LEDs is illuminated, it produces a central beam of light. When a group of LEDs on the left or right is illuminated, it produces a beam of light directed to the left or right. Proper control of the LEDs moving the illuminated group of LEDs allows the beam of light to be directed, making it directional depending on which LEDs are on and off.
[0029] The control circuit 13 generates a control image representing the brightness level of each LED in the LED array 11 as a function of a desired lighting angle. The desired lighting angle can be calculated by another computer, not shown, based on the steering wheel angle and / or vehicle speed and / or other parameters, and will not be further detailed in this document. The control circuit 13 is connected to the driver circuit 12 to transmit the control image. The driver circuit 12 supplies each LED in the LED array 11 with a voltage and current corresponding to the brightness level of each LED, according to the control image.
[0030] In this description, the driver circuit 12 and the control circuit 13 are shown separately. In practice, these two driver circuits 12 and control circuit 13 can be implemented in a single electronic circuit, which can also be located, for example, on the back of a substrate supporting the LED matrix 11.
[0031] Furthermore, a vehicle's lighting must conform to a lighting pattern to avoid dazzling oncoming vehicles. To this end, control circuit 13 implements a lighting control method described using the following figures.
[0032] Figure 2 shows a method for controlling directional lighting according to the invention which includes a step 201 of determining a light intensity image Iml, a step 202 of determining a lighting mask, a step 203 of superimposing the lighting mask on the light intensity image Iml to obtain a control image le, and a step 204 of displaying the control image le thus obtained.
[0033] Step 201 of determining a light intensity image (Iml) consists of determining which LEDs in the LED matrix 11 must be illuminated and their brightness level to obtain a directed light beam according to the desired illumination angle supplied to the control circuit 13. Several methods of determination are possible. Depending on the computing power of the control circuit 13, a person skilled in the art can choose one of the methods detailed below that best suits their implementation requirements.
[0034] Step 202, determining a lighting mask, consists of defining a lighting mask based on the desired lighting angle. Step 203, superimposing the lighting mask, involves applying it to the light intensity image to obtain the control image. The control image is then sent by the control circuit 13 to the driver circuit 12 during the display step 204. Also during the display step 204, the driver circuit 12 illuminates the LEDs in the LED matrix 11 according to the control image.
[0035] A first embodiment of step 201 of determining a light intensity image Iml is detailed using figures 3 to 5. Figure 3 details step 201 and includes a step 301 of determining initial images, a step 302 of choosing calculation, a step 303 of determining an intermediate image and two steps 304 and 305 of fixing the light intensity image Iml.
[0036] Step 301 can be performed only once during the manufacture of the lighting device and the initial images can be permanently stored in the control circuit 13. In the present example, the number of initial images is fixed at three, however, to improve the calculation of the intensity image, it is possible to use a number of images greater than three.
[0037] Figure 4 shows three initial images II, 12, and 13 determined during step 301 of initial image determination. In these images, black corresponds to LEDs off, white to LEDs on at full power, and textured areas to intermediate LED illumination levels. The three initial images II, 12, and 13 correspond to three predefined angles A1, A2, and A3 and define an optimal light emission corresponding to each of the predefined angles. Initial image II corresponds to a central image II associated with a central angle A1 of 0 degrees. Initial image II has a central axis 410 dividing the image into two equal parts, each emitting the same amount of light symmetrically with respect to the central axis 410 corresponding to the central angle A1. Initial images 12 and 13 correspond to two lateral images 12 and 13 associated with a maximum angle on the left A2 and right A3, respectively.Each lateral image 12 or 13 has a directional axis 420 or 430 dividing each initial image 12 or 13 into two unequal parts. The directional axes 420 and 430 are located at the maximum angles A2 and A3 respectively on the left and right, which are, for example, 13°.
[0038] During step 302, the desired illumination angle A is compared to the initial angles, i.e., the central angle A1 and the maximum angles A2 and A3. If the desired angle is equal to one of the initial angles A1, A2, or A3, then step 305, fixing the light intensity image Iml, is performed. If the desired angle is not equal to one of the initial angles A1, A2, or A3, then step 303 of determination of an intermediate image is carried out before carrying out step 304 of fixing the image of light intensity Iml.
[0039] Step 305 consists of assigning to the image of light intensity Iml the value of the initial image II, 12 or 13 corresponding to the initial angle Al, A2 or A3 which is equal to the desired illumination angle A.
[0040] Step 303 performs an intermediate image calculation, lint, illustrated in Figure 5. The intermediate image lint is calculated by weighted averaging two of the three initial images II, 12, and 13, corresponding to the initial angles A1, A2, and A3 that most closely bracket the desired illumination angle A. These two initial images are either II and 12, or II and 13. Image weighting can be performed in various ways. To simplify the image calculation, linear weighting can be used. For example, the pixels of each of the two initial images II and 12 (or II and 13) can be weighted by a multiplier less than 1 and inversely proportional to the difference between the desired illumination angle A and the predefined angles A1 and A2 (or A1 and A3). These weighted images are then added together to obtain the intermediate image lint.
[0041] When the desired lighting angle A is between the central angle II and the maximum angle 12, the intermediate image lint can be obtained using the formula: lint = (lk)*Il + k*I2, with k = A / (A2-A1).
[0042] When the desired lighting angle A is between the central angle II and the maximum angle 13, the intermediate image lint can be obtained using the formula: lint = (lk)*Il + k*I3, with k = A / (A3-A1).
[0043] Figure 5 shows the initial images II and 12 obtained during step 301 and the intermediate image lint obtained during step 303 for a desired illumination angle A between the central angle Al and the maximum angle A2. The intermediate image lint 410 has a directional axis 500 corresponding to the desired illumination angle A separating the image into two unequal parts.
[0044] The intermediate image thus obtained is then assigned as being equal to the image of light intensity Iml during step 304. However, as can be seen in the evening in Figure 5, the distribution of light quantity on either side of the directional axis 500 is not perfectly equal, and the quantity of light is found to be quite angularly dispersed. It is possible to compensate for these defects by increasing the overall light intensity of the image of light intensity Iml. It is also possible to use more than three initial images by adding initial angles between the central angle A1 and each of the maximum angles A2 and A3, the weighted averaging being performed with only two of the initial images corresponding to the initial angles that most closely bracket the desired illumination angle A.
[0045] A second embodiment of step 201 of image determination The light intensity Iml is detailed using Figures 6 and 7. Figure 1 details step 201 and includes a step 601 for determining a central image II, a step 602 for choosing the calculation, a step 603 for fixing the light intensity image Iml, and a step 604 for determining the light intensity image Iml.
[0046] Step 601 can be performed only once during the manufacture of the lighting device, and the central image II can be permanently stored in the control circuit 13. Figure 7 shows a central image II that is, for example, identical to the central image II of the first embodiment. The central image II has the central axis 410 dividing the image into two equal parts, each emitting the same amount of light symmetrically with respect to the central axis 410, corresponding to the central angle Al of 0 degrees.
[0047] In step 602, the desired illumination angle A is compared to the central angle AL. If the desired angle is equal to the central angle Al, then step 603, fixing the light intensity image Iml, is performed. If the desired angle is not equal to the central angle Al, then step 604, determining the light intensity image Iml, is performed.
[0048] Step 603 consists of assigning to the image of light intensity Iml the value of the central image II corresponding to the central angle Al which is equal to the desired illumination angle A.
[0049] Step 604, which determines the light intensity image Iml, performs a calculation by extending and compressing the central image II according to the desired illumination angle A. The extension and compression of parts of the central image II are, for example, carried out using two linear homotheties along the horizontal axis of the central image II. In Figure 7, image 14 corresponds to an image extended and compressed for a desired illumination angle A to the left, corresponding to the 500 axis. In this example, the points of the central image II located on the central axis 410 are moved to the 500 axis of image 14. The left part of the central image II located between the left edge and the central axis 410 is compressed to correspond to the left part of image 14 located between the left edge and the 500 axis.The right part of the central image II located between the right edge and the central axis 410 is extended to correspond to the right part of the image 14 located between the right edge and the axis 500. The image 14 thus obtained corresponds to the image of luminous intensity Iml.
[0050] For comparison with the optimum lateral image 12 of the first embodiment, Figure 7 also shows an image 14' corresponding to a desired illumination angle A equal to the maximum left angle A2 corresponding to axis 420. Image 14' is obtained by extension according to step 604. As can be seen in Figure 7, the left edge of image 14' is not as illuminated on the left edge as the optimum left image 12. To remedy this, To solve this problem, it suffices to widen the illumination beam of the central image II across the entire width of said image. However, a central image II with a widened illumination beam would no longer be optimal.
[0051] Also, a third embodiment of step 201 is detailed using figures 7 to 10. The third embodiment is a combination of the first and second embodiments detailed previously.
[0052] Figure 8 details step 201 and includes a step 801 for determining initial images II, 12 and 13, a step 802 for choosing the calculation, a step 803 for fixing the light intensity image Iml, two steps 804 and 805 for determining the intermediate image, and a step 806 for calculating the light intensity image Iml.
[0053] Step 801 can be performed only once during the manufacture of the lighting device, and the initial images II, 12, and 13 can be permanently stored in the control circuit 13. In the present example, step 801 is identical to step 301 described previously, and the three initial images II, 12, and 13 are the same as in Figure 4. The initial image II has a central axis 410 dividing the image into two equal parts, each emitting the same amount of light symmetrically with respect to the central axis 410, corresponding to the central angle AL. The initial images 12 and 13 correspond to two lateral images 12 and 13 associated with a maximum angle, respectively, on the left A2 and on the right A3. Each lateral image 12 or 13 has a directional axis 420 or 430 dividing each initial image 12 or 13 into two unequal parts. The directional axes 420 and 430 being placed at the maximum angles A2 and A3 respectively on the left and right.
[0054] In step 802, the desired illumination angle A is compared to the initial angles A1, A2, and A3, that is, to the central angle A1 and the maximum angles A2 and A3. If the desired angle A is equal to one of the initial angles A1, A2, or A3, then step 803, which fixes the light intensity image Iml, is performed. If the desired angle A is not equal to one of the initial angles A1, A2, or A3, then steps 804 and 805, which determine intermediate images 14 and 15, and step 806, which calculates the light intensity image Iml, are performed.
[0055] Step 803 consists of assigning to the image of light intensity Iml the value of the initial image II, 12 or 13 corresponding to the initial angle Al, A2 or A3 which is equal to the desired illumination angle A.
[0056] Steps 804 to 806 consist of performing a weighted average of two intermediate images 14 and 15 obtained by expansion and compression from two initial images II and 12 (or II and 13) whose predefined angles Al and A2 (or Al and A3) associated frame as closely as possible the desired lighting angle A.
[0057] Step 804, determining the intermediate image 14, performs a calculation by extension and compression of the central image II as a function of the desired illumination angle A, compared to the image of stage 604 previously described and illustrated by Figure 7. The extension and compression of parts of the central image II are, for example, carried out using two linear homotheties along the horizontal axis of the central image II. In Figure 7, the intermediate image 14 corresponds to an image stretched and compressed for a desired illumination angle A to the left, corresponding to the 500 axis. In this example, the points of the central image II located on the central axis 410 are displaced onto the 500 axis of the intermediate image 14. The left portion of the central image II, located between the left edge of the central image II and the central axis 410, is compressed to correspond to the left portion of the image 14 located between the left edge of the intermediate image 14 and the 500 axis. The right portion of the central image II, located between the right edge of the central image II and the central axis 410, is stretched to correspond to the right portion of the intermediate image 14 located between the right edge of the intermediate image 14 and the 500 axis.
[0058] Step 805, determining the intermediate image 15, performs a calculation by extending and compressing the lateral image 12 (or 13) according to the desired illumination angle A, as illustrated in Figure 9. The extension and compression of parts of the lateral image 12 are, for example, performed using two linear homotheties along the horizontal axis of the lateral image 12. In Figure 9, the intermediate image 15 corresponds to an image extended and compressed for a desired illumination angle A to the right, corresponding to the 500 axis. In this example, the points of the lateral image 12 located on the directional axis 420 are moved to the 500 axis of the intermediate image 15. The right-hand portion of the lateral image 12 located between the right edge of the lateral image 12 and the directional axis 420 is compressed to correspond to the right-hand portion of the intermediate image 15 located between the right edge of the intermediate image 15 and the axis 500.The left part of the lateral image 12 located between the left edge of the image 12 and the directional axis 420 is extended to correspond to the left part of the intermediate image 15 located between the left edge of the intermediate image 15 and the axis 500.
[0059] Following steps 804 and 805, step 806, which calculates the light intensity image Iml, performs a weighted average of the intermediate images 14 and 15, as illustrated in Figure 10. The weighting is based on the desired angle A and the initial angles A1 and A2 corresponding to the initial images II and 12 from which the intermediate images 14 and 15 are derived. As previously stated, the image weighting can be done in different ways. To simplify the image calculation, the weighting can be linear. For example, the pixels of each of the two intermediate images 14 and 15 can be weighted by a multiplier less than 1 and inversely proportional to the difference between the desired illumination angle A and the predefined angles A1 and A2 before adding these weighted images to obtain the light intensity image Iml.
[0060] In the example described, the desired lighting angle A is between the central angle II and the maximum angle 12, the image of luminous intensity Iml can be obtained using the formula: Iml = (lk)*I4 + k*I5, with k = A / (A2-A1).
[0061] Figure 10 shows the intermediate images 14 and 15 obtained during steps 804 and 805, as well as the light intensity image Iml obtained by weighted averaging. The light intensity image Iml has a much more concentrated beam than in the previous embodiments, while still exhibiting good distribution on either side of the 500 axis, corresponding to the desired illumination angle. To refine the resulting light intensity image Iml, it is always possible to use more than three initial images by adding initial angles between the central angle A1 and each of the maximum angles A2 and A3. The intermediate images are then calculated from the two initial images corresponding to the initial angles that most closely bracket the desired illumination angle A.
[0062] Since step 201 has been carried out according to one of the embodiments detailed above, it is now necessary to further detail step 202, which involves determining the lighting mask M using Figure 11. First, an optimal mask Ml must be determined, corresponding to the central angle Al, which complies with a regulatory lighting standard. The optimal mask Ml is a binary image that defines which pixels of the light intensity image must be illuminated or not to comply with a regulatory standard designed to avoid dazzling a vehicle located in front of the lighting device, as well as a vehicle approaching from the opposite direction. As an example, the optimal mask Ml complies with the European regulatory standard for vehicles traveling on the right. To this end, the optimal mask Ml has a right portion defining a first lighting height and a left portion defining a second lighting height.The optimum mask Ml also includes a transition at the central Tax 410 level to move from the first height to the second height. The first and second heights and the transition correspond to the regulatory template. For a directional beam, it is permitted to move the template provided that the transition remains in the same proportions and that it corresponds to the direction of the main lighting.
[0063] Thus, if the desired lighting angle A is equal to the central angle Al, then the optimum mask Ml is used as the lighting mask M.
[0064] Conversely, when the desired illumination angle A is not equal to the central angle A1, then the illumination mask M corresponds to a translation of the optimum mask M1 to the right or left by a number of pixels corresponding to the desired illumination angle A. During the translation to the right or left, the vertical lines of pixels on the left or right should be filled with the same vertical line of pixels located on the left edge or on the right. right edge of the optimum mask Ml.
[0065] As an example, mask M2 in Figure 11 corresponds to a leftward translation of the optimum mask M1. The translation is performed for a desired lighting angle A. Such a translation shifts the template transition along the 500 axis corresponding to the desired lighting angle, while maintaining the lighting heights to the right and left of this 500 axis. The shape of the transition remains unchanged relative to the optimum mask ML.
[0066] With the mask calculated, step 203 can be performed. Figure 12 illustrates the execution of step 203 when the desired illumination angle A is equal to 0°. Step 201 maps the central image II as the image with light intensity Iml, and step 202 maps the optimum mask Ml as the illumination mask. Obtaining the control image le by superimposing the illumination mask M onto the image with light intensity Iml involves calculating the control image using the following formula:
[0067] P(x, y, le) = P(x, y, Iml) * P(x, y, M) with P(x, y, le) corresponding to the point with coordinates x and y of the control image le, P(x, y, Iml) corresponding to the point with coordinates x and y of the light intensity image Iml, and P(x, y, M) corresponding to the point with coordinates x and y of the lighting mask M.
[0068] As an example, Figure 13 illustrates the implementation of step 203 when the desired illumination angle A is not equal to 0°, using the third embodiment of step 201. The light intensity image Iml is obtained as a function of the desired illumination angle A corresponding to the 500 axis by applying the algorithm in Figure 8. The illumination mask M corresponds to mask M2. The control image IC in Figure 13 corresponds to the superposition of the illumination mask onto the light intensity image Iml.
[0069] As can be seen in figures 12 and 13, the independent calculation of the light intensity image Iml and the lighting mask M allows us to have a control image that respects the regulatory template while having good brightness.
[0070] The control image thus calculated can be sent to the control circuit 12 during the display step 204. The LED matrix 11 then emits the light rays 15 corresponding to the control image and the optics 10 focuses the resulting beam in the direction of the desired illumination angle A.
[0071] The invention is not limited to the examples described. Those skilled in the art will understand that the examples have been described with a lighting angle only to the left to avoid unnecessarily cluttering the description, but that the invention also works with a desired lighting angle to the right. The invention is also not limited to the examples described. Those skilled in the art can make numerous variations and modifications without departing from the scope of the invention as defined by the attached claims.
Claims
Demands [Claim 1] A method for controlling directional lighting of a vehicle lighting device comprising a light-emitting diode (LED) array (11), from a desired lighting angle (A), characterized in that the method comprises the following steps: - determination (201) of a luminous intensity image (Iml) as a function of the desired illumination angle (A), - determination (202) of a lighting mask (M) as a function of the desired lighting angle (A), - superposition (203) of the lighting mask (M) on the light intensity image (Iml) to obtain a control image (le), - sends (204) the command image (the) to a driver circuit (12) of the LED matrix (11). [Claim 2] A method according to claim 1, wherein the step of determining a light intensity image (Iml) comprises the following steps: - determination (301) of at least three initial images (II, 12, 13) of luminous flux, each initial image (II, 12, 13) of luminous flux corresponding to a luminous emission by the lighting device at a predefined angle (A1, A2, A3), - when (302) the desired illumination angle (A) is equal to one of the predefined angles (Al, A2, A3), fixing (305) the image of luminous intensity (Iml) as being equal to the initial image (II, 12, 13) whose predefined angle (Al, A2, A3) is equal to the desired illumination angle (A), - when (302) the desired lighting angle (A) does not correspond to one of the predefined angles (Al, A2, A3), determination (303) of an intermediate image (lint) of the luminous flux according to the desired lighting angle (A) by a weighted average of two of the three initial images (Il and 12, Il and 13) of the luminous flux corresponding to the predefined angles (Al and A2, Al and A3) framing as closely as possible the desired lighting angle (A), and fixing (304) the luminous intensity image (Iml) as being equal to the intermediate image (lint). [Claim 3] A method according to claim 2, wherein the weighted averaging consists of adding pixels from each of the initial images (II, 12, 13) by assigning the pixels of each initial image (II, 12, 13) a multiplier (k, 1-k)) less than 1 and inversely proportional to the difference between the desired lighting angle (A) and the predefined angle (A1, A2, A3) associated with the initial image (II, 12, 13). [Claim 4] A method according to claim 1, wherein the step of determining a light intensity image (Iml) comprises the following steps: - determination (601) of an optimum image (II) for a central angle of illumination (Al), said optimum image (II) comprising a central axis (410), corresponding to the central angle of illumination (Al), between two equal parts situated between said central axis (410) and each lateral edge of the optimum image (II), - when (602) the desired illumination angle (A) is equal to the central angle (Al), fixing (603) the image of luminous intensity (Iml) as being equal to the optimum image (II), - when (602) the desired lighting angle (A) does not correspond to the central angle (Al), calculation (604) of the light intensity image (Iml) by expansion and compression of the optimum image (II), the expansion and compression being done by moving the points of the optimum image (II) corresponding to the central axis (410) onto an axis (500) of the light intensity image (Iml) corresponding to the desired lighting angle (A) and then by performing the expansion or compression of each of the parts of the optimum lighting image (II) to correspond to parts located between the axis (500) of the light intensity image (Iml) and each of the lateral edges of the light intensity image (Iml). [Claim 5] A method according to claim 1, wherein the step of determining a light intensity image (Iml) comprises the following steps: - determination (801) of at least three initial images (II, 12, 13) of luminous flux, each initial image (II, 12, 13) of luminous flux corresponding to a luminous emission by the lighting device at a predefined angle (Al, A2, A3), each initial image (II, 12, 13) comprising a predefined axis (410, 420, 430) corresponding to the predefined angle (Al, A2, A3) associated with the initial image (II, 12, 13) and two parts situated between said predefined axis (410, 420, 430) and each lateral edge of the initial image (II, 12, 13), - when (802) the desired illumination angle (A) corresponds to one of the predefined angles (Al, A2, A3), fixing (803) the image of luminous intensity (Iml) as being equal to the initial image (II, 12, 13) whose predefined angle (Al, A2, A3) is equal to the desired illumination angle (A), - when (802) the desired illumination angle (A) does not correspond to one of the predefined angles (A1, A2, A3), determination (804, 805) of two intermediate images (14, 15) according to the desired illumination angle (A) from two of the three initial images (A1 and A2, A1 and A3) of the luminous flux corresponding to the predefined angles (A1 and A2, A1 and A3) closely framing the desired illumination angle (A), the determination (804, 805) of the two intermediate images (14, 15) being carried out by expansion and compression of the two initial images (A1 and 12, A1 and 13) of the luminous flux, in which the expansion and compression is carried out by moving the points of an initial image (A1, 12) corresponding to the predefined axis (410, 420) onto an axis (500) of the intermediate image (14, 15) corresponding to the desired illumination angle (A), then by performing the expansion or compression of each of the parts of the two initial images (A1, 12) to correspond to parts located between the axis (500) of the intermediate image (14, 15) and each of the lateral edges of the intermediate image (14, 15), calculation (806) of the image luminous intensity (Iml) by a weighted average of the two intermediate images (14, 15) thus obtained. [Claim 6] A method according to claim 5, wherein the weighted averaging consists of adding pixels from each of the intermediate images (14, 15) by assigning to the pixels of each intermediate image (14, 15) a multiplier coefficient (k, 1-k) less than 1 and inversely proportional to the difference between the desired lighting angle (A) and the predefined angle (A1, A2) associated with the initial image (A1, A2) from which the intermediate image (14, 15) is derived. [Claim 7] A method according to any one of claims 2, 3, 5 or 6, wherein the three initial images (II, 12, 13) of luminous flux comprise: - an initial left image (12) corresponding to the emission of a luminous flux having a maximum orientation angle of the luminous flux to the left, - an initial right-handed image (13) corresponding to the emission of a luminous flux having a maximum orientation angle of the luminous flux to the right, and - an initial central image (I ^corresponding to an emission of a luminous flux having a maximum luminous flux towards the front of the vehicle. [Claim 8] A method according to any one of claims 1 to 7, wherein the determination (202) of a lighting mask (M) comprises the following steps: - determination of an optimum mask (Ml) for a central lighting angle (Al), said optimum mask (Al) respecting a regulatory template and including a central axis (410), - when the desired lighting angle (A) is equal to the central angle (Al), fixing the lighting mask (M) as being equal to the optimum mask (ml) - when the desired lighting angle (A) is not equal to the central angle (Al), translation of the optimum mask (Ml) to the right or to the left by a number of pixels corresponding to the desired lighting angle (A) to obtain the lighting mask (M, M2). [Claim 9] A vehicle directional lighting device comprising optics (10) placed in front of a diode matrix (11), a diode driver circuit (12) and a lighting control circuit (13), characterized in that the lighting control circuit (13) implements the method according to any one of claims 1 to 8.